WorldWideScience

Sample records for selected freshwater biota

  1. Toxicities of selected substances to freshwater biota

    Energy Technology Data Exchange (ETDEWEB)

    Hohreiter, D.W.

    1980-05-01

    The amount of data available concerning the toxicity of various substances to freshwater biota is so large that it is difficult to use in a practical situation, such as environmental impact assessment. In this document, summary tables are presented showing acute and/or chronic toxicity of selected substances for various groups of aquatic biota. Each entry is referenced to its original source so that details concerning experimental conditions may be consulted. In addition, general information concerning factors modifying toxicity, synergisms, evidence of bioaccumulation, and water quality standards and criteria for the selected substances is given. The final table is a general toxicity table designed to provide an easily accessible and general indication of toxicity of selected substances in aquatic systems.

  2. Selected chlorobornanes, polychlorinated naphthalenes and brominated flame retardants in Bjornoya (Bear Island) freshwater biota

    International Nuclear Information System (INIS)

    Levels of selected sparsely investigated persistent organic pollutants (POPs) have been measured in organisms from two Arctic lakes on Bjornoya (Bear Island). Elevated levels of chlorobornanes (CHBs) (up to 46.7 ng/g wet weight=ww), polybrominated diphenyl ethers (PBDEs) (up to 27.2 ng/g ww), polybrominated biphenyls (PBBs) (up to 1.1 ng/g ww) and polychlorinated naphthalenes (PCNs, only 4 congeners) (up to 62.7 pg/g ww), were measured in biota from Lake Ellasjoen. In Lake Oyangen, located only 5 km north of Ellasjoen, levels of these contaminants were significantly lower. ?15N-values were 7-10%o higher in organisms from Ellasjoen as compared to Oyangen. This is attributed to biological inputs related to seabird activities. The present study illustrates that contaminants such as CHBs, brominated flame retardants and PCNs accumulate in the Ellasjoen food web in a manner similar to PCBs and conventional organochlorine pesticides. Transport mechanisms that control PCB and DDT distributions, i.e. atmospheric long-range transport and biotransport by seabirds, are also relevant for the contaminants investigated in the present study. - Elevate levels of chlorobornanes, polychlorinated naphthalenes and brominated flame retardants have been measured in biota from a Norwegian Arctic lake

  3. Bioaccumulation factors for radionuclides in freshwater biota

    International Nuclear Information System (INIS)

    This report analyzes over 200 carefully selected papers to provide concise data sets and methodology for estimation of bioaccumulation factors for tritium and isotopes of strontium, cesium, iodine, manganese, and cobalt in major biotic components of freshwater environments. Bioaccumulation factors of different tissues are distinguished where significant differences occur. Since conditions in the laboratory are often unnatural in terms of chemical and ecological relationships, this review was restricted as far as possible to bioaccumulation factors determined for natural systems. Because bioaccumulation factors were not available for some shorter-lived radionuclides, a methodology for converting bioaccumulation factors of stable isotopes to those of shorter-lived radionuclides was derived and utilized. The bioaccumulation factor for a radionuclide in a given organism or tissue may exhibit wide variations among bodies of water that are related to differences in ambient concentrations of stable-element and carrier-element analogues. To account for these variations, simple models are presented that relate bioaccumulation factors to stable-element and carrier-element concentrations in water. The effects of physicochemical form and other factors in causing deviations from these models are discussed. Bioaccumulation factor data are examined in the context of these models, and bioaccumulation factor relations for the selected radionuclides are presented

  4. Application of the ERICA Assessment Tool to freshwater biota in Finland

    Energy Technology Data Exchange (ETDEWEB)

    Vetikko, Virve, E-mail: virve.vetikko@stuk.f [STUK - Radiation and Nuclear Safety Authority, Research and Environmental Surveillance, P.O. Box 14 (Laippatie 4), FI-00881, Helsinki (Finland); Saxen, Ritva, E-mail: ritva.saxen@stuk.f [STUK - Radiation and Nuclear Safety Authority, Research and Environmental Surveillance, P.O. Box 14 (Laippatie 4), FI-00881, Helsinki (Finland)

    2010-01-15

    In recent years there has been growing international interest in the assessment of doses and risks from ionising contaminants to biota. In this study the ERICA Tool, developed within the EC 6th Framework Programme, was applied to estimate incremental dose rates to biota in freshwater ecosystems in Finland mainly resulting from exposure to the Chernobyl-derived radionuclides {sup 137}Cs, {sup 134}Cs and {sup 90}Sr. Data sets consisting of measured activity concentrations in fish, aquatic plants, lake water and sediment for three selected lakes located in a region with high {sup 137}Cs deposition were applied in the assessment. The dose rates to most species studied were clearly below the screening level of 10 muGy h{sup -1}, indicating no significant impact of the Chernobyl fallout on these species. However, the possibility of higher dose rates to certain species living on or in the bottom sediment cannot be excluded based on this assessment.

  5. Application of the ERICA Assessment Tool to freshwater biota in Finland

    International Nuclear Information System (INIS)

    In recent years there has been growing international interest in the assessment of doses and risks from ionising contaminants to biota. In this study the ERICA Tool, developed within the EC 6th Framework Programme, was applied to estimate incremental dose rates to biota in freshwater ecosystems in Finland mainly resulting from exposure to the Chernobyl-derived radionuclides 137Cs, 134Cs and 90Sr. Data sets consisting of measured activity concentrations in fish, aquatic plants, lake water and sediment for three selected lakes located in a region with high 137Cs deposition were applied in the assessment. The dose rates to most species studied were clearly below the screening level of 10 ?Gy h-1, indicating no significant impact of the Chernobyl fallout on these species. However, the possibility of higher dose rates to certain species living on or in the bottom sediment cannot be excluded based on this assessment.

  6. Concordant Biogeographic Patterns among Multiple Taxonomic Groups in the Mexican Freshwater Biota

    OpenAIRE

    Quiroz-Martínez, Benjamín; Álvarez, Fernando; Espinosa, Héctor; Salgado-Maldonado, Guillermo

    2014-01-01

    In this paper we analyse the degree of concordance in species richness and taxonomic distinctness (diversity) patterns among different freshwater taxonomic groups in order to test three long held patterns described in Mexican freshwater biogeography: 1. The aquatic biota of Mexico includes two distinct faunas, a rich Neotropical component in the south and a south-eastern region and a less rich Nearctic component towards central and northern latitudes of the country. 2. A hotspot of species ri...

  7. Radionuclide transfer to freshwater biota species: review of Russian language studies

    International Nuclear Information System (INIS)

    Around 130 publications reporting studies on radionuclide transfer to freshwater biota species conducted in the former USSR were reviewed to provide the concentration ratio values. None of these studies were available up to now in the English language reviews or publications. The values derived have been compared with the CR values used for freshwater systems in the International reviews. For some radionuclides reviewed in this paper, the data are in good agreement with the mean CR values presented earlier, however for some of them, in particular, for 241Am (bivalve molluscs, gastropods and pelagic fish), 60Co (gastropods, benthic fish and insect larvae), 90Sr and 137Cs (benthic fish and zooplankton), the mean values given here are substantially different from those presented earlier. The data reported in this paper for thirty five radionuclides and eleven groups of freshwater species markedly improve the extent of available data for evaluation of radiation impact on freshwater species. - Research highlights: ? The paper provides information on concentration ratios to freshwater biota species for 35 radionuclides. Many of the data are for 90Sr and 137Cs. ? For the majority of radionuclides reviewed in this paper, the CR values are in good agreement with those given in the recent International reviews. ? For 241Am (bivalve molluscs, gastropods and pelagic fish), 60Co (gastropods, benthic fish and insect larvae), 90Sr and 137Cs (benthic fish and zooplankton), the mean values based on review of the Russian language publications are substantially different from those presented in the International reviews. ? Information presented in the paper significantly increases the availability of data on radionuclide accumulation in freshwater species.

  8. Methodology for estimating radiation dose rates to freshwater biota exposed to radionuclides in the environment

    Energy Technology Data Exchange (ETDEWEB)

    Blaylock, B.G.; Frank, M.L.; O`Neal, B.R.

    1993-08-01

    The purpose of this report is to present a methodology for evaluating the potential for aquatic biota to incur effects from exposure to chronic low-level radiation in the environment. Aquatic organisms inhabiting an environment contaminated with radioactivity receive external radiation from radionuclides in water, sediment, and from other biota such as vegetation. Aquatic organisms receive internal radiation from radionuclides ingested via food and water and, in some cases, from radionuclides absorbed through the skin and respiratory organs. Dose rate equations, which have been developed previously, are presented for estimating the radiation dose rate to representative aquatic organisms from alpha, beta, and gamma irradiation from external and internal sources. Tables containing parameter values for calculating radiation doses from selected alpha, beta, and gamma emitters are presented in the appendix to facilitate dose rate calculations. The risk of detrimental effects to aquatic biota from radiation exposure is evaluated by comparing the calculated radiation dose rate to biota to the U.S. Department of Energy`s (DOE`s) recommended dose rate limit of 0.4 mGy h{sup {minus}1} (1 rad d{sup {minus}1}). A dose rate no greater than 0.4 mGy h{sup {minus}1} to the most sensitive organisms should ensure the protection of populations of aquatic organisms. DOE`s recommended dose rate is based on a number of published reviews on the effects of radiation on aquatic organisms that are summarized in the National Council on Radiation Protection and Measurements Report No. 109 (NCRP 1991). DOE recommends that if the results of radiological models or dosimetric measurements indicate that a radiation dose rate of 0. 1 mGy h{sup {minus}1} will be exceeded, then a more detailed evaluation of the potential ecological consequences of radiation exposure to endemic populations should be conducted.

  9. Methodology for estimating radiation dose rates to freshwater biota exposed to radionuclides in the environment

    International Nuclear Information System (INIS)

    The purpose of this report is to present a methodology for evaluating the potential for aquatic biota to incur effects from exposure to chronic low-level radiation in the environment. Aquatic organisms inhabiting an environment contaminated with radioactivity receive external radiation from radionuclides in water, sediment, and from other biota such as vegetation. Aquatic organisms receive internal radiation from radionuclides ingested via food and water and, in some cases, from radionuclides absorbed through the skin and respiratory organs. Dose rate equations, which have been developed previously, are presented for estimating the radiation dose rate to representative aquatic organisms from alpha, beta, and gamma irradiation from external and internal sources. Tables containing parameter values for calculating radiation doses from selected alpha, beta, and gamma emitters are presented in the appendix to facilitate dose rate calculations. The risk of detrimental effects to aquatic biota from radiation exposure is evaluated by comparing the calculated radiation dose rate to biota to the U.S. Department of Energy's (DOE's) recommended dose rate limit of 0.4 mGy h-1 (1 rad d-1). A dose rate no greater than 0.4 mGy h-1 to the most sensitive organisms should ensure the protection of populations of aquatic organisms. DOE's recommended dose rate is based on a number of published reviews on the effects of radiation on aquatic organisms that are summarized in the National Council on Radiation Protection and Measurements Report No. 109 (NCRP 1991). DOE recommends that if the results of radiological models or dosimetric measurements indicate that a radiation dose rate of 0. 1 mGy h-1 will be exceeded, then a more detailed evaluation of the potential ecological consequences of radiation exposure to endemic populations should be conducted

  10. Toxicological benchmarks for screening contaminants of potential concern for effects on freshwater biota

    International Nuclear Information System (INIS)

    An important early step in the assessment of ecological risks at contaminated sites is the screening of chemicals detected on the site to identify those that constitute a potential risk. Part of this screening process is the comparison of measured ambient concentrations to concentrations that are believed to be nonhazardous, termed benchmarks. This article discusses 13 methods by which benchmarks may be derived for aquatic biota and presents benchmarks for 105 chemicals. It then compares them with respect to their sensitivity, availability, magnitude relative to background concentrations, and conceptual bases. This compilation is limited to chemicals that have been detected on the US Department of Energy's Oak Ridge Reservation (ORR) and to benchmarks derived from studies of toxic effects on freshwater organisms. The list of chemicals includes 45 metals and 56 industrial organic chemicals but only four pesticides. Although some individual values can be shown to be too high to be protective and others are too low to be useful for screening, none of the approaches to benchmark derivation can be rejected without further definition of what constitutes adequate protection. The most appropriate screening strategy is to use multiple benchmark values along with background concentrations, knowledge of waste composition, and physicochemical properties to identify contaminants of potential concern

  11. Linking catchment and in-stream processes for an integrated simulation of freshwater biota

    Science.gov (United States)

    Kiesel, Jens; Hering, Daniel; Jähnig, Sonja; Schmalz, Britta; Fohrer, Nicola

    2015-04-01

    Natural catchments, streams and aquatic diversity are globally degraded due to the impacts of industrial and urban development, as well as the intensification of agriculture. Degradation occurres at different spatial scales and rehabilitation measures are required in both streams and catchments, to improve conditions for the aquatic biota. Models, applied for planning restoration measures, are mostly targeting individual components of the complex chain linking the abiotic and biotic environment; e.g., models might be used just for predicting hydrological or hydraulic variables. Hereby, the cause-effect chain is compromised, which links drivers, pressures, state and impacts of the riverine system. We describe the design of an integrated, GIS-based model system considering the cause-effect chain from the catchment to the stream and aquatic biota. The models require data on climatic and physical catchment properties, and on the geometry and structure of the streams. This enables the assessment of the impact of global change as well as of more regional and local changes on the stream ecosystem on different scales. The approach is based on the Driver-Pressure-State-Impact-(Response) concept and includes the linkage of one ecohydrologic, two hydraulic and two habitat models: The ecohydrologic model SWAT was used for depicting the discharge regime and ero-sion processes controlled by land use and climate on the catchment scale. The discharge and sediment time series resulting from the hydrologic modelling were used for hydraulic simulations on the reach scale. Water depth, flow velocity, substrate changes and sediment transport were simulated in variable resolutions with the hydraulic models HEC-RAS one-dimensionally and with AdH two-dimensionally. Combined with structural river mapping, the temporally and spatially dynamic results of the hydraulic models were used for describing macroinvertebrate habitats. Two independent simulations were carried out: First, the distribution of the freshwater clam Sphaerium corneum was modelled with the species distribution model BIOMOD, based on parameters related to hydraulics and sediment transport. Second, the Habitat Evaluation Tool (HET) was developed. HET was used to simulate the prevailing macroinvertebrate community in the stream based on the river's substrates. Model results are maps and statistics of the spatial occurrence of species at different points in time which are connected to the prevailing environmental conditions. Results of the submodels show very good agreement with observed hydrological and hydraulic parameters and good agreement with observed spatio-temporal erosion. Simulated spatial species distributions are realistic when compared to observed distributions. The developed model system advances integrated modelling, but future improvements are necessary. This particularly concerns the simulation of abiotic parameters, investigation of organism preferences, the combined simulation of numerous organism groups and the simulation of interactions and feedback loops.

  12. Toxicity of 35 trace elements in coal to freshwater biota: a data base with automated retrieval capabilities. [313 references

    Energy Technology Data Exchange (ETDEWEB)

    Cushman, R. M.; Hildebrand, S. G.; Strand, R. H.; Anderson, R. M.

    1977-06-01

    Data are tabulated on the toxicity to freshwater biota of 35 trace elements with the potential for release to the environment from coal conversion effluents. The entire data base is presented on a microfiche appended to the document, in the interest of portability and accessibility. The data were gathered from a variety of research papers, compendia, and reviews. Details of water chemistry and test conditions are presented when available from the documents consulted. The data base may be used by referring directly to the tabulated data as they appear on the microfiche, or, with appropriate computer facilities, by manipulation (sorting, subsetting, or merging) of the data to meet the particular needs of the investigator. The data may be used as they appear in the data base, or the data base may be used to index the cited original papers.

  13. An international model validation exercise on radionuclide transfer and doses to freshwater biota

    International Nuclear Information System (INIS)

    Under the International Atomic Energy Agency (IAEA)'s EMRAS (Environmental Modelling for Radiation Safety) programme, activity concentrations of 60Co, 90Sr, 137Cs and 3H in Perch Lake at Atomic Energy of Canada Limited's Chalk River Laboratories site were predicted, in freshwater primary producers, invertebrates, fishes, herpetofauna and mammals using eleven modelling approaches. Comparison of predicted radionuclide concentrations in the different species types with measured values highlighted a number of areas where additional work and understanding is required to improve the predictions of radionuclide transfer. For some species, the differences could be explained by ecological factors such as trophic level or the influence of stable analogues. Model predictions were relatively poor for mammalian species and herpetofauna compared with measured values, partly due to a lack of relevant data. In addition, concentration ratios are sometimes under-predicted when derived from experiments performed under controlled laboratory conditions representative of conditions in other water bodies.

  14. An international model validation exercise on radionuclide transfer and doses to freshwater biota

    Energy Technology Data Exchange (ETDEWEB)

    Yankovich, T L [AREVA Resources Canada, 817-45th Street West, Saskatoon, SK, S7K 3X5 (Canada); Vives i Batlle, J; Vives-Lynch, S [Environmental Science, Westlakes Scientific Consulting Ltd, The Princess Royal Building, Westlakes Science and Technology Park, Moor Row, Cumbria CA24 3LN (United Kingdom); Beresford, N A; Barnett, C L; Howard, B J [Radioecology Group, Centre for Ecology and Hydrology, CEH Lancaster, Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster LA1 4AP (United Kingdom); Beaugelin-Seiller, K [Environment and Emergency Operations Division (DEI), Batiment 159 Institut de Radioprotection et de Surete Nucleaire (IRSN) Centre de Cadarache, BP 3 13115 Saint Paul-lez-Durance, Cedex (France); Brown, J E; Hosseini, A [Norwegian Radiation Protection Authority (NRPA), Emergency Preparedness and Environmental Radioactivity, Grini Naeringspark 13, PO Box 55, N-1332, Oesteraas (Norway); Cheng, J-J; Kamboj, S [Radiological Health Risk Section, Environmental Science Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 (United States); Copplestone, D [Radioactive Substances, Chemicals Team Science Department, The Environment Agency, PO Box 12, Richard Fairclough House, Knutsford Road, Warrington, Cheshire WA4 1HG (United Kingdom); Heling, R [Department of Radiation and Environment, Nuclear Research and Consultancy Group (NRG), PO Box 9035, Utrechseweg, 310 6800 ES, Arnhem (Netherlands); Kryshev, A I [State Enterprise Scientific Production Association (SPA), ' Typhoon' , 82 Lenin Avenue, 249038, Obninsk, Kaluga Region (Russian Federation); Nedveckaite, T [Institute of Physics, Radiation Protection, Savanoriu Avenue 231, LT-02053 Vilnius (Lithuania); Smith, J T, E-mail: tamara.yankovich@areva.c [School of Earth and Environmental Sciences, Burnaby Building, Burnaby Road, Portsmouth PO1 3QL (United Kingdom)

    2010-06-15

    Under the International Atomic Energy Agency (IAEA)'s EMRAS (Environmental Modelling for Radiation Safety) programme, activity concentrations of {sup 60}Co, {sup 90}Sr, {sup 137}Cs and {sup 3}H in Perch Lake at Atomic Energy of Canada Limited's Chalk River Laboratories site were predicted, in freshwater primary producers, invertebrates, fishes, herpetofauna and mammals using eleven modelling approaches. Comparison of predicted radionuclide concentrations in the different species types with measured values highlighted a number of areas where additional work and understanding is required to improve the predictions of radionuclide transfer. For some species, the differences could be explained by ecological factors such as trophic level or the influence of stable analogues. Model predictions were relatively poor for mammalian species and herpetofauna compared with measured values, partly due to a lack of relevant data. In addition, concentration ratios are sometimes under-predicted when derived from experiments performed under controlled laboratory conditions representative of conditions in other water bodies.

  15. Freshwater discharges drive high levels of methylmercury in Arctic marine biota.

    Science.gov (United States)

    Schartup, Amina T; Balcom, Prentiss H; Soerensen, Anne L; Gosnell, Kathleen J; Calder, Ryan S D; Mason, Robert P; Sunderland, Elsie M

    2015-09-22

    Elevated levels of neurotoxic methylmercury in Arctic food-webs pose health risks for indigenous populations that consume large quantities of marine mammals and fish. Estuaries provide critical hunting and fishing territory for these populations, and, until recently, benthic sediment was thought to be the main methylmercury source for coastal fish. New hydroelectric developments are being proposed in many northern ecosystems, and the ecological impacts of this industry relative to accelerating climate changes are poorly characterized. Here we evaluate the competing impacts of climate-driven changes in northern ecosystems and reservoir flooding on methylmercury production and bioaccumulation through a case study of a stratified sub-Arctic estuarine fjord in Labrador, Canada. Methylmercury bioaccumulation in zooplankton is higher than in midlatitude ecosystems. Direct measurements and modeling show that currently the largest methylmercury source is production in oxic surface seawater. Water-column methylation is highest in stratified surface waters near the river mouth because of the stimulating effects of terrestrial organic matter on methylating microbes. We attribute enhanced biomagnification in plankton to a thin layer of marine snow widely observed in stratified systems that concentrates microbial methylation and multiple trophic levels of zooplankton in a vertically restricted zone. Large freshwater inputs and the extensive Arctic Ocean continental shelf mean these processes are likely widespread and will be enhanced by future increases in water-column stratification, exacerbating high biological methylmercury concentrations. Soil flooding experiments indicate that near-term changes expected from reservoir creation will increase methylmercury inputs to the estuary by 25-200%, overwhelming climate-driven changes over the next decade. PMID:26351688

  16. Polonium-210 and other radionuclides in terrestrial, freshwater and brackish environments Results from the NKS project GAPRAD (Filling knowledge gaps in radiation protection methodologies for non-human biota)

    Energy Technology Data Exchange (ETDEWEB)

    Gjelsvik, R.; Brown, J.; Holm, E.; Roos, P.; Saxen, R.; Outola, I.

    2012-01-15

    The background and rationale to filling knowledge gaps in radiation protection methodologies for biota are presented. Concentrations of Po-210 and Pb-210 are reported for biota sampled in Dovrefjell, Norway and selected lake and brackish ecosystems in Finland. Furthermore, details in relation to Po-210 uptake and biokinetics in humans based on experimental studies are recounted. (Author)

  17. Polonium-210 and other radionuclides in terrestrial, freshwater and brackish environments Results from the NKS project GAPRAD (Filling knowledge gaps in radiation protection methodologies for non-human biota)

    International Nuclear Information System (INIS)

    The background and rationale to filling knowledge gaps in radiation protection methodologies for biota are presented. Concentrations of Po-210 and Pb-210 are reported for biota sampled in Dovrefjell, Norway and selected lake and brackish ecosystems in Finland. Furthermore, details in relation to Po-210 uptake and biokinetics in humans based on experimental studies are recounted. (Author)

  18. Terrestrial and freshwater radioecology. A selected bibliography

    International Nuclear Information System (INIS)

    This compilation of data on terrestrial and freshwater radioecology contains some 1400 references and is based on publications for which abstracts appeared in Volumes 29 and 30 of Nuclear Science Abstracts and references obtained from other sources. Many were obtained from reviews and other publications. A number of more general references have been included which are not basically on ecology but may be related, and it is hoped of interest to ecologists, e.g. use of tracers in pesticide studies. While compilation of a list in an area broad in scope is often somewhat arbitrary, an attempt was made to reference publications which were related to field or laboratory studies of wild species of plants and animals with respect to radiation effects or metabolic studies involving radionuclides, including parasites. Studies of laboratory or domestic organisms have not in general been included unless such studies are ecological in nature, e.g., on population growth or synergistic. References are included to brackish water and brackish water organisms. Environmental monitoring was included only when natural waters and wild animals or plants were involved. Other kinds of material are included such as nuclear power plant thermal pollution and reports concerning organisms at nuclear energy ins

  19. A review and model assessment of 32P and 33P uptake to biota in freshwater systems

    International Nuclear Information System (INIS)

    Bioaccumulation of key short-lived radionuclides such as 131I and 32,33P may be over-estimated since concentration ratios (CRs) are often based on values for the corresponding stable isotope which do not account for radioactive decay during uptake via the food chain. This study presents estimates for bioaccumulation of radioactive phosphorus which account for both radioactive decay and varying ambient levels of stable P in the environment. Recommended interim CR values for radioactive forms of P as a function of bioavailable stable phosphorus in the water body are presented. Values of CR are presented for three different trophic levels of the aquatic food chain; foodstuffs from all three trophic levels may potentially be consumed by humans. It is concluded that current recommended values of the CR are likely to be significantly over-estimated for radioactive phosphorus in many freshwater systems, particularly lowland rivers. Further research is recommended to field-validate these models and assess their uncertainty. The relative importance of food-chain uptake and direct uptake from water are also assessed from a review of the literature. It can be concluded that food-chain uptake is the dominant accumulation pathway in fish and hence accumulation factors for radioactive phosphorus in farmed fish are likely to be significantly lower than those for wild fish. - Highlights: ? A model is developed for radiophosphorus uptake to fish. ? Concentration ratios for 32,33P in fish may be over-estimated in freshwater systems. ? New recommended values for 32,33P concentration ratios are given. ? Farmed fish are likely to have much lower 32,33P uptake than wild fish.

  20. Selective and universal primers for trematode barcoding in freshwater snails.

    Science.gov (United States)

    Routtu, J; Grunberg, D; Izhar, R; Dagan, Y; Guttel, Y; Ucko, M; Ben-Ami, F

    2014-07-01

    Trematodes are significant pathogens of high medical, veterinary, and environmental importance. They are hard to isolate from their intermediate hosts, and their early life stages are difficult to identify morphologically. Therefore, primers were developed for trematodes to create a species barcoding system and allow selective PCR amplification in mixed samples. The specific oligonucleotide primer was universal for trematodes that infected several freshwater snail species in Israel. The diagnostic tool is based on the 18S rDNA gene. In contrast to morphological identification, trematode barcoding is rapid as it is based on a sequence of only 800 bp, and it classifies species accurately due to high polymorphism between conserved areas. PMID:24781022

  1. Accumulation of radionuclides in selected marine biota from Manjung coastal area

    International Nuclear Information System (INIS)

    Distribution of radionuclides from anthropogenic activities has been intensively studied due to the accumulation of radionuclides in marine ecosystem. Manjung area is affected by rapid population growth and socio-economic development such as heavy industrial activities including coal fired power plant, iron foundries, port development and factories, agricultural runoff, waste and toxic discharge from factories.It has radiological risk and toxic effect when effluent from the industries in the area containing radioactive materials either being transported to the atmosphere and deposited back over the land or by run off to the river and flow into coastal area and being absorbed by marine biota. Radionuclides presence in the marine ecosystem can be adversely affect human health when it enters the food chain. This study is focusing on the radionuclides [thorium (Th), uranium (U), radium-226 (226Ra), radium-228 (228Ra) and potassium-40 (40K)] content in marine biota and sea water from Manjung coastal area. Five species of marine biota including Johnius dussumieri (Ikan Gelama), Pseudorhombus malayanus (Ikan Sebelah), Arius maculatus (Ikan Duri), Portunus pelagicus (Ketam Renjong) and Charybdis natator (Ketam Salib) were collected during rainy and dry seasons. Measurements were carried out using Inductively Coupled Plasma Mass Spectrometer (ICPMS). The results show that the concentration of radionuclides varies depends on ecological environment of respective marine biota species. The concentrations and activity concentrations are used for the assessment of potential internal hazard index (Hin), transfer factor (TF), ingestion dose rate (D) and health risk index (HRI) to monitor radiological risk for human consumption

  2. Accumulation of radionuclides in selected marine biota from Manjung coastal area

    Science.gov (United States)

    Abdullah, Anisa; Hamzah, Zaini; Saat, Ahmad; Wood, Ab. Khalik; Alias, Masitah

    2015-04-01

    Distribution of radionuclides from anthropogenic activities has been intensively studied due to the accumulation of radionuclides in marine ecosystem. Manjung area is affected by rapid population growth and socio-economic development such as heavy industrial activities including coal fired power plant, iron foundries, port development and factories, agricultural runoff, waste and toxic discharge from factories.It has radiological risk and toxic effect when effluent from the industries in the area containing radioactive materials either being transported to the atmosphere and deposited back over the land or by run off to the river and flow into coastal area and being absorbed by marine biota. Radionuclides presence in the marine ecosystem can be adversely affect human health when it enters the food chain. This study is focusing on the radionuclides [thorium (Th), uranium (U), radium-226 (226Ra), radium-228 (228Ra) and potassium-40 (40K)] content in marine biota and sea water from Manjung coastal area. Five species of marine biota including Johnius dussumieri (Ikan Gelama), Pseudorhombus malayanus (Ikan Sebelah), Arius maculatus (Ikan Duri), Portunus pelagicus (Ketam Renjong) and Charybdis natator (Ketam Salib) were collected during rainy and dry seasons. Measurements were carried out using Inductively Coupled Plasma Mass Spectrometer (ICPMS). The results show that the concentration of radionuclides varies depends on ecological environment of respective marine biota species. The concentrations and activity concentrations are used for the assessment of potential internal hazard index (Hin), transfer factor (TF), ingestion dose rate (D) and health risk index (HRI) to monitor radiological risk for human consumption.

  3. Accumulation of radionuclides in selected marine biota from Manjung coastal area

    Energy Technology Data Exchange (ETDEWEB)

    Abdullah, Anisa, E-mail: coppering@ymail.com; Hamzah, Zaini; Wood, Ab. Khalik [Faculty of Applied Sciences, Universiti Teknologi MARA, 40450, Shah Alam, Selangor (Malaysia); Saat, Ahmad [Faculty of Applied Sciences, Universiti Teknologi MARA, 40450, Shah Alam, Selangor (Malaysia); Institute of Science, Universiti Teknologi MARA, 40450 Shah Alam, Selangor (Malaysia); Alias, Masitah [TNB Reasearch Sdn. Bhd., Kawasan Institusi Penyelidikan, 43000 Kajang, Selangor (Malaysia)

    2015-04-29

    Distribution of radionuclides from anthropogenic activities has been intensively studied due to the accumulation of radionuclides in marine ecosystem. Manjung area is affected by rapid population growth and socio-economic development such as heavy industrial activities including coal fired power plant, iron foundries, port development and factories, agricultural runoff, waste and toxic discharge from factories.It has radiological risk and toxic effect when effluent from the industries in the area containing radioactive materials either being transported to the atmosphere and deposited back over the land or by run off to the river and flow into coastal area and being absorbed by marine biota. Radionuclides presence in the marine ecosystem can be adversely affect human health when it enters the food chain. This study is focusing on the radionuclides [thorium (Th), uranium (U), radium-226 ({sup 226}Ra), radium-228 ({sup 228}Ra) and potassium-40 ({sup 40}K)] content in marine biota and sea water from Manjung coastal area. Five species of marine biota including Johnius dussumieri (Ikan Gelama), Pseudorhombus malayanus (Ikan Sebelah), Arius maculatus (Ikan Duri), Portunus pelagicus (Ketam Renjong) and Charybdis natator (Ketam Salib) were collected during rainy and dry seasons. Measurements were carried out using Inductively Coupled Plasma Mass Spectrometer (ICPMS). The results show that the concentration of radionuclides varies depends on ecological environment of respective marine biota species. The concentrations and activity concentrations are used for the assessment of potential internal hazard index (H{sub in}), transfer factor (TF), ingestion dose rate (D) and health risk index (HRI) to monitor radiological risk for human consumption.

  4. Long-term growth-increment chronologies reveal diverse influences of climate forcing on freshwater and forest biota in the Pacific Northwest

    Science.gov (United States)

    Black, Bryan A.; Dunham, Jason B.; Blundon, Brett W.; Brim-Box, Jayne; Tepley, Alan J.

    2015-01-01

    Analyses of how organisms are likely to respond to a changing climate have focused largely on the direct effects of warming temperatures, though changes in other variables may also be important, particularly the amount and timing of precipitation. Here, we develop a network of eight growth-increment width chronologies for freshwater mussel species in the Pacific Northwest, United States and integrate them with tree-ring data to evaluate how terrestrial and aquatic indicators respond to hydroclimatic variability, including river discharge and precipitation. Annual discharge averaged across water years (October 1–September 30) was highly synchronous among river systems and imparted a coherent pattern among mussel chronologies. The leading principal component of the five longest mussel chronologies (1982–2003; PC1mussel) accounted for 47% of the dataset variability and negatively correlated with the leading principal component of river discharge (PC1discharge; r = ?0.88; P forests where tree growth tends to be limited by drought while positive correlations occurred in forests where tree growth tends to be limited by deep or lingering snowpack. Overall, this diverse assemblage of chronologies illustrates the importance of winter precipitation to terrestrial and freshwater ecosystems and suggests that a complexity of climate responses must be considered when estimating the biological impacts of climate variability and change.

  5. Effects of selected silver nanoparticles on freshwater microbial communities

    OpenAIRE

    Matzke, Marianne; Gallego, Julian; Hassellöv, Martin; Jurkschat, Kerstin; Backhaus, Thomas

    2012-01-01

    Due to their widespread use in consumer products an exposure of the aquatic environment to nanoparticles (NPs) is most likely. Especially metal/metaloxide NPs are widely used, of which silver nanoparticles (AgNPs) have gained considerable attention due to their broad microbiocidal properties implying a specific hazard for exposed aquatic algae and bacteria.In a case study with selected AgNPs (different sizes (10, 20 and 40 nm), and different coatings (citrate coated, non-coated...

  6. Monitoring the succession of the biota grown on a selective medium for pseudomonads during storage of minced beef with molecular-based methods.

    Science.gov (United States)

    Doulgeraki, Agapi I; Nychas, George-John E

    2013-05-01

    In the present study, the succession of the biota grown on a selective medium for pseudomonads (pseudomonas agar based medium - PAB) during the storage of meat under different conditions was monitored. Thus, minced beef was stored aerobically and under modified atmosphere packaging in the presence (MAP+) and absence (MAP-) of oregano essential oil at 0, 5, 10 and 15 °C. A total of 267 pure cultures were recovered from PAB throughout the storage period and subjected to PCR-Denaturing gradient gel electrophoresis (PCR-DGGE) for their differentiation. In parallel, the direct analysis of the whole cultivable community (WCC) from the same medium was applied. These two approaches were used in order to indicate the lack of selectivity. Fifteen different DGGE fingerprints were obtained after PCR - DGGE analysis of the isolates, which were assigned to Pseudomonas putida (3 fingerprints), Pseudomonas fragi and Pseudomonas fluorescens, Pseudomonas spp., Serratia liquefaciens (2), Citrobacter freundii, Serratia grimesii, Hafnia alvei (3), Rahnella spp. and Morganella morganii. Twelve of them occurred during the direct analysis of the WCC. The biota succession found to be affected from the different storage conditions. However, the outcome of the two strategies was quite different, which is leading to the use of different appropriated molecular approaches in order to widen the knowledge of bacterial succession of meat. PMID:23498179

  7. Changes in selection regime cause loss of phenotypic plasticity in planktonic freshwater copepods.

    Science.gov (United States)

    Sereda, Sergej Vital'evi?; Wilke, Thomas; Schultheiß, Roland

    2014-01-01

    Rapid phenotypic adaptation is critical for populations facing environmental changes and can be facilitated by phenotypic plasticity in the selected traits. Whereas recurrent environmental fluctuations can favour the maintenance or de novo evolution of plasticity, strong selection is hypothesized to decrease plasticity or even fix the trait (genetic assimilation). Despite advances in the theoretical understanding of the impact of plasticity on diversification processes, comparatively little empirical data of populations undergoing diversification mediated by plasticity are available. Here we use the planktonic freshwater copepod Acanthodiaptomus denticornis from two lakes as model system to study UV stress responses of two phenotypically different populations under laboratory conditions. Our study reveals heritable lake- and sex-specific differences of behaviour, physiological plasticity, and mortality. We discuss specific selective scenarios causing these differences and argue that phenotypic plasticity will be higher when selection pressure is moderate, but will decrease or even be lost under stronger pressure. PMID:24587186

  8. A low-density SNP array for analyzing differential selection in freshwater and marine populations of threespine stickleback (Gasterosteus aculeatus)

    DEFF Research Database (Denmark)

    Ferchaud, Anne-Laure; Pedersen, Susanne H.

    2014-01-01

    Background: The threespine stickleback (Gasterosteus aculeatus) has become an important model species for studying both contemporary and parallel evolution. In particular, differential adaptation to freshwater and marine environments has led to high differentiation between freshwater and marine stickleback populations at the phenotypic trait of lateral plate morphology and the underlying candidate gene Ectodysplacin (EDA). Many studies have focused on this trait and candidate gene, although other genes involved in marine-freshwater adaptation may be equally important. In order to develop a resource for rapid and cost efficient analysis of genetic divergence between freshwater and marine sticklebacks, we generated a low-density SNP (Single Nucleotide Polymorphism) array encompassing markers of chromosome regions under putative directional selection, along with neutral markers for background. Results: RAD (Restriction site Associated DNA) sequencing of sixty individuals representing two freshwater and one marine population led to the identification of 33,993 SNP markers. Ninety-six of these were chosen for the low-density SNP array, among which 70 represented SNPs under putatively directional selection in freshwater vs. marine environments, whereas 26 SNPs were assumed to be neutral. Annotation of these regions revealed several genes that are candidates for affecting stickleback phenotypic variation, some of which have been observed in previous studies whereas others are new. Conclusions: We have developed a cost-efficient low-density SNP array that allows for rapid screening of polymorphisms in threespine stickleback. The array provides a valuable tool for analyzing adaptive divergence between freshwater and marine stickleback populations beyond the well-established candidate gene Ectodysplacin (EDA).

  9. Initial Evidence for Adaptive Selection on the NADH Subunit Two of Freshwater Dolphins by Analyses of Mitochondrial Genomes.

    Science.gov (United States)

    Caballero, Susana; Duchêne, Sebastian; Garavito, Manuel F; Slikas, Beth; Baker, C Scott

    2015-01-01

    A small number of cetaceans have adapted to an entirely freshwater environment, having colonized rivers in Asia and South America from an ancestral origin in the marine environment. This includes the 'river dolphins', early divergence from the odontocete lineage, and two species of true dolphins (Family Delphinidae). Successful adaptation to the freshwater environment may have required increased demands in energy involved in processes such as the mitochondrial osmotic balance. For this reason, riverine odontocetes provide a compelling natural experiment in adaptation of mammals from marine to freshwater habitats. Here we present initial evidence of positive selection in the NADH dehydrogenase subunit 2 of riverine odontocetes by analyses of full mitochondrial genomes, using tests of selection and protein structure modeling. The codon model with highest statistical support corresponds to three discrete categories for amino acid sites, those under positive, neutral, and purifying selection. With this model we found positive selection at site 297 of the NADH dehydrogenase subunit 2 (dN/dS>1.0,) leading to a substitution of an Ala or Val from the ancestral state of Thr. A phylogenetic reconstruction of 27 cetacean mitogenomes showed that an Ala substitution has evolved at least four times in cetaceans, once or more in the three 'river dolphins' (Families Pontoporidae, Lipotidae and Inidae), once in the riverine Sotalia fluviatilis (but not in its marine sister taxa), once in the riverine Orcaella brevirostris from the Mekong River (but not in its marine sister taxa) and once in two other related marine dolphins. We located the position of this amino acid substitution in an alpha-helix channel in the trans-membrane domain in both the E. coli structure and Sotalia fluviatilis model. In E. coli this position is located in a helix implicated in a proton translocation channel of respiratory complex 1 and may have a similar role in the NADH dehydrogenases of cetaceans. PMID:25946045

  10. Selection of spatial scale for assessing impacts of groundwater-based water supply on freshwater resources

    DEFF Research Database (Denmark)

    Hybel, Anne-Marie; Godskesen, Berit

    2015-01-01

    Indicators of the impact on freshwater resources are becoming increasingly important in the evaluation of urban water systems. To reveal the importance of spatial resolution, we investigated how the choice of catchment scale influenced the freshwater impact assessment. Two different indicators were used in this study: the Withdrawal-To-Availability ratio (WTA) and the Water Stress Index (WSI). Results were calculated for three groundwater based Danish urban water supplies (Esbjerg, Aarhus, and Copenhagen). The assessment was carried out at three spatial levels: (1) the groundwater body level, (2) the river basin level, and (3) the regional level. The assessments showed that Copenhagen's water supply had the highest impact on the freshwater resource per cubic meter of water abstracted, with a WSI of 1.75 at Level 1. The WSI values were 1.64 for Aarhus's and 0.81 for Esbjerg's water supply. Spatial resolution was identified as a major factor determining the outcome of the impact assessment. For the three case studies, WTA and WSI were 27%–583% higher at Level 1 than impacts calculated for the regional scale. The results highlight that freshwater impact assessments based on regional data, rather than sub-river basin data, may dramatically underestimate the actual impact on the water resource. Furthermore, this study discusses the strengths and shortcomings of the applied indicator approaches. A sensitivity analysis demonstrates that although WSI has the highest environmental relevance, it also has the highest uncertainty, as it requires estimations of non-measurable environmental water requirements. Hence, the development of a methodology to obtain more site-specific and relevant estimations of environmental water requirements should be prioritized. Finally, the demarcation of the groundwater resource in aquifers remains a challenge for establishing a consistent method for benchmarking freshwater impacts caused by groundwater abstraction.

  11. Seamount biota and biogeography

    Science.gov (United States)

    Wilson, Raymond R., Jr.; Kaufmann, Ronald S.

    A review of the literature and unpublished data has identified 1045 species of plants, invertebrates and fishes collected from more than 100 seamounts worldwide at depths of 29 to 3800 m. Cnidarians and decapod crustaceans among invertebrates, and scorpaenids and morids among fishes, were the most widely distributed groups on seamounts, according to published reports. Biota of seamounts is dominated by organisms inhabiting the nearest continental areas, especially at high latitudes. On shallow seamounts (endemism is estimated maximally at 15.4% among invertebrates and 11.6% among fishes. Population divergence and possibly speciation have occurred on seamounts of varying depths and distances from continental margins.

  12. Species richness of Odonata in selected freshwater systems in Zamboanga del Sur, Philippines

    Directory of Open Access Journals (Sweden)

    Roxanne D. Cayasan

    2013-07-01

    Full Text Available The Odonata is important in identifying the habitat health of freshwater ecosystems. In thisstudy, the species richness and relative abundance of Odonata were determined in 12 sampling sites inZamboanga del Sur. Field work was conducted in August-December, 2012 using the random samplingmethod. Thirty-six species belonging to 10 families were documented of which 16 (44% species arePhilippine endemic. High species richness was recorded in Cabilinan Stream which is considered to bethe most undisturbed site in the 12 sampling sites. Species richness was also considerably high in eightsampling sites despite habitat modification and water pollution from agricultural run-offs. The presenceof Oriental species which are indicators of degraded environments suggests that the streams aredisturbed. However, the presence of some endemic species indicates that these endemic fauna canthrive in disturbed habitats.

  13. Literature review of the concentration ratios of selected radionuclides in freshwater and marine fish

    Energy Technology Data Exchange (ETDEWEB)

    Poston, T.M.; Klopfer, D.C.

    1986-09-01

    Concentration ratios (CR's) used for modeling the uptake and food chain transport of radionuclides in fish have usually been conservative; that is, at the high end of reported values. This practice ensures that the dose to the consumer of contaminated fish will not be underestimated. In many models, however, conservative values have been used for all variables that have any uncertainty associated with them. As a result the dose to the consumer is overestimated. Realistic CR values need to be developed to establish model parameters that will accurately reflect tissue burdens in fish and resulting dose rates to consumers. This report reviews and summarizes published literature on the uptake and distribution of stable and radioactive isotopes of 26 elements. Based on this review, we have made recommendations on CR values to be used for modeling the accumulation of radionuclides in fish. Our recommendations are compared with CR values reported in other publications. A generic discussion of abiotic and biotic factors that influence CR values is provided so that CR values may be adjusted based on site-specific characteristics of the fishes habitat. Recommended CR values for freshwater fish and for marine fish are listed. Although this report emphasizes radionuclides, it is applicable to stable elements as well.

  14. Literature review of the concentration ratios of selected radionuclides in freshwater and marine fish

    International Nuclear Information System (INIS)

    Concentration ratios (CR's) used for modeling the uptake and food chain transport of radionuclides in fish have usually been conservative; that is, at the high end of reported values. This practice ensures that the dose to the consumer of contaminated fish will not be underestimated. In many models, however, conservative values have been used for all variables that have any uncertainty associated with them. As a result the dose to the consumer is overestimated. Realistic CR values need to be developed to establish model parameters that will accurately reflect tissue burdens in fish and resulting dose rates to consumers. This report reviews and summarizes published literature on the uptake and distribution of stable and radioactive isotopes of 26 elements. Based on this review, we have made recommendations on CR values to be used for modeling the accumulation of radionuclides in fish. Our recommendations are compared with CR values reported in other publications. A generic discussion of abiotic and biotic factors that influence CR values is provided so that CR values may be adjusted based on site-specific characteristics of the fishes habitat. Recommended CR values for freshwater fish and for marine fish are listed. Although this report emphasizes radionuclides, it is applicable to stable elements as well

  15. Changes in Selection Regime Cause Loss of Phenotypic Plasticity in Planktonic Freshwater Copepods

    OpenAIRE

    Sereda, Sergej Vital’evi?; Wilke, Thomas; Schultheiß, Roland

    2014-01-01

    Rapid phenotypic adaptation is critical for populations facing environmental changes and can be facilitated by phenotypic plasticity in the selected traits. Whereas recurrent environmental fluctuations can favour the maintenance or de novo evolution of plasticity, strong selection is hypothesized to decrease plasticity or even fix the trait (genetic assimilation). Despite advances in the theoretical understanding of the impact of plasticity on diversification processes, comparatively little e...

  16. Direct and Indirect Evidence of Size-Selective Grazing on Pelagic Bacteria by Freshwater Nanoflagellates

    OpenAIRE

    Šimek, Karel; Chrzanowski, Thomas H.

    1992-01-01

    Size-selective grazing of three heterotrophic nanoflagellates (with cell sizes of 21, 44, and 66 ?m3) isolated from Lake Arlington, Texas was examined by using a natural mixture of fluorescence labelled lake bacteria. Sizes of ingested bacteria in food vacuoles were directly measured. Larger bacterial cells were ingested at a frequency much higher than that at which they occurred in the assemblage, indicating preferential flagellate grazing on the larger size classes within the lake bacteriop...

  17. Water Quality, Stocking Density and Parasites of Freshwater Fish in Four Selected Areas of Bangladesh

    Directory of Open Access Journals (Sweden)

    A.N.H. Banu

    2004-01-01

    Full Text Available Stocking density, water quality (depth, temperature, dissolved oxygen, pH, total ammonia, hardness as CaCO3 and total alkalinity and parasites of fishes were investigated in four selected areas (Bogra, Chandpur, Jessore and Mymensingh for a period of three years. Stocking density varied from 15.74x103 to 34.38x103 ha-1. Water quality parameters (except ammonia varied significantly from one area to another. Among the parasites, the prevalence of Trichodinids was dominant followed by Monogenians, Chilodonella spp. and Myxosporidian. Correlation on physico-chemical parameters and incidence of parasites were studied.

  18. The effects of increased freshwater inflow on metal enrichment in selected Eastern Cape estuaries, South Africa

    Scientific Electronic Library Online (English)

    KK, Orr; JE, Burgess; PW, Froneman.

    2008-01-01

    Full Text Available The concentrations of select metals (Cd, Co, Cu, Fe, Pb, Ni and Zn) within the water column and sediment of the permanently open Kariega Estuary and temporary open/closed Riet and East Kleinemonde Estuaries were investigated during a dry and a wet season. Enrichment factors (EFs), using Fe as a refe [...] rence element, and baseline linear regression models for metals vs Fe were used to assess the extent of metal enrichment in the sediments. The results of the study indicate that Cd, Co Ni and Pb were enriched above baseline concentrations (1.0

  19. Initial Evidence for Adaptive Selection on the NADH Subunit Two of Freshwater Dolphins by Analyses of Mitochondrial Genomes

    OpenAIRE

    Caballero, Susana; Duchêne, Sebastian; Garavito, Manuel F.; Slikas, Beth; Baker, C. Scott

    2015-01-01

    A small number of cetaceans have adapted to an entirely freshwater environment, having colonized rivers in Asia and South America from an ancestral origin in the marine environment. This includes the ‘river dolphins’, early divergence from the odontocete lineage, and two species of true dolphins (Family Delphinidae). Successful adaptation to the freshwater environment may have required increased demands in energy involved in processes such as the mitochondrial osmotic balance. For this reason...

  20. Biota-Sediment Accumulation Factor Data

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Biota-Sediment Accumulation Factor contains approximately 20,000 biota-sediment accumulation factors (BSAFs) from 20 locations (mostly Superfund sites) for...

  1. Selective inhibition of toxic cyanobacteria by ?-carboline-containing bacterium Bacillus flexus isolated from Saudi freshwaters.

    Science.gov (United States)

    Alamri, Saad A; Mohamed, Zakaria A

    2013-10-01

    A bacterial strain SSZ01 isolated from a eutrophic lake in Saudi Arabia dominated by cyanobacterial blooms, showed an antialgal activity against cyanobacteria species. Based on the analysis of the 16S rDNA gene sequence, the isolated strain (SSZ01) most likely belonged to the genus Bacillus with a 99% similarity to Bacillus flexus strain EMGA5. The thin layer chromatography (TLC) analysis of the ethyl acetate extract of this bacterium revealed that this strain can produce harmine and norharmane compared to different ?-carboline analog standards. Harmine and norharmane were also detected in considerable amounts in bacterial growth medium, indicating a potential excretion of these compounds into the aquatic environment. The crude extract of Bacillus flexus as well as pure materials of harmine and norharmane inhibited the growth of tested species of cyanobacteria. However, the bacterial crude extract has a higher toxicity against tested species of cyanobacteria than harmine and norharmane. In addition, harmine was more toxic to cyanobacteria than norharmane. On the other hand, neither pure compounds of harmine and norharmane nor crude bacterial extract showed any antialgal activity against tested species of green algae. The results of the present study suggest that B. flexus SSZ01 or its crude extract containing harmine and norharmane could be a candidate for the selective control of cyanobacterial blooms without affecting other algal species. PMID:24235872

  2. Growth responses of selected freshwater algae to trace elements and scrubber ash slurry generated by coal-fired power plants

    Energy Technology Data Exchange (ETDEWEB)

    Vocke, R.W.

    1979-01-01

    The development and implementation of standard toxicity tests is a necessity if consistent and reliable data are to be obtained for water quality criteria. The adapted EPA AAPBT is an ideal static algal toxicity test system. The algal test medium has a chemical composition similar to natural unpolluted waters of low ionic strength. It is appropriate to use MATC water quality criteria when assessing the potential impact of pollutants generated by coal-fired power stations because these energy-generated pollutants typically enter aquatic systems in small quantities over long periods. The MATC water quality criteria are estimates of trace element and SASE levels, based on the most sensitive alga investigated, that will not cause significant changes in naturally-functioning algal populations. These levels are 0.016f mg L/sup -1/ As(V), 0.001 mg L/sup -1/ Cd(II), 0.004 mg L/sup -1/ Hg(II), 0.006 mg L/sup -1/ Se(VI), and 0.344% SASE. To provide viable working water quality criteria, an extrapolation from the laboratory to the natural environment must be made. Therefore, those oxidation states of the trace elements were selected which are the dominant states occurring in natural, unpolluted, slightly alkaline freshwaters. It must be pointed out that these MATC values are based on algal responses to single toxicants and no allowance is made for synergistic, additive, or antagonistic relationships which could occur in natural aquatic systems. Additionally, natural chelation may influence toxicity. The highly toxic nature of potential pollutants from coal-fired generating plants emphasizes the need for minimizing stack effluent pollutants and retaining scrubber ash slurry for proper disposal in an effort to maintain trace elements in concentration ranges compatible with naturally-functioning ecosystems.

  3. Ediacaran biota from Sonora, Mexico.

    OpenAIRE

    McMenamin, M A

    1996-01-01

    The Ediacaran biota is the earliest diverse community of macroscopic animals and protoctists. Body and trace fossils in the Clemente Formation of northwestern Sonora extend downward the geologic range of Ediacaran forms. Taxa present in the Clemente Formation include cf. Cyclomedusa plana, Sekwia sp., an erniettid (bearing an air mattress-like "pneu" body construction), and the trace fossils Lockeia ichnosp. and Palaeophycus tubularis. The trace fossils confirm the presence of sediment-dwelli...

  4. A freshwater biodiversity hotspot under pressure – assessing threats and identifying conservation needs for ancient Lake Ohrid

    OpenAIRE

    G. Kostoski; Albrecht, C.; Trajanovski, S.; Wilke, T.

    2010-01-01

    Freshwater habitats and species living in freshwater are generally more prone to extinction than terrestrial or marine ones. Immediate conservation measures for world-wide freshwater resources are thus of eminent importance. This is particularly true for so called ancient lakes. While these lakes are famous for being evolutionary theatres, often displaying an extraordinarily high degree of biodiversity and endemism, in many cases these biota are also experiencing extreme anthropogenic impact....

  5. Bioconcentration of TNT and RDX in coastal marine biota.

    Science.gov (United States)

    Ballentine, Mark; Tobias, Craig; Vlahos, Penny; Smith, Richard; Cooper, Christopher

    2015-05-01

    The bioconcentration factor (BCF) was measured for 2,4,6-trinitrotoluene (TNT) and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) in seven different marine species of varying trophic levels. Time series and concentration gradient treatments were used for water column and tissue concentrations of TNT, RDX, and their environmentally important derivatives 2-amino-4,6-dintrotoluene (2-ADNT) and 4-amino-2,6-dinitrotoluene (4-ADNT). BCF values ranged from 0.0031 to 484.5 mL g(-1) for TNT and 0.023 to 54.83 mL g(-1) for RDX. The use of log K ow value as an indicator was evaluated by adding marine data from this study to previously published data. For the munitions in this study, log K ow value was a good indicator in the marine environment. The initial uptake and elimination rates of TNT and RDX for Fucus vesiculosus were 1.79 and 0.24 h(-1) for TNT and 0.50 and 0.0035 h(-1) for RDX respectively. Biotransformation was observed in all biota for both TNT and RDX. Biotransformation of TNT favored 4-ADNT over 2-ADNT at ratios of 2:1 for F. vesiculosus and 3:1 for Mytilus edulis. Although RDX derivatives were measureable, the ratios of RDX derivatives were variable with no detectable trend. Previous approaches for measuring BCF in freshwater systems compare favorably with these experiments with marine biota, yet significant gaps on the ultimate fate of munitions within the biota exist that may be overcome with the use stable isotope-labeled munitions substrates. PMID:25451633

  6. Differential contribution of soil biota groups to plant litter decomposition as mediated by soil use

    OpenAIRE

    Castro-Huerta, Ricardo A.; Liliana B. Falco; Rosana V Sandler; Carlos E Coviella

    2015-01-01

    Plant decomposition is dependant on the activity of the soil biota and its interactions with climate, soil properties, and plant residue inputs. This work assessed the roles of different groups of the soil biota on litter decomposition, and the way they are modulated by soil use. Litterbags of different mesh sizes for the selective exclusion of soil fauna by size (macro, meso, and microfauna) were filled with standardized dried leaves and placed on the same soil under different use intensitie...

  7. Proposed Release Guides to Protect Aquatic Biota

    Energy Technology Data Exchange (ETDEWEB)

    Marter, W.L.

    2001-03-28

    At the request of South Carolina Department of Health and Environmental Control (SCDHEC) and the Department of Energy (DOE), the Savannah River Laboratory was assigned the task of developing the release guides to protect aquatic biota. A review of aquatic radioecology literature by two leading experts in the field of radioecology concludes that exposure of aquatic biota at one rad per day or less will not produce detectable deleterious effects on aquatic organisms. On the basis of this report, DOE recommends the use of one rad per day as an interim dose standard to protect aquatic biota.

  8. Determination of the 14C activity level in the biota of the surroundings of NPPs

    International Nuclear Information System (INIS)

    The results of 14C monitoring in the biota surrounding Czech NPPs (Temelin and Dukovany) are evaluated. The observed levels are compared with those in reference areas. Two types of area with different Suess effect load were selected as reference areas: clear sites ('A'), and sites where a medium local Suess effect is expected ('B'). The local Suess effect in the NPP areas is assumed to lie in between the 2 types of reference area. Statistical evaluation gave evidence of a significantly larger 14C activity in the biota surrounding the two NPPs in comparison with reference area B. The difference of 14C activity between the biota around Temelin and the biota in reference area A was found to be statistically significant and the interval of 14C activity increment could be determined. For Dukovany, only the upper limit of this interval (i.e., in comparison with reference area B) was demonstrable. The results of two linear samplings performed in the vicinity of Dukovany and Paks (Hungary) in 2006 are also outlined and discussed briefly.. The low 14C activity surplus in biota around those NPPs with PWR reactors is due to the low 14CO2 content of the gaseous effluents as compared to other reactor types. Other chemical species with 14C (with prevailing 14CH4) do not contribute to radiocarbon intake by photosynthesis in the surrounding biota. (orig.)

  9. Freshwater fish of the Wilderness National Park

    Directory of Open Access Journals (Sweden)

    I.A. Russell

    1999-01-01

    Full Text Available The study aimed to determine the distribution and relative abundance of freshwater fish in the Wilderness National Park. Fish assemblages in the Touw and Duiwe rivers were sampled in 1997 and 1998, with a total of 327 fish from nine species recorded. Indigenous species included two freshwater species (Pseudobarbus afer, Sandelia capensis, two catadromous species (Anguilla mossambicus, Myxus capensis, and two estuarine species (Monodactylusfalciformis, Caffrogobius multifasciatus. Three of the nine recorded species were alien (Micropterus dolomieu, Micropterus salmoides, Gambusia affinis, with the Micropterus spp., in particular, likely to have a substantial negative influence on indigenous species. A further one indigenous species, two translocated indigenous species, and five estuarine species could potentially be recorded in these rivers. River catchment management actions to restore perennial flow to the Duiwe River, to prevent the attenuation of floods, and to prevent further establishment and spread of alien and translocated biota are required to conserve indigenous fish assemblages.

  10. Host-Specificity and Dynamics in Bacterial Communities Associated with Bloom-Forming Freshwater Phytoplankton

    OpenAIRE

    Bagatini, Inessa Lacativa; Eiler, Alexander; Bertilsson, Stefan; Klaveness, Dag; Tessarolli, Leticia Piton; Henriques Vieira, Armando Augusto

    2014-01-01

    Many freshwater phytoplankton species have the potential to form transient nuisance blooms that affect water quality and other aquatic biota. Heterotrophic bacteria can influence such blooms via nutrient regeneration but also via antagonism and other biotic interactions. We studied the composition of bacterial communities associated with three bloom-forming freshwater phytoplankton species, the diatom Aulacoseira granulata and the cyanobacteria Microcystis aeruginosa and Cylindrospermopsis ra...

  11. The size selectivity of the main body of a sampling pelagic pair trawl in freshwater reservoirs during the night.

    Czech Academy of Sciences Publication Activity Database

    ?íha, Milan; J?za, Tomáš; Prchalová, Marie; Mrkvi?ka, Tomáš; ?ech, Martin; Draštík, Vladislav; Muška, Milan; Kratochvíl, Michal; Peterka, Ji?í; Tušer, Michal; Vašek, Mojmír; Kube?ka, Jan

    2012-01-01

    Ro?. 127, September (2012), s. 56-60. ISSN 0165-7836 R&D Projects: GA MZe(CZ) QH81046 Institutional support: RVO:60077344 Keywords : quantitative sampling * gear selectivity * trawl * reservoirs Subject RIV: GL - Fishing Impact factor: 1.695, year: 2012

  12. Evolutionary refugia and ecological refuges: key concepts for conserving Australian arid zone freshwater biodiversity under climate change

    OpenAIRE

    Davis, Jenny; Pavlova, Alexandra; Thompson, Ross; Sunnucks, Paul

    2013-01-01

    Refugia have been suggested as priority sites for conservation under climate change because of their ability to facilitate survival of biota under adverse conditions. Here, we review the likely role of refugial habitats in conserving freshwater biota in arid Australian aquatic systems where the major long-term climatic influence has been aridification. We introduce a conceptual model that characterizes evolutionary refugia and ecological refuges based on our review of the attributes of aquati...

  13. Selection of (bio) indicators to assess effects of freshwater use in wetlands: a case study of s'Albufera de Mallorca, Spain

    OpenAIRE

    Veraart, J.A.; Groot, R.S. de; Perelló, G.; Riddiford, N.J.; Roijackers, R.M.M.

    2004-01-01

    Parc Natural sAlbufera de Mallorca is an internationally recognised resting area for a wide array of migratory birds, and like most wetlands it has many other ecological functions and socio-economic values. In the catchment, in which the wetland is situated, expanding tourism and intensification of agriculture place much pressure on a limited amount of freshwater. The freshwater supply to the wetland decreased due to water-extraction mainly driven by intensification of agriculture in the catc...

  14. Radiation Dose Assessment Model for Marine Biota (K-BIOTA-DYN-M)

    International Nuclear Information System (INIS)

    In this study, a dynamic compartment model based on the food chain of marine biota, which can be used with easily obtainable ecological parameters, is presented to predict the activity concentration and dose rate of marine biota as a result of a nuclear. The model was applied to investigate a long-term effect of the Fukushima accident on the marine biota by using 131I, 134Cs, and 137Cs activity concentrations of seawater measured for up to about 2.5years after the accident in the port of FDNPS, which was known to be the most severely contaminated. A dynamic compartment model was presented to assess the activity concentration and whole body dose rate of marine biota, and was tested through the prediction of the activity concentration and dose rate of the marine biota using the seawater activities of 131I, 134Cs, and 137Cs measured after the accident at two locations in the port of the Fukushima Daiichi Nuclear Power Station (FDNPS), as a result the Fukushima nuclear accident that occurred on March 11, 2011. The prediction results showed the radiological effect on the population of the marine biota as a consequence of the accident was insignificant. This result is also valid for biota in a less contaminated offshore because the present assessment was made for the most highly contaminated area such as marine ecosystem in the port of FDNPS. Conclusively, the present dynamic model can be usefully applied to estimate the activity concentration and whole body dose rate of the marine biota as the consequence of a nuclear accident

  15. Radiation Dose Assessment Model for Marine Biota (K-BIOTA-DYN-M)

    Energy Technology Data Exchange (ETDEWEB)

    Keum, Dong-Kwon; Kim, Byeong-Ho; Jun, In; Lim, Kwang-Muk; Choi, Yong-Ho [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-10-15

    In this study, a dynamic compartment model based on the food chain of marine biota, which can be used with easily obtainable ecological parameters, is presented to predict the activity concentration and dose rate of marine biota as a result of a nuclear. The model was applied to investigate a long-term effect of the Fukushima accident on the marine biota by using {sup 131}I, {sup 134}Cs, and {sup 137}Cs activity concentrations of seawater measured for up to about 2.5years after the accident in the port of FDNPS, which was known to be the most severely contaminated. A dynamic compartment model was presented to assess the activity concentration and whole body dose rate of marine biota, and was tested through the prediction of the activity concentration and dose rate of the marine biota using the seawater activities of {sup 131}I, {sup 134}Cs, and {sup 137}Cs measured after the accident at two locations in the port of the Fukushima Daiichi Nuclear Power Station (FDNPS), as a result the Fukushima nuclear accident that occurred on March 11, 2011. The prediction results showed the radiological effect on the population of the marine biota as a consequence of the accident was insignificant. This result is also valid for biota in a less contaminated offshore because the present assessment was made for the most highly contaminated area such as marine ecosystem in the port of FDNPS. Conclusively, the present dynamic model can be usefully applied to estimate the activity concentration and whole body dose rate of the marine biota as the consequence of a nuclear accident.

  16. Synthesis, pathways, effects, and fate of chlorination by-products in freshwater, estuarine and marine environments. Annual report, September 10, 1976--September 30, 1977

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, D.R.; Bean, R.M.; Gibson, C.I.; Thatcher, T.O.

    1978-06-01

    The study is composed of analytical chemistry and biological divisions with freshwater and marine biological subdivisions. The objective of the analytical phase is to identify those chemical compounds, other than the free and combined available halogen, which result from the addition of chlorine to fresh or saltwater. The objectives of the biological studies are to investigate the immediate and relatively long-term toxicity of several chlorination by-products to selected aquatic biota; to follow their pathways of action; and to analyze for bioaccumulation or biomagnification. Initial analytical experimentation has been directed toward isolating and identifying nonpolar, lipophylic organohalogens that might be expected to be absorbed and biomagnified in the lipids of aquatic biota. Chlorinated natural fresh and marine water samples were obtained from Task IIa and b. Organic components were concentrated by forcing chlorinated and unchlorinated water through columns of XAD-2 resin using a positive displacement pump. Ether extracts of the XAD-2 columns were analyzed for haloforms by gas chromatography. Bromoform was found to be the major constituent in all chlorinated sea water samples. In contrast, chloroform was the only haloform produced from chlorinated freshwater. The Freshwater Biology 6-month chronic bioassay on rainbow trout has produced several results. The mortality rate, although low, indicated an interesting trend in response to increasing concentration of chlorination by-products. In addition to observed mortality, concentration was inversely related to other fish losses which are hypothesized to result from decreased aggressiveness. Fish length and weight at six months was also significantly reduced with increasing concentrations of chlorination by-products. A chronic bioassay of chlorination by-products was conducted with little-neck clams in the marine phase of the program.

  17. Bangladesh Sundarbans: Present status of the environment and Biota

    Directory of Open Access Journals (Sweden)

    Abdul Aziz

    2015-07-01

    Full Text Available The Sundarbans is a deltaic mangrove forest, formed about 7000 years ago by the deposition of sediments from the foothills of the Himalayas through the Ganges river system, and is situated southwest of Bangladesh and south of West Bengal, India. However, for the last 40 years, the discharge of sediment-laden freshwater into the Bay of Bengal through the Bangladesh part of the Sundarbans Mangrove Forests (BSMF has been reduced due to a withdrawal of water during the dry period from the Farakka Barrage in India. The result is two extremes of freshwater discharge at Gorai, the feeding River of the BSMF: a mean minimum monthly discharge varies from 0.00 to 170 m3·s?1 during the dry period with a mean maximum of about 4000 to 8880 m3·s?1 during the wet period. In the BSMF, about 180 km downstream, an additional low discharge results in the creation of a polyhaline environment (a minimum of 194.4 m3·s?1 freshwater discharge is needed to maintain an oligohaline condition during the dry period. The Ganges water carries 262 million ton sediments/year and only 7% is diverted in to southern distributaries. The low discharge retards sediment deposition in the forestlands’ base as well as the formation of forestlands. The increase in water flow during monsoon on some occasions results in erosion of the fragile forestlands. Landsat Satellite data from the 1970s to 2000s revealed a non-significant decrease in the forestlands of total Sundarbans by 1.1% which for the 6017 km2 BSMF is equivalent to 66 km2. In another report from around the same time, the estimated total forestland loss was approximately 127 km2. The Sundarbans has had great influence on local freshwater environments, facilitating profuse growth of Heritiera fomes (sundri, the tallest (at over 15 m and most commercially important plant, but now has more polyhaline areas threatening the sundri, affecting growth and distribution of other mangroves and biota. Landsat images and GIS data from 1989 to 2010 at the extreme northern part of Khulna and Chandpai Ranges revealed the formation of a large number of small rivers and creeks some time before 2000 that reduce the 443 km2 forestland by 3.61%, approximately 16 km2, and decreasing H. fomes by 28.75% and total tree cover by over 3.0%. The number of the relatively low-priced plants Bruguiera sexangula, Excoecaria agallocha and Sonneratia apetala, has, on the other hand, increased. Similar degradation could be occurring in other ranges, thereby putting the survivability of the Bangladesh Sundarbans at risk. The growing stock of 296 plants per ha in 1959 had been reduced to 144 by 1996. Trend analysis using “Table Curve 2D Programme,” reveals a decreased number of 109 plants by the year 2020. The degradation of the Bangladesh Sundarbans has been attributed to reduced sediment-laden freshwater discharge through the BSMF river system since commissioning the Farakka Barrage on 21 April 1975 in India. To reduce salinity and forestland erosion, the maintenance of sediment-laden freshwater discharge through its river system has been suggested to re-create its pre-1975 environment for the growth of H. fomes, a true mangrove and the highest carbon-storing plant of the Sundarbans. This may possibly be achieved by proper sharing of the Ganges water from the Farakka Barrage, forming a consortium of India, Nepal, Bhutan and China, and converting parts or whole of the Ganges River into water reservoir(s. The idea is to implement the Ganges Barrage project about 33 km downstream, dredging sediments of the entire Gorai River and distributaries in the Ganges floodplain, thus allowing uniform sediment-laden freshwater flow to maintain an oligohaline environment for the healthy growth of mangroves. The system will also create healthy hinterlands of the Ganges floodplain with increased crop production and revenue. The expenditure may be met through carbon trading, as Bangladesh is a signatory of the Copenhagen Accord, UN Framework Convention on Climate Change. The total carbon reserve in the BSMF in 2010 was meas

  18. Radiation dose to human and non-human biota in the republic of Korea resulting from the Fukushima nuclear accident

    International Nuclear Information System (INIS)

    This paper describes the radiation doses to human and non-human biota in the Republic of Korea, as a result of the Fukushima nuclear accident. By using the measured airborne activity and ground deposition, the effective and thyroid doses of five human age groups (infant, 5 years, 10 years, 15 years and adult) were estimated by the ECOSYS code, and the whole body absorbed dose rate of the eight Korean reference animals and plants (RAPs) was estimated by the K-BIOTA (the Korean computer code to assess the risk of radioactivity to wildlife). The first-year effective and thyroid human doses ranged from 5.7E-5 mSv in the infant group to 2.0E-4 mSv in the 5 years group, and from 5.0E-4 mSv in the infant group to 3.4E-3 mSv in the 5 years group, respectively. The life-time (70 years) effective and thyroid human doses ranged from 1.5E-4 mSv in the infant group to 3.0E-4 mSv in the 5 years group, and from 6.0E-4 mSv in the infant group to 3.5E-3 mSv in the 5 years group, respectively. The estimated maximum whole body absorbed dose rate to the Korean RAPs was 6.7E-7 mGy/d for a snake living in soil (terrestrial biota), and 2.0E-5 mGy/d for freshwater fish (aquatic biota), both of which were far less than the generic dose criteria to protect biota from ionizing radiation. Also, the screening level assessment for ERICA's (Environmental Risks from Ionizing Contaminants: Assessments and management) limiting organisms showed that the risk quotient (RQ) for the estimated maximum soil and water activity was significantly less than unity for both the terrestrial and freshwater organisms. Conclusively, the radiological risk of the radioactivity released into the environment by the Fukushima nuclear accident to the public and the non-human biota in the republic of Korea is considered negligible.

  19. Biota-sediment accumulation factors for radionuclides and sediment associated biota of the Ottawa River

    Energy Technology Data Exchange (ETDEWEB)

    Rowan, D.; Silke, R.; Carr, J., E-mail: rowand@aecl.ca [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada)

    2013-12-15

    As Ottawa River contamination is historical and resides in sediment, ecological risk and trophic transfer depend on linkages between sediment and biota. One of the ways in which this linkage is quantified is through the use of the biota sediment accumulation factor (BSAF). In this study, we present the first field estimates of BSAF for a number of radionuclides. The strongest and most consistent BSAFs were those for {sup 137}Cs in deposit feeding taxa, suggesting that sediment concentrations rather than dissolved concentrations drive uptake. For crayfish and unionid bivalves that do not feed on sediment, biota radionuclide concentrations were not related to sediment concentrations, but rather reflected concentrations in water. BSAFs would not be appropriate for these non-deposit feeding biota. BSAFs for {sup 137}Cs were not significantly different among deposit feeding taxa, suggesting similar processes for ingestion, assimilation and elimination. These data also show that the concentration factor approach used for guidance would have led to spurious results in this study for deposit feeding benthic invertebrates. Concentrations of {sup 137}Cs in Hexagenia downstream of the CRL process outfall range by about 2-orders of magnitude, in comparison to relatively uniform water concentrations. The concentration factor approach would have predicted a single value downstream of CRL, underestimating exposure to Hexagenia by almost 2-orders of magnitude at sites close to the CRL process outfall. (author)

  20. Scoping assessment of groundwater doses to biota at the Sellafield site, UK

    International Nuclear Information System (INIS)

    In the current climate of investigating the impact of discharges from the nuclear industry on non-human biota, much attention has been given to biota in marine and terrestrial environments in receipt of authorised discharges of liquid and gaseous effluent. Relatively little attention to date has been given to the exposure of biota to groundwater containing man-made radio-nuclides. This area of interest is growing especially in the field of nuclear waste repositories. A scoping assessment has been performed here to determine the impacts due to radiological contamination on organisms living within or coming into contact with groundwater at the Sellafield site, UK. The following potential exposure routes to biota were identified: 1) Organisms living within groundwater; 2) Groundwater discharges to the surface at beach springs (i.e. emerging above the low water line; 3) Groundwater discharges to nearby surface water bodies (e.g. rivers); 4) Groundwater discharges directly to the Irish Sea.. In order to evaluate impacts on organisms living within, contacting or ingesting groundwater, it was necessary to determine the activity concentration of radio-nuclides in the groundwater. For time periods up to 2120, modeling of contaminant release from in-ground inventories and transport in groundwater was carried out for this scoping study using a relatively simple assessment methodology with the MONDRIAN modeling suite. Screening assessments of radiological impacts upon wildlife have been performed for liquid discharges to groundwater from the Sellafield Ltd reprocessing plant at Sellafield, Cumbria. Impacts have been considered for biota at sites within reach of the groundwater flow network. Most calculated total weighted absorbed doses appear to be of no radiological significance whatsoever in relation to the new Environment Agency freshwater ecosystem trigger level (40 microGy h-1), thereby obviating the need to conduct further investigations. The one exception to this is for bacteria at groundwater site 205 (107 microGy h-1 in 2060 and 66.8 microGy h-1 in 2080), although this is believed to be inconsequential due to the very small size of bacteria. In addition, the maximum dose rate criteria recommended by the IAEA (400 microGy h-1) is not exceeded for any of the species of interest at any of the locations studied (author)(tk)

  1. Scoping assessment of groundwater doses to biota at the Sellafield site, UK

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, P.; Gleizon, P.; Coleman, I.A.; Watts, S.J.; Batlle, L.V.; Smith, A.D.

    2008-07-01

    In the current climate of investigating the impact of discharges from the nuclear industry on non-human biota, much attention has been given to biota in marine and terrestrial environments in receipt of authorised discharges of liquid and gaseous effluent. Relatively little attention to date has been given to the exposure of biota to groundwater containing man-made radio-nuclides. This area of interest is growing especially in the field of nuclear waste repositories. A scoping assessment has been performed here to determine the impacts due to radiological contamination on organisms living within or coming into contact with groundwater at the Sellafield site, UK. The following potential exposure routes to biota were identified: 1) Organisms living within groundwater; 2) Groundwater discharges to the surface at beach springs (i.e. emerging above the low water line; 3) Groundwater discharges to nearby surface water bodies (e.g. rivers); 4) Groundwater discharges directly to the Irish Sea.. In order to evaluate impacts on organisms living within, contacting or ingesting groundwater, it was necessary to determine the activity concentration of radio-nuclides in the groundwater. For time periods up to 2120, modeling of contaminant release from in-ground inventories and transport in groundwater was carried out for this scoping study using a relatively simple assessment methodology with the MONDRIAN modeling suite. Screening assessments of radiological impacts upon wildlife have been performed for liquid discharges to groundwater from the Sellafield Ltd reprocessing plant at Sellafield, Cumbria. Impacts have been considered for biota at sites within reach of the groundwater flow network. Most calculated total weighted absorbed doses appear to be of no radiological significance whatsoever in relation to the new Environment Agency freshwater ecosystem trigger level (40 microGy h-1), thereby obviating the need to conduct further investigations. The one exception to this is for bacteria at groundwater site 205 (107 microGy h-1 in 2060 and 66.8 microGy h-1 in 2080), although this is believed to be inconsequential due to the very small size of bacteria. In addition, the maximum dose rate criteria recommended by the IAEA (400 microGy h-1) is not exceeded for any of the species of interest at any of the locations studied (author)(tk)

  2. Derivation of a screening methodology for evaluating radiation dose to aquatic and terrestrial biota

    International Nuclear Information System (INIS)

    The United States Department of Energy (DOE) currently has in place a radiation dose standard for the protection of aquatic animals, and is considering additional dose standards for terrestrial biota. These standards are: 10 mGy/d for aquatic animals, 10 mGy/d for terrestrial plants, and, mGy/d for terrestrial animals. Guidance on suitable approaches to the implementation of these standards is needed. A screening methodology, developed through DOE's Biota Dose Assessment Committee (BDAC), serves as the principal element of DOE's graded approach for evaluating radiation doses to aquatic and terrestrial biota. Limiting concentrations of radionuclides in water, soil, and sediment were derived for 23 radionuclides. Four organism types (aquatic animals; riparian animals; terrestrial animals; and terrestrial plants) were selected as the basis for development of the screening method. Internal doses for each organism type were calculated as the product of contaminant concentration, bioaccumulation factor(s) and dose conversion factors. External doses were calculated based on the assumption of immersion of the organism in soil, sediment, or water. The assumptions and default parameters used provide for conservative screening values. The screening methodology within DOE's graded approach should prove useful in demonstrating compliance with biota dose limits and for conducting screening assessments of radioecological impact. It provides a needed evaluation tool that can be employed within a framework for protection of the environment

  3. Derivation of a screening methodology for evaluating radiation dose to aquatic and terrestrial biota

    Energy Technology Data Exchange (ETDEWEB)

    Higley, Kathryn A. E-mail: higley@engr.orst.edu; Domotor, Stephen L.; Antonio, Ernest J.; Kocher, David C

    2003-07-01

    The United States Department of Energy (DOE) currently has in place a radiation dose standard for the protection of aquatic animals, and is considering additional dose standards for terrestrial biota. These standards are: 10 mGy/d for aquatic animals, 10 mGy/d for terrestrial plants, and, mGy/d for terrestrial animals. Guidance on suitable approaches to the implementation of these standards is needed. A screening methodology, developed through DOE's Biota Dose Assessment Committee (BDAC), serves as the principal element of DOE's graded approach for evaluating radiation doses to aquatic and terrestrial biota. Limiting concentrations of radionuclides in water, soil, and sediment were derived for 23 radionuclides. Four organism types (aquatic animals; riparian animals; terrestrial animals; and terrestrial plants) were selected as the basis for development of the screening method. Internal doses for each organism type were calculated as the product of contaminant concentration, bioaccumulation factor(s) and dose conversion factors. External doses were calculated based on the assumption of immersion of the organism in soil, sediment, or water. The assumptions and default parameters used provide for conservative screening values. The screening methodology within DOE's graded approach should prove useful in demonstrating compliance with biota dose limits and for conducting screening assessments of radioecological impact. It provides a needed evaluation tool that can be employed within a framework for protection of the environment.

  4. The uptake of radiationless by some fresh water aquatic biota review

    International Nuclear Information System (INIS)

    The work presented in this paper reviews many studies carried out by the authors along the last thirty years. The behaviour of the radionuclides in the aquatic ecology of Ismailia Canal stream is of great interest for the evaluation of the possible hazards that may occur to man through the movement of such radionuclides via food chain. Laboratory investigations have been carried out in order to understand the accumulation and release of some radionuclide by some aquatic biota (aquatic macrophyte aquatic plants, some snails species and some fish species) inhabiting this fresh water stream. Different parameters such as water ph, contact time, water salinity, etc. were used in these investigations. The kinetic analysis of the uptake process of some radio nuclides by certain biota was performed. From this analysis, it was possible (through the statistical methods) to investigate that the uptake process proceeded through different steps with different rates depending on the radionuclide and the biota species. It was possible to conclude that some of the selected biota can be used as biological indicators for certain radionuclides

  5. Concentration of 129I in aquatic biota collected from a lake adjacent to the spent nuclear fuel reprocessing plant in Rokkasho, Japan.

    Science.gov (United States)

    Ueda, Shinji; Kakiuchi, Hideki; Hasegawa, Hidenao; Kawamura, Hidehisa; Hisamatsu, Shun'ichi

    2015-11-01

    The spent nuclear fuel reprocessing plant in Rokkasho, Japan, has been undergoing final testing since March 2006. During April 2006-October 2008, that spent fuel was cut and chemically processed, the plant discharged (129)I into the atmosphere and coastal waters. To study (129)I behaviour in brackish Lake Obuchi, which is adjacent to the plant, (129)I concentrations in aquatic biota were measured by accelerator mass spectrometry. Owing to (129)I discharge from the plant, the (129)I concentration in the biota started to rise from the background concentration in 2006 and was high during 2007-08. The (129)I concentration has been rapidly decreasing after the fuel cutting and chemically processing were finished. The (129)I concentration factors in the biota were higher than those reported by IAEA for marine organisms and similar to those reported for freshwater biota. The estimated annual committed effective dose due to ingestion of foods with the maximum (129)I concentration in the biota samples was 2.8 nSv y(-1). PMID:25935011

  6. Interactions of radionuclides with marine biota

    International Nuclear Information System (INIS)

    Uptake of radioactivity by marine biota can occur through consumption of radioactive food or via direct incorporation from the seawater. As uptake occurs, radioactivity begins to distribute into and onto various body tissues, or ''compartments'', at different rates. A composite uptake curve therefore is curvilinear with time. Elimination can occur via various pathways, including fecal deposition, molting, and excretion of dissolved substances, and therefore a composite loss curve also is curvilinear. Uptake and elimination can occur simultaneously, and under constant conditions over a long time period a steady-state body burden will be achieved. Many factors can affect uptake and loss rates, as well as steady-state body burdens, and some major ones are discussed. Design of radioactivity experiments involving marine biota is explored, and a case study of a ''natural experiment'' involving both reactor-produced and fallout radionuclides in a coastal environment is presented to show how much nuclide introductions can be used to learn about nuclide biomagnification, trophic level relationships, and biological distribution of radioactivity in the sea. (author)

  7. Effect of chronic selenium exposure on the freshwater bivalve Corbicula fluminea

    International Nuclear Information System (INIS)

    Selenium is essential for most of living organisms. In oxic to moderately oxic fresh-waters, Se exists predominantly in the (+VI) and (+IV) oxidation states as selenate (SeO42-) and selenite (SeO32-) respectively, whereas in the biota it is incorporated as Se(-II) into seleno-proteins or amino-acids, or as elemental selenium Se(0). At low concentrations, it acts against oxidative damages mainly as the glutathione peroxidase seleno-dependant, but it may be toxic at higher levels (for example, by replacing sulphur in important biomolecules). In filter feeders, such as the freshwater bivalve Corbicula fluminea, selected as biological model, the ventilation activity is a primary limiting step that controls the water influx and therefore the delivery of contaminants. Consequently, a series of short-term experiments were performed to study the effects of different dissolved Se concentrations and forms (selenite; selenate; selenomethionine) on the ventilation activity of Corbicula fluminea and Se tissular distribution. The modification of the ventilation activity of the Se-exposed groups, in comparison to this of reference groups (not exposed to Se) varied greatly according to the form and the concentrations of the Se used. Se concentrations in tissues indicated that selenite was the less bioavailable form whereas selenomethionine displayed the opposite trend. On the basis of this set of experiments, a limited number of conditions have been selected to provide highly contrasting ventilation flow rates and selenium bioaccumulation levels, in order to study the effects of long term exposures, i) at the molecular level, by measuring bio-markers of oxidative stress (forms of glutathione, glutathione peroxidase, glutathione reductase, superoxide dismutase, catalase, and bio-marker of genotoxicity (comet assay), ii) at the (sub)cellular level by analysing Se micro-localisation in target organs and iii) at the individual level by monitoring the variation in the ventilatory flow rate. (author)

  8. Recent changes in aquatic biota in subarctic Fennoscandia - the role of global and local environmental variables

    Science.gov (United States)

    Weckström, Jan; Leppänen, Jaakko; Sorvari, Sanna; Kaukolehto, Marjut; Weckström, Kaarina; Korhola, Atte

    2013-04-01

    The Arctic, representing a fifth of the earth's surface, is highly sensitive to the predicted future warming and it has indeed been warming up faster than most other regions. This makes the region critically important and highlights the need to investigate the earliest signals of global warming and its impacts on the arctic and subarctic aquatic ecosystems and their biota. It has been demonstrated that many Arctic freshwater ecosystems have already experienced dramatic and unpreceded regime shifts during the last ca. 150 years, primarily driven by climate warming. However, despite the indisputable impact of climate-related variables on freshwater ecosystems other, especially local-scale catchment related variables (e.g. geology, vegetation, human activities) may override the climate signal and become the primary factor in shaping the structure of aquatic ecosystems. Although many studies have contributed to an improved understanding of limnological and hydrobiological features of Artic and subarctic lakes, much information is still needed especially on the interaction between the biotic and abiotic components, i.e. on factors controlling the food web dynamics in these sensitive aquatic ecosystems. This is of special importance as these lakes are of great value in water storage, flood prevention, and maintenance of biodiversity, in addition to which they are vital resources for settlement patterns, food production, recreation, and tourism. In this study we compare the pre-industrial sediment assemblages of primary producers (diatoms and Pediastrum) and primary consumers (cladoceran and chironomids) with their modern assemblages (a top-bottom approach) from 50 subarctic Fennoscandian lakes. We will evaluate the recent regional pattern of changes in aquatic assemblages, and assess how coherent the lakes' responses are across the subarctic area. Moreover, the impact of global (e.g. climate, precipitation) and local (e.g. lake and its catchment characteristics) scale environmental changes on the aquatic biota will be compared and discussed.

  9. ACCUMULATION OF HEAVY METALS IN BIOTA OF VYRLYTSA LAKE

    Directory of Open Access Journals (Sweden)

    Tetiana Bilyk

    2011-03-01

    Full Text Available Abstract. The main task was to investigate the pollution by heavy metals of biota of Vyrlytsa Lake. Thecontents of movable forms of heavy metals in aquatic plants, fish and snails was determined by atomicabsorbtion method and were made the conclusions about general state of the water object.Keywords: heavy metals, accumulation, biota, pollution, atomic absorption spectroscopy.

  10. Transient Changes in the Biosphere as a Result of Freshwater Hosing

    Science.gov (United States)

    dePolo, P.; Morel, V.; Matsumoto, K.

    2013-12-01

    The influx of large amounts of freshwater into the North Atlantic Ocean over the course of deglaciation after the Last Glacial Maximum (LGM) has been linked with abrupt climactic shifts like the Heinrich 1 and the Younger Dryas stadials. Using the Minnesota Earth System Model for Ocean biogeochemistry (MESMO-2E), an earth system model of intermediate complexity, we evaluate the effects of a range of volumes of freshwater upon terrestrial and marine biota in equilibrated states of both LGM and modern pre-industrial boundary conditions. Preliminary analysis of the model outputs reveals a qualitative similarity between simulations that started from significantly different initial states. Additional sensitivity experiments determining the relative contributions of climate indicators (e.g. temperature and precipitation) to the success of marine and terrestrial biota will be presented.

  11. Decline of radionuclides in Columbia River biota

    International Nuclear Information System (INIS)

    In January 1971, the last of nine plutonium production reactors using direct discharge of once-through cooling waters into the Columbia River was closed. Sampling was initiated at three stations on the Columbia River to document the decline of the radionuclide body burdens in the biota of the Columbia River ecosystem. The data show that in a river-reservoir complex, the measurable body burden of fission-produced radionuclides decreased to essentially undetectable levels within 18 to 24 mo after cessation of discharge of once-through cooling water into the river. On the basis of data from the free-flowing station, we believe that this decrease would be even more rapid in an unimpounded river

  12. Threatening processes and conservation management of endemic freshwater fish in the Mediterranean basin: a review

    OpenAIRE

    Hermoso, Virgilio; Clavero, Miguel

    2011-01-01

    Mediterranean endemic freshwater fish are among the most threatened biota in the world. The Mediterranean basin has experienced substantial reductions in precipitation and water availability, which will worsen with climate change. Current water policy is directed to increase water-supply demands, especially for agriculture, and not to improve water-use efficiency and implement integrated and sustainable water management. Illegal extractions are common, exacerbating problems for important prot...

  13. Is PCBs concentration variability between and within freshwater fish species explained by their contamination pathways?

    OpenAIRE

    Lopes, C; Perga, M.E.; Peretti, A.; Roger, M.C.; Persat, H.; Babut, M.

    2011-01-01

    Many chemical, physiological, and trophic factors are known to affect ioaccumulation of polychlorinated biphenyls (PCBs) in biota. Understanding the primary factors affecting fish contamination is critical for predicting and assessing risks to upper-trophic level consumers, including humans. Here we identify PCB contamination pathways that could explain within- and between-species variability in fish concentration levels. Three freshwater river fish species (barbel, chub and bream) were sampl...

  14. Zooplankton and diatoms of temporary and permanent freshwater pans in the Mpumalanga Highveld region, South Africa

    OpenAIRE

    Riato, Luisa; Van Ginkel, Carin; Taylor, Jonathan C.

    2014-01-01

    This paper provides a description of the zooplankton and epiphytic diatom communities of permanent and temporary freshwater pans in the Mpumalanga Highveld region of South Africa. Few studies have investigated the biota of pans in this area, which is seriously threatened by mining and agricultural development. Nineteen pan sites within a 20 km radius covering a wide range of water chemistries were sampled once for zooplankton, epiphytic diatoms and water physico-chemical data in 2009. Collect...

  15. Establishing a database of radionuclide transfer parameters for freshwater wildlife

    International Nuclear Information System (INIS)

    Environmental assessments to evaluate potentials risks to humans and wildlife often involve modelling to predict contaminant exposure through key pathways. Such models require input of parameter values, including concentration ratios, to estimate contaminant concentrations in biota based on measurements or estimates of concentrations in environmental media, such as water. Due to the diversity of species and the range in physicochemical conditions in natural ecosystems, concentration ratios can vary by orders of magnitude, even within similar species. Therefore, to improve model input parameter values for application in aquatic systems, freshwater concentration ratios were collated or calculated from national grey literature, Russian language publications, and refereed papers. Collated data were then input into an international database that is being established by the International Atomic Energy Agency. The freshwater database enables entry of information for all radionuclides listed in ICRP (1983), in addition to the corresponding stable elements, and comprises a total of more than 16,500 concentration ratio (CRwo-water) values. Although data were available for all broad wildlife groups (with the exception of birds), data were sparse for many organism types. For example, zooplankton, crustaceans, insects and insect larvae, amphibians, and mammals, for which there were CRwo-water values for less than eight elements. Coverage was most comprehensive for fish, vascular plants, and molluscs. To our knowledge, the freshwater database that has now been established represents the most comprehensive set of CRwo-water values for freshwater species currently available for use in radiological environmental assessments

  16. A geochemical investigation of hydrologically derived threats to rare biota: the Drummond Nature Reserve, Western Australia

    Science.gov (United States)

    Forbes, Matthew; Vogwill, Ryan

    2012-02-01

    The Drummond Nature Reserve (DNR), a high-value conservation area 100 km northeast of Perth, Western Australia, contains two rare freshwater claypans and a diverse range of rare and threatened vascular plants. Groundwater/surface-water interactions were investigated via isotopic (?18O and ?D) and major ion analysis. The groundwater chemical and isotope analyses combined with nutrient data allowed for the assessment of potential hydrologically derived threats to the claypans and their associated conservation values. Groundwater composition is typically Na-Cl to Na-Mg-Cl; whereas the claypan's ephemeral fresh surface water is Na-Cl-HCO3. Distinct ?18O and ?D isotopic signatures for the claypan surface waters and adjoining groundwaters indicate that there currently is minimal connection between these two hydrological systems. Hence the current threat to the freshwater claypans and associated biota from rising saline and acidic groundwater is minimal. Elevated nutrient (N) levels identified in groundwaters along the reserve's western boundary may be linked to fertiliser regimes employed in adjoining agricultural lands. The ecosystem associated with the southwest claypan is particularly vulnerable to N and P inputs via surface-water flows, which could cause algal blooms, vegetation degradation and weed infestation.

  17. A probabilistic approach to obtaining limiting estimates of radionuclide concentration in biota

    International Nuclear Information System (INIS)

    The US Department of Energy has developed a graded approach for evaluating radiation doses to biota. Limiting concentrations of radionuclides in water, soil, and sediment were derived for twenty-three radionuclides. Four organism types (aquatic animals, riparian animals, terrestrial animals and terrestrial plants) were selected as the basis for method development. While environmental transfer data needed for deriving biota tissue concentrations are available for aquatic animals and terrestrial plants, less information is available for terrestrial and riparian organisms. Two methods were applied and examined for their ability to provide estimates of organism:soil or organism:water concentration factors in lieu of measured data. The kinetic/allometric approach combined with a parameter uncertainty analysis provides a needed method to estimate concentration factors across multiple species with limited input data

  18. A probabilistic approach to obtaining limiting estimates of radionuclide concentration in biota

    Energy Technology Data Exchange (ETDEWEB)

    Higley, Kathryn A. E-mail: higley@engr.orst.edu; Domotor, Stephen L.; Antonio, Ernest J

    2003-07-01

    The US Department of Energy has developed a graded approach for evaluating radiation doses to biota. Limiting concentrations of radionuclides in water, soil, and sediment were derived for twenty-three radionuclides. Four organism types (aquatic animals, riparian animals, terrestrial animals and terrestrial plants) were selected as the basis for method development. While environmental transfer data needed for deriving biota tissue concentrations are available for aquatic animals and terrestrial plants, less information is available for terrestrial and riparian organisms. Two methods were applied and examined for their ability to provide estimates of organism:soil or organism:water concentration factors in lieu of measured data. The kinetic/allometric approach combined with a parameter uncertainty analysis provides a needed method to estimate concentration factors across multiple species with limited input data.

  19. Defining the spatial area for assessing doses to non-human biota

    International Nuclear Information System (INIS)

    In order to apply any biota dose assessment methodology, assessors need a way to decide the spatial scale over which it should be applied. Any useful scaling procedure should take into account the level of biological organization at which impacts are to be assessed (usually the population). Both grain and extent of the selected scale should be considered, and the procedure must achieve an optimum balance between cost of sampling or analysis, and assuring protection of biota. That is, the procedure must define the smallest possible total area to be evaluated, divided into the maximum sized assessment units compatible with assuring protection of populations. Ecological processes occur at multiple scales which vary widely between contaminated sites. Therefore, the procedure must also allow for flexibility to apply site specific knowledge. One such procedure was developed by the U.S. Department of Energy's Biota Dose Assessment Committee to support our proposed dose assessment methodology. The procedure includes the following steps: 1) determine whether this procedure is necessary by using screening models, 2) determine and map the boundaries of areas contaminated with the same radionuclides in similar quantities, 3) determine and map the boundaries of discrete habitat types, and 4) overlay the maps and identify the intersections. Each area of discrete habitat that lies within a discrete contaminated area can be appropriately defined as an assessment unit. Our approach satisfies all the requirements for a useful scaling procedure by using site knowledge of, and professional judgement about, environmental contamination and ecological habitats to develop maps of the largest patch sizes over which biota dose assessment parameters can be averaged. In any assessment of radiation dose to biota, it is necessary to average over some assessment area. One cannot generally sample every square millimeter of a site or every organism that lives there. In virtually every case, one must collect representative samples and argue that they represent all the soil, or all the organisms, in some defined spatial area. Usually, one collects a number of samples and assumes their average, their maximum, their upper 95% confidence limit, or some other metric, represents the entire area over which they were collected. Deciding on that area is not necessarily straightforward, but there are some general guiding principles. My objectives in this paper are to discuss some of the general principles one must think about to establish an assessment area, and to describe the procedure the U.S. Department of Energy's Biota Dose Assessment Committee recommends to define an assessment area for the methodology we developed. (author)

  20. Effects of thermal discharges on aquatic biota

    International Nuclear Information System (INIS)

    The primary objective of this research is to determine the effect of sudden thermal stress on the exercise physiology of rainbow trout. Metabolic activity of fish is influenced by many factors. Two of the most important are temperature and exercise. The experiments reported here are designed to assess the simultaneous interactions of these two environmental features. In these studies, the tolerance of the fish to thermal stress is evaluated by measuring the blood glucose levels. Fish respond to environmental stress by exhibiting an elevation of the blood sugar level. The metabolic effects of exercise are determined by measuring the production of lactic acid in muscle tissue and determining the level of this metabolite in the circulating blood. Bioassays involving gradual and abrupt cold shock are required for development of criteria applicable to assessment of potential impact on biota inhabiting mixing zones following termination of heated discharges. Thermal conditions in such areas are highly variable. Any detrimental effect is related to such features as original acclimation temperature and resistance to cold of the different species involved, as well as temperature decline rates, prevailing minimum temperatures, and durations of exposure to that minimum

  1. Lixiviados de biosólidos sobre la biota dulceacuícola

    Directory of Open Access Journals (Sweden)

    Eduardo Andrés Flores Salinas

    2010-04-01

    Full Text Available El objetivo de este estudio es conocer los efectos que producen los lixiviados de los biosólidos sobre diversos representantes de la biota dulceacuícola. Los efectos sobre el crecimiento o la mortalidad(CL50 en las diferentes especies se evalúan a través de diversos bioensayos. Nannochloris oculata resultó afectada en su crecimiento por concentraciones mayores a 500 ppm de lixiviados.Las CL50, a las 48 h., para las especies de la fauna fueron 8.6%, 42.4% y >80% para Oreochromis niloticus, Lecane quadridentata y Limnodrilus hoffmeisteri, respectivamente. Los drenajes del suelo adicionado con biosólidos también afectaron a N. oculata, mientras que las CL50, a las 48 h; para la fauna acuática fueron 90 t/ha, 206t/ha y 432 t/ha para las especies ya mencionadas.Las concentraciones obtenidas en los bioensayos son altas y difícilmente se presentarán en la naturaleza, a menos que por descuido en el manejo de los biosólidos se concentren loslixiviados en el campo, lleguen y permanezcan en los ecosistemas dulceacuícolas.

  2. Central Northwest Pacific biota and their radioactivity

    International Nuclear Information System (INIS)

    Ecological and radiological surveys of biota around a proposed dumping site have been carried out by the Japanese Fisheries Agency. Micronekton were collected with a KOC net towed at prescribed depths. Fish nekton were collected with a KMT net towed from 1 to 2 hours either obliquely or horizontally at prescribed depths. This large net enabled the collection of larger organisms not collectable with KOC nets. Benthos were collected via benthos nets. Deep sea rattails and gammarids were collected with trapnets. In 1985, larger gear with mouth diameters of 1.8m were used with older gear having mouth diameters of 0.9m and used previously. New large gear allowed better collecting efficiency. Radioactivity measurements were carried out by gammaspectrometry with GeLi detectors on ashed samples. In almost all samples, Cs-137 was detected. In addition Co-60 was detected in some samples. Data obtained by the Tokai Regional Fisheries Research Laboratory were examined and summarized by the Ecology Working Group under the Executive Committee on Environmental Safety Assessment of Sea Dumping of Low level Radioactive Wastes in the Radioactive Waste Management Center

  3. Overview of the EMRAS biota dosimetry working group

    International Nuclear Information System (INIS)

    Current principle of radiation protection systems is protection of human, because the human is assumed as the most sensitive organism. Protection framework of human is also believed to be effective for protection of non-human species. On the other hand, it is recently attracting the international interests how sustainability of the ecological services is influenced by environmental disturbances such as chemicals and radiation. Therefore, international concern about protection framework of nonhuman biota has arisen. By the international concern, European and American countries were respectively developed models to evaluate effects of radiation to biota. However, the models are based on their own assumptions, so that the international validity has not been confirmed. Therefore, in IAEA, biota dosimetry working group (BWG) was established in Environmental Modeling for Radiation Safety (EMRAS) program, which aimed to intercompare the models to validate their assumptions and estimations. This paper reports summary of the activity in EMRAS biota dosimetry working group. (author)

  4. Enhanced activities of organically bound tritium in biota samples.

    Czech Academy of Sciences Publication Activity Database

    Sv?tlík, Ivo; Fejgl, Michal; Malátová, I.; Tomášková, Lenka

    2014-01-01

    Ro?. 93, NOV (2014), s. 82-86. ISSN 0969-8043 Institutional support: RVO:61389005 Keywords : NE-OBT * HTO * NPPs * combustion * biota Subject RIV: CH - Nuclear ; Quantum Chemistry Impact factor: 1.231, year: 2014

  5. Mudflat biota since the 1930s: change beyond return?

    Science.gov (United States)

    Reise, Karsten; Herre, Elisabeth; Sturm, Manfred

    2008-03-01

    Where, since the 1980s, patchy and variable green algal mats are prevailing, distinct belts of an amphipod ( Corophium volutator) and seagrass ( Zostera spp.) had dominated in the 1930s. The zonation between tide marks has been mapped in a sheltered sedimentary bay in the Wadden Sea near the island of Sylt (coastal eastern North Sea). Maps on vegetation from 1924 and on selected macrobenthos from 1932 and 1934 are compared with biannual surveys conducted from 1988 to 2006. Rising high water levels and eutrophication are suggested to be major causes of the observed long-term changes. In front of a saltmarsh, a sandy beach developed and partly displaced former cyanobacterial mats. Advancing sandiness may have inhibited C. volutator and facilitated lugworms, Arenicola marina, in the upper tidal zone. A variable occurrence of green algal mats arising in the 1980s affected infauna and seagrass by smothering the biota underneath. This dissolved a coherent belt of Zostera noltii. In the lower tidal zone, natural disturbances had lasting effects on the occurrence of mussels with attached fucoid algae. The spectrum of species became enriched by alien species (13% of macrobenthic taxa). A reversal to habitat structure and biotic zonation of the 1920-1930s does not seem possible. Aliens, in combination with climate change, are expected to further divert the ecological pattern to new configurations.

  6. The U.S. Department of Energy's graded approach for evaluating radiation doses to non-human biota

    International Nuclear Information System (INIS)

    The United States Department of Energy (DOE) has been active in developing requirements, methods, and guidance for protection of non-human biota from the effects of ionizing radiation since the late 1980's. Radiation protection of the environment is an emerging issue that will likely require attention in environmental monitoring programs, and in decisions regarding cleanup and long-term stewardship of radioactively-contaminated sites. The DOE currently has a radiation dose limit for protecting aquatic organisms, and has considered dose limits for terrestrial biota. Practical, cost-effective guidance for implementation of these dose rate guidelines are needed. In response, DOE has developed methods, models, and guidance within a graded approach for evaluating radiation doses to non-human biota. The methodology was developed using an interdisciplinary team approach that included both 'developers' and 'users' through DOE's Biota Dose Assessment Committee (BDAC). The first phase of the graded or multi-tiered approach consists of a general screening methodology that provides limiting concentrations of radionuclides, termed Biota Concentration Guides (BCGs), for use in screening water, sediment, and soil to determine if dose guidelines for non-human biota are exceeded. BCGs were derived for twenty-three target radionuclides. Four organism types (aquatic animals, riparian animals, terrestrial animals, and terrestrial plants) were selected as the basis for methods development. Internal doses were calculated as the product of media concentration, bioaccumulation factor(s), and dose conversion factors. External doses were calculated based on the assumption of immersion of the organism in soil, sediment, or water. Kinetic and allometric techniques were used to fill data gaps in predicting radionuclide concentration factors across a large range of terrestrial and riparian species of animals. The assumptions and default parameters result in conservative BCGs for screening purposes. If the BCGs are exceeded, methods for site-specific screening, followed by detailed analysis, are also provided. A user-selected dose standard can be entered in place of default dose guidelines; parameter values, radiation weighting factors, and organism residence times can be modified within site-specific phases of the graded approach. A recent effort by DOE to encode the graded approach methodology into the 'next generation' biota dose evaluation tool, 'RESRAD-BIOTA', is near completion. The RESRAD-BIOTA computer code provides complete analysis capabilities, from general screening to more realistic organism-specific dose estimation. The RESRAD-BIOTA code contains many advanced features such as: dose conversion factors for eight ellipsoid organism geometries; sensitivity analysis; and text and graphic reports for easy interpretation of results. DOE's graded approach to non-human biota dose evaluation is being widely implemented at DOE's facilities. The graded approach is a cost-effective tool for demonstrating compliance with dose limits for non-human biota, and for conducting ecological screening assessments. In can be employed within an international framework for radiation protection of the environment. (author)

  7. The biology and functional morphology of Macoma biota (Bivalvia: Tellinidae: Macominae

    Directory of Open Access Journals (Sweden)

    Pedro Ribeiro Piffer

    2011-06-01

    Full Text Available Macoma biota Arruda & Domaneschi, 2005, is a recently described species known only from the intertidal zone of Praia da Cidade, Caraguatatuba Bay, in the state of São Paulo, southeastern Brazil. The main purpose of the present paper is to describe the biology of M. biota, beginning with a detailed analysis of its anatomy and functional morphology and how these attributes are correlated with its habitat and life history. The morphology of the organs in the pallial cavity and their sorting devices indicate that this species has efficient mechanisms to process large amounts of particles that enter this cavity via the inhalant current. M. biota can rapidly select the material suitable for ingestion and direct the undesired excess to the rejection mantle tracts. These characteristics along with the siphon's behavior and the digestive tract configuration reveal that this species can be classified primarily as a deposit feeder, like other species of the genus; however, it can also behave as a suspension feeder, depending on the environmental conditions.

  8. Freshwater and fish

    International Nuclear Information System (INIS)

    Severe radioactive contamination of the freshwater environment could have serious consequences for both drinking water and fish. Most of the Nordic countries have an abundance of freshwater lakes and rivers. Finland alone has about 56,000 lakes, each with a surface area of 1 hectare or more. Nearly 10% of Finland's surface is covered with lakes and rivers. In Sweden, about 9% of the surface area is freshwater, in Norway about 5%, and in Denmark only about 2%. Freshwater plays a minor role in Iceland, but even there numerous rivers discharge from the volcanic soils to the Ocean. Cs-137 and 90Sr are likely to be the most important radionuclides with respect to long term radioactive contamination of freshwater. If radioactive deposition occurs in the absence of snow and ice radionuclides will contaminate the surface water directly and may rapidly enter the aquatic food chain. Fish which eat contaminated plankton become contaminated almost immediately. Deposition during summer increases the transfer for radionuclides to fish since fish metabolism is faster during the warm season. During the cold period, fish metabolism is slow and thus uptake and excretion of radiocaesium are also slow. (EG)

  9. Bioaccumulation and distribution of /sup 95m/Tc in an experimental freshwater pond

    International Nuclear Information System (INIS)

    An acute release of /sup 95m/Tc was made to a small experimental freshwater pond to determine the behavior of technetium in a freshwater ecosystem. The objectives of the study were (1) to determine the distribution of /sup 95m/Tc in the components of the ecosystem and (2) to determine the concentration in freshwater biota. Prior to the release of /sup 95m/Tc, the pond was stocked with aquatic macrophytes, fish, and invertebrates. All components of the pond were sampled for a period of 37 d. Analyses of filtered and unfiltered water samples showed that /sup 95m/Tc did not sorb significantly to particulates suspended in the water but remained dissolved. Sediments accumulated /sup 95m/Tc slowly as the experiment progressed. In the biota, periphyton accumulated /sup 95m/Tc rapidly, reaching the highest concentration (3482 dpm/g dry wt) 4 h after the release and maintaining a relatively high concentration throughout the experiment. Fish and invertebrates accumulated /sup 95m/Tc gradually. Elimination studies and tissue analyses showed that a large percentage of the body burden was in the digestive system of all fish, suggesting that fish were accumulating /sup 95m/Tc through the food chain. Biological half-lives determined from elimination studies for carp (Cyprinus carpio), mosquitofish (Gambusia affinis), and snails (Helisoma sp.) were 2.5, 4.3, and 21.3 d, respectively. Calculated concentration factors for the same species were 11 for carp, 75 for mosquito fish, and 121 for snails. The estimated size of the biomass components in the ecosystem in descending order were: periphyton, macrophytes, invertebrates, fish, and algae. Based on biomass estimates and concentrations of the /sup 95m/Tc in the aquatic biota, approximately 1% of the /sup 95m/Tc accumulated in the biota

  10. Bioaccumulation and distribution of sup(95m)Tc in an experimental freshwater pond

    International Nuclear Information System (INIS)

    The objectives of the study were (1) to determine the distribution of sup(95m)C in the components of the ecosystem and (2) to determine the concentration in freshwater biota. Prior to the release of sup(95m)Tc, the pond was stocked with aquatic macrophytes, fish, and invertebrates. All components of the pond were sampled for a period of 37 days. Analyses of filtered and unfiltered water samples showed that sup(95m)Tc did not sorb significantly to particulates suspended in the water but remained dissolved. Sediments accumulated sup(95m)Tc slowly as the experiment progressed. In the biota, periphyton accumulated sup(95m)Tc rapidly, reaching the highest concentration (3482 dis/min per g dry wt) 4 hours after the release and maintaining a relatively high concentration throughout the experiment. Fish and invertebrates accumulated sup(95m)Tc gradually. Elimination studies and tissue analyses showed that a large percentage of the body burden was in the digestive system of all fish, suggesting that fish were accumulating sup(95m)Tc through the food chain. Biological half-lives determined from elimination studies for carp (Cyprinus carpio), mosquitofish (Gambusia affinis), and snails (Helisoma sp.) were 2.5, 4.3, and 21.3 days, respectively. Calculated concentration factors for the same species were 11 for carp, 75 for mosquitofish, and 121 for snails. The estimated sizes of the biomass components in the ecosystem in descending order were: periphyton, macrophytes, invertebrates, fish, and algae. Based on biomass estimates and concentrations of the sup(95m)Tc in the aquatic biota, approximately 1% of the sup(95m)Tc accumulated in the biota. Thus, most of the technetium released into a freshwater pond ecosystem remained dissolved in the water with only a small percentage accumulating in the biota and sediments

  11. Effects of Selection and Drift on G Matrix Evolution in a Heterogeneous Environment: A Multivariate Qst–Fst Test With the Freshwater Snail Galba truncatula

    OpenAIRE

    Chapuis, Elodie; Martin, Guillaume; Goudet, Jérôme

    2008-01-01

    Unraveling the effect of selection vs. drift on the evolution of quantitative traits is commonly achieved by one of two methods. Either one contrasts population differentiation estimates for genetic markers and quantitative traits (the Qst–Fst contrast) or multivariate methods are used to study the covariance between sets of traits. In particular, many studies have focused on the genetic variance–covariance matrix (the G matrix). However, both drift and selection can cause changes in G. To un...

  12. Do diagnóstico à conservação da biodiversidade: o estado da arte do programa BIOTA/FAPESP / From diagnosis to conservation: the state of the art of biodiversity conservation in the BIOTA/FAPESP program

    Scientific Electronic Library Online (English)

    Jean Paul, Metzger; Lilian, Casatti.

    Full Text Available O principal objetivo deste estudo foi de avaliar a contribuição do Programa BIOTA/FAPESP, um dos maiores programas do Brasil voltados para o estudo da biodiversidade, em questões relacionadas com a conservação da biodiversidade, em particular no desenvolvimento de indicadores ecológicos, definição d [...] e áreas prioritárias e viabilização da conservação. Uma revisão da literatura nestes tópicos também é apresentada, visando uma melhor contextualização dos avanços e caminhos futuros a serem seguidos pelo programa BIOTA/FAPESP. Foi diagnosticado que este Programa encontra-se em uma fase de inventários pontuais, de curto prazo, essencialmente no nível de comunidade, e em ambientes terrestres e aquáticos continentais. Alguns problemas para o uso destes dados em conservação foram identificados e devem ser considerados para a definição de uma estratégia de conservação. São sugeridos possíveis caminhos futuros para a obtenção de dados mais direcionados para o uso para conservação da biodiversidade, em particular com: i) a adoção de protocolos de inventário visando facilitar a comparação de dados obtidos em diferentes locais; ii) a indução de levantamentos biológicos de diferentes taxa em áreas potenciais para a conservação; iii) o estímulo de projetos que aliem pesquisa e ação, em particular no caso de restauração ecológica; iv) a articulação do programa BIOTA com outros programas mais aplicados (por exemplo, o Programa de Políticas Públicas da FAPESP) ou que permitam o monitoramento e entendimento de aspectos funcionais dos sistemas ecológicos (Programa de Pesquisas Ecológicas de Longa Duração do CNPq). Abstract in english The main objective of this study was to analyze the contribution of the BIOTA/FAPESP program, one of the largest biodiversity programs in Brazil, in conservation issues, such as in the development of ecological indicators, definition of priority areas for conservation, and conservation viability ana [...] lyzes. We found that the program was in its first phase (1999-2005) mainly focused on short-term punctual inventories at the community level, and in terrestrial and freshwater habitats. We identified some limitations in the use of the collected data for conservation purposes, and suggest possible measures to avoid those problems and bridge the gap between the biodiversity diagnosis and conservation: i) to adopt inventory protocols which would allow an easy comparison of data obtained in different geographical regions; ii) to stimulate multiple taxa inventories in areas with high conservation potential; iii) to encourage the integration of research with action, specially in the case of restoration projects; and iv) to link the BIOTA program with other applied programs (for example, the FAPESP Program of Public Policy) or programs that would allow the monitoring and understanding of functional aspects of the ecosystems (e.g., Long Term Ecological Research Program from CNPq).

  13. Freshwater Microcosms-Based Assessment of Eco-toxicological Effects of a Chemical Effluent from the Pilcam Industry in Cameroon

    OpenAIRE

    J. E. Djomo; Tchounwou, P. B.; Kemka, N.; S. H. Zebaze; A. L. Meyabeme Elono; T. Njine; A . Monkiedje

    2004-01-01

    We studied the acute toxicity of a raw effluent from a battery manufacturing plant (Pilcam) in Douala, Cameroon, to a freshwater fish (Oreochromis niloticus), and subsequently evaluated its sub-acute effects on water quality and the biota in freshwater microscosms. The acute toxicity test was based on 96 hrs static renewal bioassays that resulted in 96-h LC50 and LC90 values of 16 and 20.7% (v/v), respectively. The sub-acute experiments were conducted by exposing several species of aquatic or...

  14. CROATIAN FRESHWATER FISHERY

    Directory of Open Access Journals (Sweden)

    Višnja Knjaz

    2007-07-01

    Full Text Available The basic characteristics of freshwater fishery in Croatia are predominantly negative trend in the past twenty years. Even though the total fish pond area covers more than 12,000 hectares, only 6,200 hectares of carp ponds and 58,700 m2 of trout ponds have been exploited. In 2006 the production of total freshwater fish reached 6,547 tons, out of which the production of consumable fish amounted to 5,067 tons and the juveniles 1,480 tons. The export of freshwater fish to EU countries, Macedonia, Bosnia and Herzegovina, Serbia and Monte Negro shows the positive trend and the Republic of Croatia continuously records a foreign trade surplus (987,000 US$. It must be pointed out, though, that the import of trout from Bosnia and Herzegovina significantly increased in the past three years which resulted in the decrease of the foreign trade surplus in that sector. The freshwater fishery in Croatia has been overly burdened by many problems

  15. PBDEs in freshwater mussels and fish from Flanders, Belgium

    Energy Technology Data Exchange (ETDEWEB)

    Covaci, A.; Voorspoels, S.; Schepens, P. [Antwerp Univ. (Belgium). Toxicological Center; Bervoets, L.; Hoff, P.; Voets, J.; Campenhout, K. van; Blust, R. [Antwerp Univ. (Belgium). Dept. of Ecophysiology, Biochemistry and Toxicology

    2004-09-15

    Polybrominated diphenylethers (PBDEs), a class of brominated flame retardants (BFRs), are widely used in textiles, plastics, electronic equipment and other materials for more than 30 years. Due to their massive use, PBDEs have become ubiquitously present in aquatic organisms and it was recently evidenced that their levels seem to increase rapidly. Higher PBDE concentrations were found in biota from freshwater compared to similar marine species. This is probably due to a higher pollution load found near point pollution sources that are almost exclusively inland located. Zebra mussels (Dreissena polymorpha) fulfil the requirements of a good biomonitoring organism for freshwater ecosystems: they are easy to collect and to handle, are available in sufficient numbers, have a relative long lifespan, are sedentary and resistant to various types of pollution without suffering a too high mortality and have a high filtration rate which favours the bioaccumulation of organic contaminants. Fish species are another suitable tool for the biomonitoring of organic contaminants. The occurrence of PBDEs in fish species from Europe has already received some attention, but the amount of data is still limited. The aim of this study was to evaluate the occurence of PBDEs in zebra mussels and several representative freshwater fish species (eel, carp and gibel carp) at different sites in Flanders, Belgium. In parallel, other organohalogenated contaminants, such as polychlorinated biphenyls (PCBs), p,p'-DDE and hexachlorobenzene (HCB) were also measured and their relationship with PBDEs was investigated.

  16. LADTAP-2, Organ Doses to Man and Other Biota from Aquatic Environment

    International Nuclear Information System (INIS)

    1 - Description of problem or function: LADTAP2 performs environmental dose analyses for releases of liquid effluents from light-water nuclear power plants into surface waters during routine operation. The analyses estimate radiation doses to individuals, population groups, and biota from ingestion (aquatic foods, water, and terrestrial irrigated foods) and external exposure (shoreline, swimming, and boating) pathways. The calculated doses provide information for National Environmental Policy Act (NEPA) evaluations and for determining compliance with Appendix I of 10 CFR 50 (the 'ALARA' philosophy). The program consists of a hydrologic model chosen to represent mixing in the effluent impoundment system and the receiving surface waters and the exposure pathway models which estimate exposure of selected groups at various water usage locations in the environment. Two types of population doses are calculated. An ALARA analysis is performed based on exposure of people within 50 miles of the site, and a NEPA analysis is performed based on exposure of the entire U.S. population to effluents from the site. A population-dose analysis prepared in the form of a cost-benefit table presents the total-body and thyroid doses from each radionuclide released and the population doses (total-body and thyroid) per curie of each radionuclide released. 2 - Method of solution: The impoundment system is represented by one of four hydrologic models: direct release to the receiving water, linear flow with no mixing (the plug-flow model), linear flow through the impoundment with partial recirculation through the reactor (the partially mixed model), or complete mixing in the impoundment with partial recirculation through the reactor (the completely mixed model). The last three account for radiological decay during transit through the impoundment system. Optional models are available to estimate dilution in nontidal rivers and near-shore lake environments. The consequence calculation part of LADTAP2 starts with the water concentration at a specific usage location in the environment. The effluent concentration from the impoundment system is related to the water concentrations at the usage locations by two parameters, a dilution factor and a transit time (for radiological decay in transport through the surface water system). The water concentration at the usage location is applied to specific pathway models to estimate the resulting exposure. The pathways included are: ingestion of aquatic foods, such as fish, invertebrates, and aquatic plants; external exposure to shoreline; external exposure to water through boating or swimming; ingestion of drinking water (freshwater sites only); and ingestion of irrigated terrestrial food crops. 3 - Restrictions on the complexity of the problem - Maxima of: 200 nuclides in the release source term, 19 sport fish harvest locations, 19 commercial fish harvest locations, 19 sport invertebrate harvest locations, 19 commercial invertebrate harvest locations, 8 body organs. The radionuclide library contains data for 169 radionuclides

  17. Plutonium in biota from an east Tennessee floodplain forest

    Energy Technology Data Exchange (ETDEWEB)

    Garten Jr, Charles T [ORNL; Dahlman, R. C. [Oak Ridge National Laboratory (ORNL)

    1978-06-01

    Plutonium 239, 240 concentrations were measured in biota from a 30-yr-old contaminated floodplain forest in Tennessee. Concentration ratios relative to soil, for plutonium in litter, invertebrate cryptozoans, herbaceous ground vegetation, orthoptera and small mammals were approximately 10-1, 10-2, 10-3, 10-3, and 10-4, respectively. Concentration ratios (CR) for plutonium in biota from the floodplain forest are less than CR values from other contaminated ecosystems in the USA. Presumably, this is due to humid conditions and greater rainfall which minimize resuspension as a physical transport mechanism to biota. Plutonium and radiocesium concentrations are correlated in biota from the forest at Oak Ridge and also from Mortandad Canyon in New Mexico. The cause of the covariance between concentrations of these elements is unknown. Nevertheless, the existence of these relationships suggests that it is possible to predict plutonium in biota from radiocesium concentrations when both nuclides have a common origin and occur together in a contaminated terrestrial environment.

  18. Plutonium in biota from an east Tennessee floodplain forest

    International Nuclear Information System (INIS)

    239 240Pu concentrations were measured in biota from a 30-year-old contaminated floodplain forest in Tennessee. Concentration ratios relative to soil, for plutonium in litter, invertebrate cryptozoans, herbaceous ground vegetation, orthoptera and small mammals were approximately 10-1, 10-2, 10-3, and 10-4, respectively. Concentration ratios (CR) for plutonium in biota from the floodplain forest are less than CR values from other contaminated ecosystems in the USA. Presumably, this is due to humid conditions and greater rainfall which minimize resuspension as a physical transport mechanism to biota. Plutonium and radiocesium concentrations are correlated in biota from the forest at Oak Ridge and also from Mortandad Canyon in New Mexico. The cause of the covariance between concentrations of these elements is unknown. Nevertheless, the existence of these relationships suggests that it is possible to predict plutonium in biota from radiocesium concentrations when both nuclides have a common origin and occur together in a contaminated terrestrial environment. (author)

  19. Molecular Phylogeny and Phylogeography of the Australian Freshwater Fish Genus Galaxiella, with an Emphasis on Dwarf Galaxias (G. pusilla)

    OpenAIRE

    Unmack, Peter J; Bagley, Justin C; Adams, Mark; Hammer, Michael P.; Johnson, Jerald B

    2012-01-01

    The freshwater fauna of Southern Australia is primarily restricted to the southwestern and southeastern corners of the continent, and is separated by a large, arid region that is inhospitable to this biota. This geographic phenomenon has attracted considerable interest from biogeographers looking to explain evolutionary diversification in this region. Here, we employed phylogenetic and phylogeographic approaches to evaluate the effect of this barrier on a group of four galaxiid fish species (...

  20. Davis Pond Freshwater Prediversion Biomonitoring Study: Freshwater Fisheries and Eagles

    Science.gov (United States)

    Jenkins, Jill A.; Bourgeois, E. Beth; Jeske, Clint W.

    2008-01-01

    In January 2001, the construction of the Davis Pond freshwater diversion structure was completed by the U.S. Army Corps of Engineers. The diversion of freshwater from the Mississippi River is intended to mitigate saltwater intrusion from the Gulf of Mexico and to lessen the concomitant loss of wetland areas. In addition to the freshwater inflow, Barataria Bay basin would receive nutrients, increased flows of sediments, and water-borne and sediment-bound compounds. The purpose of this biomonitoring study was, therefore, to serve as a baseline for prediversion concentrations of selected contaminants in bald eagle (Haliaeetus leucocephalus) nestlings (hereafter referred to as eaglets), representative freshwater fish, and bivalves. Samples were collected from January through June 2001. Two similarly designed postdiversion studies, as described in the biological monitoring program, are planned. Active bald eagle nests targeted for sampling eaglet blood (n = 6) were generally located southwest and south of the diversion structure. The designated sites for aquatic animal sampling were at Lake Salvador, at Lake Cataouatche, at Bayou Couba, and along the Mississippi River. Aquatic animals representative of eagle prey were collected. Fish were from three different trophic levels and have varying feeding strategies and life histories. These included herbivorous striped mullet (Mugil cephalus), omnivorous blue catfish (Ictalurus furcatus), and carnivorous largemouth bass (Micropterus salmoides). Three individuals per species were collected at each of the four sampling sites. Freshwater Atlantic rangia clams (Rangia cuneata) were collected at the downstream marsh sites, and zebra mussels (Dreissena spp.) were collected on the Mississippi River. The U.S. Geological Survey (USGS) Biomonitoring of Environmental Status and Trends (BEST) protocols served as guides for fish sampling and health assessments. Fish are useful for monitoring aquatic ecosystems because they accumulate pesticides and other contaminants. Biomarker data on individual fish, generated at the USGS National Wetlands Research Center (Lafayette, La.), included percent white blood cells in whole blood, spleen weight to body weight ratio, liver weight to body weight ratio, condition factor, splenic macrophage aggregates, and liver microsomal 7-ethoxyresorufin-o-deethylase (EROD) activity. Fish age was estimated by comparing total lengths with values from the same species in the Southeast United States as determined from the literature. Contaminant analyses were coordinated by the U.S. Fish and Wildlife Service (USFWS) Analytical Control Facility (Laurel, Md.), where residues of organochlorine (OC) pesticides, total polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), aliphatic hydrocarbons (AHs), and trace elements were determined. The organic contaminant data were generated at the Mississippi State University Chemical Lab (Mississippi State, Miss.), and the inorganic contaminant data were generated by the Texas A&M University Geochemical and Environmental Research Group (College Station, Tex.). Statistical tests were performed to assess relationships among contaminants, fish age, fish species, and collection sites.

  1. Extreme primary and secondary protein structure variability in the chimeric male-transmitted cytochrome c oxidase subunit II protein in freshwater mussels: Evidence for an elevated amino acid substitution rate in the face of domain-specific purifying selection

    Directory of Open Access Journals (Sweden)

    Stewart Donald T

    2008-05-01

    Full Text Available Abstract Background Freshwater unionoidean bivalves, and species representing two marine bivalve orders (Mytiloida and Veneroida, exhibit a mode of mtDNA inheritance involving distinct maternal (F and paternal (M transmission routes concomitant with highly divergent gender-associated mtDNA genomes. Additionally, male unionoidean bivalves have a ~550 bp 3' coding extension to the cox2 gene (Mcox2e, that is apparently absent from all other metazoan taxa. Results Our molecular sequence analyses of MCOX2e indicate that both the primary and secondary structures of the MCOX2e region are evolving much faster than other regions of the F and M COX2-COX1 gene junction. The near N-terminus ~2/3 of the MCOX2e region contains an interspecifically variable number of predicted transmembrane helices (TMH and interhelical loops (IHL whereas the C-terminus ~1/3 is relatively conserved and hydrophilic while containing conserved functional motifs. MCOX2e displays an overall pattern of purifying selection that leads to the preservation of TMH/IHL and C-terminus tail sub-regions. However, 14 amino acid positions in the MCOX2e TMH/IHL sub-region might be targeted by diversifying selection, each representing a site where there exists interspecific variation for the constituent amino acids residing in a TMH or IHL. Conclusion Our results indicate that Mcox2e is unique to unionoidean bivalves, likely the result of a single insertion event that took place over 65 MYA and that MCOX2e is functional. The predicted TMH number, length and position variability likely stems from substitution-based processes rather than the typically implicated insertion/deletion events. MCOX2e has relatively high rates of primary and secondary structure evolution, with some amino acid residues potentially subjected to site-specific positive selection, yet an overall pattern of purifying selection leading to the preservation of the TMH/IHL and hydrophilic C-terminus tail subregions. The more conserved C-terminus tail (relative to the TMH/IHL sub-region of MCOX2e is likely biologically active because it contains functional motifs. The rapid evolution of primary and secondary structure in MCOX2e, combined with the action of both positive and purifying selection, provide supporting evidence for the hypothesis that MCOX2e has a novel reproductive function within unionoidean bivalves. All tolled, our data indicate that unionoidean bivalve MCOX2 is the first reported chimeric animal mtDNA-encoded protein.

  2. Productivity and salinity structuring of the microplankton revealed by comparative freshwater metagenomics

    OpenAIRE

    Eiler, Alexander; Zaremba-Niedzwiedzka, Katarzyna; Martínez-García, Manuel; McMahon, Katherine D.; Stepanauskas, Ramunas; Andersson, Siv G. E.; Bertilsson, Stefan

    2013-01-01

    Little is known about the diversity and structuring of freshwater microbial communities beyond the patterns revealed by tracing their distribution in the landscape with common taxonomic markers such as the ribosomal RNA. To address this gap in knowledge, metagenomes from temperate lakes were compared to selected marine metagenomes. Taxonomic analyses of rRNA genes in these freshwater metagenomes confirm the previously reported dominance of a limited subset of uncultured lineages of freshwater...

  3. Radiation exposure to marine biota around the Fukushima Daiichi NPP.

    Science.gov (United States)

    Keum, Dong-Kwon; Kim, Byeong-Ho; Lim, Kwang-Muk; Choi, Yong-Ho

    2014-05-01

    The dose rates for six marine organisms, pelagic fish, benthic fish, mollusks, crustaceans, macroalgae, and polychaete worms, representative in marine ecosystems, have been predicted by the equilibrium model with the measured seawater activity concentrations at three locations around the Fukushima Daiich nuclear power plant after the accident on March 11, 2011. Model prediction showed that total dose rates for the biota in the costal sea reached 4.8E4 ?Gy/d for pelagic fish, 3.6E6 ?Gy/d for crustaceans, 3.8E6 ?Gy/d for benthic fish, 5.2E6 ?Gy/d for macroalgae, 6.6E6 ?Gy/d for mollusks, and 8.0E6 ?Gy/d for polychaete worms. The predicted total dose rates remained above the UNSCEAR's (United Nations Scientific Committee on the Effect of Atomic Radiation) benchmark level (1.0E4 ?Gy/d for an individual aquatic organism), for only the initial short period, which seems to be insufficiently long to bring about any detrimental effect on the marine biota at the population level. Furthermore, the total dose rates for benthic fish and crustaceans approximated using the measured activity concentration of the biota and bottom sediment was well below the benchmark level. From these results, it may be concluded that the impact of the ionizing radiation on the marine biota around the Fukushima NPP as a consequence of the accident would be insignificant. PMID:24374805

  4. Comparison of dose estimate results from radioecological risk assessment models RESRAD-BIOTA, ERICA Tool and SENES Risk Model using a case study

    International Nuclear Information System (INIS)

    There are many software programs designed to estimate the risk to non-human biota from exposure to radioactivity. Three models have been selected for comparison in this study: US DOE RESRAD-BIOTA Model, EC ERICA Tool and SENES Risk Model. It appears that the methodology for these models is similar, whereas the parameters used to model a case study are different, creating different outputs. Issues surrounding combined or 'lumped' parameters were identified with implications on the transparency and uncertainty of results. These issues are explored so that they may be avoided by choosing the appropriate model and implementation for a given scenario. (author)

  5. Derivation of transfer parameters for use within the ERICA Tool and the default concentration ratios for terrestrial biota

    International Nuclear Information System (INIS)

    An ability to predict radionuclide activity concentrations in biota is a requirement of any method assessing the exposure of biota to ionising radiation. Within the ERICA Tool fresh weight whole-body activity concentrations in organisms are estimated using concentration ratios (the ratio of the activity concentration in the organism to the activity concentration in an environmental media). This paper describes the methodology used to derive the default terrestrial ecosystem concentration ratio database available within the ERICA Tool and provides details of the provenance of each value for terrestrial reference organisms. As the ERICA Tool considers 13 terrestrial reference organisms and the radioisotopes of 31 elements, a total of 403 concentration ratios were required for terrestrial reference organisms. Of these, 129 could be derived from literature review. The approaches taken for selecting the remaining values are described. These included, for example, assuming values for similar reference organisms and/or biogeochemically similar elements, and various simple modelling approaches

  6. Comparative food chain behaviour and distribution of actinide elements in and around a contaminated fresh-water pond

    International Nuclear Information System (INIS)

    The bioaccumulation of sup(233,234)U, 238U, 238Pu, sup(239,240)Pu, 241Am, and 244Cm in both native and introduced biota was studied at Pond 3513, a former low-level radioactive waste settling basin (0.4 ha surface area) at Oak Ridge National Laboratory. This system, which was decommissioned in 1976 after more than 30 years' use, contains approximately 5 Ci of sup(239,240)Pu; inventories of other actinide isotopes are considerably less. Significantly higher concentrations of actinides in fish that were allowed access to sediments indicated that sedimentary particulates may be the primary source of transuranics to biota in shallow fresh-water ecosystems. The study determined habitat, in particular the degree of association of an organism with the sediment/water interface, to be the primary factor in controlling transuranic concentrations in aquatic biota. In most of the biological samples analysed, excluding samples suspected of being contaminated by sediment, 241Am/239Pu, 244Cm/239Pu, and 238U/239Pu ratios were greater than the respective ratios in sediment while sup(233,234)U/238U, and sup(239,240)Pu/238Pu (aquatic biota only) ratios were not different from the respective ratios in sediment. The relative uptake of actinides from contaminated sediment by aquatic and terrestrial biota at this site was U>Cm>=Am>Pu. The relative extractability of actinides from shoreline sediment (using 1 M HNO3 and 0.01 M HCl) was U>Cm approximately equal to Am>Pu. Concentrations of transuranics in water, terrestrial vegetation, and vertebrate carcasses were less than 10% of the recommended public exposure maximum permissible concentration (MPC) of the ICRP, even in this highly contaminated system, which has radioactive inventories atypical of any other fresh-water site now in use or planned for future use in association with nuclear power technologies. (author)

  7. Filling knowledge gaps in radiation protection methodologies for non-human biota. Final summary report

    Energy Technology Data Exchange (ETDEWEB)

    Brown, J.; Gjelsvik, R. (Norwegian Radiation Protection Authority (Norway)); Holm, E. (Univ. of Lund (Sweden)); Roos, P. (Technical Univ. of Denmark, Risoe National Lab. for Sustainable Energy, Roskilde (Denmark)); Saxen, R.; Outola, I. (Radiation and Nuclear Safety Authority (Finland))

    2009-03-15

    The activities of the GAPRAD project are summarised in this report. The background and rationale to GAPRAD are presented and explained. Most notably this relates to a lack of information on naturally occuring radionuclides in terrestrial and aquatic systems that have direct applicability for use in environmental impact assessments. Results from field activities are presented from the Dovrefjell area in Norway (terrestrial study) and selected lake and brackish water systems in Finland. The data mainly concern activity concentrations of Po-210 in environmental media and selected biota allowing concentration ratios to be derived where appropriate. Furthermore, details in relation to Po-210 uptake and biokinetics in humans based on experimental work conducted within the project are presented. (au)

  8. Filling knowledge gaps in radiation protection methodologies for non-human biota. Final summary report

    International Nuclear Information System (INIS)

    The activities of the GAPRAD project are summarised in this report. The background and rationale to GAPRAD are presented and explained. Most notably this relates to a lack of information on naturally occuring radionuclides in terrestrial and aquatic systems that have direct applicability for use in environmental impact assessments. Results from field activities are presented from the Dovrefjell area in Norway (terrestrial study) and selected lake and brackish water systems in Finland. The data mainly concern activity concentrations of Po-210 in environmental media and selected biota allowing concentration ratios to be derived where appropriate. Furthermore, details in relation to Po-210 uptake and biokinetics in humans based on experimental work conducted within the project are presented. (au)

  9. Derivation of a Screening Methodology for Evaluating Radiation Dose to Aquatic and Terrestrial Biota

    Energy Technology Data Exchange (ETDEWEB)

    Higley, Kathryn A.(OREGON STATE UNIVERSITY); Domotor, S L.(DOE); Antonio, Ernest J.(BATTELLE (PACIFIC NW LAB)); Kocher, David (Oak Ridge National Laboratory)

    2003-06-06

    The United States Department of Energy (DOE) currently has in place a radiation dose standard for the protection of aquatic organisms, and is considering proposing dose standards for both aquatic and terrestrial biota. These standards are: 10 mGy/d for aquatic animals; 10 mGy/d for terrestrial plants; and 1 mGy/d for terrestrial animals. Guidance on suitable approaches to implementation of these standards is needed. A screening methodology was developed as the first part of DOE's three-step graded approach for evaluating radiation doses to aquatic and terrestrial biota. Limiting concentrations of radionuclides in water, soil, and sediment media were derived for twenty-three target radionuclides. Four organism types (aquatic animals; riparian animals; terrestrial animals; and terrestrial plants) were selected as the basis for methods development. Internal doses for each organism type were calculated as the product of media concentration, bioaccumulation factors(s) and dose conversion factors. External doses were calculated based on the assumption of immersion of the organism in soil, sediment, or water. The assumptions and default parameters used provide for conservative screening values.

  10. Enhanced activities of organically bound tritium in biota samples

    International Nuclear Information System (INIS)

    A pilot study aimed on possible occurrence of elevated activity of non-exchangable organically bound tritium (NE-OBT) in biota was performed. The first results showed a significant surplus of NE-OBT activity in biota of the valley of Mohelno reservoir and Jihlava river. The liquid releases of HTO from the nuclear power plant Dukovany is the source of tritium in this area. This area can be a source of various types of natural samples for future studies of tritium pathways. - Highlights: • A survey of tritium occurrence was performed in the vicinity of NPP Dukovany. • Elevated activities of NE-OBT were found in the surrounding of Mohelno reservoir. • A combustion system was designed and applied for purpose of NE-OBT determination

  11. What are the toxicological effects of mercury in Arctic biota?

    DEFF Research Database (Denmark)

    Dietz, Rune; Sonne, Christian

    2012-01-01

    This review critically evaluates the available mercury (Hg) data in Arctic marine biota and the Inuit population against toxicity threshold values. In particular marine top predators exhibit concentrations of mercury in their tissues and organs that are believed to exceed thresholds for biological effects. Species whose concentrations exceed threshold values include the polar bears (Ursus maritimus), beluga whale (Delphinapterus leucas), pilot whale (Globicephala melas), hooded seal (Cystophora cristata), a few seabird species, and landlocked Arctic char (Salvelinus alpinus). Toothed whales appear to be one of the most vulnerable groups, with high concentrations of mercury recorded in brain tissue with associated signs of neurochemical effects. Evidence of increasing concentrations in mercury in some biota in Arctic Canada and Greenland is therefore a concern with respect to ecosystem health.

  12. What are the toxicological effects of mercury in Arctic biota?

    Science.gov (United States)

    Dietz, Rune; Sonne, Christian; Basu, Niladri; Braune, Birgit; O'Hara, Todd; Letcher, Robert J; Scheuhammer, Tony; Andersen, Magnus; Andreasen, Claus; Andriashek, Dennis; Asmund, Gert; Aubail, Aurore; Baagøe, Hans; Born, Erik W; Chan, Hing M; Derocher, Andrew E; Grandjean, Philippe; Knott, Katrina; Kirkegaard, Maja; Krey, Anke; Lunn, Nick; Messier, Francoise; Obbard, Marty; Olsen, Morten T; Ostertag, Sonja; Peacock, Elizabeth; Renzoni, Aristeo; Rigét, Frank F; Skaare, Janneche Utne; Stern, Gary; Stirling, Ian; Taylor, Mitch; Wiig, Øystein; Wilson, Simon; Aars, Jon

    2013-01-15

    This review critically evaluates the available mercury (Hg) data in Arctic marine biota and the Inuit population against toxicity threshold values. In particular marine top predators exhibit concentrations of mercury in their tissues and organs that are believed to exceed thresholds for biological effects. Species whose concentrations exceed threshold values include the polar bears (Ursus maritimus), beluga whale (Delphinapterus leucas), pilot whale (Globicephala melas), hooded seal (Cystophora cristata), a few seabird species, and landlocked Arctic char (Salvelinus alpinus). Toothed whales appear to be one of the most vulnerable groups, with high concentrations of mercury recorded in brain tissue with associated signs of neurochemical effects. Evidence of increasing concentrations in mercury in some biota in Arctic Canada and Greenland is therefore a concern with respect to ecosystem health. PMID:23231888

  13. Assimilation potential of water column biota: Mesocosm-based evaluations

    Digital Repository Service at National Institute of Oceanography (India)

    Ramaiah, N.; Ansari, Z.A.; Sadhasivan, A.; Naik, S.; Sawkar, K.

    are modern man's 'creations. These problems are threatening people's well-being not only at local but also at regional and global levels. Water pollution is any physical and chemical change in surface and groundwater that can adversely affect living organisms... situations. Objectives The underlying purpose of this study is an examination of the changes that biotic components undergo under altered conditions, in 232 Assimilation potential of water column biota I terms of their community structure, general well-being...

  14. What are the toxicological effects of mercury in Arctic biota?

    DEFF Research Database (Denmark)

    Dietz, Rune; Sonne, Christian; Basu, Niladri; Braune, Birgit; O'Hara, Todd; Letcher, Robert J.; Scheuhammer, Tony; Andersen, Magnus; Andreasen, Claus; Andriashek, Dennis; Asmund, Gert; Aubail, Aurore; Baagøe, Hans J.; Born, Erik W.; Chan, Hing M.; Derocher, Andrew E.; Grandjean, Philippe; Knott, Katrina; Kirkegaard, Maja; Krey, Anke; Lunn, Nick; Messier, Francoise; Obbard, Marty; Olsen, Morten Tange; Ostertag, Sonja; Peacock, Elizabeth; Renzoni, Aristeo; Riget, Frank Farsø; Skaare, Janneche Utne; Stern, Gary; Stirling, Ian; Taylor, Mitch; Wiig, Oystein; Wilson, Simon; Aars, Jon

    2013-01-01

    This review critically evaluates the available mercury (Hg) data in Arctic marine biota and the Inuit population against toxicity threshold values. In particular marine top predators exhibit concentrations of mercury in their tissues and organs that are believed to exceed thresholds for biological effects. Species whose concentrations exceed threshold values include the polar bears (Ursus maritimus), beluga whale (Delphinapterus leucas), pilot whale (Globicephala melas), hooded seal (Cystophora ...

  15. What are the toxicological effects of mercury in Arctic biota?

    DEFF Research Database (Denmark)

    Dietz, Rune; Sonne, Christian; Basu, Niladri; Braune, Birgit; O'Hara, Todd; Letcher, Robert J; Scheuhammer, Tony; Andersen, Magnus; Andreasen, Claus; Andriashek, Dennis; Asmund, Gert; Aubail, Aurore; Baagøe, Hans J.; Born, Erik W; Chan, Hing M; Derocher, Andrew E; Grandjean, Philippe; Knott, Katrina; Kirkegaard, Maja; Krey, Anke; Lunn, Nick; Messier, Francoise; Obbard, Marty; Olsen, Morten T; Ostertag, Sonja; Peacock, Elizabeth; Renzoni, Aristeo; Rigét, Frank F; Skaare, Janneche Utne; Stern, Gary; Stirling, Ian; Taylor, Mitch; Wiig, Oystein; Wilson, Simon; Aars, Jon

    2012-01-01

    This review critically evaluates the available mercury (Hg) data in Arctic marine biota and the Inuit population against toxicity threshold values. In particular marine top predators exhibit concentrations of mercury in their tissues and organs that are believed to exceed thresholds for biological effects. Species whose concentrations exceed threshold values include the polar bears (Ursus maritimus), beluga whale (Delphinapterus leucas), pilot whale (Globicephala melas), hooded seal (Cystophora ...

  16. Conversion ratios for the foodstuffs and biota environmental surveillance program

    Energy Technology Data Exchange (ETDEWEB)

    Fresquez, P.R.; Ferenbaugh, J.K.

    1998-09-01

    The foodstuffs and biota monitoring programs at Los Alamos National Laboratory (LANL) comprises two of the five Environmental Surveillance Programs mandated by Department of Energy Orders, and LANL has conducted these studies since the early 1970s (ESR 1997). Because foodstuffs and biota commonly contain very small amounts of radionuclides in the edible portions of the tissue, samples are commonly ashed to concentrate the radioisotope(s) in order to adequately detect the element; therefore, results are usually reported in units per gram of ash. To compensate for the differing water contents in various matrices (gram of ash are usually two to four orders of magnitude higher than live weights), units in gram of ash are converted to units of gram of dry material--the standard representation of data. Further, results in units per gram dry weight are converted to units of wet weight in order to estimate radiation doses to the public from the ingestion of these products. This paper reports the mean ash to dry and dry to wet weight moisture conversion ratios for a variety of foodstuffs and biota that have been collected as part of the Environmental Surveillance Program at LANL from 1990 to present.

  17. Effects of Freshwater Discharge in Sandy Beach Populations: The Mole Crab Emerita brasiliensis in Uruguay

    Science.gov (United States)

    Lercari, D.; Defeo, O.

    1999-10-01

    Sandy beaches are ecosystems which are heavily affected by human activities. An example of this is freshwater discharges, which are known to change salinity, temperature and nutrient regimes and degrade nearshore environments. However, the effects of this kind of disturbance on sandy beach fauna have been little studied. This paper reports the spatial effects of a man-made freshwater canal discharge on the population structure, abundance and reproductive characteristics of the sandy beach mole crab Emerita brasiliensis. Along the 22 km of sandy beach sampled, the mole crab showed a marked longshore variability in population structure and abundance. Abundance of different population components (juveniles, males, females and ovigerous females) significantly decreased towards the canal. Population structure by sex and size, individual weight, fecundity and female maturity patterns at size also displayed a non-linear response to the distance from the freshwater discharge. Only the size structure of males did not follow this pattern. For males, spatial heterogeneity enhanced the detection of density-dependence at less disturbed sites. The authors conclude that artificial freshwater discharges could significantly influence the distribution, abundance and life-history traits of the biota of sandy beaches, and that further study of these ecosystems should include human activities as important factors affecting spatial and temporal trends. The need to consider different spatial and temporal scales in order to detect the effect of anthropogenically-driven impacts in sandy beach populations is stressed.

  18. A Probabilistic Approach to Obtaining Limiting Estimates of Radionuclide Concentrations in Biota

    Energy Technology Data Exchange (ETDEWEB)

    Higley, Kathryn A.(OREGON STATE UNIVERSITY); Domotor, S L.(DOE); Antonio, Ernest J.(BATTELLE (PACIFIC NW LAB))

    2003-06-06

    The U.S. Department of Energy has developed a graded approach fo assessing compliance with radiation standards for protection of biota. Limiting concentrations of radionuclides in water, soil, and sediment were derived for twenty-three radionuclides. Four organisms types (aquatic animals, rparian animals, terrestrial animals, and terrestrial plants) were selected as the basis for methods development. While data are available for aquatic animals and terrestrial plants, less information is available for terrestrial and riparian organisms. Two methods were examined for their ability to provide estimates of organism:soil and organism:water concentration factors in lieu of measured data. The kinetic/allometric approach combined with an uncertainty analysis apprach was able to estimate concentration factors across multiple species with limited input data.

  19. Speciation of pyrithione in freshwaters

    OpenAIRE

    Lofts, S.

    2009-01-01

    Pyrithione (PT) is used as an active agent in some shampoos and other household products, and consequently may enter freshwaters following use. Dissolved metal (copper, zinc) salts of pyrithione are toxic to freshwater organisms, with toxicity dependent upon the metal. For this reason, the chemical speciation of pyrithione may be important in controlling its environmental toxicity. The objective of this work was to gather and assess data on the binding equilibria of pyrithione that could be u...

  20. Distribution patterns and transport of plutonium in freshwater environments with emphasis on primary producers

    International Nuclear Information System (INIS)

    The major repository for transuranic elements entering aquatic ecosystems is the bed sediment. Observed K/sub d/ values for plutonium across a wide spectrum of aquatic systems are surprisingly uniform (on the order of 105). Plutonium arrives at the bed sediment as a result of association with and subsequent settling of suspended particulate matter. Consequently, the major role of phytoplankton in plutonium kinetics in aquatic systems has been postulated to be one of plutonium removal from the water column. The very high affinity of plutonium for particulate matter in aquatic systems makes it difficult to use the traditional expression of Concentration Factor (CF) as a measure of the tendency of biota to accumulate this element. A proposed term, Trophic Transfer Factor (TTF), relates concentrations observed in biota to that of the sediment. The underlying assumption is that, due to the high K/sub d/'s, accumulation in tissues of organisms at higher trophic levels will be dominated by gut absorption rather than by direct uptake from water. Plutonium in most freshwater systems is transported predominately in association with suspended particulate matter. In some organically rich systems, a fraction of the hydrologically mobile plutonium pool may be complexed or otherwise associated with naturally occurring organic acids. Although this association may result in increased environmental mobility, it does not appear to result in increased availability to aquatic biota

  1. Marine and freshwater concentration ratios (CRwo-water): review of Japanese data

    International Nuclear Information System (INIS)

    The water-to-organism (whole body) concentration ratio (CRwo-water), which is defined as the ratio of the concentration of a radionuclide in the biota (Bq kg?1 fresh weight) to that in water (Bq L?1), has been used in mathematical models for environmental radiation protection. In the present paper, published global fallout 90Sr, 137Cs, 106Ru, 144Ce and 239+240Pu activity concentration data and stable element concentration data for Na, K, Ca, Mg, Fe, Cu and Mn for organisms living in freshwater or seawater areas in Japan were collated. The data suitable for obtaining CRwo-water values were identified. CRwo-water values of 137Cs were similar for pelagic fish, benthic fish and whitebait (immature, small fish) with respective geometric means of 30 (range: 4.4–69), 32 (range: 15–54) and 33 (range: 13–84). The calculated CRwo-water values of the other radionuclides and stable elements were generally similar to other previously reported values; with the exception that those for Ce were lower for marine biota and those of Cu were higher for freshwater fish

  2. Quantifying the effect of catchment land-use and water nutrient concentrations on freshwater river and stream biodiversity

    OpenAIRE

    Weijters, M.J.; J.H. Janse; Alkemade, J.R.M.; Verhoeven, J.T.A.

    2009-01-01

    A major threat to freshwater taxon diversity is the alteration of natural catchment Land use into agriculture, industry or urban areas and the associated eutrophication of the water. In order to stop freshwater biodiversity loss, it is essential to quantify the relationships between freshwater diversity and catchment Land use and water nutrient concentrations. 2. A literature survey was carried out on biodiversity data from rivers and streams. Fish and macroinvertebrates were selected as foc...

  3. Anthropogenic radionuclides in biota samples from the Caspian Sea

    International Nuclear Information System (INIS)

    The Caspian Sea has been recently a subject of many scientific studies mainly related to sea level changes and pollution. For this purpose, two sampling expeditions were organised by IAEA in the Caspian Sea in 1995 and 1996. The aim was to investigate oceanographic conditions, water dynamics and the distribution of anthropogenic radionuclides 90Sr, 137Cs and 239,240Pu in the water column. Considering the unique biodiversity of the Caspian Sea, there has also been interest to obtain information on radionuclide concentrations in biota samples, first of all in sturgeons and in caviar as their production is strongly linked to economical regional needs. The radioactive contamination of Caspian Sea biota has been investigated by analyzing natural 210Po and anthropogenic 137Cs, 239,240Pu and 241Am in biota samples collected in April 1999 offshore of Astrakhan, in the north Caspian Sea. More biota samples from the South West Caspian Sea (Artom Island, June 1999; Devechi District and Neftechala, November 1999) were collected and analyzed for 210Po, 137Cs, 90Sr, 239,240Pu and 241Am. The sampled species were different types of sturgeons (Sevruga, Russkyi Osyotr and Beluga) as well as fresh spawn and caviar. Other fish species (e.g. Cyprinidae) and one algae sample (Cladofila) have also been analysed. Flesh parts have only been analysed in the case of fish samples. The samples were freeze-dried, ground sieved and canned to be counted by gamma-spectrometry for determination of 137Cs. Analytical separation and purification procedures were carried out later. 210Po, 239,240Pu as well as 241Am were measured by alpha-spectrometry whereas 90Sr was measured by beta-spectrometry. The data are reported. In general, radionuclide activities in fish and caviar do not represent any risk for their consumption as they are very low. 239,240Pu and 241Am were close to the limit of detection. When measurable, the 238Pu/239,240Pu ratio is close to the fallout value. 90Sr activities are quite similar in all samples, while concentrations of 137Cs are higher in sturgeons than in cyprinidae fish. This affects the 137Cs/90Sr ratio which varies from 6 to 350. In the caviar and spawn samples, the 137Cs is not as concentrated as in the fish, whereas 90Sr is slightly higher. One caviar sample from the South Western region shows higher levels of plutonium and americium. The algae sample, as expected, has been concentrating these radionuclides as well

  4. Modelling Radiation Exposure and Radionuclide Transfer for Non-human Species. Report of the Biota Working Group of EMRAS Theme 3

    International Nuclear Information System (INIS)

    Internationally, the ICRP, IAEA and European Commission (EC) are addressing environmental protection as an element of their revision of Recommendations and Basic Safety Standards. Some countries already have requirements and guidelines for the protection of non-human biota. For instance, in England and Wales, the requirement to assess impacts affecting Natura 2000 sites has been interpreted to include ionising radiation. In the USA, biota protection guidelines and dose rates are contained in USDOE Orders 5400.5 and 450.1. In response to these developments, a number of models and approaches have been developed specifically to estimate the exposure of non-human biota to ionising radiations. Some countries (e.g. Canada, Finland, England and Wales, and the USA) are now using these within their national regulatory frameworks for (existing and proposed) nuclear and other sites that may release radioactivity to the environment. Software and/or documentation for some of these approaches are readily available and hence third parties are able to use them when conducting assessments. The Biota Working Group (BWG) of the IAEA Environmental Modelling for Radiation Safety programme was formed in 2004 to address the relative lack of validation and intercomparison of the different models and approaches. The primary objective of the BWG, was: 'to improve Member State's capabilities for protection of the environment by comparing and validating models being used, or developed, for biota dose assessment (that may be used) as part of regulatory process of licensing and compliance monitoring of authorised releases of radionuclides'. Group members included modellers, regulators, industry and researchers. In total, 15 models and approaches were applied to one or more of the four exercises conducted by the BWG. The models/approaches applied encompass those being developed, and in some instances, used in a regulatory context, in Belgium, Canada, France, Lithuania, Russia, the UK and the USA, as well as the outputs of recent EC EURATOM programmes. The participating models included those freely available to any interested users. The four intercomparison exercises included evaluations of the basic components of the models assuming 1 Bq per unit media or 1 Bq kg-1 in the organism, and two scenario (one freshwater and one terrestrial) applications in which model predictions were compared to available field measurements. The work of the BWG has clearly demonstrated that the largest contribution to variability between model predictions, and comparison with available data, is the parameterisation of the models transfer components. The methods used to determine absorbed dose rate contribute relatively little to variability between model outputs. The report concludes with recommendations for future activities within the EMRAS II programme.

  5. Dose modelling comparison for terrestrial biota: IAEA EMRAS II Biota Working Group's Little Forest Burial Ground scenario

    OpenAIRE

    Johansen, M.P.; Barnett, C. L.; Beresford, N. A.; Brown, J.E.; ?erne, M.; Howard, B. J.; Kamboj, S.; Keum, D-K.; Smodiš, B.; Twining, J.R.; Vandenhove, H.; Vives i Batlle, J.; Wood, M.D.(Österreichische Akademie der Wissenschaften, Institut für Hochenergiephysik, A-10560 Wien, Austria 28 28 Funded by the Austrian Ministry for Traffic and Research under the contract GZ 616.360/2-IV GZ 616.363/2-VIII, and by the Fonds für Wissenschaft und Forschung FWF No. P08929-PHY.); Yu, C.

    2011-01-01

    Radiological doses to terrestrial biota have been examined in a model inter-comparison study that emphasised the identification of factors causing variability in dose estimation. Radiological dose rates were modelled for ten species representing a diverse range of terrestrial plant and animals with varying behavioural and physical attributes. Dose to these organisms may occur from a range of gamma (Co-60, Cs-137), beta (Sr-90) and alpha (Th-232, U-234 and U-238, Pu-238, Pu-239/240 and Am-24...

  6. Interactions between marine biota and ENSO: a conceptual model analysis

    Directory of Open Access Journals (Sweden)

    M. Heinemann

    2011-01-01

    Full Text Available We develop a conceptual coupled atmosphere-ocean-ecosystem model for the tropical Pacific to investigate the interaction between marine biota and the El Niño-Southern Oscillation (ENSO. Ocean and atmosphere are represented by a two-box model for the equatorial Pacific cold tongue and the warm pool, including a simplified mixed layer scheme. Marine biota are represented by a three-component (nutrient, phytoplankton, and zooplankton ecosystem model.

    The atmosphere-ocean model exhibits an oscillatory state which qualitatively captures the main physics of ENSO. During an ENSO cycle, the variation of nutrient upwelling, and, to a small extent, the variation of photosynthetically available radiation force an ecosystem oscillation. The simplified ecosystem in turn, due to the effect of phytoplankton on the absorption of shortwave radiation in the water column, leads to (1 a warming of the tropical Pacific, (2 a reduction of the ENSO amplitude, and (3 a prolongation of the ENSO period. We qualitatively investigate these bio-physical coupling mechanisms using continuation methods. It is demonstrated that bio-physical coupling may play a considerable role in modulating ENSO variability.

  7. Effects of shoreline treatment methods on intertidal biota in Prince William Sound

    International Nuclear Information System (INIS)

    Several studies conducted in Prince William Sound during 1989 were directed at assessing short term biological effects of treatment methods considered or employed for treating oil contaminated beaches. The four treatment alternatives evaluated in this paper are: low pressure warm water wash (LP-WW); high pressure hot water wash (HP-HW); the dispersant Corexit 7664; and the beach cleaner Corexit 9580 M2. Effects on the biota were assessed primarily on the basis of changes in the abundance of dominant taxa and the magnitude of selected community attributes (such as percent cover by algae or animals, and number of taxa). Significant reductions in one or more community or population attributes, and increases in the percent of dead mussels were observed in response to all types of treatment but the strongest and most consistent effects were observed following high pressure hot water treatment, which was also accompanied by heavy mortality in rockweed. Generally, the programs were not designed to discriminate among the potential causes of damage. However, available data suggest that neither chemical nor LP-WW treatments caused significant thermal impacts in the intertidal biota. In contrast, temperature appeared to cause significant mortality in the dominant plants and grazing and filter-feeding animals in HP-HW treatment sites. Observations of displacement and mortality for clams and mussels suggest that physical effects may be substantial in some cases. Of the types of treatment examined, dispersant and beach cleaner treatments appeared to be accompanied with the smallest number of significant changes in abundance; however, this conclusion is weak because the LP-WW wash accompanying chemical applications during the tests was sometimes less rigorous than when performed by itself. LP-WW treatment was accompanied by an intermediate level of changes whereas HP-HW treatment was accompanied with the highest percentage of changes, nearly all of which were decreases

  8. Assessing impacts of ionizing radiation on non-human biota: the ERICA tool

    International Nuclear Information System (INIS)

    There have been significant developments in the last few years concerning methods to explicitly quantify impacts on the environment arising from exposure by ionising radiation. Central to the ERICA integrated approach is the quantification of environmental risk whereby data on environmental transfer and dosimetry are combined to provide a measure of exposure which is compared to exposure levels at which detrimental effects are known to occur. In view of the large data sets underpinning the assessment approach and the potential to introduce errors when performing numerous calculations manually, a supporting computer-based tool (the ERICA Tool) has been developed. The ERICA Tool is a computerised, flexible software system that has a structure based upon the ERICA Integrated Assessment tiered approach to assessing the radiological risk to biota. The user is guided through the assessment process, recording information and decisions as the assessment progresses. The tool allows the necessary calculations to be performed to estimate risks to selected biota. Tier 1 assessments use pre-calculated environmental media concentration limits to estimate risk quotients and require inputs in the form of media concentrations. At Tier 2 dose-rates are calculated but at this stage, the user is allowed to examine and edit most of the parameters used in the calculation. For Tier 3 assessments, the same flexibility as Tier 2 is allowed but assessments may be run probability if the underling parameter probability distribution functions are defined. Results from the tool can be put into context using incorporated data on dose-effects relationships and background dose-rates. (author)

  9. Assessing impacts of ionizing radiation on non-human biota : The ERICA Tool

    International Nuclear Information System (INIS)

    There have been significant developments in the last few years concerning methods to explicitly quantify impacts on the environment arising from exposure by ionising radiation. Central to the ERICA integrated approach is the quantification of environmental risk whereby data on environmental transfer and dosimetry are combined to provide a measure of exposure which is compared to exposure levels at which detrimental effects are known to occur. In view of the large data sets underpinning the assessment approach and the potential to introduce errors when performing numerous calculations manually, a supporting computer-based tool (the ERICA Tool) has been developed. The ERICA Tool is a computerised, flexible software system that has a structure based upon the ERICA Integrated Assessment tiered approach to assessing the radiological risk to biota. The user is guided through the assessment process, recording information and decisions as the assessment progresses. The tool allows the necessary calculations to be performed to estimate risks to selected biota. Tier 1 assessments use pre-calculated environmental media concentration limits to estimate risk quotients and require inputs in the form of media concentrations. At Tier 2 dose-rates are calculated but at this stage, the user is allowed to examine and edit most of the parameters used in the calculation. For Tier 3 assessments, the same flexibility as Tier 2 is allowed but assessments may be run probabilistically if the underling parameter probability distribution functions are defined. Results from the Tool can be put into context using incorporated data on dose-effects relationships and background dose-rates. (author)

  10. Toxicity of coal mining effluents on freshwater mussels and aquatic biota in the upper Tennessee River Basin

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Based on these results, the Service recommends that mining effluents be analyzed for the full suite of metals and water quality parameters pH, hardness, specific...

  11. A review and model assessment of 32P and 33P uptake to biota in freshwater systems

    OpenAIRE

    Smith, J.T.; Bowes, M. J.; Cailes, C.R.

    2011-01-01

    Bioaccumulation of key short-lived radionuclides such as 131I and 32,33P may be overestimated since concentration ratios (CRs) are often based on values for the corresponding stable isotope which do not account for radioactive decay during uptake via the food chain. This study presents estimates for bioaccumulation of radioactive phosphorus which account for both radioactive decay and varying ambient levels of stable P in the environment. Recommended interim CR values for radioactive forms of...

  12. Native Freshwater Fish and Mussel Species Richness

    Data.gov (United States)

    U.S. Environmental Protection Agency — These data represent predicted current distributions of all native freshwater fish and freshwater mussels in the Middle-Atlantic region. The data are available for...

  13. The levels of heavy metals in water and all aquatic in Ismailia canal, (Egypt) compared with the international permissible limits and accumulative studies for these metals in biota

    International Nuclear Information System (INIS)

    The concentration of Pb, Cd, Cu, Zu, Ni, Fe and Mn were determined in water, and in different organs of fishes, bivalves, snails and plants in Ismailia canal, Egypt. Moreover, accumulation of the investigated heavy metals by aquatic biota in Ismailia canal and the concentration factor values for this accumulation were calculated to qualify the degree of pollution and compare these levels with the international permissible limits. Results showed that Pb, Cd, Cu and Zn were exceeded the permissible limits especially in the industrial area of Abu- Zaabal, Kalubia governorate. The relative order of heavy metal levels in the canal water was: Fe>Mn>Pb>Zn>Ni>Cd>Cu.Accumulation of heavy metals by the aquatic biota was determined. The accumulation of heavy metals by common snails, namely physa acuta and biomphalaria alexandrina and the bivalve oyster Caelatura (caelatura) companyoi was found mainly in the edible parts (soft parts), whereas, the accumulation by their shells, which are mainly formed of calcium carbonate was via adsorption and surface complexation, since all the accumulated heavy metals were released by adding 0.1 M HCl for few minutes . Moreover, accumulation of heavy metals by common plants namely water hyacinth plant (Eichhornia crassipes) and freshwater weeds were determined. It was found that the accumulation of heavy metals was higher in roots than in leaves. On the other hand, the accumulation of heavy metals by common fish namely, Oreochromis niloticus (Nile Tilapia) was measured in its organs : muscles, liver, gills and gonads. It was found that there is variation of distribution of heavy metals among fish organs. Since the high accumulation of heavy metals among the investigated biota, they can be used as biological indicator for pollution of heavy metals in aquatic ecosystem . The average values and standard deviation for all measurements were determined. Data obtained were compared with the permissible concentrations of the environmental protection agency on water quality criteria (W.Q.C.)

  14. Pu-239 organ specific dosimetric model applied to non-human biota

    Science.gov (United States)

    Kaspar, Matthew Jason

    There are few locations throughout the world, like the Maralinga nuclear test site located in south western Australia, where sufficient plutonium contaminate concentration levels exist that they can be utilized for studies of the long-term radionuclide accumulation in non-human biota. The information obtained will be useful for the potential human users of the site while also keeping with international efforts to better understand doses to non-human biota. In particular, this study focuses primarily on a rabbit sample set collected from the population located within the site. Our approach is intended to employ the same dose and dose rate methods selected by the International Commission on Radiological Protection and adapted by the scientific community for similar research questions. These models rely on a series of simplifying assumptions on biota and their geometry; in particular; organisms are treated as spherical and ellipsoidal representations displaying the animal mass and volume. These simplifications assume homogeneity of all animal tissues. In collaborative efforts between Colorado State University and the Australian Nuclear Science and Technology Organisation (ANSTO), we are expanding current knowledge on radionuclide accumulation in specific organs causing organ-specific dose rates, such as Pu-239 accumulating in bone, liver, and lungs. Organ-specific dose models have been developed for humans; however, little has been developed for the dose assessment to biota, in particular rabbits. This study will determine if it is scientifically valid to use standard software, in particular ERICA Tool, as a means to determine organ-specific dosimetry due to Pu-239 accumulation in organs. ERICA Tool is normally applied to whole organisms as a means to determine radiological risk to whole ecosystems. We will focus on the aquatic model within ERICA Tool, as animal organs, like aquatic organisms, can be assumed to lie within an infinite uniform medium. This model would scientifically be valid for radionuclides emitting short-range radiation, as with Pu-239, where the energy is deposited locally. Two MCNPX models have been created and evaluated against ERICA Tool's aquatic model. One MCNPX model replicates ERICA Tool's intrinsic assumptions while the other uses a more realistic animal model adopted by ICRP Publication 108 and ERICA Tool for the organs "infinite" surrounding universe. In addition, the role of model geometry will be analyzed by focusing on four geometry sets for the same organ, including a spherical geometry. ERICA Tool will be compared to MCNPX results within and between each organ geometry set. In addition, the organ absorbed dose rate will be calculated for six rabbits located on the Maralinga nuclear test site as a preliminary test for further investigation. Data in all cases will be compared using percent differences and Student's t-test with respect to ERICA Tool's results and the overall average organ mean absorbed dose rate.

  15. Population Dynamics of Biota on the Roots of Azolla microphylla Kaulfuss

    Directory of Open Access Journals (Sweden)

    NITA ETIKAWATI

    2000-01-01

    Full Text Available Azolla was a special fern that their associations with Anabaena azollae able to fix free nitrogen from air, to produce protein. Although by the ages, biota diversity those habits on the roots of Azolla increased and effected to protein concentration. The research was to find out population dynamics of biota on the roots of Azolla microphylla Kaulfuss and the growth peak. This study used Completely Randomized Design with 10 kinds of biota, i.e. bacteria, Fungi, Actinomycetes, Protozoa, Alga, Crustacean, Rotifers, Coelenterate, Insect and Molluscs, and it was used 3 replications. Research was conducted within 4 weeks and the populations of biota were observed every week. Data were statistically analyzed using Analysis Variant and Duncan’s Multiple Range Test. The population dynamics of biota on the roots of Azolla microphylla Kaulfuss were influenced on its quantity and composition, and the growth peak is done in 2nd week.

  16. Annual variation of radioactivity in marine biota in the pacific off Fukushima after TEPCO's Fukushima Daiichi Nuclear Power Station accident

    International Nuclear Information System (INIS)

    Many kinds of marine biota could be observed in the coastal area around off Fukushima after this accident, and it is suggested that the changes of activity are caused by the feeding and sediment effects in biota. (author)

  17. Agrochemical residue-biota interactions in soil and aquatic ecosystems

    International Nuclear Information System (INIS)

    Two FAO/IAEA coordinated research programmes are concerned with isotopic tracer-aided studies of agrochemical residue-biota interactions in soils and aquatic ecosystems. They currently involve 18 studies in 14 countries: Brazil, Canada, Egypt, F.R. Germany, Hungary, India, Indonesia, Iraq, Israel, Malaysia, Thailand, Turkey, USA and USSR. The aim was to develop, standardize and apply labelled substrate techniques for comparative assays of primary autotrophic and microheterotrophic production and decay, and complementary tracer techniques to determine the fate, persistence and bioconcentration of trace contaminants. Comparable data were studied concerning the current status of water bodies and likely changes due to contaminants. Soil capacity to decompose undesirable contaminants and residues, and to promote desirable transformations were studied. The techniques were also applied as a diagnostic and prognostic tool, with priority given to rice ecosystems

  18. Taiwan's industrial heavy metal pollution threatens terrestrial biota

    International Nuclear Information System (INIS)

    The bioconcentration levels of essential (Cu, Fe, Mg, Mn, and Zn) and non-essential (As, Cd, Hg, Pb, and Sn) elements have been investigated in different terrestrial biota such as fungi, plant, earthworm, snail, crab, insect, amphibian, lizard, snake, and bat including the associated soil, to investigate the ecosystem health status in Kenting National Park, Taiwan. High bioconcentrations of Cd, Hg, and Sn in snail, earthworm, crab, lizard, snake, and bat indicated a contaminated terrestrial ecosystem. High concentrations of Cd, Hg, and Sn in plant species, effective bioaccumulation of Cd by earthworm, snail, crab and bat, as well as very high levels of Hg found in invertebrates, amphibians, and reptiles revealed a strong influence from industrial pollution on the biotic community. This study for the first time presents data on the impact of heavy metal pollution on various terrestrial organisms in Taiwan. - Metal effects occur at any terrestrial levels in Taiwan

  19. Biological Sampling and Analysis in Sinclair and Dyes Inlets, Washington: Chemical Analyses for 2007 Puget Sound Biota Study

    Energy Technology Data Exchange (ETDEWEB)

    Brandenberger, Jill M.; Suslick, Carolynn R.; Johnston, Robert K.

    2008-10-09

    Evaluating spatial and temporal trends in contaminant residues in Puget Sound fish and macroinvertebrates are the objectives of the Puget Sound Ambient Monitoring Program (PSAMP). In a cooperative effort between the ENVironmental inVESTment group (ENVVEST) and Washington State Department of Fish and Wildlife, additional biota samples were collected during the 2007 PSAMP biota survey and analyzed for chemical residues and stable isotopes of carbon (?13C) and nitrogen (?15N). Approximately three specimens of each species collected from Sinclair Inlet, Georgia Basin, and reference locations in Puget Sound were selected for whole body chemical analysis. The muscle tissue of specimens selected for chemical analyses were also analyzed for ?13C and ?15N to provide information on relative trophic level and food sources. This data report summarizes the chemical residues for the 2007 PSAMP fish and macro-invertebrate samples. In addition, six Spiny Dogfish (Squalus acanthias) samples were necropsied to evaluate chemical residue of various parts of the fish (digestive tract, liver, embryo, muscle tissue), as well as, a weight proportional whole body composite (WBWC). Whole organisms were homogenized and analyzed for silver, arsenic, cadmium, chromium, copper, nickel, lead, zinc, mercury, 19 polychlorinated biphenyl (PCB) congeners, PCB homologues, percent moisture, percent lipids, ?13C, and ?15N.

  20. Cable Bacteria in Freshwater Sediments

    DEFF Research Database (Denmark)

    Risgaard-Petersen, Nils; Kristiansen, Michael

    2015-01-01

    In marine sediments cathodic oxygen reduction at the sediment surface can be coupled to anodic sulfide oxidation in deeper anoxic layers through electrical currents mediated by filamentous, multicellular bacteria of the Desulfobulbaceae family, the so-called cable bacteria. Until now, cable bacteria have only been reported from marine environments. In this study, we demonstrate that cable bacteria also occur in freshwater sediments. In a first step, homogenized sediment collected from the freshwater stream Giber Å, Denmark, was incubated in the laboratory. After 2 weeks, pH signatures and electric fields indicated electron transfer between vertically separated anodic and cathodic half-reactions. Fluorescence in situ hybridization revealed the presence of Desulfobulbaceae filaments. In addition, in situ measurements of oxygen, pH, and electric potential distributions in the waterlogged banks of Giber Å demonstrated the presence of distant electric redox coupling in naturally occurring freshwater sediment. At the same site, filamentous Desulfobulbaceae with cable bacterium morphology were found to be present. Their 16S rRNA gene sequence placed them as a distinct sister group to the known marine cable bacteria, with the genus Desulfobulbus as the closest cultured lineage. The results of the present study indicate that electric currents mediated by cable bacteria could be important for the biogeochemistry in many more environments than anticipated thus far and suggest a common evolutionary origin of the cable phenotype within Desulfobulbaceae with subsequent diversification into a freshwater and a marine lineage.

  1. Nearctic freshwater tardigrades: a review

    Directory of Open Access Journals (Sweden)

    Juliana G. HINTON

    2007-09-01

    Full Text Available The distribution and ecology of limno-terrestrial Tardigrada in the Nearctic realm remain poorly known. This is especially true of freshwater tardigrades (i.e., species found in permanently submerged habitats, which have received much less attention than terrestrial species. We reviewed the literature on Nearctic freshwater tardigrades. Of 204 Nearctic limno-terrestrial tardigrade species, 44 have been collected from sediments and aquatic vegetation of streams, rivers, ponds, lakes, groundwater and cryoconite holes. Of these, 17 are hydrophilous species found exclusively or primarily in aquatic environments. Most of the remainder are probably washed in accidentally from terrestrial substrates. Among the hydrophilous species, five are endemic to the Nearctic realm and three cosmopolitan. Hypsibius dujardini is the most widely-distributed hydrophilous species. There are no regional collections of Nearctic freshwater tardigrades comparable to those for terrestrial species. Aquatic tardigrades are benthic, and are found in sediments and on aquatic vegetation. Hypsibius dujardini and other widespread species are found in both substrates, and there is thus no evidence of substrate specificity. Numerically, tardigrades usually comprise a minor component of benthic invertebrate communities. Nothing is known of their trophic relationships or dispersal in these habitats. The density of Nearctic freshwater tardigrade species peaks in the spring and/or fall. Future research should increase the spatial and temporal scale of study, and employ adequate replication.

  2. Cable Bacteria in Freshwater Sediments.

    Science.gov (United States)

    Risgaard-Petersen, Nils; Kristiansen, Michael; Frederiksen, Rasmus B; Dittmer, Anders Lindequist; Bjerg, Jesper Tataru; Trojan, Daniela; Schreiber, Lars; Damgaard, Lars Riis; Schramm, Andreas; Nielsen, Lars Peter

    2015-09-01

    In marine sediments cathodic oxygen reduction at the sediment surface can be coupled to anodic sulfide oxidation in deeper anoxic layers through electrical currents mediated by filamentous, multicellular bacteria of the Desulfobulbaceae family, the so-called cable bacteria. Until now, cable bacteria have only been reported from marine environments. In this study, we demonstrate that cable bacteria also occur in freshwater sediments. In a first step, homogenized sediment collected from the freshwater stream Giber Å, Denmark, was incubated in the laboratory. After 2 weeks, pH signatures and electric fields indicated electron transfer between vertically separated anodic and cathodic half-reactions. Fluorescence in situ hybridization revealed the presence of Desulfobulbaceae filaments. In addition, in situ measurements of oxygen, pH, and electric potential distributions in the waterlogged banks of Giber Å demonstrated the presence of distant electric redox coupling in naturally occurring freshwater sediment. At the same site, filamentous Desulfobulbaceae with cable bacterium morphology were found to be present. Their 16S rRNA gene sequence placed them as a distinct sister group to the known marine cable bacteria, with the genus Desulfobulbus as the closest cultured lineage. The results of the present study indicate that electric currents mediated by cable bacteria could be important for the biogeochemistry in many more environments than anticipated thus far and suggest a common evolutionary origin of the cable phenotype within Desulfobulbaceae with subsequent diversification into a freshwater and a marine lineage. PMID:26116678

  3. Toxicity to freshwater organisms from oils and oil spill chemical treatments in laboratory microcosms

    International Nuclear Information System (INIS)

    Toxicity of oil and diesel fuel to freshwater biota may be increased by use of oil spill cleaning agents. - Toxicity and temporal changes in toxicity of freshwater-marsh-microcosms containing South Louisiana Crude (SLC) or diesel fuel and treated with a cleaner or dispersant, were investigated using Chironomus tentans, Daphnia pulex, and Oryzias latipes. Bioassays used microcosm water (for D. pulex and O. latipes) or soil slurry (for C. tentans) taken 1,7, 31, and 186 days after treatment. SLC was less toxic than diesel, chemical additives enhanced oil toxicity, the dispersant was more toxic than the cleaner, and toxicities were greatly reduced by day 186. Toxicities were higher in the bioassay with the benthic species than in those with the two water-column species. A separate experiment showed that C. tentans' sensitivity was intermediate to that of Tubifex tubifex and Hyallela azteca. Freshwater organisms, especially benthic invertebrates, thus appear seriously effected by oil under the worst-case-scenario of our microcosms. Moreover, the cleaner and dispersant tested were poor response options under those conditions

  4. Incipient toxicity of lithium to freshwater organisms representing a salmonid habitat

    International Nuclear Information System (INIS)

    Because the eventual development of fusion power reactors could increase the mining, use and disposal of lithium five-fold by the year 2000, potential effects from unusual amounts of lithium in aquatic environments were investigated. Freshwater oganisms representing a Pacific Northwest salmonid habitat were exposed to elevated conentrations of lithium. Nine parameters were used to determine the incipient toxicity of lithium to rainbow trout (Salmo gairdneri), insect larvae (Chironomus sp.), and Columbia River periphyton. All three groups of biota were incipiently sensitive to lithium at concentrations ranging between 0.1 and 1 mg/L. These results correspond with the incipient toxicity of beryllium, a chemically similar component of fusion reactor cores. A maximum lithium concentration of 0.01 mg/L occurs naturally in most freshwater environments (beryllium is rarer). Therefore, a concentration range of 0.01 to 0.1 mg/L may be regarded as approaching toxic concentrations when assessing the hazards of lithium in freshwaters

  5. RÉGIMEN DE CAUDAL ECOLÓGICO, HERRAMIENTA DE GESTIÓN PARA CONSERVAR LA BIOTA ACUÁTICA / ECOLOGICAL FLOW REGIMEN, MANAGEMENT TOOLTO PRESERVE ACUATIC BIOTA

    Scientific Electronic Library Online (English)

    Mónica Lucía, Izquierdo Santacruz; Sandra Milena, Madroñero Palacios.

    2013-06-01

    Full Text Available RESUMEN En el presente artículo de revisión se consolidó información sobre el Régimen de Caudal Ecológico, al constituirse en una herramienta de gestión en la conservación de la Biota Acuática. De esta manera, se considera relevante informar a la comunidad académica y actores de gestión, sobre la im [...] portancia de la gestión del recurso hídrico, el análisis de conceptos sobre el caudal ambiental y ecológico, la descripción de las diferentes metodologías que permiten su determinación y la normatividad ambiental que lo protege. Finalmente, se hace especial énfasis, en la metodología ecohidráulica en la que se aplica el modelo IFIM-PHABSIM, considerada la modelación del hábitat fluvial, que precisa de información sobre la relación entre la densidad de organismos acuáticos y variables hidráulicas de velocidad, profundidad y sustrato; obteniendo como resultado curvas de idoneidad de hábitat e índices de idoneidad, que permitirán entender el funcionamiento de los ecosistemas acuáticos, utilizando dicha información en el manejo y planificación del recurso hídrico. Abstract in english ABSTRACT In this review article was consolidated information about ecological flow regime to become a management tool in the conservation of aquatic biota. This way is considered important to inform the academic community and development actors on the importance of water resource management, the ana [...] lysis of the environmental and ecological flow concepts the description of the different methodologies allowing his determination and environmental regulations related to water management and ecological flow. Finally emphasizing in the methodologies ecohydraulic, implementing of IFIM-PHABSIM model ,considered the methodology of the fluvial habitat modeling, which is required in the relationship information between the density of aquatic organisms and the hydraulic, speed variable, depth and substrate composition. Obtaining as a result habitat suitability curves and indices of suitability which will allow understanding the functioning of aquatic ecosystems, using that information in the management and planning of water resources.

  6. Spatial and temporal trends of contaminants in terrestrial biota from the Canadian Arctic

    Energy Technology Data Exchange (ETDEWEB)

    Gamberg, Mary [Gamberg Consulting, Box 10460, Whitehorse, YT, Y1A 7A1 (Canada)]. E-mail: mary.gamberg@northwestel.net; Braune, Birgit [Canadian Wildlife Service, Environment Canada, National Wildlife Research Centre, Carleton University, Raven Road, Ottawa, ON, K1A 0H3 (Canada); Davey, Eric [Athabasca Tribal Council, Environmental Affairs, 9206 McCormick Drive, Fort McMurray, AB, T9H 1C7 (Canada); Elkin, Brett [Northwest Territories Department of Resources, Wildlife and Economic Development, Yellowknife, NT X1A 3S8 (Canada); Hoekstra, Paul F. [Department of Environmental Biology, University of Guelph, Guelph, ON, N1G 2W1 (Canada); Kennedy, David [Northwest Territories Department of Resources, Wildlife and Economic Development, Yellowknife, NT X1A 3S8 (Canada); Macdonald, Colin [Northern Environmental Consulting, Pinawa, MB, R0E 1L0 (Canada); Muir, Derek [National Water Research Institute, Environment Canada, Burlington, ON, L7R 4A6 (Canada); Nirwal, Amar [Department of Chemistry and Chemical Engineering, Royal Military College of Canada, Box 17000, Stn Forces, Kingston, ON, K7K 7B4 (Canada); Wayland, Mark [Canadian Wildlife Service, Environment Canada, Prairie and Northern Region, 115 Perimeter Road, Saskatoon, SK, S7N 0X4 (Canada); Zeeb, Barbara [Department of Chemistry and Chemical Engineering, Royal Military College of Canada, Box 17000, Stn Forces, Kingston, ON, K7K 7B4 (Canada)

    2005-12-01

    Contaminants in the Canadian Arctic have been studied over the last twelve years under the guidance of the Northern Contaminants Program. This paper summarizes results from that program from 1998 to 2003 with respect to terrestrial animals in the Canadian Arctic. The arctic terrestrial environment has few significant contaminant issues, particularly when compared with freshwater and marine environments. Both current and historical industrial activities in the north may have a continuing effect on biota in the immediate area, but effects tend to be localized. An investigation of arctic ground squirrels at a site in the Northwest Territories that had historically received applications of DDT concluded that DDT in arctic ground squirrels livers was the result of contamination and that this is an indication of the continuing effect of a local point source of DDT. Arsenic concentrations were higher in berries collected from areas around gold mines in the Northwest Territories than from control sites, suggesting that gold mining may significantly affect arsenic levels in berries in the Yellowknives Dene traditional territory. Although moose and caribou from the Canadian Arctic generally carry relatively low contaminant burdens, Yukon moose had high renal selenium concentrations, and moose and some woodland caribou from the same area had high renal cadmium levels, which may put some animals at risk of toxicological effects. Low hepatic copper levels in some caribou herds may indicate a shortage of copper for metabolic demands, particularly for females. Similarities in patterns of temporal fluctuations in renal element concentrations for moose and caribou suggest that environmental factors may be a major cause of fluctuations in renal concentrations of some elements. Concentrations of persistent organochlorines and metals in beaver and muskrat from the Northwest Territories, and carnivores from across the Canadian Arctic were very low and considered normal for terrestrial wildlife. Two new classes of persistent fluorinated contaminants, perfluorooctane sulfonate (PFOS) and perfluoroalkyl carboxylates (PFCAs) were found in arctic carnivores and were most abundant in arctic fox and least abundant in mink. Although trace element concentrations in king and common eider ducks were low and not of toxicological concern, the number of nematode parasites in common eiders was positively correlated with total and organic mercury concentrations. Future research should focus on cadmium in moose and caribou, mercury in caribou, and emerging contaminants, with an effort to sample moose and caribou annually where possible to explore the role of naturally occurring cycles in apparent temporal trends.

  7. Spatial and temporal trends of contaminants in terrestrial biota from the Canadian Arctic

    International Nuclear Information System (INIS)

    Contaminants in the Canadian Arctic have been studied over the last twelve years under the guidance of the Northern Contaminants Program. This paper summarizes results from that program from 1998 to 2003 with respect to terrestrial animals in the Canadian Arctic. The arctic terrestrial environment has few significant contaminant issues, particularly when compared with freshwater and marine environments. Both current and historical industrial activities in the north may have a continuing effect on biota in the immediate area, but effects tend to be localized. An investigation of arctic ground squirrels at a site in the Northwest Territories that had historically received applications of DDT concluded that DDT in arctic ground squirrels livers was the result of contamination and that this is an indication of the continuing effect of a local point source of DDT. Arsenic concentrations were higher in berries collected from areas around gold mines in the Northwest Territories than from control sites, suggesting that gold mining may significantly affect arsenic levels in berries in the Yellowknives Dene traditional territory. Although moose and caribou from the Canadian Arctic generally carry relatively low contaminant burdens, Yukon moose had high renal selenium concentrations, and moose and some woodland caribou from the same area had high renal cadmium levels, which may put some animals at risk of toxicological effects. Low hepatic copper levels in some caribou herds may indicate a shortage of copper for metabolic demands, particularly for females. Similarities in patterns of temporal fluctuations in renal element concentrations for moose and caribou suggest that environmental factors may be a major cause of fluctuations in renal concentrations of some elements. Concentrations of persistent organochlorines and metals in beaver and muskrat from the Northwest Territories, and carnivores from across the Canadian Arctic were very low and considered normal for terrestrial wildlife. Two new classes of persistent fluorinated contaminants, perfluorooctane sulfonate (PFOS) and perfluoroalkyl carboxylates (PFCAs) were found in arctic carnivores and were most abundant in arctic fox and least abundant in mink. Although trace element concentrations in king and common eider ducks were low and not of toxicological concern, the number of nematode parasites in common eiders was positively correlated with total and organic mercury concentrations. Future research should focus on cadmium in moose and caribou, mercury in caribou, and emerging contaminants, with an effort to sample moose and caribou annually where possible to explore the role of naturally occurring cycles in apparent temporal trends

  8. CHARACTERIZATION AND IDENTIFICATION OF FRESHWATER MICROALGAL STRAINS TOWARD BIOFUEL PRODUCTION

    OpenAIRE

    Xun Yang; Pinghuai Liu,; Zongdi Hao,; Jie Shi; Seng Zhang

    2011-01-01

    Fifty-three algal cultures were isolated from freshwater lakes in Hainan, China. Four microalgal isolates were selected because they could be successfully cultivated at high density and demostrated a strong fluorescence after being stained with nile red. These cultures were identified as strains of Chlorella sp. C11, Chlamydomonas reinhardtii C22, Monoraphidium dybowskii C29, and Chlorella sp. HK12 through microscopic and 18S rDNA analysis. Under similar conditions, the lipid productivity of ...

  9. Fukushima nuclear accident: preliminary assessment of the risks to non-human biota

    International Nuclear Information System (INIS)

    This study assesses the 'radio-ecological' impacts of Fukushima nuclear accident on non-human biota using the ERICA Tool, which adopts an internationally verified methodology. The paper estimates the impacts of the accident on terrestrial and marine biota based on the environmental data reported in literature for Japan, China, South Korea and the USA. Discernible impacts have been detected in the marine biota around Fukushima Daiichi nuclear power plant. This study confirms that the Fukushima accident had caused heavier damage to marine bionts compared with terrestrial flora and fauna, in Japan. (authors)

  10. Fukushima nuclear accident: preliminary assessment of the risks to non-human biota.

    Science.gov (United States)

    Aliyu, Abubakar Sadiq; Ramli, Ahmad Termizi; Garba, Nuraddeen Nasiru; Saleh, Muneer Aziz; Gabdo, Hamman Tukur; Liman, Muhammad Sanusi

    2015-02-01

    This study assesses the 'radio-ecological' impacts of Fukushima nuclear accident on non-human biota using the ERICA Tool, which adopts an internationally verified methodology. The paper estimates the impacts of the accident on terrestrial and marine biota based on the environmental data reported in literature for Japan, China, South Korea and the USA. Discernible impacts have been detected in the marine biota around Fukushima Daiichi nuclear power plant. This study confirms that the Fukushima accident had caused heavier damage to marine bionts compared with terrestrial flora and fauna, in Japan. PMID:24827576

  11. Contrasting size evolution in marine and freshwater diatoms

    Science.gov (United States)

    Litchman, E.; Klausmeier, C. A.; Yoshiyama, K.

    2009-01-01

    Diatoms are key players in the global carbon cycle and most aquatic ecosystems. Their cell sizes impact carbon sequestration and energy transfer to higher trophic levels. We report fundamental differences in size distributions of marine and freshwater diatoms, with marine diatoms significantly larger than freshwater species. An evolutionary game theoretical model with empirical allometries of growth and nutrient uptake shows that these differences can be explained by nitrogen versus phosphorus limitation, nutrient fluctuations and mixed layer depth differences. Constant and pulsed phosphorus supply select for small sizes, as does constant nitrogen supply. In contrast, intermediate frequency nitrogen pulses common in the ocean select for large sizes or the evolutionarily stable coexistence of large and small sizes. Size-dependent sinking interacts with mixed layer depth (MLD) to further modulate optimal sizes, with smaller sizes selected for by strong sinking and shallow MLD. In freshwaters, widespread phosphorus limitation, together with strong sinking and shallow MLD produce size distributions with smaller range, means and upper values, compared with the ocean. Shifting patterns of nutrient limitation and mixing may alter diatom size distributions, affecting global carbon cycle and the structure and functioning of aquatic ecosystems. PMID:19202058

  12. Are metals of antifouling paints transferred to marine biota?

    Scientific Electronic Library Online (English)

    Wladimir C., Paradas; Gilberto M., Amado Filho.

    2007-03-01

    Full Text Available Devido sua alta toxicidade, o TBT está banido desde 2003, o que resultou na re-utilização de tintas a base de cobre. O objetivo deste trabalho é determinar se os metais provenientes das tintas anti-incrustantes (AFP) são transferidos para organismos bentônicos da Baía de Guanabara (BG) (Rio de janei [...] ro, Brasil). Concentrações de metais foram analisadas em duas espécies de algas Ulva flexuosa e U. fasciata e no isópoda, Sphaeroma serratum, em duas áreas de marinas em locais de substrato artificial coberto com tintas AFP e em locais de substrato natural. Também foram coletadas amostras em uma área oceânica (controle). Concentrações de Cd, Cr, Cu, Pb e Zn foram determinadas por Espectrofotometria de Absorção Atômica. Concentrações mais elevadas de Cu, Pb e Zn foram detectadas na BG em ambas espécies de algas em relação a área controle. Dentre as espécies de algas e do isópoda da BG, as populações coletadas sobre as superfícies cobertas com AFP apresentaram concentrações significativamente mais elevadas do que as populações do substrato natural. Os resultados obtidos demonstram que a liberação de metais presentes nas AFP dos decks e embarcações, estão sendo acumulados pelas algas e isópodas. Esses resultados indicam que o revestimento com AFP é a principal fonte de metais para a biota de marinas em áreas da BG. Abstract in english Because of its high toxicity, TBT (trybutiltin) was banned since 2003, which resulted in a greater re-use of Cu as based-biocide in antifouling paints (AFP). The aim of this work is to determine if metals form of AFP are transferred to benthic organisms from Guanabara Bay (GB) (Rio de Janeiro, Brazi [...] l). Metal concentrations were measured in two main fouling algae species Ulva flexuosa and U. fasciata and one isopod species, Sphaeroma serratum, in two GB marinas areas from sites with artificial substrate covered by AFP and natural substrate.In addition, control samples were collected in an adjacent open ocean area. Concentrations of Cd, Cr, Cu, Pb and Zn were determined by Atomic Absortion Spectrophotometry. Higher concentrations of Cu, Pb and Zn were detected in both algal species from GB in relation to control areas. Among samples of algae and isopod species from GB, populations collected over artificial surfaces covered by AFP presented significantly higher metal concentration than population of rocky natural substrate. Our data showed that the leaching of metals by antifouling paints present on decks and boats are being taken up by algae and isopods. These results indicate that antifouling coatings are the main source of heavy metal to biota of GB marina area.

  13. Making sense of ocean biota: How evolution and biodiversity of land organisms differ from that of the plankton

    Indian Academy of Sciences (India)

    Victor Smetacek

    2012-09-01

    The oceans cover 70% of the planet’s surface, and their planktonic inhabitants generate about half the global primary production, thereby playing a key role in modulating planetary climate via the carbon cycle. The ocean biota have been under scientific scrutiny for well over a century, and yet our understanding of the processes driving natural selection in the pelagic environment – the open water inhabited by drifting plankton and free-swimming nekton – is still quite vague. Because of the fundamental differences in the physical environment, pelagic ecosystems function differently from the familiar terrestrial ecosystems of which we are a part. Natural selection creates biodiversity but understanding how this quality control of randommutations operates in the oceans ? which traits are selected for under what circumstances and by which environmental factors, whether bottom-up or top-down ? is currently a major challenge. Rapid advances in genomics are providing information, particularly in the prokaryotic realm, pertaining not only to the biodiversity inventory but also functional groups. This essay is dedicated to the poorly understood tribes of planktonic protists (unicellular eukaryotes) that feed the ocean’s animals and continue to run the elemental cycles of our planet. It is an attempt at developing a conceptually coherent framework to understand the course of evolution by natural selection in the plankton and contrast it with the better-known terrestrial realm. I argue that organism interactions, in particular co-evolution between predators and prey (the arms race), play a central role in driving evolution in the pelagic realm. Understanding the evolutionary forces shaping ocean biota is a prerequisite for harnessing plankton for human purposes and also for protecting the oceanic ecosystems currently under severe stress from anthropogenic pressures.

  14. Cable Bacteria in Freshwater Sediments

    DEFF Research Database (Denmark)

    Risgaard-Petersen, Nils; Kristiansen, Michael; Frederiksen, Rasmus; Lindequist Dittmer, Anders; Bjerg, Jesper Jensen; Trojan, Daniela; Schreiber, Lars; Damgaard, Lars Riis; Schramm, Andreas; Nielsen, Lars Peter

    2015-01-01

    In marine sediments cathodic oxygen reduction at the sediment surface can be coupled to anodic sulfide oxidation in deeper anoxic layers through electrical currents mediated by filamentous, multicellular bacteria of the Desulfobulbaceae family, the so-called cable bacteria. Until now, cable bacteria have only been reported from marine environments. In this study, we demonstrate that cable bacteria also occur in freshwater sediments. In a first step, homogenized sediment collected from the freshw...

  15. Differential concentration of plutonium isotopes in Rocky Flats Biota

    International Nuclear Information System (INIS)

    Data for 238Pu and 239Pu concentrations in samples from grassland biota and soil at Rocky Flats, Colorado, were studied to compare environmental behavior of these isotopes. Mean isotope ratios (239,240Pu pCi/g / 238Pu pCi/g) were lower for the small mammals and arthropods than for the soil, litter, and standing vegetation. The isotopic ratio was also found to be inversely related to soil sample depth. These results suggested that, relative to 239Pu, 238Pu was concentrating in small mammals and arthropods and moving downward into the soil at a faster rate. Further investigations, however, indicated that isotopic ratios were likely biased towards lower values of the ratio as the total plutonium concentration in a sample decreased. This bias can be understood as a leftward shift of the value of the most probable and mean ratio. This shift occurs when the frequency distribution of the numerator (239Pu) and denominator (238Pu) of the ratio are truncated (have their lower tail removed) by eliminating values below some detection limit. If, as in this example, the distribution of the denominator variable is of lower magnitude than the numerator and, therefore, nearer the detection limit and truncated to a larger degree, the resulting ratio frequency distribution is shifted to lower values compared to the ratio of two untruncated variables. (author)

  16. Biologically transformed zinc and its subsequent availability to marine biota

    International Nuclear Information System (INIS)

    A series of experiments performed to define the mode of formation of the complexed zinc fraction using radiotracers and to discern if this fraction, once formed by biological means, is available for accumulation by marine biota, are discussed. Fractionation of excreted 65Zn by shrimp Lysmata seticaudata and mussels Mytilus galloprovincialis for excretion periods ranging from 0 to 47 days are measured and respective percentage of total 65Zn excreted and retained on 0.45? filters, percentage filtrate on resin and in eluate are calculated. Zinc-65 transformations in waters conditioned by the presence of dead shrimp during the time range of 1 to 218 days and respective percentages of 65Zn labelled and non-labelled shrimp, on filter, on chelex and in eluate are reported. It is also observed that 65Zn accumulation by shell is virtually unaffected by the different forms of radiozinc, whereas the discrimination between the forms occurs in the soft parts and especially the highly metabolically active byssus

  17. Footprints of climate change on Mediterranean Sea biota

    KAUST Repository

    Marbà, Núria

    2015-08-13

    The Mediterranean Sea ranks among the ocean regions warming fastest. There is evidence for impacts of climate change on marine Mediterranean organisms but a quantitative assessment is lacking. We compiled the impacts of warming reported in the literature to provide a quantitative assessment for the Mediterranean Sea. During the last three decades the summer surface temperature has increased 1.15°C. Strong heat wave events have occurred in years 1994, 2003, and 2009. Impacts of warming are evident on growth, survival, fertility, migration and phenology of pelagic and benthic organisms, from phytoplankton to marine vegetation, invertebrates and vertebrates. Overall, 50% of biological impacts in the Mediterranean Sea occur at summer surface temperature anomaly ? 4.5°C and at summer surface temperature of 27.5°C. The activation energy (geometric mean 1.58 ± 0.48 eV), the slope of the Arrhenius equation describing the temperature-dependence of biological processes, for the response of Mediterranean marine biota to warming reveals that these responses in the Mediterranean are far steepest than possibly explained by the direct effect of warming alone. The observations are biased toward the northern and western sectors of the basin, likely underestimating the impacts of warming in areas where warming is particularly intense.

  18. Metals in New Jersey's Pinelands National Reserve Sediments, Surface Water and Biota: An Emphasis on Mercury

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Technical data on the nature and extent of chemical contaminants in sediments and biota of the streams comprising the Pinelands National Reserve Pinelands in New...

  19. Survey of contaminants in soils and biota at the Seney National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — A survey was conducted in 1987 to assess the presence and degree of contamination in soils and various biota at Seney National Wildlife Refuge, located in the...

  20. Contaminant Assessment of Biota and Sediments in the Albermarle-Pamlico region

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The U.S. Fish and Wildlife Service conducted a baseline contaminants study of the aquatic biota and sediments in the AlbemarlePamlico region in 198788. Sites in the...

  1. Soil biota and ecosystem development in post-mining sites - conclusions and practical implications.

    Czech Academy of Sciences Publication Activity Database

    Frouz, Jan

    Boca Raton : Taylor & Francis CRC Press, 2013, s. 290-302. ISBN 978-1-4665-9931-4 Institutional support: RVO:60077344 Keywords : soil biota * ecosystem development * post-mining sites Subject RIV: DF - Soil Science

  2. Panbiogeographical analysis of Costa Rican freshwater fishes

    Directory of Open Access Journals (Sweden)

    Jonathan Herrera-Vásquez

    2008-03-01

    Full Text Available Track analysis and Parsimony analysis of endemicity (PAE were performed to analyze the distribution pattern of Costa Rican freshwater fishes. A basic matrix (presence/absence was prepared using the distribution of 77 freshwater fish. The data were analyzed with CLIQUE software in order to find generalized tracks (cliques. Data also were analyzed with the software NONA and Winclada version 1.00.08 in order to perform the Parsimony Analysis of Endemicity (PAE. Fourteen equally probable cliques were found with 31 species in each and the intersection of the amount was selected as a generalized track dividing the country in two main zones: Atlantic slope from Matina to Lake Nicaragua and Pacific slope from the Coto River to the basin of the Tempisque River connected with some branches oriented to the central part of the country. PAE analysis found ten cladogram areas (72 steps, CI=0.45, RI=0.64, using the "strict consensus option" two grouping zones were identified: Atlantic slope and Pacific slope. Both PAE and Track Analysis show the division of the two slopes and the orientation of the generalized track suggests new biogeographical evidence on the influence of both old and new southern elements to explain the migrations of freshwater fish into Central America during two different geological events. Rev. Biol. Trop. 56 (1: 165-170. Epub 2008 March 31.Con el objetivo de analizar el patrón de distribución de peces de agua dulce de Costa Rica se aplicó un análisis de trazos y de parsimonía de endemismos (PAE. Se construyó una matriz básica utilizando la distribución de 77 especies. Se utilizó el programa CLIQUE con la intención de encontrar los trazos generalizados y NONA y Winclada, versión 1.00.08, con el fin de llevar a cabo el PAE. Se encontró un total de 14 cliques igualmente probables con 31 especies. De esta cantidad se construyó un trazo generalizado que constituye la intersección del total, dividiendo el país en dos zonas: Atlántico, desde Matina hasta el Lago de Nicaragua y Pacífico desde el río Coto hasta el río Tempisque conectado con la región central del país. El PAE encontró diez cladogramas de áreas (72 pasos, CI=0.45, RI=0.64, cuyo consenso estricto identificó dos zonas de agrupamiento: Atlántico y Pacífico. Ambos análisis muestran la división entre las dos vertientes y la orientación de los trazos generalizados sugiere nueva evidencia de la influencia biogeográfica de los denominados elementos de migración antiguo y nuevo del sur, los cuales se habían sugerido empíricamente en el pasado para explicar las migraciones hacia Centroamérica en dos periodos geológicos diferentes.

  3. Panbiogeographical analysis of Costa Rican freshwater fishes

    Scientific Electronic Library Online (English)

    Jonathan, Herrera-Vásquez; William, Bussing; Federico, Villalobos.

    2008-03-01

    Full Text Available Con el objetivo de analizar el patrón de distribución de peces de agua dulce de Costa Rica se aplicó un análisis de trazos y de parsimonía de endemismos (PAE). Se construyó una matriz básica utilizando la distribución de 77 especies. Se utilizó el programa CLIQUE con la intención de encontrar los tr [...] azos generalizados y NONA y Winclada, versión 1.00.08, con el fin de llevar a cabo el PAE. Se encontró un total de 14 cliques igualmente probables con 31 especies. De esta cantidad se construyó un trazo generalizado que constituye la intersección del total, dividiendo el país en dos zonas: Atlántico, desde Matina hasta el Lago de Nicaragua y Pacífico desde el río Coto hasta el río Tempisque conectado con la región central del país. El PAE encontró diez cladogramas de áreas (72 pasos, CI=0.45, RI=0.64), cuyo consenso estricto identificó dos zonas de agrupamiento: Atlántico y Pacífico. Ambos análisis muestran la división entre las dos vertientes y la orientación de los trazos generalizados sugiere nueva evidencia de la influencia biogeográfica de los denominados elementos de migración antiguo y nuevo del sur, los cuales se habían sugerido empíricamente en el pasado para explicar las migraciones hacia Centroamérica en dos periodos geológicos diferentes. Abstract in english Track analysis and Parsimony analysis of endemicity (PAE) were performed to analyze the distribution pattern of Costa Rican freshwater fishes. A basic matrix (presence/absence) was prepared using the distribution of 77 freshwater fish. The data were analyzed with CLIQUE software in order to find gen [...] eralized tracks (cliques). Data also were analyzed with the software NONA and Winclada version 1.00.08 in order to perform the Parsimony Analysis of Endemicity (PAE). Fourteen equally probable cliques were found with 31 species in each and the intersection of the amount was selected as a generalized track dividing the country in two main zones: Atlantic slope from Matina to Lake Nicaragua and Pacific slope from the Coto River to the basin of the Tempisque River connected with some branches oriented to the central part of the country. PAE analysis found ten cladogram areas (72 steps, CI=0.45, RI=0.64), using the "strict consensus option" two grouping zones were identified: Atlantic slope and Pacific slope. Both PAE and Track Analysis show the division of the two slopes and the orientation of the generalized track suggests new biogeographical evidence on the influence of both old and new southern elements to explain the migrations of freshwater fish into Central America during two different geological events. Rev. Biol. Trop. 56 (1): 165-170. Epub 2008 March 31.

  4. Dynamic modelling of radionuclide uptake by Fukushima coastal biota - Dynamic modelling of radionuclide uptake by marine biota: application to Fukushima assessment

    Energy Technology Data Exchange (ETDEWEB)

    Vives i Batlle, Jordi [Belgian Nuclear Research Centre, Boeretang 200, 2400 Mol (Belgium)

    2014-07-01

    Radiological assessments to non-human marine biota are usually carried out by assuming that the activity concentration in an organism is proportional to the activity concentration in an adjacent volume of water, via a concentration factor (CF). It is also assumed that radionuclides in the water are in isotopic equilibrium with the sediments via a sediment distribution coefficient (K{sub d}). These assumptions are not valid in accidental situations where the biota and the sediments react with a time delay to large variations of activity concentration in seawater. A simple dynamic model was developed to factorise the dynamics of radionuclide uptake and turnover in biota and sediments, as determined by a balance between the residence time of radionuclides in seawater/sediments and the biological half-life of elimination in the biota. The model calculates activity concentration of {sup 131}I, {sup 134}Cs, {sup 137}Cs and {sup 90}Sr in seabed sediment, fish, crustaceans, molluscs and macro-algae from surrounding activity concentrations in seawater, with which to derive internal and external dose rates. A central element of this new model is the inclusion of sediment processes in dynamic transfer modelling. The model is adapted to include depletion of radionuclides adsorbed onto suspended particulates (particle scavenging), molecular diffusion, pore water mixing and bioturbation (modelled effectively as a diffusive process) represented by a simple set of differential equations that is coupled with the biological uptake/turnover processes. In this way, the model is capable of reproducing activity concentration in sediment to give a more realistic calculation of the external dose to biota compared with the simpler approach based on CF and K{sub d} values used in previous assessments. The model is applied to the assessment of the radiological impact of the Fukushima accident on marine biota in the early phase of the accident. It is shown that previous assessment of the external doses to marine biota using a K{sub d} assumption for the sediment contribution are largely overestimated compared with using the dynamic sediment model, as shown by comparison with actual monitoring data for sediments. Likewise, it is also shown that the activity concentration in the biota (and, consequently, the internal dose rate) is better predicted by a dynamic model than with the simpler concentration factor approach. (authors)

  5. Dynamic modelling of radionuclide uptake by Fukushima coastal biota - Dynamic modelling of radionuclide uptake by marine biota: application to Fukushima assessment

    International Nuclear Information System (INIS)

    Radiological assessments to non-human marine biota are usually carried out by assuming that the activity concentration in an organism is proportional to the activity concentration in an adjacent volume of water, via a concentration factor (CF). It is also assumed that radionuclides in the water are in isotopic equilibrium with the sediments via a sediment distribution coefficient (Kd). These assumptions are not valid in accidental situations where the biota and the sediments react with a time delay to large variations of activity concentration in seawater. A simple dynamic model was developed to factorise the dynamics of radionuclide uptake and turnover in biota and sediments, as determined by a balance between the residence time of radionuclides in seawater/sediments and the biological half-life of elimination in the biota. The model calculates activity concentration of 131I, 134Cs, 137Cs and 90Sr in seabed sediment, fish, crustaceans, molluscs and macro-algae from surrounding activity concentrations in seawater, with which to derive internal and external dose rates. A central element of this new model is the inclusion of sediment processes in dynamic transfer modelling. The model is adapted to include depletion of radionuclides adsorbed onto suspended particulates (particle scavenging), molecular diffusion, pore water mixing and bioturbation (modelled effectively as a diffusive process) represented by a simple set of differential equations that is coupled with the biological uptake/turnover processes. In this way, the model is capable of reproducing activity concentration in sediment to give a more realistic calculation of the external dose to biota compared with the simpler approach based on CF and Kd values used in previous assessments. The model is applied to the assessment of the radiological impact of the Fukushima accident on marine biota in the early phase of the accident. It is shown that previous assessment of the external doses to marine biota using a Kd assumption for the sediment contribution are largely overestimated compared with using the dynamic sediment model, as shown by comparison with actual monitoring data for sediments. Likewise, it is also shown that the activity concentration in the biota (and, consequently, the internal dose rate) is better predicted by a dynamic model than with the simpler concentration factor approach. (authors)

  6. An overview of UV-absorbing compounds (organic UV filters) in aquatic biota.

    Science.gov (United States)

    Gago-Ferrero, Pablo; Díaz-Cruz, M Silvia; Barceló, Damià

    2012-11-01

    The purpose of this article is to summarize biological monitoring information on UV-absorbing compounds, commonly referred as organic UV filters or sunscreen agents, in aquatic ecosystems. To date a limited range of species (macroinvertebrates, fish, and birds), habitats (lakes, rivers, and sea), and compounds (benzophenones and camphors) have been investigated. As a consequence there is not enough data enabling reliable understanding of the global distribution and effect of UV filters on ecosystems. Both liquid chromatography and gas chromatography coupled with mass spectrometry-based methods have been developed and applied to the trace analysis of these pollutants in biota, enabling the required selectivity and sensitivity. As expected, the most lipophilic compounds occur most frequently with concentrations up to 7112 ng g(-1) lipids in mussels and 3100 ng g(-1) lipids (homosalate) in fish. High concentrations have also been reported for 4-methylbenzilidenecamphor (up to 1800 ng g(-1) lipids) and octocrylene (2400 ng g(-1) lipids). Many fewer studies have evaluated the potential bioaccumulation and biomagnification of these compounds in both fresh and marine water and terrestrial food webs. Estimated biomagnification factors suggest biomagnification in predator-prey pairs, for example bird-fish and fish-invertebrates. Ecotoxicological data and preliminary environmental assessment of the risk of UV filters are also included and discussed. PMID:22669305

  7. Soil biota effects on local abundances of three grass species along a land-use gradient.

    Science.gov (United States)

    Heinze, J; Werner, T; Weber, E; Rillig, M C; Joshi, J

    2015-09-01

    Biotic plant-soil interactions and land-use intensity are known to affect plant individual fitness as well as competitiveness and therefore plant-species abundances in communities. Therefore, a link between soil biota and land-use intensity on local abundance of plant species in grasslands can be expected. In two greenhouse experiments, we investigated the effects of soil biota from grassland sites differing in land-use intensity on three grass species that vary in local abundances along this land-use gradient. We were interested in those soil-biota effects that are associated with land-use intensity, and whether these effects act directly or indirectly. Therefore, we grew the three plant species in two separate experiments as single individuals and in mixtures and compared their performance. As single plants, all three grasses showed a similar performance with and without soil biota. In contrast, in mixtures growth of the species in response to the presence or absence of soil biota differed. This resulted in different soil-biota effects that tend to correspond with patterns of species-specific abundances in the field for two of the three species tested. Our results highlight the importance of indirect interactions between plants and soil microorganisms and suggest that combined effects of soil biota and plant-plant interactions are involved in structuring plant communities. In conclusion, our experiments suggest that soil biota may have the potential to alter effects of plant-plant interactions and therefore influence plant-species abundances and diversity in grasslands. PMID:25964063

  8. Extraction of Freshwater and Energy from Atmosphere

    OpenAIRE

    Bolonkin, Alexander

    2007-01-01

    Author offers and researches a new, cheap method for the extraction of freshwater from the Earth atmosphere. The suggected method is fundamentally dictinct from all existing methods that extract freshwater from air. All other industrial methods extract water from a saline water source (in most cases from seawater). This new method may be used at any point in the Earth except Polar Zones. It does not require long-distance freshwater transportation. If seawater is not utilized...

  9. RNA interference in marine and freshwater sponges

    OpenAIRE

    Rivera, Ajna S.; Hammel, Jörg U.; Haen, Karri M; Danka, Elizabeth S.; Cieniewicz, Brandon; Winters, Ian P; Posfai, Dora; Wörheide, Gert; Lavrov, Dennis V.; Knight, Scott W; Hill, Malcolm S.; Hill, April L; Nickel, Michael

    2011-01-01

    Background: The marine sponge Tethya wilhelma and the freshwater sponge Ephydatia muelleri are emerging model organisms to study evolution, gene regulation, development, and physiology in non-bilaterian animal systems. Thus far, functional methods (i.e., loss or gain of function) for these organisms have not been available. Results: We show that soaking developing freshwater sponges in double-stranded RNA and/or feeding marine and freshwater sponges bacteria expressing double-stranded RNA ...

  10. Comparative food-chain behavior and distribution of actinide elements in and around a contaminated fresh-water pond

    International Nuclear Information System (INIS)

    The bioaccumulation of 233234U, 238U, 238Pu, 239240Pu, 241Am, and 244Cm in both native and introduced biota was studied at Pond 3513, a former low-level radioactive waste settling basin at Oak Ridge National Laboratory. This system, which was decommissioned in 1976 after more than 30 years use, contains approximately 5 Ci of 239240Pu; inventories of other actinide isotopes are considerably less. Significantly higher concentrations of actinides in fish that were allowed access to sediments indicated that sedimentary particulates may be the primary source of transuranics to biota in shallow fresh-water ecosystems. Our study determined habitat, in particular the degree of association of an organism with the sediment-water interface, to be the primary factor in controlling transuranic concentrations in aquatic biota. In most of the biological samples analyzed, excluding samples suspected of being contaminated by sediment, 241Am/239Pu, 244Cm/239Pu, and 238U/239Pu ratios were greater than the respective ratio in sediment while 233234U/238U, and 239240Pu/238Pu ratios were not different from the respective ratios in sediment. The relative uptake of actinides from contaminated sediment by aquatic and terrestrial biota at this site was U > Cm greater than or equal to Am > Pu. The relative extractability of actinides from shoreline sediment was U > Cm approx. = Am > Pu; we also observed the same relative ranking for sediment-water exchange in situ. Concentrations of transuranics in water, terrestrial vegetation, and vertebrate carcasses were less than 10% of the recommended public exposure maximum permissible concentration (MPC) of the ICRP

  11. Natural radioactivity in some specimens of the marine biota

    International Nuclear Information System (INIS)

    Marine environment contamination by natural radionuclides (uranium and 238U daughters) is evaluated using marine -fauna and flora elements concentrating fission - and radioactivated products released by nuclear facilities. Total alpha and beta radiometry is done in the the biota to determine the radionuclide concentration. Uranium, 226Ra and 210PO assay is done to estimate their contribution to natural radioactivity in the chosen biological indicators. Several analytical techniques required by each radionuclide are used. Potassium assay is done to evaluate the contribution of 40K to the natural radioactivity, and calcium assay to determine Ra/Ca and U/Ca ratios in the samples. For total alpha radiometry in algae the higher average value is detected in Phaeophyta (84.1 pCi/kg fresh weight); maximum concentration in animals is registered in Bunodosoma caissarum (43.1 pCi/kg fresh weight). For algae, the higher average total beta radiometry detected is in Chlorophyta (6.9 nCi/kg fresh weight); the maximum value found in animals refers to Thais Haemastoma (7.54 nCi/kg fresh weight). Potassium higher average ratio for algae occurs in Chlorophyta (12.77% ashes); for animals, the maximum value is found in Bunodosoma caissarum (13.80% ashes). The uranium concentration factor is maximum in Perna perna bissus (684) while the minimum is registered in Thais haemastoma and Sargassum vulgare (44). The 226Ra concentration factor is maximum in Sargassum vulgare (2143) and minimum in Bunodosoma caissarum (32). Maximum average ratio for 210PO in algae occurs in Phaephyta (11.5 pCi/g dry weight) and the maximum concentration for animals in Perna perna (31.5 pCi/g dry weight). The techniques employed proved to be efficient for the objectives aimed at. (Author)

  12. Marine biota sightings during 3D marine seismic surveys

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Joao Luiz Martinez de; Uller, George A. [CGG do Brasil, Rio de Janeiro, RJ (Brazil); Derntl, Jose Renato; Ribeiro, Camila Castroviejo da Silva; Pereira, Edisio [GEOCOOP Cooperativa de Trabalho, Rio de Janeiro, RJ (Brazil); Miranda, Cristina Maschio de [Nautilus Cooperativa de Trabalho (Brazil); Ferraz, Alexandre Almeida; Costa, Leandro Damiao Soares da [Okeanos Consultoria e Meio Ambiente Ltda. (Brazil)

    2004-07-01

    This work intends to make a correlation between the presence of the marine biota and the seismic source activity (air guns) during seismic surveys, in Campos (BM-C-25 and BM-C-16) and Santos (BM-S-3) Basin, since July 2003 until March 2004. Environmental data were acquired onboard of the Seismic Vessel CGG Harmattan by a team of four oceanographers (environmental technicians), working on the highest place of the Vessel to record and identify the animals whenever was possible. The data were recorded in forms where fields about the biotic and environmental aspects were filled. In 212 days of observations, 2580,1 hours of sighting's effort were recorded; the air guns worked during 37,6% of the time of the effort. These efforts were made during the daylight reaching an average value of 11,35 hours/day. Sightings were divided into the suborders Odontocetes and Mysticetes, and others (fishes, turtles and non identified mammals). 175 sightings were recorded, being 54% when the air gun was off (24% Mysticetes, 56% Odontocetes, 20% others). Similarly, when the air gun was working, 46% of the records were made (24% Mysticetes, 61% Odontocetes, 6% others); the major concentration (58%) of individuals was inside the 1000 m radius around the ship, followed by 14% of the individuals occurring between 3001-4000 m radius away from the ship. The analysis of the data suggests a non-evasive behavior related to the working of the seismic source, corroborating the results reached by other publications using the data collected onboard CGG Vessels. (author)

  13. Using Natural Geochemical Tracers to Discern the Dominant Sources of Freshwater into Biscayne Bay, Southeast Florida

    Science.gov (United States)

    Stalker, J. C.; Price, R. M.; Swart, P. K.

    2005-05-01

    Biscayne Bay is a sub-tropical estuary located on the carbonate platform of south Florida. The water occupying Biscayne Bay is a balance of saltwater influx from the open ocean and freshwater inputs from precipitation, surface water runoff, and submarine groundwater discharge. The bays watershed includes a total of 3 million inhabitants, the major urban centers of Miami and Ft. Lauderdale, as well as the Everglades system. With the development of south Florida, the natural diffuse groundwater and stream flow into the bay has been replaced by a large system of canals and levees in an effort to control flooding and drain swampland. The Comprehensive Everglades Restoration Plan includes changes in the freshwater deliveries to Biscayne Bay from point-source discharges via canals to non-point source discharges via wetlands and groundwater flow. The balance of salinity in Biscayne Bay effects sensitive seagrass and tidal ecosystems including numerous species of corals and other biota. A comprehensive understanding of the flow of freshwater into the bay is crucial to future planned developments and restorations. The goal of this study is to use naturally occurring geochemical constituents as tracers to identify and quantify the sources of freshwater, i.e. rainfall, canal flow, and groundwater, discharge to Biscayne Bay. In this study, discrete samples of precipitation, canal water, terrestrial groundwater, marine groundwater, and bay surface water are collected monthly and analyzed for the stable isotopes of hydrogen and oxygen as well as for major cations and anions. Initial results indicate that fresh groundwater has an isotopic signature (del 18O = -2.66 per mil, del D, -7.60 per mil) similar to rainfall (del 18O = -2.86 per mil, del D =-4.78 per mil). In contrast canal water has a heavy isotopic signature (del 18O = -0.46 per mil, del D = -2.48 per mil) due to evaporation. Thus it is possible to use stable isotopes of oxygen and hydrogen to separate canal water from precipitation and groundwater as a source of freshwater into the bay. Other geochemical constituents, such as calcium and magnesium are being investigated to further discern between the sources of canal water, rainfall and fresh groundwater. Both the stable isotopes and ion values will be placed in a mixing model to quantify and discern the dominant sources of freshwater into the Bay in both time and space.

  14. [Cultivation technics for freshwater fish].

    Science.gov (United States)

    Rosenthal, H

    1990-07-01

    A general overview is presented on the various cultivation techniques in modern freshwater aquaculture. Included are overall production figures for finfish production in the most important producing countries of Europe. Major emphasis is placed on the situation of aquaculture development in the Federal Republic of Germany, providing details on the structure of the industry in the states of Bavaria, Lower Saxony, and Schleswig-Holstein. The trend towards intensification and its implications to system performance is described. The development of recirculation systems, particular for eel farming, is outlined, indicating the various problems related to system design, local conditions and species requirements. Future trends and research needs are identified. PMID:2205459

  15. Productivity and salinity structuring of the microplankton revealed by comparative freshwater metagenomics.

    Science.gov (United States)

    Eiler, Alexander; Zaremba-Niedzwiedzka, Katarzyna; Martínez-García, Manuel; McMahon, Katherine D; Stepanauskas, Ramunas; Andersson, Siv G E; Bertilsson, Stefan

    2014-09-01

    Little is known about the diversity and structuring of freshwater microbial communities beyond the patterns revealed by tracing their distribution in the landscape with common taxonomic markers such as the ribosomal RNA. To address this gap in knowledge, metagenomes from temperate lakes were compared to selected marine metagenomes. Taxonomic analyses of rRNA genes in these freshwater metagenomes confirm the previously reported dominance of a limited subset of uncultured lineages of freshwater bacteria, whereas Archaea were rare. Diversification into marine and freshwater microbial lineages was also reflected in phylogenies of functional genes, and there were also significant differences in functional beta-diversity. The pathways and functions that accounted for these differences are involved in osmoregulation, active transport, carbohydrate and amino acid metabolism. Moreover, predicted genes orthologous to active transporters and recalcitrant organic matter degradation were more common in microbial genomes from oligotrophic versus eutrophic lakes. This comparative metagenomic analysis allowed us to formulate a general hypothesis that oceanic- compared with freshwater-dwelling microorganisms, invest more in metabolism of amino acids and that strategies of carbohydrate metabolism differ significantly between marine and freshwater microbial communities. PMID:24118837

  16. Atlantic origin of Nordic Seas freshwater anomalies

    Science.gov (United States)

    Glessmer, Mirjam S.; Eldevik, Tor; Nilsen, J. Even Ø.; Våge, Kjetil

    2013-04-01

    The Nordic Seas freshwater content is an indicator of climate change. An enhanced hydrological cycle and melting of Arctic sea ice introduce freshwater to the Arctic Ocean, which is then discharged to the Nordic Seas. But the freshwater budget of the Nordic Seas is also influenced by saline Atlantic inflow from the south. We use a most comprehensive dataset of hydrographic observations to determine sources and propagation of anomalous freshwater content in the Nordic Seas over the last 60 years. Complimentary we use a state-of-the-art 600-year climate model simulation for a closed and quantitative assessment. We find consistently, both in model and observational data, that the Atlantic inflow determines most of the variability of the Nordic Seas freshwater content, and that anomalies propagate from the Atlantic inflow through the Norwegian Sea into the Greenland - and later on Iceland Sea with a propagation time around the Nordic Seas of approximately seven years.

  17. Estimation of Freshwater Flow to Joe Bay, South Florida.

    Science.gov (United States)

    Zucker, M. A.; Hittle, C. D.

    2002-05-01

    During the last century, drainage canals were constructed as part of the Central and Southern Flood Control (C&SF) project. Flood control was achieved but degradation to the Everglades ecosystem was evident. Problems related to Florida Bay include sea grass die off, algae blooms, and extreme salinity conditions. Modifications to the C&SF project are proposed as part of the Comprehensive Everglades Restoration Plan (CERP). One objective of CERP is to improve the timing and distribution of freshwater flow within the Everglades ecosystem and to Florida Bay. Several CERP projects propose changes to the existing canal network that borders Everglades National Park (ENP) in southern Miami-Dade County. An examination of flows to Joe Bay, a small embayment on the northeastern shores of Florida Bay, has provided baseline information on current spatial and temporal water deliveries prior to CERP modifications. Understanding the existing complex water delivery system and the effects the system has on Everglades hydrology will provide a necessary benchmark against which to measure restoration success. The study was initiated by the U.S. Geological Survey (USGS) in May 1999 to estimate creek flows to Joe Bay and determine the relative amounts derived from Taylor Slough and overflow from the C-111 Canal. It is important to understand the source of freshwater to Joe Bay before it enters Florida Bay. Taylor Slough transports freshwater to northeastern Florida Bay from the northwest while overflow from the C-111 Canal provides freshwater to northeastern Florida Bay from the northeast. Joe Bay, receives part of the freshwater from each of these sources via sheet flow and small estuarine creeks, and subsequently discharges southward to northeastern Florida Bay via Trout Creek. Trout Creek contributes approximately 50 percent of the total freshwater flow to northeastern Florida Bay (Hittle 2001). Eight non-gaged creeks entering Joe Bay were selected for acoustic Doppler current profiler (ADCP) measurements. The ADCP discharge measurements were then correlated with computed real-time discharge measurements from nearby USGS flow stations. Regression analysis was used to estimate flow at the Joe Bay creeks from June 1999 to April 2000. The R2 values for the estimated flow at eight Joe Bay creeks ranged between 0.51 and 0.93. From June 1999 to April 2000, flow volumes to eastern and western Joe Bay equaled 6.8 x 107m3 and 5.6 x 107 m3 respectively; flow into eastern Joe Bay was 21 percent greater than flow into western Joe Bay. Maximum freshwater discharge to Florida Bay occurred following Tropical Storm Harvey and Hurricane Irene, which occurred on September 21 1999, and October 15, 1999, respectively. Flow into western Joe Bay (3.5 x 107 m3) during the storms was 26 percent greater than flow into eastern Joe Bay (2.7 x 107 m3). However, dry season flow (January to April 2000) into eastern Joe Bay (2.6 x 107 m3) which was supplied primarily by the C-111 Canal, was much greater than flow into western Joe Bay (2.5 x 106 m3). Thus, the total flow into eastern Joe Bay exceeded total flow into western Joe Bay, even though western Joe Bay received more freshwater during storm events. During the storms, the S-197 structure was opened to allow the C-111 Canal to discharge outside of Florida Bay. This reduced the overflow from the C-111 Canal to both Joe and northeastern Florida Bays. Hittle, C.D., Patino, E, and Zucker, M. 2000, Freshwater Flow From Estuarine Creeks into Northeastern Florida Bay. U.S. Geological Survey Water-Resources Investigation 01-4164,p.32.

  18. Freshwater autotrophic picoplankton: a review

    Directory of Open Access Journals (Sweden)

    John G. STOCKNER

    2002-02-01

    Full Text Available Autotrophic picoplankton (APP are distributed worldwide and are ubiquitous in all types of lakes of varying trophic state. APP are major players in carbon production in all aquatic ecosystems, including extreme environments such as cold ice-covered and/or warm tropical lakes and thermal springs. They often form the base of complex microbial food webs, becoming prey for a multitude of protozoan and micro-invertebrate grazers, that effectively channel APP carbon to higher trophic levels including fish. In this review we examine the existing literature on freshwater autotrophic picoplankton, setting recent findings and current ecological issues within an historic framework, and include a description of the occurrence and distribution of both single-cell and colonial APP (picocyanobacteria in different types of lakes. In this review we place considerable emphasis on methodology and ecology, including sampling, counting, preservation, molecular techniques, measurement of photosynthesis, and include extensive comment on their important role in microbial food webs. The model outlined by Stockner of an increase of APP abundance and biomass and a decrease of its relative importance with the increase of phosphorus concentration in lakes has been widely accepted, and only recently confirmed in marine and freshwater ecosystems. Nevertheless the relationship which drives the APP presence and importance in lakes of differing trophic status appears with considerable variation so we must conclude that the success of APP in oligotrophic lakes worldwide is not a certainty but highly probable.

  19. Bioaccumulation factor of 137Cs in some marine biotas from West Bangka Indonesia

    International Nuclear Information System (INIS)

    Radionuclides may be released from nuclear facilities to the marine environment. Concentrations of radionuclides within marine biotic systems can be influenced by a number of factors, including the type of biota, its source, the radionuclide, and specific characteristics of the sampled specimens and the marine environment (salinity, etc.). The bioconcentration factor for a marine organism is the ratio of the concentration of a radionuclide in that organism to the concentration found in its marine water environment - under conditions of equilibrium. Information on the bioaccumulation of Cs-137 in marine organisms is required to risk assessment evaluates the potential risks to human health. Bioaccumulation of Cs was investigated in marine biota from west Bangka such as Marine cat fish (Arius thalassinus), Baramundi (Lates calcarifer), Mackerel (Scomberomorus commerson), Striped eel catfish (Plotosus lineatus), eel tailed fish (Euristhmus microceps), Yellowtail fusilier (Caesio erythrogaster), Coastal crab (Scylla sp), White shrimp (Penaeus merguiensis) and marine bivalve mollusk (Anadara granosa). Muscle of these marine biota, sediments and water were assayed for Cs-137 by HPGe gamma spectrometer. The bioaccumulation factor for fishes were calculated by ratio of concentration Cs-137 in muscle biota to the its concentration in water. The bioaccumulation factor for mollusks were calculates by ratio of concentration Cs-137 in muscle biota to the its concentration in sediments. The bioaccumulation factor were range 4.99 to 136.34

  20. The Trace Element Analysis in Freshwater Fish Species, Water and Sediment in Iyidere Stream (Rize-Turkey

    Directory of Open Access Journals (Sweden)

    Ugur Cevik

    2012-01-01

    Full Text Available Many environmental problems like dam construction, agricultural debris, flooding and industrial establishments threaten Iyidere stream (Rize, Turkey on the southeastern coast of the Black Sea (Turkey. The trace element concentrations in water, fish and sediments in Iyidere stream (Rize, Turkey were investigated in this study. The concentration of six different elements in ten freshwater fish species and sediment was determined using energy dispersive X-ray fluorescence method. A radioisotope excited X-ray fluorescence analysis using the method of multiple standard addition is applied for the elemental analysis of fish and sediments. Water samples for trace metals were analyzed using standard spectrophotometry methods. A qualitative analysis of spectral peaks showed that ten different freshwater fish samples (Chondrostoma colchicum, Chalcalburnus chalcoides, Salmo trutta labrax, Alburnoides bipunctatus, Leuciscus cephalus, Barbus taurus escherichia, Capoeta tinca, Neogobius kessleri, Rutilus frisii, Lampetra lanceolata and sediment contained phosphorus (P, sulphur (S, chlorine (Cl, potassium (K, calcium (Ca and titanium (Ti. Heavy metals as toxic elements for biota (Pb, Cd, Hg, Zn and Mn etc. were not detected in fish, water and sediments. Thus, It can be declared that freshwater fish of Iyidere does not contains health risks for consumers in terms of metal pollution.

  1. Radionuclides in biota collected near a dicalcium phosphate plant, southern Catalonia, Spain

    International Nuclear Information System (INIS)

    Industrial waste containing radioactive U-decay series isotopes was released into the Ebro River, Spain, over a period of >20 years from a dicalcium phosphate (DCP) plant. This release raised activities of several natural radionuclides (e.g. 238U, 234U, 230Th, 232Th and 226Ra) in biota taken from the area near the DCP plant. Plants and animals selected for this study included the green algae (Cladophora glomerata), the blue mussel (Mytilus edulis), the zebra mussel (Dreissena polymorpha) and the scavenger catfish (Silurus glanis) because they are all common in the area. Multiple sampling points were chosen for this study: (1) a site in the Riba-Roja Reservoir, above the DCP plant's area of influence, (2) four sites in the area surrounding the DCP plant, close to the town of Flix, and (3) a location in the Ebro Delta Estuary in Fangar Bay. Significant differences in the activities (in Bq kg-1 of dry weight) for the radioisotopes included in this study among samples were attributed to sample location and the species evaluated. For instance, relatively high activities for uranium and radium were obtained in algae collected around the DCP plant, compared to results obtained for algae samples taken from the unimpacted Riba-Roja Reservoir. In contrast, for zebra mussels, enhanced activities were observed for all radionuclides and, in particular, for thorium and radium isotopes within the area of influence. Among catfish samples, activity values from different locations were not significantly different, though slightly higher activities were observed at the sampling point just downstream of the DCP factory. (author)

  2. Survey for contaminants in sediments and fish at selected sites on the Illinois River and tributaries

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — A basinwide survey of contaminants in sediments and biota at several locations on the Illinois River and selected tributaries was conducted during the 1989 field...

  3. Environmental Contaminants Monitoring in Selected Wetlands of Wyoming: Biologically Active Elements Study

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Sediment, water and biota were collected from selected wetlands in Wyoming for the Biologically Active Elements BAE Study in 1988, 1989 and 1990 to identify...

  4. The freshwater reservoir effect in radiocarbon dating

    DEFF Research Database (Denmark)

    Philippsen, Bente

    2013-01-01

    The freshwater reservoir effect can result in anomalously old radiocarbon ages of samples from lakes and rivers. This includes the bones of people whose subsistence was based on freshwater fish, and pottery in which fish was cooked. Water rich in dissolved ancient calcium carbonates, commonly known as hard water, is the most common reason for the freshwater reservoir effect. It is therefore also called hardwater effect. Although it has been known for more than 60 years, it is still less well-recognized by archaeologists than the marine reservoir effect. The aim of this study is to examine the order of magnitude and degree of variability of the freshwater reservoir effect over short and long timescales. Radiocarbon dating of recent water samples, aquatic plants, and animals, shows that age differences of up to 2000 14C years can occur within one river. The freshwater reservoir effect has also implications for radiocarbon dating of Mesolithic pottery from inland sites of the Ertebølle culture in Northern Germany. The surprisingly old ages of the earliest pottery most probably are caused by a freshwater reservoir effect. In a sediment core from the Limfjord, northern Denmark, the impact of the freshwater reservoir effect on radiocarbon dating in an estuarine environment is examined. Here, freshwater influence causes reservoir ages to vary between 250 and 700 14C years during the period 5400 BC - AD 700. The examples in this study show clearly that the freshwater reservoir effect can seriously corrupt radiocarbon dating at inland sites. Reservoir effects should therefore be considered whenever food remains on pottery or the bones of omnivores are radiocarbon dated - irrespective of the site’s distance to the coast.

  5. Dynamic modelling of radionuclide uptake by marine biota: application to the Fukushima nuclear power plant accident.

    Science.gov (United States)

    Vives I Batlle, Jordi

    2016-01-01

    The dynamic model D-DAT was developed to study the dynamics of radionuclide uptake and turnover in biota and sediments in the immediate aftermath of the Fukushima accident. This dynamics is determined by the interplay between the residence time of radionuclides in seawater/sediments and the biological half-lives of elimination by the biota. The model calculates time-variable activity concentration of (131)I, (134)Cs, (137)Cs and (90)Sr in seabed sediment, fish, crustaceans, molluscs and macroalgae from surrounding activity concentrations in seawater, with which to derive internal and external dose rates. A central element of the model is the inclusion of dynamic transfer of radionuclides to/from sediments by factorising the depletion of radionuclides adsorbed onto suspended particulates, molecular diffusion, pore water mixing and bioturbation, represented by a simple set of differential equations coupled with the biological uptake/turnover processes. In this way, the model is capable of reproducing activity concentration in sediment more realistically. The model was used to assess the radiological impact of the Fukushima accident on marine biota in the acute phase of the accident. Sediment and biota activity concentrations are within the wide range of actual monitoring data. Activity concentrations in marine biota are thus shown to be better calculated by a dynamic model than with the simpler equilibrium approach based on concentration factors, which tends to overestimate for the acute accident period. Modelled dose rates from external exposure from sediment are also significantly below equilibrium predictions. The model calculations confirm previous studies showing that radioactivity levels in marine biota have been generally below the levels necessary to cause a measurable effect on populations. The model was used in mass-balance mode to calculate total integrated releases of 103, 30 and 3 PBq for (131)I, (137)Cs and (90)Sr, reasonably in line with previous estimates. PMID:25773012

  6. Pathogenic agents in freshwater resources

    Science.gov (United States)

    Geldreich, Edwin E.

    1996-02-01

    Numerous pathogenic agents have been found in freshwaters used as sources for water supplies, recreational bathing and irrigation. These agents include bacterial pathogens, enteric viruses, several protozoans and parasitic worms more common to tropical waters. Although infected humans are a major source of pathogens, farm animals (cattle, sheep, pigs), animal pets (dogs, cats) and wildlife serve as significant reservoirs and should not be ignored. The range of infected individuals within a given warm-blooded animal group (humans included) may range from 1 to 25%. Survival times for pathogens in the water environment may range from a few days to as much as a year (Ascaris, Taenia eggs), with infective dose levels varying from one viable cell for several primary pathogenic agents to many thousands of cells for a given opportunistic pathogen.As pathogen detection in water is complex and not readily incorporated into routine monitoring, a surrogate is necessary. In general, indicators of faecal contamination provide a positive correlation with intestinal pathogen occurrences only when appropriate sample volumes are examined by sensitive methodology.Pathways by which pathogens reach susceptible water users include ingestion of contaminated water, body contact with polluted recreational waters and consumption of salad crops irrigated by polluted freshwaters. Major contributors to the spread of various water-borne pathogens are sewage, polluted surface waters and stormwater runoff. All of these contributions are intensified during periods of major floods. Several water-borne case histories are cited as examples of breakdowns in public health protection related to water supply, recreational waters and the consumption of contaminated salad crops. In the long term, water resource management must focus on pollution prevention from point sources of waste discharges and the spread of pathogens in watershed stormwater runoff.

  7. Modeling ecosystem processes with variable freshwater inflow to the Caloosahatchee River Estuary, southwest Florida. I. Model development

    Science.gov (United States)

    Buzzelli, Christopher; Doering, Peter H.; Wan, Yongshan; Sun, Detong; Fugate, David

    2014-12-01

    Variations in freshwater inflow have ecological consequences for estuaries ranging among eutrophication, flushing and transport, and high and low salinity impacts on biota. Predicting the potential effects of the magnitude and composition of inflow on estuaries over a range of spatial and temporal scales requires reliable mathematical models. The goal of this study was to develop and test a model of ecosystem processes with variable freshwater inflow to the sub-tropical Caloosahatchee River Estuary (CRE) in southwest Florida from 2002 to 2009. The modeling framework combined empirically derived inputs of freshwater and materials from the watershed, daily predictions of salinity, a box model for physical transport, and simulation models of biogeochemical and seagrass dynamics. The CRE was split into 3 segments to estimate advective and dispersive transport of water column constituents. Each segment contained a sub-model to simulate changes in the concentrations of organic nitrogen and phosphorus (ON and OP), ammonium (NH4+), nitrate-nitrite (NOx-), ortho-phosphate (PO4-3), phytoplankton chlorophyll a (CHL), and sediment microalgae (SM). The seaward segment also had sub-models for seagrasses (Halodule wrightii and Thalassia testudinum). The model provided realistic predictions of ON in the upper estuary during wet conditions since organic nitrogen is associated with freshwater inflow and low salinity. Although simulated CHL concentrations were variable, the model proved to be a reliable predictor in time and space. While predicted NOx- concentrations were proportional to freshwater inflow, NH4+ was less predictable due to the complexity of internal cycling during times of reduced freshwater inflow. Overall, the model provided a representation of seagrass biomass changes despite the absence of epiphytes, nutrient effects, or sophisticated translocation in the formulation. The model is being used to investigate the relative importance of colored dissolved organic matter (CDOM) vs. CHL in submarine light availability throughout the CRE, assess if reductions in nutrient loads are more feasible by controlling freshwater quantity or N and P concentrations, and explore the role of inflow and flushing on the fates of externally and internally derived dissolved and particulate constituents.

  8. Best Management Practices for Freshwater Pond Aquaculture

    Science.gov (United States)

    This chapter in the book “Environmental Best Management Practices for Aquaculture” describes freshwater pond aquaculture systems and management practices to reduce environmental impacts of pond aquaculture. Pond aquaculture systems for channel catfish, crawfish, baitfish, hybrid striped bass, and o...

  9. Management of freshwater invasive alien species.

    Czech Academy of Sciences Publication Activity Database

    Francis, R. A.; Pyšek, Petr

    London : Earthscan, 2012 - (Francis, R.), s. 435-446 ISBN 978-1-84971-228-6 Institutional support: RVO:67985939 Keywords : biological invasions * management * freshwater habitats Subject RIV: EF - Botanics

  10. Effects of pollution on freshwater fish

    International Nuclear Information System (INIS)

    Studies of the effects of pollution on freshwater fish are reviewed. Subjects include: inorganic industrial pollutants, man-made disturbances and radioactive pollutants. Topics include uptake distribution, retention, mortality, and lethal doses

  11. Xenobiotics in freshwater streams of Hesse, Germany

    OpenAIRE

    Quednow, Kristin

    2009-01-01

    The present study was elaborated within the scope of the INTAFERE (Integrated Analysis of Mobile Organic Foreign Substances in Rivers) project which investigates the occurrence of xenobiotics in small freshwater streams with particular consideration of social impact factors. The aim of this study is to investigate the seasonal and spatial variance of organic micropollutants in small fresh water streams and to identify possible sources and sinks. Therefore four small freshwater river systems i...

  12. Freshwater fishes of Tsitsikamma National Park

    OpenAIRE

    I.A. Russell

    2002-01-01

    This study aimed to determine the distribution and relative abundance of freshwater fishes in the Tsitsikamma National Park. Fish assemblages in six river systems were sampled in 2001, with a total of 323 fish from eight species recorded. Indigenous fish collected included four freshwater species (Pseudobarbus afer, Pseudobarbus tenuis, Sandelia capensis, Anguilla mossambica), three estuarine species (Monodactylus falciformis, Caffrogobius gilchristi, Myxus cape...

  13. Monitoring endangered freshwater biodiversity using environmental DNA

    DEFF Research Database (Denmark)

    Thomsen, Philip Francis; Kielgast, Jos; Iversen, Lars L.; Wiuf, Carsten Henrik; Rasmussen, Morten; Gilbert, M Thomas P; Orlando, Ludovic Antoine Alexandre; Willerslev, Eske

    2012-01-01

    Freshwater ecosystems are among the most endangered habitats on Earth, with thousands of animal species known to be threatened or already extinct. Reliable monitoring of threatened organisms is crucial for data-driven conservation actions but remains a challenge owing to nonstandardized methods that depend on practical and taxonomic expertise, which is rapidly declining. Here, we show that a diversity of rare and threatened freshwater animals-representing amphibians, fish, mammals, insects and c...

  14. Ecology of freshwater mussels in disturbed environments

    OpenAIRE

    Österling, Martin

    2006-01-01

    The number of species extinctions is increasing at an alarming rate. Long-lived freshwater mussels of the order Unionoida, which include a parasitic stage on a host fish, are highly threatened. Habitat degradation by turbidity and sedimentation is thought to be one major reason for their decline. The objective of this thesis was to examine recruitment patterns and identify the causes of the lack of recruitment in the threatened unionoid freshwater pearl mussel (Margaritifera margaritifera). I...

  15. Observation of radionuclides in marine biota off the coast of Fukushima prefecture after TEPCO's Fukushima Daiichi Nuclear Power Plant accident

    International Nuclear Information System (INIS)

    Monitoring and surveying radioactivity in seawater and biota in the marine environment off the coast of Fukushima prefecture in the Pacific are important for understanding the dispersion of artificial radionuclides after TEPCO's Fukushima Daiichi Nuclear Power Plant (F1NPP) accident. Marine biota were collected in the coastal area of Fukushima prefecture after this accident due to investigate the activities of 134Cs, 137Cs, and 110mAg in marine biota, including not only fish and shellfish but also benthos. It is well known that 108mAg, one of the radioactive isotopes of Ag, was observed in some kinds of squid and octopus before this accident. As the results, 110mAg was observed in many kinds of marine biota off the coastal area of Fukushima. It is suggested that rapid change in the radioactivities in seawater, resuspension of particles from sediments and food chain effects led to high radionuclide activities in marine biota after this accident. (author)

  16. Freshwater Commercial Bycatch: an Understated Conservation Problem

    Energy Technology Data Exchange (ETDEWEB)

    Raby, Graham D.; Colotelo, Alison HA; Blouin-Demers, Gabriel; Cooke, Steven J.

    2011-04-01

    Commercial fisheries bycatch in marine systems has been regarded as a global conservation concern by environmental groups, scientists, government, and the public for decades. Fortunately, some headway has been made to mitigate the negative impacts of bycatch in marine environments. In a survey of the literature, we found that despite freshwater commercial fisheries yields comprising 11% of the global commercial catch, bycatch research focusing on freshwater commercial fisheries represented only {approx}3% of the total bycatch literature. This paucity of research is particularly alarming given that freshwater animals and habitats are some of the world's most imperiled. The limited inland bycatch literature that does exist includes examples of population declines attributed to commercial bycatch (e.g., freshwater dolphins in the Yangtze River in China) and illustrates that in some systems bycatch can be substantial (e.g., lake trout bycatch in the Laurentian Great Lakes). Encouraging results from the marine realm can serve as models for bycatch research in freshwater, and lead to measurable gains in conservation of freshwater ecosystems. We summarize existing work on inland bycatch in an effort to draw attention to this understated and understudied conservation problem.

  17. Toxicity of underground coal gasification condenser water and selected constituents to aquatic biota

    Energy Technology Data Exchange (ETDEWEB)

    DeGraeve, G.M.; Overgast, R.L.; Bergman, H.L.

    1980-01-01

    Graphs and tables are used to report the findings of a study on the effects of underground coal gasification condenser water on rainbow trout, fathead minnows, and Daphnia pulicaria. It was found that the condenser water is acutely toxic to all three species, and further studies with two of its constituents, phenol and ammonia, and a mixture of the two, showed that they react synergistically and may account for most of the acute toxicity of the condenser water.

  18. Effect of long term cropping hybrid sorrel (Rumex patientia x Rumex tianshanicus) on soil biota.

    Czech Academy of Sciences Publication Activity Database

    Hed?nec, Petr; Novotný, D.; Us?ak, S.; Honzík, R.; Vá?a, V.; Pet?íková, V.; Frouz, Jan

    2015-01-01

    Ro?. 78, July (2015), s. 92-98. ISSN 0961-9534 R&D Projects: GA MŠk(CZ) 7E08081 Institutional support: RVO:60077344 Keywords : basal soil respiration * composition of soil biota * hybrid sorrel * microbial biomass C * specific microbial respiration (qCO2) Impact factor: 3.394, year: 2014

  19. Investigation on applicability of Biota dose assessment model to Japanese environment

    International Nuclear Information System (INIS)

    We examined applicability of established assessment tools to Japanese environment, which are developed to evaluate radiological impact for biota. In this study, we chose two assessment tools, the one is RESRAD-BIOTA which was developed by US-DOE, and the other is ERICA assessment tools which developed by EURATOM. We considered paddy field as the typical Asian environment and used maximum of global fallout nuclide concentrations which were monitored in Joetsu. From our trial calculation for general screening, Tier 1 of ERICA suggested that concentration of 137Cs in aquatic systems is exceeded the screening level. On the other hand, RESRAD-BIOTA, concentration of 90Sr, and terrestrial systems in ERICA were less than screening levels. Thus, we proceeded to apply the ERICA Tier 2 using with same parameter set in Tier 1, and found that each species was not exceeded the screening level. Finally, we calculated dosimetries of considerable species living in paddy field. We tested both tools and we adopted ERICA because of flexibility in body dimensions of adding organism. From our calculation, we concluded that graded approaches which are adopted in RESRAD-BIOTA and ERICA are effective to apply Japanese environment. (author)

  20. Global priorities for conservation of threatened species, carbon storage, and freshwater services : scope for synergy?

    DEFF Research Database (Denmark)

    Larsen, Frank Wugt; Londoño-Murcia, Maria C.

    2011-01-01

    The potential of global biodiversity conservation efforts to also deliver critical benefits, such as carbon storage and freshwater services, is still unclear. Using spatially explicit data on 3,500 range-restricted threatened species, carbon storage, and freshwater provision to people, we conducted tradeoff analyses, explicitly addressing both biodiversity and ecosystem services in selection of priority areas, to explore the potential for aligning these objectives. These analyses revealed a promising scope for aligning objectives, in particular for biodiversity and freshwater, which is not evident from previous studies that merely analyzed overlap of biodiversity and ecosystem services derived for each objective independently. However, this alignment is not complete. By revealing important synergies and tradeoffs among services, these analyzes suggest particular regions and service combinations for which spatial planning and appropriate conservation mechanisms (e.g., payments for ecosystem services) can be used to realize synergies and mitigate tradeoffs.

  1. COMMUNITY DEVELOPMENT IN FRESHWATER MICROCOSMS

    Energy Technology Data Exchange (ETDEWEB)

    Rees, John T.

    1978-01-01

    Two cylindrical freshwater microcosms with a volume of 700 {ell} were maintained under controlled laboratory conditions for 190 days. The two microcosms were identical with regard to initial chemical composition and biological inocula, with the exceptions that in one microcosm (designated Tank 2) mosquitofish (Gambusia) and herbivorous catfish (Placostomas) were added. Three distinct communities developed in the tanks: (1) a phytoplankton-zooplankton assemblage and (2) two periphyton-zoobenthos communities associated with the sides and bottom of the tank, respectively. Community development and successional patterns were similar in both tanks. Major differences between the tanks involved timing of succession of the zooplankton and zoobenthos, attributable to predation by fish, principally Gambusia. A major drawback for these microcosms as use for experimental analogs such as lakes was a luxuriant periphyton growth which eventually overwhelmed the biomass of the system. The tanks displayed a degree of successional replicability, a large number of species, and a diversity of community development. Microcosms of this size could find use as experimental systems for higher level trophic manipulation and observation of life cycles not amenable to field studies.

  2. Ultimobranchial gland of freshwater catfish, Heteropneustes fossilis, in response to calcitonin administration

    Scientific Electronic Library Online (English)

    Ajai K., Srivastav; Sarita, Singh; Diwakar, Mishra; S.K., Srivastav.

    2009-12-01

    Full Text Available The absence o!!f a hypocalcemic effect of calcitonin (CT) in fishes has been suggested due to exceedingly high plasma levels of CT; the fish may be saturated with respect of circulating CT and therefore unable to respond to exogenously administered CT. Earlier it has been suggested that a hypocalcem [...] ic action of injected CT may be obscured by changes in the release of endogenous CT and other calcium regulating hormones. In this study we have used artificial freshwater, calcium-deficient freshwater and calcium-rich freshwater and injected the fish with CT. The aim behind selecting these media were (i) in calcium-deficient medium there would be reduced circulating levels of CT, (ii) in calcium-rich medium there would be diminished secretion of prolactin (this hormone is hypercalcemic in fish), and (iii) by keeping the fish in calcium-rich medium we can test the antihypercalcemic action of CT. Moreover, the present study would reveal the changes in the ultimobranchial gland (UBG) after keeping the fish in all the above three media and/or injecting the fish with CT. Freshwater catfish, Heteropneustes fossilis, were administered intraperitoneally daily with vehicle or 0.5 U/100g body wt of salmon calcitonin (CT) and kept in artificial freshwater, calcium-rich freshwater and calcium-deficient freshwater for 10 days. Blood samples were collected on 1, 3, 5, and 10 days following the treatment and analyzed for serum calcium levels. The ultimobranchial gland (UBG) was also fixed for histological studies on these intervals. In artificial freshwater there was no change in the serum calcium levels of calcitonin-injected fish. The ultimobranchial gland of calcitonin-injected fish exhibited a progressive decrease in the nuclear volume from day 5 onwards. On day 10 vacuolization in the gland was also noticed. In vehicle-injected fish (control) kept in calcium-rich freshwater hypercalcemia has been noticed which persists till the end of the experiment. In calcitonin-treated fish maintained in calcium-rich freshwater there is no change in serum calcium level as compared to vehicle-injected fish. In vehicle-injected fish the UBG depicts decreased staining response and increased nuclear volume at day 5. On day 10 the nuclear volume is further increased and few degenerating cells have been noticed. Calcitonin fails to induce any histological change in the UBG as compared to control. In vehicle-injected fish kept in calcium-deficient freshwater the serum calcium levels decrease from day 1 to day 3. The levels exhibit hypercalcemia on day 10. CT treatment to the fish kept in calcium-deficient freshwater evokes a decrease in the calcium levels on day 1 and day 3. A significant hypercalcemia has been noticed on day 5 and day 10. In vehicle-injected fish kept in calcium-deficient freshwater the UBG reveals a decreased staining response on day 10. In CT-injected fish maintained in calcium-deficient freshwater the UBG depicts an increased nuclear volume and few exhausted cells on day 10. It can be concluded that CT can provoke hypocalcemia only when the fish is kept in medium which reduces the circulating levels of this hormone. The UBG of the fish kept in different calcemic media responded in a manner to indicate that it produces hypocalcemic factor - CT.

  3. An assessment of mercury in waters, sediments and biota of Vermont and New Hampshire lakes [Draft

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The present report summarizes findings of a threeyear field study of mercury in freshwater lakes of Vermont and New Hampshire. The study was undertaken jointly by...

  4. Towards a universal sampling protocol for soil biotas in the humid tropics / Em direção a um protocolo universal de amostragem de biotas do solo nos trópicos úmidos

    Scientific Electronic Library Online (English)

    David Edward, Bignell.

    2009-08-01

    Full Text Available Este trabalho faz uma revisão dos métodos de inventariado da biota edáfica nos trópicos úmidos para documentar a (hipotética) perda de biodiversidade do solo associada ao desmatamento e à intensificação agrícola nas margens de florestas. A biota foi agrupada em oito categorias, cada uma corresponden [...] te a um grande grupo funcional considerado importante ou essencial para a função do solo. Um inventário cuidadoso dos organismos do solo pode auxiliar a gestão de ecossistemas e a sustentabilidade da produção agrícola. As vantagens e desvantagens de métodos de amostragem baseados em transectos ou em malhas são discutidas e ilustradas por protocolos publicados, desde o original "transeto TSBF", passando por versões desenvolvidas para o projeto "Alternatives to Slash-and-Burn" (ASB), até o esquema final (com suas variantes) adotado pelo projeto "Conservation and Sustainable Management of Below-ground Biodiversity" (CSM-BGBD). Considerou-se a importância de repetição de amostras e argumenta-se que os novos protocolos de amostragem são: inclusivos, ou seja, desenhados para amostrar os oito grupos bióticos ao mesmo tempo no campo; dimensionados espacialmente, pois fornecem dados de biodiversidade nos níveis de lugar, localidade, paisagem e região e associam esses dados ao uso e cobertura do solo; e estatisticamente robustos, como evidenciado por uma aleatorização parcial das localizações dos lotes de amostragem. Abstract in english This paper reviews the methods for the inventory of below-ground biotas in the humid tropics, to document the (hypothesized) loss of soil biodiversity associated with deforestation and agricultural intensification at forest margins. The biotas were grouped into eight categories, each of which corres [...] ponded to a major functional group considered important or essential to soil function. An accurate inventory of soil organisms can assist in ecosystem management and help sustain agricultural production. The advantages and disadvantages of transect-based and grid-based sampling methods are discussed, illustrated by published protocols ranging from the original "TSBF transect", through versions developed for the alternatives to Slash-and-Burn Project (ASB) to the final schemes (with variants) adopted by the Conservation and Sustainable Management of Below-ground Biodiversity Project (CSM-BGBD). Consideration is given to the place and importance of replication in below-ground biological sampling and it is argued that the new sampling protocols are inclusive, i.e. designed to sample all eight biotic groups in the same field exercise; spatially scaled, i.e. provide biodiversity data at site, locality, landscape and regional levels, and link the data to land use and land cover; and statistically robust, as shown by a partial randomization of plot locations for sampling.

  5. Radiation dose and countermeasure model for a decision support system on freshwater ecosystems contaminated with radionuclides

    International Nuclear Information System (INIS)

    With the participation of several European institutions The MOIRA project (A MOdel based computerised system for management support to Identify optimal remedial strategies for Restoring radionuclide contaminated Aquatic ecosystems, European Commission contract FI4P-CT96-0036) has developed a computerised Decision Support System that will allow decision makers to choose optimal intervention strategies for freshwater ecosystems with different radioactive contamination scenarios. An important factor for the decision analysis is the radiation dose resulting to humans and biota from the contamination. Not less important is to quantify the impact that intervention strategies may have on the potential resulting dose. With that aim, the system is incorporating a dose and countermeasure model, very flexible, that is able to estimate dose to the critical individuals and collective dose to the affected population, as well as maximum dose to fish species, representative of the threats to biota from radioactive contamination of water bodies. The model main characteristics are: Applicable to different water bodies (in principle lakes and rivers) contaminated with Cs-137 and/or Sr-90. The model is driven by the time series of radionuclide concentrations in the water, in the bottom sediments and fish (predator and prey species), which are the output from other environmental models of the MOIRA system. Main sub-models: individual and collective external dose and ingestion dose for 6 age groups; dose to fish. Countermeasures. External dose assessment takes into account exposure pathways as direct dose from the water body and dose from the shoreline deposits. The model makes use of external dose factors available in the literature, shielding factors applicable for the different situations considered, and mean exposure times. Countermeasures modelled: restriction of access to contaminated areas. For internal dose from ingestion, the exposure pathways considered are: ingestion of water, consumption of fish (prey, predator), consumption of crops irrigated by contaminated water (5 categories), and consumption of milk and meat from livestock (cow, sheep, and pig) watered with contaminated water or fed with contaminated crops. Countermeasures modelled: restrictions to water and food consumption, and restrictions to water use for irrigation, based on contamination levels or on user defined periods. Models for calculating concentrations of radionuclides in crops, soil and livestock products are based on a dynamic compartment structure based on validated models described in the specialised literature. The paper makes a summary description of the model, its applications and importance in a Decision Support System for the restoration of contaminated freshwater ecosystems, based on a Multiattribute approach. (author)

  6. 137Cs in freshwater fish in Finland

    International Nuclear Information System (INIS)

    The paper deals with an evaluation of the importance of Finnish freshwater fish as a source of 137Cs in the diet. Freshwater fish were analysed for 137Cs in 1982. The 137Cs concentration factors from water to edible fish were determined for the same year. The evaluation is based on an extensive surface water investigation performed from 1965 to 1967. Along with the continuous fallout monitoring since the beginning of the 1960'es, this material makes it possible to valuate the 137Cs levels in surface water right up to the 1980'es. In 1982 the Finns received an average of 90 Bq 137Cs from freshwater fish. This dose constitutes a quarter of the 137Cs uptake from the total food consumtion in Finland in 1982

  7. Ecosystem Services : In Nordic Freshwater Management

    DEFF Research Database (Denmark)

    Magnussen, Kristin; Hasler, Berit

    2014-01-01

    Human wellbeing is dependent upon and benefit from ecosystem services which are delivered by well-functioning ecosystems. Ecosystem services can be mapped and assessed consistently within an ecosystem service framework. This project aims to explore the use and usefulness of the ecosystem service framework in freshwater management, particularly water management according to the Water Framework Directive (WFD). There are several examples of how ecosystem services have been used in WFD related studies in all the Nordic countries. Most of them involve listing, describing and categorizing freshwater ecosystem services, while there are few comprehensive Cost Benefit Analyses and analyses of disproportionate costs that apply this framework. More knowledge about ecosystem services and the value of ecosystem services for freshwater systems is needed.

  8. Freshwater exposure pathways in the Nordic countries

    International Nuclear Information System (INIS)

    The report relates to a subproject under a Nordic project called ''Large reactor accidents - consequences and mitigating actions''. The report summarizes information available, primarily in the Nordic countries, on freshwater exposure pathways. Experimental and theoretical data concerning the deposition and run-off of the nuclides *sp90*Sr and*Sp137*Cs is presented. Internal exposure via drinking water and freshwater fish is dealt with, as well as external exposure due to swimming, boating, contact with fishing utensils and use of beach areas. In addition is exposure via irrigated agricultural products considered. (RF)

  9. Radioisotopes speciation and biological availability in freshwater

    International Nuclear Information System (INIS)

    Supposed speciation can increase by one order of magnitude the biological availability of actinides in freshwater, such an increase being exceptional. Raw modeling purposes can usefully be satisfied with the existing data. More precise information is necessary for exact estimations of radioactivity hazards in case of severe local radiocontaminations in specific freshwater bodies. This symposium thus is very useful to provide information on the link between speciation and biological and ecotoxicological end-effects, including the metabolic pathways of different physiochemical forms of a specific radionuclide. Bioaccessability of organisms for nuclides has to be checked as carefully as bioavailability of nuclides. (author)

  10. Effects of Pollution on Freshwater Organisms.

    Science.gov (United States)

    Choudri, B S; Baawain, Mahad

    2015-10-01

    This review includes works published in the general scientific literature during 2014 on the effects of anthropogenic pollutants on freshwater organisms. It begins with two broad sections: research reviews and broad field studies and surveys. This is followed by reviews of research categorized in sections to reflect the pollutant class. These sections include wastewater, stormwater and non-point source pollution, nutrients, sediment cap materials and suspended clays, botanical extracts, surfactants, metals, persistent organic pollutants, pharmaceuticals, endocrine disruptors, pesticides, petroleum hydrocarbons and polycyclic aromatic hydrocarbons (PAHs), ionic liquids, and nanomaterials. The final section includes works describing innovations in the field of freshwater pollution research. PMID:26420103

  11. Sulfate reduction in freshwater peatlands

    Energy Technology Data Exchange (ETDEWEB)

    Oequist, M.

    1996-12-31

    This text consist of two parts: Part A is a literature review on microbial sulfate reduction with emphasis on freshwater peatlands, and part B presents the results from a study of the relative importance of sulfate reduction and methane formation for the anaerobic decomposition in a boreal peatland. The relative importance of sulfate reduction and methane production for the anaerobic decomposition was studied in a small raised bog situated in the boreal zone of southern Sweden. Depth distribution of sulfate reduction- and methane production rates were measured in peat sampled from three sites (A, B, and C) forming an minerotrophic-ombrotrophic gradient. SO{sub 4}{sup 2-} concentrations in the three profiles were of equal magnitude and ranged from 50 to 150 {mu}M. In contrast, rates of sulfate reduction were vastly different: Maximum rates in the three profiles were obtained at a depth of ca. 20 cm below the water table. In A it was 8 {mu}M h{sup -1} while in B and C they were 1 and 0.05 {mu}M h{sup -1}, respectively. Methane production rates, however, were more uniform across the three nutrient regimes. Maximum rates in A (ca. 1.5 {mu}g d{sup -1} g{sup -1}) were found 10 cm below the water table, in B (ca. 1.0 {mu}g d{sup -1} g{sup -1}) in the vicinity of the water table, and in C (0.75 {mu}g d{sup -1} g{sup -1}) 20 cm below the water table. In all profiles both sulfate reduction and methane production rates were negligible above the water table. The areal estimates of methane production for the profiles were 22.4, 9.0 and 6.4 mmol m{sup -2} d{sup -1}, while the estimates for sulfate reduction were 26.4, 2.5, and 0.1 mmol m{sup -2} d{sup -1}, respectively. The calculated turnover times at the sites were 1.2, 14.2, and 198.7 days, respectively. The study shows that sulfate reducing bacteria are important for the anaerobic degradation in the studied peatland, especially in the minerotrophic sites, while methanogenic bacteria dominate in ombrotrophic sites Examination paper. 67 refs, 6 figs, 3 tabs

  12. CROATIAN FRESHWATER FISHERIES IN 1997

    Directory of Open Access Journals (Sweden)

    Mirko Turk

    1998-10-01

    Full Text Available Data on the production and fish catch according to species, on the surface of the fish ponds, on the means of fish catching and on the distribution of the production and the catch in 1997 is presented. The surface area used for production of fish has decreased for 836 ha or 8.40%. The total fish amount was bigger for 477 tons, or 10,52%. The feeding coefficient is 2.6 kg decreased 35% for in comparison to the bigger compared to the previous year. The amount of the fertilizer used is bigger for 37.30%. The fry carp growing ponds make up 6.50% of the total fish pond surfaces, the young carp ponds 22.04/0, and the ponds with consumption fish 70.31%. The total amount in the carp ponds was 446 kg/ha, and in the trout ponds it was 160.8 tons/ha. The most produced fish species is the carp with 79.32%, followed by the trout with 11.50%, the herbivorous fish with 4.25%, while all the other fish species make up 4.93% of the entire production. In the structure of herbivorous fish the grass carp is leading with 69,23%, followed by the big head carp with 29.74% and the silver carp with 1.03%. Compared to the previous year the production of the carp, grass carp and tench is increased. Fish catch in open waters has decreased by 5.53% in comparison to the previous year. In the production and catch of the total freshwater fish, carp made up 75.34%, herbivorous fish made up 3.89%, trout 10.66%, sheat fish, pike perch and pike 2.70% and all other fish species 7.41%. As far as the distribution of production and catch of fish is concerned, 52,80% were sold on the market, 37.94% were used for reproduction (stocking the fish farms, mortality was 1.43%, and for personal use (sports fishing 7.83%. The number of fisheries workers has decreased for 8.17%, and the production per worker is bigger for 22.25%, compared to the previous year. Average production per worker was 7.17% tons of fish.

  13. CROATIAN FRESHWATER FISHERIES IN 1996.

    Directory of Open Access Journals (Sweden)

    Mirko Turk

    1997-07-01

    Full Text Available Data on the production and fish catch according to species, on the surface of the fish ponds, on the means of fish catching and on the distribution of the production and the catch in 1996 is presented. The surface area used for production of fish has decreased by 1357 ha or 11.99%. The total fish amount has decreased by 1,921.00 tons or 29.76%. The feeding coefficient is 4 kg (33.33% bigger compared to the previous year. The amount of the fertilizer used has decreased by 18.79%. The fry carp growing ponds make up 5.99% of the total fish pond surfaces, the young carp ponds 21.13%, and the ponds with consumption fish 71.53%. The total fish amount in the carp ponds was 376 kg/ha, and in the trout ponds it was 146.6 tons/ha. The most produced fish species is the carp with 82.21 %, followed by the trout with 8.57%, the herbivorous fish with 4.78%, while all the other fish species make up 4.44% of the entire production. In the structure of herbivorous fish the grass carp is leading with 64,28%, followed by the big head carp with 26.02% and the silver carp with 9.70%. Compared to the previous year the production of the trout and tench has somewhat increased, while the production of all the other species of fish has decreased. Fish catch in open waters has increased by 19.23% in comparison to the previous year. In the production and catch of the total freshwater fish, carp made up 77.46%, the herbivorous fish made up 4.32%, trout 4.32%, sheat fish, pike perch and pike 2.99% and all other fish species 7.36%. As far as the distribution of production and catch is concerned, 46.91% were sold on the market, 39.19% were used for reproduction (stocking the fish farms, mortalities were 6.23%, and for personal use (sports fishing 7.67% was used. The number of fisheries workers has decreased by 17.75%, and the production per worker has also decreased by 26.62%, compared to the previous year. Average production per worker was 5.87 tons of fish.

  14. Sulfate reduction in freshwater peatlands

    International Nuclear Information System (INIS)

    This text consist of two parts: Part A is a literature review on microbial sulfate reduction with emphasis on freshwater peatlands, and part B presents the results from a study of the relative importance of sulfate reduction and methane formation for the anaerobic decomposition in a boreal peatland. The relative importance of sulfate reduction and methane production for the anaerobic decomposition was studied in a small raised bog situated in the boreal zone of southern Sweden. Depth distribution of sulfate reduction- and methane production rates were measured in peat sampled from three sites (A, B, and C) forming an minerotrophic-ombrotrophic gradient. SO42- concentrations in the three profiles were of equal magnitude and ranged from 50 to 150 ?M. In contrast, rates of sulfate reduction were vastly different: Maximum rates in the three profiles were obtained at a depth of ca. 20 cm below the water table. In A it was 8 ?M h-1 while in B and C they were 1 and 0.05 ?M h-1, respectively. Methane production rates, however, were more uniform across the three nutrient regimes. Maximum rates in A (ca. 1.5 ?g d-1 g-1) were found 10 cm below the water table, in B (ca. 1.0 ?g d-1 g-1) in the vicinity of the water table, and in C (0.75 ?g d-1 g-1) 20 cm below the water table. In all profiles both sulfate reduction and methane production rates were negligible above the water table. The areal estimates of methane production for the profiles were 22.4, 9.0 and 6.4 mmol m-2 d-1, while the estimates for sulfate reduction were 26.4, 2.5, and 0.1 mmol m-2 d-1, respectively. The calculated turnover times at the sites were 1.2, 14.2, and 198.7 days, respectively. The study shows that sulfate reducing bacteria are important for the anaerobic degradation in the studied peatland, especially in the minerotrophic sites, while methanogenic bacteria dominate in ombrotrophic sites Examination paper. 67 refs, 6 figs, 3 tabs

  15. Total petroleum hydrocarbons in edible marine biota from Northern Persian Gulf.

    Science.gov (United States)

    Nozar, Seyedeh Laili Mohebbi; Pauzi, Mohamad Zakaria; Salarpouri, Ali; Daghooghi, Behnam; Salimizadeh, Maryam

    2015-04-01

    To provide a baseline information for consumer's health, distribution of total petroleum hydrocarbons in 18 edible marine biota species from northern Persian Gulf was evaluated. The samples were purchased from fish market of Hormozgan Province, South of Iran. Marine biota samples included different species with various feeding habits and were analyzed based on ultraviolet florescence spectroscopy. Petroleum hydrocarbons showed narrow variation, ranging from 0.67 to 3.36 ?g/g dry weight. The maximum value was observed in silver pomfret. Anchovy and silver pomfret with the highest content of petroleum hydrocarbons were known as good indicator for oil pollution in the studied area. From public health point of view, the detected concentrations for total petroleum hydrocarbons were lower than hazardous guidelines. The results were recorded as background data and information in the studied area; the continuous monitoring of pollutants is recommended, according to the rapid extension of industrial and oily activities in Hormozgan Province. PMID:25819925

  16. A Kinetic-Allometric Approach to Predicting Tissue Radionuclide Concentrations for Biota

    Energy Technology Data Exchange (ETDEWEB)

    Higley, Kathryn A.(OREGON STATE UNIVERSITY); Domotor, S L.(DOE); Antonio, Ernest J.(BATTELLE (PACIFIC NW LAB))

    2003-06-06

    Allometry, or the biology of scaling, is the study of size and its consequences. It has become a useful tool for comparative phsiology. There are several allometric equations that relate body size to many parameters, including ingestion rate, lifespan, inhalation rate, home range and more. While these equations were originally derived from empirical observations, there is a growing body of evidence that these relationships have their origins in the dynamics of energy transport mechanisms. As part of an ongoing effort to assist the Department of Energy in developing generic methods for evaluating radiation dose to biota, we have examined the utility of applyig allometric techniques to predicting radionuclide tissue concentration across a large range of terrestrial and riparian species of animals. This particular study examined twenty-three elements. Initial investigations suggest that the allometric approach can provide a useful tool to derive limiting values of uptake and elimination factors for biota.

  17. Acute toxicity of heavy metals towards freshwater ciliated protists

    International Nuclear Information System (INIS)

    The acute toxicity of five heavy metals to four species of freshwater ciliates (Colpidium colpoda, Dexiotricha granulosa, Euplotes aediculatus, and Halteria grandinella) was examined in laboratory tests. After exposing the ciliates to soluble compound of cadmium, copper, chromium, lead, and nickel at several selected concentrations, the mortality rate was registered and the LC5 values (with 95% confidence intervals) were calculated. Large differences appeared in sensitivities of the four species to the metals. H. grandinella showed the highest sensitivity for cadmium (0.07 mg l-1, LC5) and lead (0.12 mg l-1, LC5), whilst E. aediculatus showed the highest sensitivity for nickel (0.03 mg l-1, LC5). The comparison with data obtained with other species indicate that Halteria grandinella and Euplotes aediculatus are excellent and convenient bioindicator for evaluating the toxicity of waters and wastewaters polluted by heavy metals. The short time (24 h) and simplicity of the test procedure enable this test to be used in laboratory studies. - Ciliated protozoa are suitable bioindicators of heavy metal pollution in freshwater environments

  18. Sustainable management and conservation of biota in agricultural soils of the Republic of Moldova

    OpenAIRE

    Senicovscaia, Irina

    2012-01-01

    In present research the ways and methods of the sustainable management and conservation of the soil biota in the modern agricultural ecosystems of the Republic of Moldova are considered. The database of invertebrates, microorganisms and enzymatic activities of different zonal soils in the long-term field experiments has been developed and constantly is updated with a view to the operative evaluation of the degradation processes and ecological effectiveness of the land management. The current ...

  19. A well-preserved aneuretopsychid from the Jehol Biota of China (Insecta, Mecoptera, Aneuretopsychidae)

    OpenAIRE

    Conrad Labandeira; ChungKun Shih; Dong Ren

    2011-01-01

    The Aneuretopsychidae is an unspeciose and enigmatic family of long-proboscid insects that presently consist of one known genus and three species from the Late Jurassic to Early Cretaceous of north-central Asia. In this paper, a new genus and species of fossil aneuretopsychid is described and illustrated, Jeholopsyche liaoningensis gen. et sp. n. Fossils representing this new taxon were collected from mid Early Cretaceous strata of the well known Jehol Biota in Liaoning Province, China. This ...

  20. The Soil Biota Composition along a Progressive Succession of Secondary Vegetation in a Karst Area

    OpenAIRE

    Jie ZHAO; Li, Shengping; He, Xunyang; Liu, Lu; Wang, Kelin

    2014-01-01

    Karst ecosystems are fragile and are in many regions degraded by anthropogenic activities. Current management of degraded karst areas focuses on aboveground vegetation succession or recovery and aims at establishing a forest ecosystem. Whether progressive succession of vegetation in karst areas is accompanied by establishment of soil biota is poorly understood. In the present study, soil microbial and nematode communities, as well as soil physico-chemical properties were studied along a progr...

  1. Pesticide Interactions with N source and Tillage: Effects on soil biota and ecosystem services

    DEFF Research Database (Denmark)

    Jensen, John; Petersen, Søren O; Elsgaard, Lars; Krogh, Paul Henning

    2014-01-01

    Pesticide effects on soil biota must be interpreted in the context of the specific management practice, including rotation, fertilization, tillage, and pest control. Tillage, foe example, has been shown to reduce earthworm populations by up to 80%, depending on timing and specific tillage technique. Such disturbances may fully or partly obscure the effects of pesticides. The direct effects of pesticides and other management factors and their interactions must, therefore, be quantified before int...

  2. Soil and soil biota in reclaimed and non-reclaimed post mining sites.

    Czech Academy of Sciences Publication Activity Database

    Frouz, Jan; Pižl, Václav; Elhottová, Dana

    Lexington : BLRS, 2006, s. 215-220. [Billings Land Reclamation Symposium /10./. Billings (US), 04.06.2006-08.06.2006] R&D Projects: GA ?R GA526/01/1055; GA ?R(CZ) GA526/06/0728; GA AV ?R 1QS600660505 Institutional research plan: CEZ:AV0Z60660521 Keywords : soil * soil biota * post mining sites Subject RIV: EH - Ecology, Behaviour

  3. Historical records of radioactive contamination in biota at the 200 Areas of the Hanford Site

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, A.R.; Markes, B.M.; Schmidt, J.W.; Shah, A.N.; Weiss, S.G.; Wilson, K.J.

    1994-06-01

    This document summarizes and reports a literature search of 85 environmental monitoring records of wildlife and vegetation (biota) at the 200 East Area and the 200 West Area of the Hanford Site since 1965. These records were published annually and provided the majority of the data in this report. Additional sources of data have included records of specific facilities, such as site characterization documents and preoperational environmental surveys. These documents have been released for public use. Records before 1965 were still being researched and therefore not included in this document. The intent of compiling these data into a single source was to identify past and current concentrations of radionuclides in biota at specific facilities and waste sites within each operable unit that may be used to help guide cleanup activities in the 200 Areas to be completed under the Comprehensive Environmental Response and Liability Act (CERCLA). The 200 East Area and 200 West Area were the locations of the Hanford Site separation and process facilities and waste management units. For the purposes of this document, a sample was of interest if a Geiger-Mueller counter equipped with a pancake probe-indicated beta/gamma emitting radioactivity above 200 counts per minute (cpm), or if laboratory radioanalyses indicated a radionuclide concentration equaled or exceeded 10 picocuries per gram (pCi/g). About 4,500 individual cases of monitoring for radionuclide uptake or transport in biota in the 200 Areas environs were included in the documents reviewed. About 1,900 (i.e., 42%) of these biota had radionuclide concentrations in excess of 10 pCi/g. These radionuclide transport or uptake cases were distributed among 45 species of wildlife (primarily small mammals and feces) and 30 species of vegetation. The wildlife species most commonly associated with radioactive contamination were the house mouse and the deer mouse and of vegetation species, the Russian thistle.

  4. Historical records of radioactive contamination in biota at the 200 Areas of the Hanford Site

    International Nuclear Information System (INIS)

    This document summarizes and reports a literature search of 85 environmental monitoring records of wildlife and vegetation (biota) at the 200 East Area and the 200 West Area of the Hanford Site since 1965. These records were published annually and provided the majority of the data in this report. Additional sources of data have included records of specific facilities, such as site characterization documents and preoperational environmental surveys. These documents have been released for public use. Records before 1965 were still being researched and therefore not included in this document. The intent of compiling these data into a single source was to identify past and current concentrations of radionuclides in biota at specific facilities and waste sites within each operable unit that may be used to help guide cleanup activities in the 200 Areas to be completed under the Comprehensive Environmental Response and Liability Act (CERCLA). The 200 East Area and 200 West Area were the locations of the Hanford Site separation and process facilities and waste management units. For the purposes of this document, a sample was of interest if a Geiger-Mueller counter equipped with a pancake probe-indicated beta/gamma emitting radioactivity above 200 counts per minute (cpm), or if laboratory radioanalyses indicated a radionuclide concentration equaled or exceeded 10 picocuries per gram (pCi/g). About 4,500 individual cases of monitoring for radionuclide uptake or transport in biota in the 200 Areas environs were included in the documents reviewed. About 1,900 (i.e., 42%) of these biota had radionuclide concentrations in excess of 10 pCi/g. These radionuclide transport or uptake cases were distributed among 45 species of wildlife (primarily small mammals and feces) and 30 species of vegetation. The wildlife species most commonly associated with radioactive contamination were the house mouse and the deer mouse and of vegetation species, the Russian thistle

  5. An adaptation of human food chain models to predicting internal exposure of biota: the Faster model

    International Nuclear Information System (INIS)

    There is an acknowledged lack of available data to derive parameters describing the transfer of many radionuclides from soil to wild species. Furthermore, many approaches to estimating the internal exposure of biota assume equilibrium transfer from soil to biota. However, as environmental impact assessments may need to be conducted for many scenarios (e.g. chronic or acute releases to air and ground waters) assumptions of equilibrium soil to biota transfer many be neither sufficient nor conservative. Much effort has previously been devoted to derive semi-mechanistic models to enable the transfer of radionuclides through human food chains to be predicted dynamically. A logical first step to addressing the data gaps in our ability to predict internal activity concentrations of biota is to consider adapting these models for wild species. Here we describe the development of a semi-mechanistic model to estimate activity concentrations in wild mammals by adaptation of existing human food chain models. Interception, weathering, plant uptake and soil migration parameters are derived from previously published models or collations such as IAEA Technical Report Series No. 364. Allometric relationships dependent on body mass are used to estimate wild animal parameters including, for most radionuclides, biological half-life. Comparison of predictions with observed data allows limited comment on the validity of model predictions. For instance, predicted Cs values are within observed ranges, and an increase in Cs activity concentrations from prey-carnivore as observed by many authors is predicted. Predicted values for 90Sr, 226Ra and U also appear reasonable whilst those for the actinide elements are low compared with the limited available data. To date a simple source-grass-herbivore-carnivore food chain has been considered; the potential for further development of the model is discussed. (author)

  6. Root responses to nutrients and soil biota: drivers of species coexistence and ecosystem productivity

    OpenAIRE

    Kroon, H., de; Hendriks, M.; van Ruijven, J; Ravenek, J.; Padilla, F.M.; Jongejans, E; E. J. W. Visser; Mommer, L.

    2012-01-01

    Summary 1. Although a major part of plant biomass is underground, we know little about the contribution of different species to root biomass in multispecies communities. We summarize studies on root dis- tributions and plant responses to species-specific soil biota and formulate three hypotheses to explain how root responses may drive species coexistence and ecosystem productivity. 2. Recent studies suggest that root growth of some species may be stimulated in species mixtures compared ...

  7. ANAEROBIC DIGESTION OF ANIMAL MANURE – IMPLICATIONS FOR CROP YIELDS AND SOIL BIOTA IN ORGANIC FARMING

    DEFF Research Database (Denmark)

    Johansen, Anders; Pommeresche, Reidun; Riely, Hugh; Løes, Anne-Kristin

    2015-01-01

    Anaerobic digestion of farmyard manures may help farmers to produce bioenergy instead of using fossil fuels, support cycling of nutrients and reduce greenhouse gas emission. However, compared to pristine slurry, digested slurry has a reduced content of organic carbon which may impact the soil biota negatively due to substrate shortage. Our knowledge on these processes and their influence on soil quality is scarce. Hence, a field experiment with two organic cropping systems (grass-clover ley and ...

  8. Making sense of ocean biota: How evolution and biodiversity of land organisms differ from that of the plankton

    Digital Repository Service at National Institute of Oceanography (India)

    Smetacek, V.

    The oceans cover 70% of the planet’s surface, and their planktonic inhabitants generate about half the global primary production, thereby playing a key role in modulating planetary climate via the carbon cycle. The ocean biota have been under...

  9. Modelling of Biota Dose Effects. Report of Working Group 6 Biota Dose Effects Modelling of EMRAS II Topical Heading Reference Approaches for Biota Dose Assessment. Environmental Modelling for RAdiation Safety (EMRAS II) Programme

    International Nuclear Information System (INIS)

    Environmental assessment models are used for evaluating the radiological impact of actual and potential releases of radionuclides to the environment. They are essential tools for use in the regulatory control of routine discharges to the environment and in planning the measures to be taken in the event of accidental releases. They are also used for predicting the impact of releases which may occur far into the future, for example, from underground radioactive waste repositories. It is important to verify, to the extent possible, the reliability of the predictions of such models by a comparison with measured values in the environment or with the predictions of other models. The IAEA has been organizing programmes on international model testing since the 1980s. These programmes have contributed to a general improvement in models, in the transfer of data and in the capabilities of modellers in Member States. IAEA publications on this subject over the past three decades demonstrate the comprehensive nature of the programmes and record the associated advances which have been made. From 2009 to 2011, the IAEA organized a project entitled Environmental Modelling for RAdiation Safety (EMRAS II), which concentrated on the improvement of environmental transfer models and the development of reference approaches to estimate the radiological impacts on humans, as well as on flora and fauna, arising from radionuclides in the environment. Different aspects were addressed by nine working groups covering three themes: reference approaches for human dose assessment, reference approaches for biota dose assessment and approaches for addressing emergency situations. This publication describes the work of the Biota Effects Modelling Working Group

  10. Concentrations and characteristics of organochlorine pesticides in aquatic biota from Qiantang River in China

    International Nuclear Information System (INIS)

    The Qiantang River is a typical river flowing through an agricultural area in China. It was studied in 2006 for its aquatic biota quality by determining 13 organochlorine pesticides (OCPs) in the edible parts of crabs, clams, shrimp, fish, aquatic plants, as well as water and sediments collected from seven sites along its upper reaches all the way downstream. The levels of all insecticides were in the range of 17 ± 13 (water plants), 35 ± 36 (shrimp), 32 ± 14 (crabs), 39 ± 21 (clams), 47±35 (fish) ng/g wet weight (ww) and in the range of 2936 ± 2356 (water plants), 5827 ± 6013 (shrimp), 2102 ± 966 (crabs), 1859 ± 1018 (clams), 3624 ± 11331 (fish) ng/g lipid. DDT and its metabolites were the predominant contaminants in most biota. A linear relationship was observed between the log bio-concentration factor (BCF) and log octanol-water partition coefficients (Kow) for fish, clams and shrimp. Composition analyses in various environmental media indicated a recent usage of lindane and dicofol into the river. - OCP residues still exist in aquatic biota from Qiantang River after the ban of OCPs twenty years ago

  11. Cretaceous biota of the Triângulo Mineiro region (Brazil: A review of recent finds

    Directory of Open Access Journals (Sweden)

    Candeiro, C. R. A.

    2007-06-01

    Full Text Available The Bauru Group (Adamantina, Uberaba, and Marília Formations crop out in the Triângulo Mineiro region, Minas Gerais State, Brazil, and yield a rich continental biota. Invertebrate and vertebrate taxa from underlying and overlying strata, as well as biostratigraphical correlations with other fossil sites in Argentina, suggest an Upper Cretaceous age for this biota. The diversity of the fossil assemblage recorded in these formations is summarized here and includes: frogs, lizards, crocodiles, titanosaurs, abelisaurid and carcharodontosaurid dinosaurs. This fossil assemblage provides important clues to understand faunas from other southern landmasses, particularly those from the Cretaceous of the African continent.Los afloramientos del Grupo Bauru (formaciones Adamantina, Uberaba y Marília en la región del Triângulo Mineiro, Provincia de Minas Gerais, Brasil, posee un rico contenido de biota continental. Los taxa de invertebrados y vertebrados de estos estratos, así como las correlaciones biostratigráficas con otros yacimientos fósiles de Argentina, sugieren una edad del Cretácico Tardío. La diversidad de la asociación fósil registrada en las formaciones del Triângulo Mineiro se resume en el presente trabajo e incluye: sapos, lagartos, tortugas, cocodrilianos, titanosaurideos, dinosaurios abelisaurideos y carcharodontosaurideos. Esta asociación es importante para la comprensión de las faunas del sur de América y también de las del Cretácico de África.

  12. On the Origin of Pantepui montane biotas: A Perspective Based on the Phylogeny of Aulacorhynchus toucanets

    Science.gov (United States)

    Bonaccorso, Elisa; Guayasamin, Juan M.

    2013-01-01

    To understand the origin of Pantepui montane biotas, we studied the biogeography of toucanets in the genus Aulacorhynchus. These birds are ideal for analyzing historical relationships among Neotropical montane regions, given their geographic distribution from Mexico south to Bolivia, including northern Venezuela (Cordillera de la Costa), and the Pantepui. Analyses were based on molecular phylogenies using mitochondrial and nuclear DNA sequences. Topology tests were applied to compare alternative hypotheses that may explain the current distribution of Aulacorhynchus toucanets, in the context of previous hypotheses of the origin of Pantepui montane biotas. Biogeographic reconstructions in RASP and Lagrange were used to estimate the ancestral area of the genus, and an analysis in BEAST was used to estimate a time framework for its diversification. A sister relationship between the Pantepui and Andes+Cordillera de la Costa was significantly more likely than topologies indicating other hypothesis for the origin of Pantepui populations. The Andes was inferred as the ancestral area for Aulacorhynchus, and the group has diversified since the late Miocene. The biogeographic patterns found herein, in which the Andes are the source for biotas of other regions, are consistent with those found for flowerpiercers and tanagers, and do not support the hypothesis of the geologically old Pantepui as a source of Neotropical montain diversity. Based on the high potential for cryptic speciation and isolation of Pantepui populations, we consider that phylogenetic studies of additional taxa are important from a conservation perspective. PMID:23840663

  13. Concentrations and characteristics of organochlorine pesticides in aquatic biota from Qiantang River in China

    Energy Technology Data Exchange (ETDEWEB)

    Zhou Rongbing [Department of Environmental Science, Zhejiang University, Hangzhou, Zhejiang 310028 (China)], E-mail: brz3000@163.com; Zhu Lizhong [Department of Environmental Science, Zhejiang University, Hangzhou, Zhejiang 310028 (China)], E-mail: zlz@zju.edu.cn; Chen Yuyun; Kong Qingxia [Department of Environmental Science, Zhejiang University, Hangzhou, Zhejiang 310028 (China)

    2008-01-15

    The Qiantang River is a typical river flowing through an agricultural area in China. It was studied in 2006 for its aquatic biota quality by determining 13 organochlorine pesticides (OCPs) in the edible parts of crabs, clams, shrimp, fish, aquatic plants, as well as water and sediments collected from seven sites along its upper reaches all the way downstream. The levels of all insecticides were in the range of 17 {+-} 13 (water plants), 35 {+-} 36 (shrimp), 32 {+-} 14 (crabs), 39 {+-} 21 (clams), 47{+-}35 (fish) ng/g wet weight (ww) and in the range of 2936 {+-} 2356 (water plants), 5827 {+-} 6013 (shrimp), 2102 {+-} 966 (crabs), 1859 {+-} 1018 (clams), 3624 {+-} 11331 (fish) ng/g lipid. DDT and its metabolites were the predominant contaminants in most biota. A linear relationship was observed between the log bio-concentration factor (BCF) and log octanol-water partition coefficients (K{sub ow}) for fish, clams and shrimp. Composition analyses in various environmental media indicated a recent usage of lindane and dicofol into the river. - OCP residues still exist in aquatic biota from Qiantang River after the ban of OCPs twenty years ago.

  14. Non-human biota dose assessment. Sensitivity analysis and knowledge quality assessment

    International Nuclear Information System (INIS)

    This report provides a summary of a programme of work, commissioned within the BIOPROTA collaborative forum, to assess the quantitative and qualitative elements of uncertainty associated with biota dose assessment of potential impacts of long-term releases from geological disposal facilities (GDF). Quantitative and qualitative aspects of uncertainty were determined through sensitivity and knowledge quality assessments, respectively. Both assessments focused on default assessment parameters within the ERICA assessment approach. The sensitivity analysis was conducted within the EIKOS sensitivity analysis software tool and was run in both generic and test case modes. The knowledge quality assessment involved development of a questionnaire around the ERICA assessment approach, which was distributed to a range of experts in the fields of non-human biota dose assessment and radioactive waste disposal assessments. Combined, these assessments enabled critical model features and parameters that are both sensitive (i.e. have a large influence on model output) and of low knowledge quality to be identified for each of the three test cases. The output of this project is intended to provide information on those parameters that may need to be considered in more detail for prospective site-specific biota dose assessments for GDFs. Such information should help users to enhance the quality of their assessments and build greater confidence in the results. (orig.)

  15. Evolution of Asian Interior Arid-Zone Biota: Evidence from the Diversification of Asian Zygophyllum (Zygophyllaceae)

    Science.gov (United States)

    Li, Hong-Lei; Yu, Sheng-Xiang; Zhang, Lin-Jing; Wang, Wei

    2015-01-01

    The Asian interior arid zone is the largest desert landform system in the Northern Hemisphere, and has high biodiversity. Little is currently known about the evolutionary history of its biota. In this study, we used Zygophyllum, an important and characteristic component of the Asian interior arid zone, to provide new insights into the evolution of this biota. By greatly enlarged taxon sampling, we present the phylogenetic analysis of Asian Zygophyllum based on two plastid and one nuclear markers. Our phylogenetic analyses indicate that Asian Zygophyllum and Sarcozygium form a clade and Sarcozygium is further embedded within the shrub subclade. An integration of phylogenetic, biogeographic, and molecular dating methods indicates that Zygophyllum successfully colonized the Asian interior from Africa in the early Oligocene, and Asian Zygophyllum became differentiated in the early Miocene and underwent a burst of diversification in the late Miocene associated with the expansion of Asian interior arid lands due to orogenetic and climatic changes. Combining diversification patterns of other important components of the Asian interior arid zone, we propose a multi-stage evolution model for this biota: the late Eocene–early Oligocene origin, the early Miocene expansion, and the middle-late Miocene rapid expansion to the whole Asian interior arid zone. This study also demonstrates that, for Zygophyllum and perhaps other arid-adapted organisms, arid biomes are evolutionary cradles of diversity. PMID:26393796

  16. Interactions between above- and belowground biota : importance for small-scale vegetation mosaics in a grassland ecosystem

    OpenAIRE

    Blomqvist, N.M.; Olff, H.; Blaauw, M.B.; Bongers, T.; Putten, W. H. van der

    2000-01-01

    Grasslands are often characterised by small-scale mosaics in plant community composition that contribute to their diversity. Although above- and belowground biota can both cause such mosaics, few studies have addressed their interacting effects. We studied multi-trophic interactions between aboveground vertebrate grazers, subterranean ants, plant-pathogenic soil biota (especially nematodes) and the vegetation in a temperate grassland. We found that when rabbits and cattle locally omit vegetat...

  17. Radionuclide and heavy metal concentrations in water, sediments and biota in the vicinity of Cluff mining operations

    International Nuclear Information System (INIS)

    Data is presented on the concentrations of U, Ra-226, Pb-210, Th-230, Th, As, Cu, Pb, Mo, Ni and Zn in water, sediments, aquatic macrophytes and fish near a high grade uranium mining facility. Baseline data acquired in 1975 and 1978-79 is compared to post-development environmental monitoring data from 1980 to 1985. Distribution coefficients (KD) for sediment, and transfer coefficients (T.C.) for biota and derived from the water, sediment and biota concentrations

  18. Using growth measures in the freshwater shrimp Caridina nilotica as biomarkers of Roundup® pollution of South African freshwater systems

    Science.gov (United States)

    Mensah, P. K.; Muller, W. J.; Palmer, C. G.

    There has been global concern about the effect of toxic chemicals on aquatic biota due to the upsurge in contamination of aquatic ecosystems by these chemicals, which includes pesticides. Roundup® and other glyphosate-based herbicides are frequently used in the chemical control of weeds and invading alien plant species in South Africa. These bio-active chemicals ultimately get into water courses directly or indirectly through processes such as drifting, leaching, surface runoff and foliar spray of aquatic nuisance plants. However, there is no South African water quality guideline to protect indigenous freshwater non-target organisms from the toxic effects of glyphosate-based herbicides. This study evaluated the possible use of growth measures in Caridina nilotica as biomarkers of Roundup® pollution as part of developing glyphosate water quality guideline for the protection of aquatic life in South Africa. Using static-renewal methods in a 25-day growth toxicity test, 40 days post hatch shrimps were exposed to different sub-lethal Roundup® concentrations of 0.0 (control), 2.2, 2.8, 3.4, 4.3 and 5.4 mg/L. Shrimps were fed daily with TetraMin® flake food and test solutions changed every third day. Shrimp total lengths and wet weights were measured every fifth day. These data were used to determine the shrimp’s growth performance and feed utilization in terms of percent weight gain (PWG), percent length gain (PLG), specific growth rate (SGR), condition factor (CF), feed intake (FI), feed conversion ratio (FCR) and feed conversion efficiency (FCE). Moulting was observed for 14 days and the data used to determine the daily moult rate for each concentration. Results of growth performance and food utilization indices showed that growth was significantly impaired in all exposed groups compared to control (p < 0.05). Moulting frequency was also higher in all exposed groups than in control (p < 0.05). Although all the tested growth measures proved to be possible biomarkers of Roundup® pollution, moulting frequency gives a clearer indication of the sub-lethal effects of Roundup® toxicity.

  19. Actinorhodopsin genes discovered in diverse freshwater habitats and among cultivated freshwater Actinobacteria

    Czech Academy of Sciences Publication Activity Database

    Sharma, A. K.; Sommerfeld, K.; Bullerjahn, G. S.; Matteson, A. R.; Wilhelm, S. W.; Jezbera, Jan; Brandt, U.; Doolittle, W.F.; Hahn, M.W.

    2009-01-01

    Ro?. 3, ?. 6 (2009), s. 726-737. ISSN 1751-7362 Institutional research plan: CEZ:AV0Z60170517 Keywords : rhodopsins * actinorhodopsin * freshwater * Actinobacteria * Superior * Erie Subject RIV: EE - Microbiology, Virology Impact factor: 6.397, year: 2009

  20. Tetanus after envenomations caused by freshwater stingrays.

    Science.gov (United States)

    Torrez, Pasesa P Q; Quiroga, Mariana M; Said, Renato; Abati, Paulo A M; França, Francisco O S

    2015-04-01

    Injuries caused by freshwater stingray are common in several regions of South America, although they are underreported. The riverside inhabitants are the main victims in the Amazonian and Midwest regions of South America. The fishermen are injured mainly in the new focus of colonization of the rivers by freshwater stingrays. With the increasing population in these regions, where freshwater stingrays are found, there has been a significant increase in injuries within the general population. The highest increase occurred among tourists from other regions, where these animals are not known, when visiting these areas. The envenomations from the stingray causes prolonged and intense pain, both local and regionally. Generally these are associated with other local inflammatory manifestations, such as swelling and erythema. The injury often progresses to necrosis and it is considered potentially tetanogenic. A secondary infection is also a frequent local complication and most frequently is caused by Aeromonas species, usually Aeromonas hydrophila. Herein we report the first 2 cases of tetanus after freshwater stingray injuries: a 51-year-old men who had tetanus and recovered without sequel and the second a 67-year-old men who had severe tetanus and a deep, necrotizing soft-tissue infection with sepsis, septic shock and evolution to death. PMID:25576234

  1. Freshwater savings from marine protein consumption

    Science.gov (United States)

    Gephart, Jessica A.; Pace, Michael L.; D'Odorico, Paolo

    2014-01-01

    Marine fisheries provide an essential source of protein for many people around the world. Unlike alternative terrestrial sources of protein, marine fish production requires little to no freshwater inputs. Consuming marine fish protein instead of terrestrial protein therefore represents freshwater savings (equivalent to an avoided water cost) and contributes to a low water footprint diet. These water savings are realized by the producers of alternative protein sources, rather than the consumers of marine protein. This study quantifies freshwater savings from marine fish consumption around the world by estimating the water footprint of replacing marine fish with terrestrial protein based on current consumption patterns. An estimated 7 600 km3 yr-1 of water is used for human food production. Replacing marine protein with terrestrial protein would require an additional 350 km3 yr-1 of water, meaning that marine protein provides current water savings of 4.6%. The importance of these freshwater savings is highly uneven around the globe, with savings ranging from as little as 0 to as much as 50%. The largest savings as a per cent of current water footprints occur in Asia, Oceania, and several coastal African nations. The greatest national water savings from marine fish protein occur in Southeast Asia and the United States. As the human population increases, future water savings from marine fish consumption will be increasingly important to food and water security and depend on sustainable harvest of capture fisheries and low water footprint growth of marine aquaculture.

  2. 2008 NWFSC Tidal Freshwater Genetics Results

    Energy Technology Data Exchange (ETDEWEB)

    David Teel

    2009-05-01

    Genetic Analysis of Juvenile Chinook Salmon for inclusion in 'Ecology of Juvenile Salmon in Shallow Tidal Freshwater Habitats in the Vicinity of the Sandy River Delta, Lower Columbia River, 2008. Annual Report to Bonneville Power Administration, Contract DE-AC05-76RL01830.'

  3. CROATIAN FRESHWATER FISHERIES IN 1995

    Directory of Open Access Journals (Sweden)

    Mirko Turk

    1996-06-01

    Full Text Available The data on the production and catch of fish according to sorts, pond ackerage, fishing means as well as the distribution of production and catch in 1995 have been stated in the paper. Ackerages used for the fish production have been increased by 1710 acres or 6.51%; total fish prinos* is less for 1,252 tons or 17.05%. The highest production of fish was reched by the fish farm Donji Miholjac with 859 kg/ha. A nutritive coefficient is 3.0 kg and it is less by 3.22% compared with the previous year. The nutritive coefficient is less than 2.0 kg in three fish-farms but it is greater than 4.0 kg in five large fish farms. Mostly corn but also wheat dominate in fish nutrition. The fertilizers consumption has been reduced by 14.53%. Of total pond ackerage, growing fish farms occupy 1.25%, new fish farms occupy 17.90% and consumptive fish farms occupy 79.64%. Total fish production in carp ponds is 507 kg/ha and 136.1 ton/ha in trout ponds. With 84.33%, carp is the mostly produced fish sorts, herbivore fish follow it with 3.89% and the production of all other fish makes 11.78% of the total. With 83.97%, grass carp takes the first place in the structure of herbivore fish. It is followed by the big head carp with 9.28% and silver carp with 6.75%. The trout production has been slightly increased by 6. 3%. Pike has appeared again and all other fish sorts has been reduced. Fish catch in open water has been increased by 7.06% compared with the previous year. When we sum up total production and catch of fresh-water fish, we can conclude that carp contributes with 81.08%; herbivore fish with 3.67%; trouts with 5.53%; sheat-fish, pike-perch and pike with 2.74% and all other fish sorts with 6.98%. As to the distribution of production and catch, there has been 49.02% sold on markets, 38.02% has been spent on farm reproduction (set back in ponds, the percentage of mortalities is 7.90%. Sport fishers have spent 5.06% of fish. The number of employees has been reduced by 12.05% and fish production per employee has also been reduced by 1.10% compared with the previous year. It has been produced 8.0 tons of fish per employee. In 1995, the production has been greatest in Dragani?i: 15.60 tons of fish per employee.

  4. CROATIAN FRESHWATER FISHERIES IN 1994

    Directory of Open Access Journals (Sweden)

    Mirko Turk

    1995-09-01

    Full Text Available Data on the production and catch of fish according to species, on the surface of the fish ponds, on the means of fish catching and on the distribution of the product and catch in 1994 is presented. The surface area used for production of fish has decreased by 274 ha or 2,51%. The total amount of fish has decreased by 1.263 tons or 14,78%. The highest production of fish was reached by the fish farm Donji Miholjac with 1.231 kg/ha. The feeding coefficient is 3,10 kg. Only on one fish farm was the feeding coefficient less than 2.0 kg (1,40 and on two large farms this coefficient was greater than 5,00 kg. The main fish food is still wheat followed by corn. The amount of fertilizer used was decreased by 14,40%. The fry carp growing ponds make up 0,92% of the surface area of the entire fish farm, the young carp ponds 21,77% and the culturing ponds for consumption fish 76,55%. The total amount of fish in the carp ponds was 660 kg/ha, and in the trout ponds it was 123.4 tons/ha. The carp is the highest produced fish with 80, 35%, then the herbivorous fish with 5,65 and all other fish make up 14% of the total production. In the structure of herbivorous fish the grass carp is leading with 54, 70%, followed by the big head carp with 25,54% and the silver carp with 19,76%. In comparison with the previous year the production of "all other fish- has significantly increased (287%, and sheat fish 18,90%, while the production of trench has decreased (71%. Fish catch in open waters has increased by 20,57% in comparison to the previous year. Carp made up 78,07% of the total production and catch of freshwater fish, the herbivorous fish made up 5,40%, trout 4,38%, the sheat fish, pike perch and pike 2,86% and all other fish species 9,28%. As far as the distribution of production and catch, 51,60% were sold on the market, 37,54% were used for reproduction (stocking the fish farms , mortalities were 6,35% and for personal use (sports fishing 4,50% was used. The number of fisheries workers decreased by 10,72% and the production per worker decreased by 3,12% in comparison to the previous year. According to each worker their was an average production of 9,00 tons of fish. In 1994 the highest production of fish was reached in Garešnica with 14,70 tons of fish per worker.

  5. Selected bibliography of terrestrial freshwater, and marine radiation ecology

    International Nuclear Information System (INIS)

    An extensive bibliography is presented of publications related to field or laboratory studies of wild species of plants and animals with respect to radiation effects or metabolic studies involving radionuclides. The references are listed under the following headings: status and needs of radiation ecology; environmental radioactivity; radionuclide concentration; ionizing radiation effects; techniques utilizing radionuclides and ionizing radiation in ecology; measurement of ionizing radiation; peaceful uses of atomic energy; waste disposal; nuclear testing and ecological consequences of a nuclear war; glossaries, standards, and licensing procedures; reviews of radionuclides in the environment; and sources of information

  6. Freshwater flux to Sermilik Fjord, SE Greenland

    Directory of Open Access Journals (Sweden)

    S. H. Mernild

    2010-10-01

    Full Text Available Terrestrial inputs of freshwater flux to Sermilik Fjord, SE Greenland, were estimated, indicating ice discharge to be the dominant source of freshwater. A freshwater flux of 40.4 ± 4.9×109 m3 y?1 was found (1999–2008, with an 85% contribution originated from ice discharge (65% alone from Helheim Glacier, 11% from terrestrial surface runoff (from melt water and rain, 3% from precipitation at the fjord surface area, and 1% from subglacial geothermal and frictional melting due to basal ice motion. The results demonstrate the dominance of ice discharge as a primary mechanism for delivering freshwater to Sermilik Fjord. Time series of ice discharge for Helheim Glacier, Midgård Glacier, and Fenris Glacier were calculated from satellite-derived average surface velocity, glacier width, and estimated ice thickness, and fluctuations in terrestrial surface freshwater runoff were simulated based on observed meteorological data. These simulations were compared and bias corrected against independent glacier catchment runoff observations. Modeled runoff to Sermilik Fjord was variable, ranging from 2.9 ± 0.4×109 m3 y?1 in 1999 to 5.9 ± 0.9×109 m3 y?1 in 2005. The sub-catchment runoff of the Helheim Glacier region accounted for 25% of the total runoff to Sermilik Fjord. The runoff distribution from the different sub-catchments suggested a strong influence from the spatial variation in glacier coverage, indicating high runoff volumes, where glacier cover was present at low elevations.

  7. Effect of zeolite on toxicity of ammonia in freshwater sediments: Implications for toxicity identification evaluation procedures

    Energy Technology Data Exchange (ETDEWEB)

    Besser, J.M.; Ingersoll, C.G. [Geological Survey, Columbia, MO (United States); Leonard, E.N.; Mount, D.R. [Environmental Protection Agency, Duluth, MN (United States). Mid-Continent Ecology Div.

    1998-11-01

    Techniques for reducing ammonia toxicity in freshwater sediments were investigated as part of a project to develop toxicity identification and evaluation (TIE) procedures for whole sediments. Although ammonia is a natural constituent of freshwater sediments, pollution can lead to ammonia concentrations that are toxic to benthic invertebrates, and ammonia can also contribute to the toxicity of sediments that contain more persistent contaminants. The authors investigated the use of amendments of a natural zeolite mineral, clinoptilolite, to reduce concentrations of ammonia in sediment pore water. Zeolites have been widely used for removal of ammonia in water treatment and in aqueous TIE procedures. The addition of granulated zeolite to ammonia-spiked sediments reduced pore-water ammonia concentrations and reduced ammonia toxicity to invertebrates. Amendments of 20% zeolite (v/v) reduced ammonia concentrations in pore water by {ge}70% in spiked sediments with ammonia concentrations typical of contaminated freshwater sediments. Zeolite amendments reduced toxicity of ammonia-spiked sediments to three taxa of benthic invertebrates (Hyalella azteca, Lumbriculus variegatus, and Chironomus tentans), despite their widely differing sensitivity to ammonia toxicity. In contrast, zeolite amendments did not reduce acute toxicity of sediments containing high concentrations of cadmium or copper or reduce concentrations of these metals in pore waters. These studies suggest that zeolite amendments, used in conjunction with toxicity tests with sensitive taxa such as H. azteca, may be an effective technique for selective reduction of ammonia toxicity in freshwater sediments.

  8. Effect of zeolite on toxicity of ammonia in freshwater sediments: Implications for toxicity identification evaluation procedures

    Science.gov (United States)

    Besser, J.M.; Ingersoll, C.G.; Leonard, E.N.; Mount, D.R.

    1998-01-01

    Techniques for reducing ammonia toxicity in freshwater sediments were investigated as part of a project to develop toxicity identification and evaluation (TIE) procedures for whole sediments. Although ammonia is a natural constituent of freshwater sediments, pollution can lead to ammonia concentrations that are toxic to benthic invertebrates, and ammonia can also contribute to the toxicity of sediments that contain more persistent contaminants. We investigated the use of amendments of a natural zeolite mineral, clinoptilolite, to reduce concentrations of ammonia in sediment pore water. Zeolites have been widely used for removal of ammonia in water treatment and in aqueous TIE procedures. The addition of granulated zeolite to ammonia-spiked sediments reduced pore-water ammonia concentrations and reduced ammonia toxicity to invertebrates. Amendments of 20% zeolite (v/v) reduced ammonia concentrations in pore water by ???70% in spiked sediments with ammonia concentrations typical of contaminated freshwater sediments. Zeolite amendments reduced toxicity of ammonia-spiked sediments to three taxa of benthic invertebrates (Hyalella azteca, Lumbriculus variegatus, and Chironomus tentans), despite their widely differing sensitivity to ammonia toxicity. In contrast, zeolite amendments did not reduce acute toxicity of sediments containing high concentrations of cadmium or copper or reduce concentrations of these metals in pore waters. These studies suggest that zeolite amendments, used in conjunction with toxicity tests with sensitive taxa such as H. azteca, may be an effective technique for selective reduction of ammonia toxicity in freshwater sediments.

  9. Humic substances influence sodium metabolism in the freshwater crustacean Daphnia magna.

    Science.gov (United States)

    Glover, Chris N; Pane, Eric F; Wood, Chris M

    2005-01-01

    Humic substances are ubiquitous components of natural waters with important roles in alleviating metal toxicity to aquatic organisms. Recent literature reports suggest that humic substances may also exert direct influences on biota. This study investigated the influence of two commercially available humic substances on sodium metabolism in Daphnia magna, a hyperregulating freshwater crustacean. Environmentally realistic levels of Suwannee River natural organic matter (SRN) and Aldrich humic acid (AHA) significantly enhanced sodium transport. This effect was described as an uncompetitive stimulation of sodium influx, as characterised by an increased maximal sodium transport rate (Jmax), accompanied by a decreased uptake affinity (increased Km). SRN exposure also significantly promoted the unidirectional loss of sodium from the daphnids to the water, an effect not observed in the presence of AHA. A 24-h preexposure to AHA before influx measurement had no effect on AHA-induced stimulation of sodium influx. Conversely, 24-h preexposure to SRN resulted in influx values that returned to control (humic-free) levels. Whole-body sodium levels reduced by SRN exposure were also restored to control levels following 24-h SRN preexposure. The significance and potential mechanisms of these actions are discussed, and the toxicological implications of these findings are assessed. PMID:15887087

  10. Polychlorinated biphenyls in freshwater salmonids from the Kerguelen Islands in the Southern Ocean

    Energy Technology Data Exchange (ETDEWEB)

    Jaffal, A. [Laboratoire d' Eco-Toxicologie, EA 2069 Vignes et Vins de Champagne, Universite de Reims Champagne-Ardenne, F51687 Reims Cedex 2 (France); Givaudan, N. [UMR8079, CNRS, Orsay F-91405 (France); Univ Paris-Sud, Ecologie Systematique et Evolution, Orsay F-91405 (France); Betoulle, S. [Laboratoire d' Eco-Toxicologie, EA 2069 Vignes et Vins de Champagne, Universite de Reims Champagne-Ardenne, F51687 Reims Cedex 2 (France); Terreau, A. [IPEV Institut Polaire Francais, F29280 Plouzane (France); Paris-Palacios, S.; Biagianti-Risbourg, S. [Laboratoire d' Eco-Toxicologie, EA 2069 Vignes et Vins de Champagne, Universite de Reims Champagne-Ardenne, F51687 Reims Cedex 2 (France); Beall, E. [ECOBIOP, UMR 1224 INRA-Universite de Pau-Pays de l' Adour F63310 St-Pee-sur-Nivelle (France); Roche, H., E-mail: helene.roche@u-psud.fr [UMR8079, CNRS, Orsay F-91405 (France); Univ Paris-Sud, Ecologie Systematique et Evolution, Orsay F-91405 (France)

    2011-05-15

    The Subantarctic Kerguelen Islands (49{sup o}S, 70{sup o}E) contain freshwater ecosystems among the most isolated in the world. Concentrations of polychlorinated biphenyls (PCBs) were assessed in the muscle of 48 brook trout and 38 brown trout caught during summer and spring 2006 in the rivers, lakes and ponds of Kerguelen. The sum of 29 PCBs averaged 404 and 358 ng g{sup -1} lipid, and dioxin-like PCB was 19 and 69 ng g{sup -1} lipid, in brook and brown trout, respectively. The values showed a high variability and some fish accumulated PCBs at levels similar to those of fish from impacted areas. While inter-sex differences were limited, the season and the morphotype appeared to have the most influence. Fish captured in summer had muscle PCB concentrations about three times higher than those caught in spring and the 'river' morphotype of brook trout showed the highest PCB levels. - Highlights: > First assessment of PCB contamination of biota in Kerguelen Islands, Sub-Antarctica. > PCB bioaccumulation level in trout varies from very high to undetectable. > Habitat and morphotype are the most influential factors on the variability. > Distribution pattern of PCBs in the muscle of fish is morphotype dependent. - Salmonids in hydrosystems of the Kerguelen Islands (Southern Ocean) show a high PCB bioaccumulation.

  11. River dolphins can act as population trend indicators in degraded freshwater systems.

    Science.gov (United States)

    Turvey, Samuel T; Risley, Claire L; Barrett, Leigh A; Yujiang, Hao; Ding, Wang

    2012-01-01

    Conservation attention on charismatic large vertebrates such as dolphins is often supported by the suggestion that these species represent surrogates for wider biodiversity, or act as indicators of ecosystem health. However, their capacity to act as indicators of patterns or trends in regional biodiversity has rarely been tested. An extensive new dataset of >300 last-sighting records for the Yangtze River dolphin or baiji and two formerly economically important fishes, the Yangtze paddlefish and Reeves' shad, all of which are probably now extinct in the Yangtze, was collected during an interview survey of fishing communities across the middle-lower Yangtze drainage. Untransformed last-sighting date frequency distributions for these species show similar decline curves over time, and the linear gradients of transformed last-sighting date series are not significantly different from each other, demonstrating that these species experienced correlated population declines in both timing and rate of decline. Whereas species may be expected to respond differently at the population level even in highly degraded ecosystems, highly vulnerable (e.g. migratory) species can therefore display very similar responses to extrinsic threats, even if they represent otherwise very different taxonomic, biological and ecological groupings. Monitoring the status of river dolphins or other megafauna therefore has the potential to provide wider information on the status of other threatened components of sympatric freshwater biotas, and so represents a potentially important monitoring tool for conservation management. We also show that interview surveys can provide robust quantitative data on relative population dynamics of different species. PMID:22666410

  12. River Dolphins Can Act as Population Trend Indicators in Degraded Freshwater Systems

    Science.gov (United States)

    Turvey, Samuel T.; Risley, Claire L.; Barrett, Leigh A.; Yujiang, Hao; Ding, Wang

    2012-01-01

    Conservation attention on charismatic large vertebrates such as dolphins is often supported by the suggestion that these species represent surrogates for wider biodiversity, or act as indicators of ecosystem health. However, their capacity to act as indicators of patterns or trends in regional biodiversity has rarely been tested. An extensive new dataset of >300 last-sighting records for the Yangtze River dolphin or baiji and two formerly economically important fishes, the Yangtze paddlefish and Reeves’ shad, all of which are probably now extinct in the Yangtze, was collected during an interview survey of fishing communities across the middle-lower Yangtze drainage. Untransformed last-sighting date frequency distributions for these species show similar decline curves over time, and the linear gradients of transformed last-sighting date series are not significantly different from each other, demonstrating that these species experienced correlated population declines in both timing and rate of decline. Whereas species may be expected to respond differently at the population level even in highly degraded ecosystems, highly vulnerable (e.g. migratory) species can therefore display very similar responses to extrinsic threats, even if they represent otherwise very different taxonomic, biological and ecological groupings. Monitoring the status of river dolphins or other megafauna therefore has the potential to provide wider information on the status of other threatened components of sympatric freshwater biotas, and so represents a potentially important monitoring tool for conservation management. We also show that interview surveys can provide robust quantitative data on relative population dynamics of different species. PMID:22666410

  13. Polychlorinated biphenyls in freshwater salmonids from the Kerguelen Islands in the Southern Ocean

    International Nuclear Information System (INIS)

    The Subantarctic Kerguelen Islands (49oS, 70oE) contain freshwater ecosystems among the most isolated in the world. Concentrations of polychlorinated biphenyls (PCBs) were assessed in the muscle of 48 brook trout and 38 brown trout caught during summer and spring 2006 in the rivers, lakes and ponds of Kerguelen. The sum of 29 PCBs averaged 404 and 358 ng g-1 lipid, and dioxin-like PCB was 19 and 69 ng g-1 lipid, in brook and brown trout, respectively. The values showed a high variability and some fish accumulated PCBs at levels similar to those of fish from impacted areas. While inter-sex differences were limited, the season and the morphotype appeared to have the most influence. Fish captured in summer had muscle PCB concentrations about three times higher than those caught in spring and the 'river' morphotype of brook trout showed the highest PCB levels. - Highlights: ? First assessment of PCB contamination of biota in Kerguelen Islands, Sub-Antarctica. ? PCB bioaccumulation level in trout varies from very high to undetectable. ? Habitat and morphotype are the most influential factors on the variability. ? Distribution pattern of PCBs in the muscle of fish is morphotype dependent. - Salmonids in hydrosystems of the Kerguelen Islands (Southern Ocean) show a high PCB bioaccumulation.

  14. Is PCBs concentration variability between and within freshwater fish species explained by their contamination pathways?

    Science.gov (United States)

    Lopes, C; Perga, M-E; Peretti, A; Roger, M-C; Persat, H; Babut, M

    2011-10-01

    Many chemical, physiological, and trophic factors are known to affect bioaccumulation of polychlorinated biphenyls (PCBs) in biota. Understanding the primary factors affecting fish contamination is critical for predicting and assessing risks to upper-trophic level consumers, including humans. Here we identify PCB contamination pathways that could explain within- and between-species variability in fish concentration levels. Three freshwater river fish species (barbel, chub and bream) were sampled at three sites along the Rhone River (France) where fish consumption is partially prohibited because of PCB levels exceeding the European health-based benchmark. The trophic position was assessed using an innovative approach based on stable isotope analyses and Bayesian inference, which takes into account both isotope data variability and parameter uncertainty. The effect of foraging habitat on fish contamination was addressed using stable isotope mixing models. The fish trophic position and PCB concentrations were found to be unrelated while the exploitation of sediment detrital carbon as a food source appeared to be a critical factor affecting fish contamination. Fish length, PCB concentration of the sediment, and individual fish foraging habitat (exploitation of detrital versus planktonic carbon sources) explained 80% of within- and between-species variability observed in PCB concentrations. These results, obtained for species that have overlapping TPs and exploit different carbon sources, reveal that the important factor in fish PCB contamination is not only what fish consume, but also and essentially the feeding location. PMID:21893333

  15. Bacterial resistance to oxytetracycline in different life stages of Indian freshwater carp aquaculture system

    OpenAIRE

    Singh A.K.; Rathore G.; Singh V.; Mani I.; Singh R.K.; Mishra S.K.; Mishra B.N.; Verma O.P.

    2009-01-01

    In India antibiotics are frequently used for preventing and controlling bacterial pathogens incarp aquaculture system, yet no studies have been performed to evaluate the ecological impact of itsintensive and prolonged use. In this work the frequency of oxytetracycline-resistant bacteria from water,palletized feed and different life stages of fish from Indian freshwater carp aquaculture system as well asthe level of resistance of selected strains was investigated. Viable as well as antibiotic-...

  16. CROATIAN FRESHWATER FISHERY IN 2001 and 2002

    Directory of Open Access Journals (Sweden)

    Irena Jahutka

    2003-09-01

    Full Text Available For each segment of freshwater fisheries — freshwater aquaculture, commercial and sport and recreational fisheries — there is a legal obligation for data submission to the Ministry of agriculture and forestry, Directorate of fisheries. Within the segments of commercial and sport and recreational fisheries the data submission obligation refers to the period beginning with the year 2003, while in the segment of aquaculture that obligation includes also the year 2002. Data collected for freshwater aquaculture contain the information on production of freshwater fish, total production areas, food, fertilizers and subsidies for freshwater fish farming. Data collected for commercial and sport and recreational fisheries contain the information on catch quantities and number of commercial and sport and recreational fishermen. Freshwater fish production in the year 2001 was 5,549. 50 tons, while the total fresh water fish production in the year 2002 decreased for 1.00% compared to the previous year, amounting to 5,501.07 tons. Although total fresh water fish production constantly decreases comparing to previous years, trout production has increased and the maximum production was noted in the year 2002. Total area of the freshwater fish farms in the year 2001 increased compared to the year 2000 for 2.14% amounting to 11,880.41 ha. Actual production area slightly increased in comparison to the previous year as well and amounted to 9,214.11 ha. In the year 2002 total area of freshwater fish farms was 11,491.29 ha, and 72.13% of that figure was the actual production area, that is 8,288.27 ha. Production per unit area in the year 2001 was 485.31 kg/ha for warm–water species and 280.44 t/ha for cold–water species. In the year 2002 production per unit area for warm–water species was 462.95 kg/ha, and for cold–water species 315.26 t/ha. During the year 2001, in total, 10,575.82 t of food was spent and 1,891 tons of fertilizers and lime, while in the year 2002 12,195.40 tons of food and 2,104 tons of fertilizers and lime. Regarding the number of commercial fishermen the decrease was noted for the period of 2001–2002 in comparison with the period 1998–2000. The total number of sport and recreational fisheren in the year 2001 was 57,781 and in the year 2002 their number was 56,210. During the years 2001 and 2002 subsidies for 8 freshwater species were issued amounting as follows: for carp, grass carp, bighead carp and silver carp the subsidies were 4.00 kn/kg, and for tench, trout, pikeperch, catfish and pike the amount was 6.00 kn/kg.

  17. Physical processes in freshwater ecosystems

    International Nuclear Information System (INIS)

    In the present paper the main methodological approaches to model the physical processes controlling the migration of radionuclides through water ecosystems are presented and discussed. These processes include the dispersion and the transport through the water and the migration from and to the bottom sediments caused by the settling and the re-suspension of contaminated particles of suspended matter. The equations that control the above processes and that are used by most existing state-of-the-art models are listed and briefly discussed and motivated. Values of the parameters in the equations have been selected following a review of information available from the scientific literature. (author)

  18. Heterogeneity of soil nutrients and subsurface biota in a dryland ecosystem

    Science.gov (United States)

    Housman, D.C.; Yeager, C.M.; Darby, B.J.; Sanford, R.L., Jr.; Kuske, C.R.; Neher, D.A.; Belnap, J.

    2007-01-01

    Dryland ecosystems have long been considered to have a highly heterogeneous distribution of nutrients and soil biota, with greater concentrations of both in soils under plants relative to interspace soils. We examined the distribution of soil resources in two plant communities (dominated by either the shrub Coleogyne ramosissima or the grass Stipa hymenoides) at two locations. Interspace soils were covered either by early successional biological soil crusts (BSCs) or by later successional BSCs (dominated by nitrogen (N)-fixing cyanobacteria and lichens). For each of the 8 plant type??crust type??locations, we sampled the stem, dripline, and 3 interspace distances around each of 3 plants. Soil analyses revealed that only available potassium (Kav) and ammonium concentrations were consistently greater under plants (7 of 8 sites and 6 of 8 sites, respectively). Nitrate and iron (Fe) were greater under plants at 4 sites, while all other nutrients were greater under plants at less than 50% of the sites. In contrast, calcium, copper, clay, phosphorus (P), and zinc were often greater in the interspace than under the plants. Soil microbial biomass was always greater under the plant compared to the interspace. The community composition of N-fixing bacteria was highly variable, with no distinguishable patterns among microsites. Bacterivorous nematodes and rotifers were consistently more abundant under plants (8 and 7 sites, respectively), and fungivorous and omnivorous nematodes were greater under plants at 5 of the 8 sites. Abundance of other soil biota was greater under plants at less than 50% of the sites, but highly correlated with the availability of N, P, Kav, and Fe. Unlike other ecosystems, the soil biota was only infrequently correlated with organic matter. Lack of plant-driven heterogeneity in soils of this ecosystem is likely due to (1) interspace soils covered with BSCs, (2) little incorporation of above-ground plant litter into soils, and/or (3) root deployment patterns. ?? 2007 Elsevier Ltd. All rights reserved.

  19. Polonium-210 and Lead-210 in marine biota from a coastal region with high natural radioactivity

    International Nuclear Information System (INIS)

    Coastal sediments and marine fish from a region with high natural radioactivity in Cox Bazar Bangladesh, were analyzed in order to investigate the levels of naturally occurring radionuclides. Sediment from the sea shore in high ambient radiation dose rate areas contained naturally occurring radionuclides at high concentrations. These sediments displayed 226Ra, 232Th and 235U activity concentrations of 2184 ± 88 Bq kg-1 dry weight (d.w.), 3808 ± 200 Bq kg-1 (d.w.) and 123 ± 15 Bq kg-1 (d.w.), respectively. In contrast with these high values, radionuclide concentrations in sand from other areas of the Cox's Bazar coast were as low as 42 ± 3, 70 ± 4 and < 8 Bq kg-1 (d.w.) for the same radionuclides, respectively, which are comparable to concentrations determined in many coastal areas elsewhere. The presence of sand deposits with high concentration of uranium series radionuclides could potentially originate high accumulation of alpha emitting radionuclides such as 210Po in marine biota, and food chain transfer to man. 210Po is a major contributor to the radiation dose both in marine organisms and sea food consumers. Determination of 210Po in marine fish and shrimp from the area lead to concentration values ranging from 4.5±0.3 to 124±3 Bq kg-1 (d.w.) in fish and 82.9±1.6 Bq kg-1 (d.w.) in shrimp. Similar concentrations are commonly reported in marine biota from several regions. Therefore, in spite of the deposits of heavy mineral sands containing high concentrations of radionuclides such as 210Pb and 210Po no significant raise in the accumulation of these radionuclides in biota seems to occur, which suggests that radionuclides are tightly bound in sediment grains and are not significantly bioavailable. (author)

  20. Freshwater fishes of Bontebok National Park

    Directory of Open Access Journals (Sweden)

    I.A. Russell

    2001-08-01

    Full Text Available Fish assemblages were sampled at six sites in the Breede River in the Bontebok National Park during 1999 and 2000. A total of 380 fish from 12 species was recorded. Indigenous fish collected included one freshwater species (Barbus andrewi, two catodromous species (Anguilla mossambica, Myxus capensis. and three estuarine species (Gilchris- tella aestuaria, Monodactylusfalciformis, Mugil cephalus. Four of the species recorded were aliens (Tinea tinea, Lepomis macrochirus, Micropterus salmoides, Micropterus dolomieu and two species translocated from other South African rivers (Tilapia sparrmanii, Clarias gariepinus. A further two indigenous species (Sandelia capensis, Pseudobarbus biirchelli could potentially occur within the park, though the high abundance of alien predators means that there is little chance for recolonisation from tributaries higher in the Breede River system. There is little opportunity to meaningfully conserve most indigenous freshwater fish in Bontebok National Park.

  1. Freshwater fishes of Tsitsikamma National Park

    Directory of Open Access Journals (Sweden)

    I.A. Russell

    2002-12-01

    Full Text Available This study aimed to determine the distribution and relative abundance of freshwater fishes in the Tsitsikamma National Park. Fish assemblages in six river systems were sampled in 2001, with a total of 323 fish from eight species recorded. Indigenous fish collected included four freshwater species (Pseudobarbus afer, Pseudobarbus tenuis, Sandelia capensis, Anguilla mossambica, three estuarine species (Monodactylus falciformis, Caffrogobius gilchristi, Myxus capensis, and one alien (Micropterus salmoides. One additional indigenous species (Galaxias zebratus and two aliens (Salmo trutta, Oncorhynchus mykiss could potentially occur within the park. The topography and locality of the park presents a unique opportunity to meaningfully conserve the endangered P. tenuis as well as other fish characteristic of the eastern reaches of the Cape Floristic Region. Management action is required to minimise opportunities for further establishment and spread of alien fish species and to conserve indigenous fish assemblages within the park.

  2. Assessing the freshwater distribution of yellow eel

    Directory of Open Access Journals (Sweden)

    Lasne É.

    2009-04-01

    Full Text Available In the global context of the decline in wild species, modeling the distribution of populations is a crucial aspect of ecological management. This can be a major challenge, especially for species, such as the European eel, that have complex life cycles, exhibit cryptic behavior, or migrate over long distances. A review of the literature suggests that eel size data could be used to assess and analyze freshwater distribution of eel. We argue that analyses based on small yellow eels (? 300 mm along the longitudinal course of rivers could provide a valuable tool for population monitoring. We propose a standardized catchment recruitment index and a colonization index based on the probability of occurrence (presence/absence data using logistic models for different size classes. The model developed here provides a convenient guide for assessing yellow eel stages in freshwater areas, and should have concrete applications for management of the species.

  3. Freshwater aquatic plant biomass production in Florida

    Energy Technology Data Exchange (ETDEWEB)

    Reddy, K.R.; Sutton, D.L.; Bowes, G.

    1983-01-01

    About 8% (1.2 million ha) of the total surface area of Florida is occupied by freshwater. Many of these water bodies are eutrophic. Nutrients present in these water bodies can be potentially used to culture aquatic plants as a possible feedstock for methane production. This paper summarizes the results of known research findings on biomass production potential of freshwater aquatic plants in Florida and identifies key research needs to improve the quality and quantity of biomass yields. Among floating aquatic plants, biomass yield potential was in the order of water-hyacinth > water lettuce > pennywort > salvinia > duckweed > azolla. Pennywort, duckweed, and azolla appear to perform well during the cooler months compared to other aquatic plants. Among emergent plants, biomass yield potential was in the order of southern wild rice > cattails > soft rush > bulrush. Cultural techniques, nutrient management, and environmental factors influencing the biomass yields were discussed. 68 references.

  4. Superhydrophobic resistance to dynamic freshwater biofouling inception.

    Science.gov (United States)

    Krishnan, K Ghokulla; Malm, Peter; Loth, Eric

    2015-01-01

    Superhydrophobic nanotextured surfaces have gained increased usage in various applications due to their non-wetting and self-cleaning abilities. The aim of this study was to investigate nanotextured surfaces with respect to their resistance to the inception of freshwater biofouling at transitional flow conditions. Several coatings were tested including industry standard polyurethane (PUR), polytetrafluoroethylene (PTFE), capstone mixed polyurethane (PUR + CAP) and nanocomposite infused polyurethane (PUR + NC). Each surface was exposed to freshwater conditions in a lake at 4 m s(-1) for a duration of 45 min. The polyurethane exhibited the greatest fouling elements, in terms of both height and number of elements, with the superhydrophobic nanocomposite based polyurethane (PUR + NC) showing very little to no fouling. A correlation between the surface characteristics and the degree of fouling inception was observed. PMID:26618394

  5. Behaviour of molluscs in cantabrian biota with respect to the activity present in the marine medium

    International Nuclear Information System (INIS)

    The behaviour of molluscs with regard to the activity present in the marine medium is studied. For this purpose three large groups are considered, with special reference to their ecology and their particular mode of incorporating activity. Determinations are made of the total alpha and beta activity, as well as that due to elements such as 90Sr, 137Cs and natural U, in the organisms in question and in their eco-environment. A comparison is likewise established between the biocoenoses inhabiting Cantabrian and Mediterranean biota. (author)

  6. Lack of observed impacts of gas production of Bongkot Field, Thailand on marine biota

    International Nuclear Information System (INIS)

    The impact of metal releases, associated with gas production, on biota in the Lower Gulf of Thailand was evaluated based on metal concentrations in finfish and on the composition of sediment fauna. Results indicate that metal concentrations, particularly Hg, in species of snapper and grouper collected near the gas production platform were not significantly different from those of the same species of fish caught from the regional, presumably non-impacted, fishery. Also, there were no significant differences in faunal communities in sediments collected near petroleum production activities from those in sediments collected at remote sites. (author)

  7. Radioactive contamination of the environment and biota on Novaya Zemlya following nuclear weapon tests

    International Nuclear Information System (INIS)

    Data of radiochemical studies have shown that in key elements of ecosystems on the archipelago (lake and sea waters, bottom deposits, mosses lichens, birds and deer) the content of Cs137 and other radioisotopes is within the background level. Bottom deposits and soils of local territories of the abandoned nuclear test sites are the exception (the concentration of radioisotopes in the environment and biota amounts to 5000 Bq/rg and more). It is recommended that mosses and lichens on the ground and benthonic organisms in the sea should be used as biological indicators of artificial radiological background

  8. Lack of observed impacts of gas production of Bongkot Field, Thailand on marine biota

    Energy Technology Data Exchange (ETDEWEB)

    Windom, H.L. [Skidaway Institute of Oceanography, Savannah, GA (United States); Cranmer, G. [Metoc plc, Liphook (United Kingdom)

    1998-10-01

    The impact of metal releases, associated with gas production, on biota in the Lower Gulf of Thailand was evaluated based on metal concentrations in finfish and on the composition of sediment fauna. Results indicate that metal concentrations, particularly Hg, in species of snapper and grouper collected near the gas production platform were not significantly different from those of the same species of fish caught from the regional, presumably non-impacted, fishery. Also, there were no significant differences in faunal communities in sediments collected near petroleum production activities from those in sediments collected at remote sites. (author)

  9. Natural radionuclides in certain intertidal biota and the radiotoxicological concerns, Gulf of Mannar, India

    International Nuclear Information System (INIS)

    Protection of non-human biota from ionizing radiation, especially in the vicinity of nuclear installations is a very important aspect for nuclear engineers and ecologists. In order to ensure that certain limits of contamination are not exceeded, for the absolute protection of biota and humans is mandatory for nuclear agencies. 210Po (t1/2 = 138.4 days) and 210Pb (t1/2 = 22 years), in marine food has received much interest from the marine scientific community because of the high toxicity and radioactive dose they deliver to marine organisms and human beings when compared to anthropogenic radionuclides released into coastal waters. The present study focused on determining 210Po and 210Pb in some intertidal biota such as crustaceans and mollusks and the exposure risk assessment performed. The study was carried out along the coast of Kudankulam. Samples were processed and analysed as per the standard protocol of IAEA. A portion of 10 g dried fish sample with 0.2 Bq 208Po tracer was wet-digested using a mixed solution of HNO3, H2O2 and HCl. After the resultant solutions were evaporated to dryness, each residue was dissolved in 0.5 N HCL of 50 ml for plating Polonium. Polonium was spontaneously deposited on both sides of a silver disc from the solution for plating for 6 h at a temperature of 80-90 deg C. Both sides of the silver disc are counted with an alpha-ray counter (RC 605A, Nucleonix; efficiency of 35% for a 241Am standard; minimum detectable limit is 0.02 Bq), and the results were combined. After plating, the solution was stored for 6 months in glass bottles to allow the growth of 210Po from 210Pb. Subsequent determination of the ingrown 210Po was carried out as described above for the determination of 210Pb. The average 208Po recovery of 93 ± 2% was obtained by this method. The concentration of both the radionuclides was noticed higher in the organs associated with digestion and metabolism. Filter feeding bivalve molluscs registered the maximum activity of 210Po in their whole body compared to grazing gastropods and other crustaceans. The sensitive indicator, 210Po:210Pb ratio was calculated to be greater than unity in most of the analysed tissues. The ecological sensitivity of biota to the radiation exposure and the safeness of the environment was analysed by calculating the external and internal dose rate. The total weighted internal dose rate was higher than the external dose rate. The calculated hazard quotient for molluscs was lesser than the global bench mark dose rate of 10 ?Gy h-1. (author)

  10. A freshwater biodiversity hotspot under pressure - assessing threats and identifying conservation needs for ancient Lake Ohrid

    Science.gov (United States)

    Kostoski, G.; Albrecht, C.; Trajanovski, S.; Wilke, T.

    2010-07-01

    Freshwater habitats and species living in freshwater are generally more prone to extinction than terrestrial or marine ones. Immediate conservation measures for world-wide freshwater resources are thus of eminent importance. This is particularly true for so called ancient lakes. While these lakes are famous for being evolutionary theatres, often displaying an extraordinarily high degree of biodiversity and endemism, in many cases these biota are also experiencing extreme anthropogenic impact. Lake Ohrid, the European biodiversity hotspot, is a prime example for a lake with a magnitude of narrow range endemic taxa that are under increasing anthropogenic pressure. Unfortunately, evidence for a "creeping biodiversity crisis" has accumulated over the last decades, and major socio-political changes have gone along with human-mediated environmental changes. Based on field surveys, monitoring data, published records, and expert interviews, we aimed to (1) assess threats to Lake Ohrids' (endemic) biodiversity, (2) summarize existing conservation activities and strategies, and (3) outline future conservation needs for Lake Ohrid. We compiled threats to both specific taxa (and in cases to particular species) as well as to the lake ecosystems itself. Major conservation concerns identified for Lake Ohrid are: (1) watershed impacts, (2) agriculture and forestry, (3) tourism and population growth, (4) non-indigenous species, (5) habitat alteration or loss, (6) unsustainable exploitation of fisheries, and (7) global climate change. Of the 11 IUCN (International Union for Conservation of Nature and Natural Resources) threat classes scored, seven have moderate and three severe impacts. These latter threat classes are energy production and mining, biological resource use, and pollution. We review and discuss institutional responsibilities, environmental monitoring and ecosystem management, existing parks and reserves, biodiversity and species measures, international conservation activities, and ongoing research on conservation and raising of public awareness. Following this summary, we evaluate the status quo and future of Lake Ohrid and its biota. Given the number of identified threats, it is clear that only concerted international action can stop or at least slow down further degradation of Lake Ohrid and the creeping biodiversity crisis already evident. A comprehensive conservation strategy should include measures that result in an immediate reduction of pollution, particularly with phosphorous, in order to slow down the ongoing eutrophication process. The existing watershed management should become more effective. Implementation and particularly with a view to the enforcement of national laws should be enhanced. Increased research on the lakes' limnology, biodiversity, and conservation management practices are necessary. The latter research should identify conservation priorities. Public awareness should be enhanced. Facing these parallel needs to protect the unique biodiversity of Lake Ohrid, we suggest urging (a) implementation and enforcement of the General Management Plan that would ensure long-term integrated and sustainable use of the lake and its watershed, (b) scientific studies on ecology, biodiversity and effects of human impact, (c) the establishment of Core Conservation areas (CCA), including underwater reserves, and (d) Coastal Zone Management (CZM) areas that would constitute buffer zones for the CCA around the lake. These activities should, among others, ultimately lead to a trans-boundary major conservation area of the Ohrid-Prespa region that would allow long-term integration of both humans and nature.

  11. A freshwater biodiversity hotspot under pressure – assessing threats and identifying conservation needs for ancient Lake Ohrid

    Directory of Open Access Journals (Sweden)

    G. Kostoski

    2010-07-01

    Full Text Available Freshwater habitats and species living in freshwater are generally more prone to extinction than terrestrial or marine ones. Immediate conservation measures for world-wide freshwater resources are thus of eminent importance. This is particularly true for so called ancient lakes. While these lakes are famous for being evolutionary theatres, often displaying an extraordinarily high degree of biodiversity and endemism, in many cases these biota are also experiencing extreme anthropogenic impact.

    Lake Ohrid, the European biodiversity hotspot, is a prime example for a lake with a magnitude of narrow range endemic taxa that are under increasing anthropogenic pressure. Unfortunately, evidence for a "creeping biodiversity crisis" has accumulated over the last decades, and major socio-political changes have gone along with human-mediated environmental changes.

    Based on field surveys, monitoring data, published records, and expert interviews, we aimed to (1 assess threats to Lake Ohrids' (endemic biodiversity, (2 summarize existing conservation activities and strategies, and (3 outline future conservation needs for Lake Ohrid. We compiled threats to both specific taxa (and in cases to particular species as well as to the lake ecosystems itself. Major conservation concerns identified for Lake Ohrid are: (1 watershed impacts, (2 agriculture and forestry, (3 tourism and population growth, (4 non-indigenous species, (5 habitat alteration or loss, (6 unsustainable exploitation of fisheries, and (7 global climate change.

    Of the 11 IUCN (International Union for Conservation of Nature and Natural Resources threat classes scored, seven have moderate and three severe impacts. These latter threat classes are energy production and mining, biological resource use, and pollution. We review and discuss institutional responsibilities, environmental monitoring and ecosystem management, existing parks and reserves, biodiversity and species measures, international conservation activities, and ongoing research on conservation and raising of public awareness. Following this summary, we evaluate the status quo and future of Lake Ohrid and its biota. Given the number of identified threats, it is clear that only concerted international action can stop or at least slow down further degradation of Lake Ohrid and the creeping biodiversity crisis already evident. A comprehensive conservation strategy should include measures that result in an immediate reduction of pollution, particularly with phosphorous, in order to slow down the ongoing eutrophication process. The existing watershed management should become more effective. Implementation and particularly with a view to the enforcement of national laws should be enhanced. Increased research on the lakes' limnology, biodiversity, and conservation management practices are necessary. The latter research should identify conservation priorities. Public awareness should be enhanced. Facing these parallel needs to protect the unique biodiversity of Lake Ohrid, we suggest urging (a implementation and enforcement of the General Management Plan that would ensure long-term integrated and sustainable use of the lake and its watershed, (b scientific studies on ecology, biodiversity and effects of human impact, (c the establishment of Core Conservation areas (CCA, including underwater reserves, and (d Coastal Zone Management (CZM areas that would constitute buffer zones for the CCA around the lake.

    These activities should, among others, ultimately lead to a trans-boundary major conservation area of the Ohrid-Prespa region that would allow long-term integration of both humans and nature.

  12. Trends in freshwater and marine aquaculture

    OpenAIRE

    Lacroix, Denis

    1998-01-01

    The demand for fish products, from freshwater and from the sea, is globally increasing ail over the world. This major trend can be explained by the development of mankind, not only in quantity (one billion people more in the last 15 years) but also because food consumption habits are changing: for southern countries, fish products consumption is first a diversification of protein sources. For northern countries, it is a new style of eating with diet, tasteful and original products coming from...

  13. THE FATIGUE BEHAVIOR OF FRESHWATER ICE

    OpenAIRE

    Nixon, W; Smith, R.

    1987-01-01

    Cyclic loading (fatigue) tests have been performed on freshwater ice subjected to reversed bending. A technique has been developed to take replicas of the fracture surfaces, which have been examined to measure porosity and to seek evidence of cyclic crack growth. Some striations have been found, but the relative contributions of plastic deformation and cleavage mechanisms remain unclear. Further investigation is needed to see if cracks grow immediately on cyclic stressing from existing defect...

  14. Ecosystem Services : In Nordic Freshwater Management

    DEFF Research Database (Denmark)

    Magnussen, Kristin; Hasler, Berit; Zandersen, Marianne

    2014-01-01

    Human wellbeing is dependent upon and benefit from ecosystem services which are delivered by well-functioning ecosystems. Ecosystem services can be mapped and assessed consistently within an ecosystem service framework. This project aims to explore the use and usefulness of the ecosystem service framework in freshwater management, particularly water management according to the Water Framework Directive (WFD). There are several examples of how ecosystem services have been used in WFD related stud...

  15. Reclaiming freshwater sustainability in the Cadillac Desert

    OpenAIRE

    Sabo, John L.; Sinha, Tushar; Bowling, Laura C.; Schoups, Gerrit H. W.; Wallender, Wesley W.; Campana, Michael E.; Cherkauer, Keith A.; Fuller, Pam L.; Graf, William L.; Jan W. Hopmans; Kominoski, John S.; Taylor, Carissa; Trimble, Stanley W.; Webb, Robert H; Wohl, Ellen E.

    2010-01-01

    Increasing human appropriation of freshwater resources presents a tangible limit to the sustainability of cities, agriculture, and ecosystems in the western United States. Marc Reisner tackles this theme in his 1986 classic Cadillac Desert: The American West and Its Disappearing Water. Reisner's analysis paints a portrait of region-wide hydrologic dysfunction in the western United States, suggesting that the storage capacity of reservoirs will be impaired by sediment infilling, croplands will...

  16. Bioaccumulation and biomagnification of halogenated organic pollutants in mangrove biota from the Pearl River Estuary, South China.

    Science.gov (United States)

    Sun, Yu-Xin; Zhang, Zai-Wang; Xu, Xiang-Rong; Hu, Yong-Xia; Luo, Xiao-Jun; Cai, Ming-Gang; Mai, Bi-Xian

    2015-10-15

    Four biota species were collected from mangrove ecosystems of the Pearl River Estuary to investigate the bioaccumulation and biomagnification of polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane (DDT), polybrominated diphenyl ethers (PBDEs), dechlorane plus (DP), and decabromodiphenyl ethane (DBDPE). Concentrations of ?PCBs, ?DDTs, ?PBDEs, DP, DBDPE and anti-Cl11-DP (the dechlorination product of anti-DP) in mangrove biota ranged from 32.1-466, 153-3819, 3.88-59.8, 0.18-6.88, not detected (nd)-30.6 and nd-2.65ng/g lipid weight, respectively. Daggertooth pike conger (Muraenesox cinereus) had higher concentrations of contaminants than the other three biota species. Significant positive relationship between anti-Cl11-DP and anti-DP levels was observed in mangrove biota. DDTs were the predominant HOPs in all biota species, followed by PCBs and PBDEs. All the target compounds exhibited biomagnification, with biomagnification factors greater than 1 in the studied feeding relationships. Food web magnification was found for ?PCBs, ?DDTs, ?PBDEs and DP, with trophic magnification factors of 2.76, 2.61, 2.20 and 2.31, respectively. PMID:26209127

  17. Nutrients in a freshwater lagoon, lagos, nigeria

    International Nuclear Information System (INIS)

    Water samples were taken from a freshwater lagoon of Nigeria for determination of inorganic nutrients and other water constituents at different sampling points of Owo river and Ologe lagoon at bimonthly intervals for a period of two years from January, 1997 to December, 1998. Indications of the pristine nature of the environment were considerable lower concentrations of dissolved phosphate, nitrate and ammonia than the global averages for unpolluted freshwater. Less significant differences were observed between spatial and seasonal variations in NO/sub 3/ -N and NH/sub 3/ -N concentration. PO/sub 3/O/sub 4/ -P concentrations on the other hand showed no significant difference. Phosphorus level was below 0.1 mg/l throughout the study period which signal eutrophy in lotic systems. Nitrogen/phosphorus ratios in Owo river and lagoon system (3.0 -3.2) were lower than expected in P-limited freshwater systems, where molar ratio of N/P is generally >10 to 15. Hence, the nutrient limiting aquatic primary productivity and the most critical to control in the entire study area was nitrogen. (author)

  18. THE DEVELOPMENT OF FRESHWATER FISHING IN ELAZI?

    Directory of Open Access Journals (Sweden)

    Zeki BOYRAZ

    2015-04-01

    Full Text Available Increasing world population has more demand for healthy food day after day. Our research draws attention to increasing freshwater fishery in Elaz?? that increased its importance depending on the fishery activities in inland water in recent years. Our reasearch area, Elaz??, is situated in the Upper F?rat part, in the southwest of Eastern Anatolia Region. The main factor that allows freshwater fishery develop in the research field is the existence of fresh water. The most important river within the city borders is F?rat and its tributaries. Hazar Lake has a 86 km2 surface area and it is 30 km far from the city center. Also the Keban Dam, 675 km2 and Karakaya Dam, 268 km2 make up the city borders. Other important dams like Kralk?z?, 57 km2 and Özlüce 26 km2 are situated in near distances. In this study we will focus on the potential and development of the freshwater fishery in Elaz??.

  19. Extraction of Freshwater and Energy from Atmosphere

    CERN Document Server

    Bolonkin, Alexander

    2007-01-01

    Author offers and researches a new, cheap method for the extraction of freshwater from the Earth atmosphere. The suggected method is fundamentally dictinct from all existing methods that extract freshwater from air. All other industrial methods extract water from a saline water source (in most cases from seawater). This new method may be used at any point in the Earth except Polar Zones. It does not require long-distance freshwater transportation. If seawater is not utilized for increasing its productivity, this inexpensive new method is very environment-friendly. The author method has two working versions: (1) the first variant the warm (hot) atmospheric air is lifted by the inflatable tube in a high altitude and atmospheric steam is condenced into freswater: (2) in the second version, the warm air is pumped 20-30 meters under the sea-surface. In the first version, wind and solar heating of air are used for causing air flow. In version (2) wind and propeller are used for causing air movment. The first method...

  20. Vegetative community control of freshwater availability: Phoenix Islands case study

    Science.gov (United States)

    Engels, M.; Heinse, R.

    2014-12-01

    On small low islands with limited freshwater resources, terrestrial plant communities play a large role in moderating freshwater availability. Freshwater demands of vegetative communities are variable depending on the composition of the community. Hence, changes to community structure from production crop introductions, non-native species invasions, and climate change, may have significant implications for freshwater availability. Understanding how vegetative community changes impact freshwater availability will allow for better management and forecasting of limited freshwater supplies. To better understand these dynamics, we investigated three small tropical atolls in the Phoenix Island Protected Area, Kiribati. Despite their close proximity, these islands receive varying amounts of rainfall, are host to different plant communities and two of the islands have abandoned coconut plantations. Using electromagnetic induction, ground penetrating radar, soil samples, climate and satellite data, we present preliminary estimates of vegetative water demand for different tropical plant communities.

  1. Trade-offs in osmoregulation and parallel shifts in molecular function follow ecological transitions to freshwater in the Alewife.

    Science.gov (United States)

    Velotta, Jonathan P; McCormick, Stephen D; Schultz, Eric T

    2015-10-01

    Adaptation to freshwater may be expected to reduce performance in seawater because these environments represent opposing selective regimes. We tested for such a trade-off in populations of the Alewife (Alosa pseudoharengus). Alewives are ancestrally anadromous, and multiple populations have been independently restricted to freshwater (landlocked). We conducted salinity challenge experiments, whereby juvenile Alewives from one anadromous and multiple landlocked populations were exposed to freshwater and seawater on acute and acclimation timescales. In response to acute salinity challenge trials, independently derived landlocked populations varied in the degree to which seawater tolerance has been lost. In laboratory-acclimation experiments, landlocked Alewives exhibited improved freshwater tolerance, which was correlated with reductions in seawater tolerance and hypo-osmotic balance, suggesting that trade-offs in osmoregulation may be associated with local adaptation to freshwater. We detected differentiation between life-history forms in the expression of an ion-uptake gene (NHE3), and in gill Na(+) /K(+) -ATPase activity. Trade-offs in osmoregulation, therefore, may be mediated by differentiation in ion-uptake and salt-secreting pathways. PMID:26374626

  2. Po-210 and other radionuclides in terrestrial and freshwater environments

    Energy Technology Data Exchange (ETDEWEB)

    Gjelsvik, Runhild; Brown, Justin (eds.) (Norwegian Radiation Protection Authority (Norway)); Holm, Elis (Univ. of Lund (Sweden)); Roos, Per (Risoe DTU (Denmark)); Saxen, Ritva; Outola, Iisa (STUK - Radiation and Nuclear Safety Authority (Finland))

    2009-01-15

    This report provides new information on Po-210 (and where appropriate its grandparent Pb-210) behaviour in environmental systems including humans. This has primarily been achieved through measurements of Po-210 in aquatic and terrestrial environments that has led to the derivation of information on the levels of this radioisotope in plants, animals and the biotic components of their habitat (i.e. water, soil) providing basic information on transfer where practicable. For freshwater environments, Po-210 concentration ratios derived for freshwater benthic fish and bivalve mollusc were substantially different to values collated from earlier review work. For terrestrial environments, activity concentrations of Po-210 in small mammals (although of a preliminary nature because no correction was made for ingrowth from Pb-210) were considerably higher than values derived from earlier data compilations. It was envisaged that data on levels of naturally occurring radionuclides would render underpinning data sets more comprehensive and would thus allow more robust background dose calculations to be performed subsequently. By way of example, unweighted background dose-rates arising from internal distributions of Po-210 were calculated for small mammals in the terrestrial study. The biokinetics of polonium in humans has been studied following chronic and acute oral intakes of selected Po radioisotopes. This work has provided information on gastrointestinal absorption factors and biological retention times thus improving the database upon which committed effective doses to humans are derived. The information generated in the report, in its entirety, should be of direct relevance for both human and non-human impact assessments. (au)

  3. Study on the Groundwater Flow along the Seawater / Freshwater Interface

    Science.gov (United States)

    Marui, A.; Kusunose, K.

    2003-12-01

    The shape of Seawater / Freshwater Interface is effected by the groundwater flow at the coastal area, and decide the position of submarine groundwater discharge that should be existed everywhere in the world. The hydraulic gradient is too small to estimate the groundwater flow in the area, usually. On the other hand, the groundwater that discharges to the marine have to runs along this interface. And the water discharged to the marine is from the deep zone. That_fs why the water discharges to the marine (runs on the interface) might have many information of the deep zone of groundwater. The Hasunuma Beach Park located on the Kujyukuri Long Beach close to the New Tokyo Int_fl Airport is selected of the study for the groundwater flow along the Seawater / Freshwater Interface. The layered aquifer in the deposited rocks lies in the area, until over than 1000 m depth. The shape of the interface was observed by some kinds of physical sounding from the surface (e.g. specific electricity, AMT method), the logging data in the observation well (EC, T, Flow meter logging, Electric logging etc.) and water quality analysis (incl. Isotopes). And the Flow Meter measurement in the well was done, so that the actual groundwater flow was measured in the aquifer (in the crack of the aquifer, exactly). The observed groundwater flow is thought on the interface and the important element of the shape (angle and depth) of the interface, simultaneously. Two interfaces are found at the well point (200 m onshore). The shape of the interface was also confirmed from a diving work that found the submarine discharge of fresh groundwater at 320 m offshore. The distribution of pressure (hydraulic gradient) in the aquifer and the shape of the interface are made cleared by these tests. The progress expression of the Glover_fs solution was suggested by the study.

  4. Po-210 and other radionuclides in terrestrial and freshwater environments

    International Nuclear Information System (INIS)

    This report provides new information on Po-210 (and where appropriate its grandparent Pb-210) behaviour in environmental systems including humans. This has primarily been achieved through measurements of Po-210 in aquatic and terrestrial environments that has led to the derivation of information on the levels of this radioisotope in plants, animals and the biotic components of their habitat (i.e. water, soil) providing basic information on transfer where practicable. For freshwater environments, Po-210 concentration ratios derived for freshwater benthic fish and bivalve mollusc were substantially different to values collated from earlier review work. For terrestrial environments, activity concentrations of Po-210 in small mammals (although of a preliminary nature because no correction was made for ingrowth from Pb-210) were considerably higher than values derived from earlier data compilations. It was envisaged that data on levels of naturally occurring radionuclides would render underpinning data sets more comprehensive and would thus allow more robust background dose calculations to be performed subsequently. By way of example, unweighted background dose-rates arising from internal distributions of Po-210 were calculated for small mammals in the terrestrial study. The biokinetics of polonium in humans has been studied following chronic and acute oral intakes of selected Po radioisotopes. This work has provided information on gastrointestinal absorption factors and biological retention times thus improving the database upon which committed effective doses to humans are derived. The information generated in the report, in its entirety, should be of direct relevance for both human and non-human impact assessments. (au)

  5. A Complete Guide to the Freshwater Fishes of Southern Africa

    OpenAIRE

    Skelton, P.H.

    2012-01-01

    Those of us interested in freshwater fishes and related environmental issues have waited several years for Paul Skelton's A Complete Guide to the Freshwater Fishes of Southern Africa. The final result proves to be well worth the long wait, for with this book the author manages to disseminate a reasonable amount of detailed information on freshwater fishes to the layman, angler and naturalist. Although Skelton's book is not specifically aimed at the scientist, it contains condensed, updated an...

  6. Selenium accumulation in aquatic biota downstream of a uranium mining and milling operation

    International Nuclear Information System (INIS)

    Uranium mining and milling operations have the potential to release trace elements such as arsenic, molybdenum, nickel, selenium and uranium and ions (e.g., sulfate, ammonium) into the receiving aquatic ecosystem. The major implication of elevated environmental selenium is its propensity to accumulate in the aquatic food chain, potentially impairing fish reproduction. The objective of this study was to investigate the accumulation of selenium in the major compartments of aquatic ecosystems (lakes) upstream and downstream of a uranium mine in northern Saskatchewan, Canada. Selenium concentrations in aquatic biota were elevated in the exposure lake although water and sediment concentrations were low (0.43 ?g/L and 0.54 ?g/g dry weight, respectively). Biomagnification of selenium resulted in approximately 1.5 to 6 fold increase in the selenium concentration between plankton, invertebrates and fish. However, no biomagnification was observed between forage and predatory fish. Although some aquatic biota (e.g., forage fish) exceeded the lower limit of the proposed 3 to 11 ?g/g (dry weight) dietary toxicity threshold for fish, no adverse effects of selenium could be identified in this aquatic system. Continued environmental monitoring is recommended to avoid potential selenium impacts

  7. Natural Isotope Radium in Marine Biota at Kapar, Klang Coastal Area

    International Nuclear Information System (INIS)

    The activities concentration of 226Ra and 228Ra in marine biota at Kapar coastal area nearby Sultan Salahudin Abdul Aziz Shah Power Station (SJSSAAS) had been analyzed. The techniques that had been used to determine the activities concentration of 226Ra dan 228Ra are radiochemistry procedures and liquid scintillation counter (LSC). Results shows that the distribution of radium isotopes depend on the location and during sampling periods. The activities concentration of 226Rai and 228Rai in tissue were ranged 11.82 ± 5.23 Bq/ kg - 17.67 ± 6.81 Bq/ kg and 40.42 ± 16.20 Bq/ kg - 67.86 ± 23.11 Bq/ kg, respectively. The mean activities concentration of radium isotopes in bivalvia such as cockles (anadara granosa) are 61.73 ± 24.15 Bq/ kg (226Raag) and 232.62 ± 119.44 Bq/ kg (228Raag). Meanwhile for green mussles (perna viridis), the mean activities concentration of 226Rapv dan 228Rapv are 38.24 ± 14.19 Bq/ kg dan 99.59 ± 44.91 Bq/ kg, respectively. Concentration Factor (CF) in marine biota is higher than 1 x 104 and it is because of the accumulated radium isotopes is low and has a high affinity for organic matter. The study also shows the effectiveness of dose in radium isotopes were measured to ensure the safety of users and it is still below the limit allowed Malaysia which is 1 mSv / year. (author)

  8. Climate-change impacts on sandy-beach biota: crossing a line in the sand.

    Science.gov (United States)

    Schoeman, David S; Schlacher, Thomas A; Defeo, Omar

    2014-08-01

    Sandy ocean beaches are iconic assets that provide irreplaceable ecosystem services to society. Despite their great socioeconomic importance, beaches as ecosystems are severely under-represented in the literature on climate-change ecology. Here, we redress this imbalance by examining whether beach biota have been observed to respond to recent climate change in ways that are consistent with expectations under climate change. We base our assessments on evidence coming from case studies on beach invertebrates in South America and on sea turtles globally. Surprisingly, we find that observational evidence for climate-change responses in beach biota is more convincing for invertebrates than for highly charismatic turtles. This asymmetry is paradoxical given the better theoretical understanding of the mechanisms by which turtles are likely to respond to changes in climate. Regardless of this disparity, knowledge of the unique attributes of beach systems can complement our detection of climate-change impacts on sandy-shore invertebrates to add rigor to studies of climate-change ecology for sandy beaches. To this end, we combine theory from beach ecology and climate-change ecology to put forward a suite of predictive hypotheses regarding climate impacts on beaches and to suggest ways that these can be tested. Addressing these hypotheses could significantly advance both beach and climate-change ecology, thereby progressing understanding of how future climate change will impact coastal ecosystems more generally. PMID:25121188

  9. The 2.1 Ga Old Francevillian Biota: Biogenicity, Taphonomy and Biodiversity

    DEFF Research Database (Denmark)

    El Albani, Abderrazak; Bengtson, Stefan

    2014-01-01

    The Paleoproterozoic Era witnessed crucial steps in the evolution of Earth's surface environments following the first appreciable rise of free atmospheric oxygen concentrations similar to 2.3 to 2.1 Ga ago, and concomitant shallow ocean oxygenation. While most sedimentary successions deposited during this time interval have experienced thermal overprinting from burial diagenesis and metamorphism, the ca. 2.1 Ga black shales of the Francevillian B Formation (FB2) cropping out in southeastern Gabon have not. The Francevillian Formation contains centimeter-sized structures interpreted as organized and spatially discrete populations of colonial organisms living in an oxygenated marine ecosystem. Here, new material from the FB2 black shales is presented and analyzed to further explore its biogenicity and taphonomy. Our extended record comprises variably sized, shaped, and structured pyritized macrofossils of lobate, elongated, and rodshaped morphologies as well as abundant non-pyritized disk-shaped macrofossils and organic-walled acritarchs. Combined microtomography, geochemistry, and sedimentary analysis suggest a biota fossilized during early diagenesis. The emergence of this biota follows a rise in atmospheric oxygen, which is consistent with the idea that surface oxygenation allowed the evolution and ecological expansion of complex megascopic life.

  10. Perfluorinated compounds in water, sediment, soil and biota from estuarine and coastal areas of Korea

    International Nuclear Information System (INIS)

    Soil, sediment, water, and biota collected from the western coast of Korea were analyzed to determine occurrence and sources of perfluorinated compounds (PFCs). PFCs were significantly concentrations of PFCs were measured in some water and biological samples, while concentrations of PFCs in soils and sediments were relatively low. The most widely detected compound was found to be perfluorooctanesulfonate (PFOS), with a maximum concentration in water of 450 ng/L and in fish of 612 ng/g, dw. PFOS concentrations in water and biota were both less than those thought to cause toxicity. However, in both cases concentrations were within a factor of 10 of the toxicity threshold concentration. Concentrations of PFCs were significantly greater downstream than those upstream on the same river, suggesting point sources. Overall, the detection of PFCs at relatively great concentrations in various environmental matrixes from this region of Korea suggests that further studies characterizing PFCs and their potential risk to both humans and wildlife are needed. - Among various environmental media measured, water and biological samples showed relatively high degrees of PFC contamination with the existence of point sources mainly upstream of coastal areas in Korea.

  11. Selenium accumulation in aquatic biota downstream of a uranium mining and milling operation.

    Science.gov (United States)

    Muscatello, J R; Janz, D M

    2009-02-01

    Uranium mining and milling operations have the potential to release trace elements such as arsenic, molybdenum, nickel, selenium and uranium and ions (e.g., sulfate, ammonium) into the receiving aquatic ecosystem. The major implication of elevated environmental selenium is its propensity to accumulate in the aquatic food chain, potentially impairing fish reproduction. The objective of this study was to investigate the accumulation of selenium in the major compartments of aquatic ecosystems (lakes) upstream and downstream of a uranium mine in northern Saskatchewan, Canada. Selenium concentrations in aquatic biota were elevated in the exposure lake although water and sediment concentrations were low (0.43 microg/L and 0.54 microg/g dry weight, respectively). Biomagnification of selenium resulted in approximately 1.5 to 6 fold increase in the selenium concentration between plankton, invertebrates and fish. However, no biomagnification was observed between forage and predatory fish. Although some aquatic biota (e.g., forage fish) exceeded the lower limit of the proposed 3 to 11 microg/g (dry weight) dietary toxicity threshold for fish, no adverse effects of selenium could be identified in this aquatic system. Continued environmental monitoring is recommended to avoid potential selenium impacts. PMID:19036410

  12. Efectos de la biota edáfica en las interacciones planta-insecto a nivel foliar

    Directory of Open Access Journals (Sweden)

    E. de la Peña

    2009-01-01

    Full Text Available A pesar de la inmensa diversidad de especies que habitan en el suelo y de la importancia funcional que tiene la biota edáfica tanto a nivel de comunidad como de ecosistema, la teoría ecológica ha tenido tradicionalmente sólo en cuenta las interacciones que ocurren en la parte aérea de las plantas. Recientemente esta situación ha cambiado y durante los últimos diez años se han publicado numerosos estudios que destacan la importancia que tienen las interacciones bióticas entre plantas y organismos edáficos sobre diferentes procesos que se dan enla parte aérea. Estos estudios han demostrado que las interacciones que se dan entre las raíces y los herbívoros edáficos, los hongos mutualistas y la flora microbiana, tienen efecto no sólo en el crecimiento de las plantas sino también en niveles tróficos superiores como son los herbívoros foliares, parasitoides, hiperparasitoides y polinizadores. En este artículo se hace una breve revisión de los mecanismos fundamentales que median la relación entre la biota edáfica y las interacciones bióticas de la parte aérea. Por último, se proponen abordajes complementarios como son la utilización de modelos espaciales y el estudio de estas interacciones desde una perspectiva evolutiva.

  13. Probabilistic risk evaluation for triclosan in surface water, sediments, and aquatic biota tissues.

    Science.gov (United States)

    Lyndall, Jennifer; Fuchsman, Phyllis; Bock, Michael; Barber, Timothy; Lauren, Darrel; Leigh, Katrina; Perruchon, Elyse; Capdevielle, Marie

    2010-07-01

    Triclosan, an antimicrobial compound used in personal care products, occurs in the aquatic environment due to residual concentrations in municipal wastewater treatment effluent. We evaluate triclosan-related risks to the aquatic environment, for aquatic and sediment-dwelling organisms and for aquatic-feeding wildlife, based on measured and modeled exposure concentrations. Triclosan concentrations in surface water, sediment, and biota tissue are predicted using a fugacity model parameterized to run probabilistically, to supplement the limited available measurements of triclosan in sediment and tissue. Aquatic toxicity is evaluated based on a species sensitivity distribution, which is extrapolated to sediment and tissues assuming equilibrium partitioning. A probabilistic wildlife exposure model is also used, and estimated doses are compared with wildlife toxicity benchmarks identified from a review of published and proprietary studies. The 95th percentiles of measured and modeled triclosan concentrations in surface water, sediment, and biota tissues are consistently below the 5th percentile of the respective species sensitivity distributions, indicating that, under most scenarios, adverse affects due to triclosan are unlikely. PMID:20821705

  14. STUDI ANALISIS PENGUJIAN LOGAM BERAT PADA BADAN AIR, BIOTA DAN SEDIMEN DI PERAIRAN MUARA DAS BARITO

    Directory of Open Access Journals (Sweden)

    Dini Sofarini

    2010-02-01

    Full Text Available This research aimed to determine heavy metal content at water body, sediment and biota, determining plankton what overflows and parameter of water quality which not fulfill standard criterion quality of water in Estuary of Barito River. Result of research showed that heavy metal rate at body of water especially Hg (0,2753 mg/l, and Pb (0,17667 mg/l residing at biota (Giant Prawn have accumulate by heavy metal of Hg. Pb, Cu, As, Cr6+ and Cd. Sediment residing at Estuary of Barito River have accumulate by heavy metal but still under maximum boundary which have been specified. Metal rate residing in boundary sill that is cadmium metal rate (Cd with assess metal range average 0,5655 - 0,8891 ppm, residing in of sill which have been specified equal to 0,3 ppm. Status of water quality at station perception according to Model of STORET categorized is weight, while pursuant to Model of Environmental Quality Index ( EQI categorized as impure territorial water.

  15. ANAEROBIC DIGESTION OF ANIMAL MANURE – IMPLICATIONS FOR CROP YIELDS AND SOIL BIOTA IN ORGANIC FARMING

    DEFF Research Database (Denmark)

    Johansen, Anders; Pommeresche, Reidun

    Anaerobic digestion of farmyard manures may help farmers to produce bioenergy instead of using fossil fuels, support cycling of nutrients and reduce greenhouse gas emission. However, compared to pristine slurry, digested slurry has a reduced content of organic carbon which may impact the soil biota negatively due to substrate shortage. Our knowledge on these processes and their influence on soil quality is scarce. Hence, a field experiment with two organic cropping systems (grass-clover ley and arable system; at two slurry-application levels) was established in 2011, to study how application of digestates affects crop yields, soil characteristics and soil biota (earthworms, springtails, microbiota). The grass-clover system showed comparable yield levels over 3 years when digested slurry was compared to untreated slurry. Digested slurries had no influence on soil nutrient concentrations or on soil organic matter levels over the first 2 years. Application of high levels of manure increased the mortality of bothsurface-dwelling and soil-living earthworms just after application, but the long-term effect of manure application seemed more positive, especially at low application levels. Springtails and microorganisms seemed only little affected by application of digested slurry.

  16. Organochlorine pesticides in sediment and biota in the coastal region to the South of the Pinar del Rio Province, Cuba

    International Nuclear Information System (INIS)

    A study was conducted to assess the levels of persistent organochlorine pesticides in the coastal region near to a large rice field to the south of the Pinar del Rio Province in Cuba. Samples of sediment and biota (Isognomon alatus) were taken periodically over a period of 14 months. Analysis of organochlorines, polychlorinated biphenyls and other related compounds was done using gas chromatography-electron capture detection with a mean recovery of 87% and a detection limit of 0.25 ?g/kg. Only DDT, DDE and DDD were found in the sediment and biota samples, with small differences in concentration between sampling sites during the dry season. After the rainy season began, the residues in sediment were very low, while the concentrations in biota remained comparatively unchanged, ranging from 11.2 to 23.8 ?g/kg total DDT. (author). 4 refs, 2 tabs

  17. Radionuclide accumulation by aquatic biota exposed to contaminated water in artificial ecosystems before and after its passage through the ground

    International Nuclear Information System (INIS)

    This study was designed to investigate the comparative accumulation of radionuclides from contaminated water in artificial ecosystems before and after the water's passage through the ground. Fish, clams, algae, and an emergent vascular plant were experimentally exposed to mixtures of radionuclides in three aqueous streams. Two streams consisted of industrial water discharged directly into a leaching trench, and the same water after it had migrated through the ground for a distance of 260 meters. The third stream was river water, which served as a background or control. Biota exposed to river water in the control stream had very low concentrations of 60Co, less than 3 pCi per gram dry weight (pCi/g DW). Other radionuclides were essentially unmeasurable. Biota exposed to trench water accumulated very high relative concentrations of 60Co. Biota exposed to trench water also had measurable concentrations of 155Eu, 144Ce, 141Ce, 125Sb, 124Sb, 103Ru, 106Ru, 137Cs, 95Zr, 95Nb, 58Co, 54Mn, 59Fe, 65Zn, 90Sr, /sup 239,240/Pu, and 238Pu. Biota exposed to ground water had concentrations of 60Co that ranged between 50 and 1200 pCi/g DW. Fish flesh had the lowest concentration of 60Co and algae the highest. Strontium-90 was measured in the tissues of aquatic biota at concentrations ranging between 360 pCi/g DW in clam flesh to 3400 pCi/g DW in leaves and stems of Veronica. Leaves and fruits of tomato plants rooted in the ground water accumulated 90Sr at concentrations of 160 pCi in fruits and 4200 pCi in leaves. Data indicate that 60Co and 90Sr migrated through the ground along with ground-water flow and were available to all classes of aquatic biota and tomato plants rooted in the water via root uptake, sorption, and food chain transfers. 8 refs., 4 figs., 6 tabs

  18. In vivo bafilomycin-sensitive Na(+) uptake in young freshwater fish

    Science.gov (United States)

    Fenwick; Wendelaar Bonga SE; Flik

    1999-12-01

    In vivo treatment with external bafilomycin A(1), a selective inhibitor of V-ATPase H(+) pumps, reduced whole-body Na(+) influx by up to 90 % in young tilapia and 70 % in young carp. The inhibition was rapidly reversible, with whole-body Na(+) influx rebounding to 280 % of pre-treatment values within 20 min of removal from the bafilomycin. This rebound effect is consistent with the prior accumulation of protons during the period when the cells were exposed to bafilomycin. Bafilomycin also inhibited Cl(-) uptake, an effect that was still apparent 30 min after the removal of bafilomycin. These data provide circumstantial evidence for previous suggestions that Na(+) uptake in freshwater fish is associated with a proton-motive force created by a proton pump and indirect evidence for the major significance of this mechanism in the branchial uptake of Na(+) by freshwater fish. PMID:10574743

  19. Assessment of Total Mercury (HgT) in Sediments and Biota of Indian Sundarban Wetland and Adjacent Coastal Regions

    OpenAIRE

    Mousumi Chatterjee; Lucas Sklenars; Chenery, Simon R.; Michael J. Watts; Andrew Lewis Marriott; Debyendu Rakshit; Sarkar, Santosh K.

    2014-01-01

    The distribution of total mercury (HgT) in surface sediments (0-5 cm; n = 12; particle size < 63 µm) and representative biota (benthic polychaetes, bivalve mollusks and finfish) were observed in the Sundarban mangrove wetland and adjacent regions nearby the Indian Ganges river estuary. Relatively low concentrations of HgT were measured in sediments ranging from 0.008 µg g-1 to 0.056 µg g-1. There exist sharp differences in HgT accumulation in biota which revealed the following decreasing t...

  20. An international comparison of models and approaches for the estimation of the radiological exposure of non-human biota

    International Nuclear Information System (INIS)

    Over the last decade a number of models and approaches have been developed for the estimation of the exposure of non-human biota to ionising radiations. In some countries these are now being used in regulatory assessments. However, to date there has been no attempt to compare the outputs of the different models used. This paper presents the work of the International Atomic Energy Agency's EMRAS Biota Working Group which compares the predictions of a number of such models in model-model and model-data inter-comparisons

  1. An international comparison of models and approaches for the estimation of the radiological exposure of non-human biota.

    Energy Technology Data Exchange (ETDEWEB)

    Beresford, N. A.; Balonov, M.; Beaugelin-Seiller, K.; Brown, J.; Copperstone, D.; Hingston, J. L.; Horyna, J.; Hosseini, A.; Howard, B. J.; Kamboj, S.; Nedveckaite, T.; Olyslaegers, G.; Sazykina, T.; Vives i Batlle, J.; Yankovich , T. L.; Yu, C.; Environmental Science Division; Centre for Ecology and Hydrology; Inter. Atomic Energy Agency; Inst. de Radioprotection et de Surete Nucleaire; Norwegian Radiatioin Protection Authority; England & Wales Environment Agency; SUJB; Inst. of Physics; SCK CEN; SPA-Typhoon; Westlakes Scientific Consulting Limited; Atomic Energy Canada Limited

    2008-01-01

    Over the last decade a number of models and approaches have been developed for the estimation of the exposure of non-human biota to ionizing radiations. In some countries these are now being used in regulatory assessments. However, to date there has been no attempt to compare the outputs of the different models used. This paper presents the work of the International Atomic Energy Agency's EMRAS Biota Working Group which compares the predictions of a number of such models in model-model and model-data inter-comparisons.

  2. An international comparison of models and approaches for the estimation of the radiological exposure of non-human biota

    Energy Technology Data Exchange (ETDEWEB)

    Beresford, Nicholas A. [Centre for Ecology and Hydrology - Lancaster, Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster LA1 4AP (United Kingdom)], E-mail: nab@ceh.ac.uk; Balonov, Mikhail [International Atomic Energy Agency (Austria); Beaugelin-Seiller, Karine [Institut de Radioprotection et de Surete Nucleaire (France); Brown, Justin [Norwegian Radiation Protection Authority (Norway); Copplestone, David; Hingston, Joanne L. [England and Wales Environment Agency (United Kingdom); Horyna, Jan [SUJB (Czech Republic); Hosseini, Ali [Norwegian Radiation Protection Authority (Norway); Howard, Brenda J. [Centre for Ecology and Hydrology - Lancaster, Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster LA1 4AP (United Kingdom); Kamboj, Sunita [Argonne National Laboratory (United States); Nedveckaite, Tatjana [Institute of Physics (Lithuania); Olyslaegers, Geert [SCK CEN (Belgium); Sazykina, Tatiana [SPA-Typhoon (Russian Federation); Vives i Batlle, Jordi [Westlakes Scientific Consulting Limited (United Kingdom); Yankovich, Tamara L. [Atomic Energy Canada Limited (Canada); Yu, Charley [Argonne National Laboratory (United States)

    2008-11-15

    Over the last decade a number of models and approaches have been developed for the estimation of the exposure of non-human biota to ionising radiations. In some countries these are now being used in regulatory assessments. However, to date there has been no attempt to compare the outputs of the different models used. This paper presents the work of the International Atomic Energy Agency's EMRAS Biota Working Group which compares the predictions of a number of such models in model-model and model-data inter-comparisons.

  3. Comparative study of RESRAD-BIOTA and ERICA programs in assessment of radiation effect on pelagic fish

    International Nuclear Information System (INIS)

    RESRAD-BIOTA and ERICA are two comparatively mature programs to assess non-human species radiation effect in the world. The comparison and analysis of these two programs were carried out from the definition of reference organism, screening method, computation theory, and so on. These two programs were used to assess radiation effect of radioactive liquid on a kind of aquatic biota near a Chinese nuclear power plant sited in coastal area. Finally, the computation results, advantages and disadvantages of these two programs are compared and analyzed. (authors)

  4. Carbon-14 Specific Activity Model Validation for Biota in Wetland Environments

    International Nuclear Information System (INIS)

    In many cases, contaminants, such as radionuclides, can show highly localized spatial distributions in natural systems. Therefore, a key question for environmental assessment and monitoring becomes, how can these localized distributions of contaminants in the environment lead to organism exposure, and ultimately, the potential for effects to receptor biota? To address this question, an important first step is to conduct field surveys at sites of interest to map out the spatial distribution and extent of contaminants in areas that are being occupied and utilized by resident receptor biota. Work can then be conducted to establish predictive relationships between contaminant concentrations in biota tissues and those in environmental media with which biota interact, to gain an understanding of how representative ambient contaminant concentrations are of biota exposure. The objectives of this study were: - To conduct a field survey in a wetland ecosystem to characterize the spatial distribution of carbon- 14 (14C), a radionuclide with dynamics in natural systems that can be described using a specific activity model; and - To determine whether 14C concentrations in environmental media reflect those measured in tissues of resident flora and fauna. A detailed field campaign was carried out in summer 2001 to characterize the spatial distribution and areal coverage of 14C in Duke Swamp, a wetland ecosystem on Atomic Energy of Canada Limited (AECL)'s Chalk River Laboratories (CRL) site that receives 14C through releases from an up-gradient Waste Management Area (WMA), primarily through groundwater influx. Sampling of surface vegetation (dominantly comprised of Sphagnum moss) was conducted at a total of 69 locations, with complementary sampling of air, soil, fungi, aerial insects, ground-dwelling insects, amphibians, small mammals and snakes being carried out at a subset of five locations with varying 14C concentrations. Concentrations of 14C in resident Duke Swamp biota were compared to levels measured in environmental media (including moss, soil and air) to determine whether concentrations in such media reflect animal exposure, for application in routine environmental monitoring programs on the CRL site. In general, for most types of receptor animals, 14C specific activities were found to be similar to or less than those measured in air, soil and surface vegetation at all locations sampled, suggesting that in most cases, estimates of 14C levels in animals could either be realistically or conservatively predicted based on the values measured in environmental media. In the case of fungi, receptor-to-media 14C specific activity ratios fell between 0.04 and 0.23 relative to air, between 0.03 and 0.70 relative to soil, and between 0.078 and 0.31 relative to moss. Small mammal specific activities also generally fell well below those that would be predicted based on specific activities measured in environmental media, with ratios ranging from 0.11 to 0.36 relative to air, from 0.17 to 0.85 relative to soil and from 0.21 to 0.58 relative to moss. Similar ratios were also established for snakes; however, a notable exception occurred for amphibians, a type of animal that tends to spend relatively more time in aquatic environments than the other species tested. In the case of Duke Swamp amphibians, animal-to-air 14C specific activity ratios ranged from 0.40 to 2.3, animal-to-soil ratios ranged from 0.81 to 3.4 and animal-to-moss ratios ranged from 1.5 to 2.4. These higher 14C levels in amphibians relative to the environmental media may be due to increased 14C exposure of aquatic or amphibious animals that occupy systems receiving inputs via groundwater. In such systems, 14C is incorporated in aquatic plants and animals, and later transferred to higher predatory species, such as amphibians, that consume them. Therefore, with the exception of amphibians and other aquatic receptor species, it is reasonable to estimate concentrations of 14C in receptor biota in wetland environments like Duke Swamp at CRL, based on measurements of 14C in environm

  5. Practical aids for freshwater spill response

    International Nuclear Information System (INIS)

    The current research program at API is focused on the environmental and human health effects from oil spills in freshwater habitats. Components of the program include lessons learned from spill response, development of decision-making protocols for the use of chemicals during initial response operations, preparation of a manual for spill response and contingency planning, and a review of the literature on environmental and human health effects from inland spills. API has reviewed past inland spill responses to identify lessons learned. A survey questionnaire has been developed to collect information from freshwater spill responders on their successes and difficulties in response operations. The questionnaire is tailored to focus on the impact to the operations from the absence of technical/scientific data on environmental effects or operation effectiveness/efficiency as well as to identify situations in which the use of particular response or cleanup options is likely to be effective. The questionnaires will be available at the Conference. Published case studies also will be examined for lessons-learned information. The results will be used to identify and prioritize API research needs in freshwater spill response. General concerns about the effectiveness of the toxicity associated with chemicals in spill response has prevented their use in fresh water. API has begun a detailed survey and interview process with state and federal regulatory personnel to identify their concerns and decision criteria to evaluate the use of chemicals in initial spill response. Ten classes of chemicals were identified for consideration: dispersants, shoreline cleaners, shoreline protection agents, herding agents, solidifiers, demulsifiers, emulsion inhibitors, foaming agents, oxidizing agents, and burning agents

  6. Freshwater flux to Sermilik Fjord, SE Greenland

    Directory of Open Access Journals (Sweden)

    S. H. Mernild

    2010-07-01

    Full Text Available Fluctuations in terrestrial surface freshwater flux to Sermilik Fjord, SE Greenland, were simulated and analyzed. SnowModel, a state-of-the-art snow-evolution, snow and ice melt, and runoff modeling system, was used to simulate the temporal and spatial terrestrial runoff distribution to the fjord based on observed meteorological data (1999–2008 from stations located on and around the Greenland Ice Sheet (GrIS. Simulated runoff was compared and verified against independent glacier catchment runoff observations (1999–2005. Modeled runoff to Sermilik Fjord was highly variable, ranging from 2.9×109 m3 y?1 in 1999 to 5.9×109 m3 y?1 in 2005. The uneven spatial runoff distribution produced an areally-averaged annual maximum runoff at the Helheim glacier terminus of more than 3.8 m w.eq. The sub-catchment runoff of the Helheim glacier region accounted for 25% of the total runoff to Sermilik Fjord. The runoff distribution from the different sub-catchments suggested a strong influence from the spatial variation in glacier coverage. To assess the Sermilik Fjord freshwater flux, simulated terrestrial runoff and net precipitation (precipitation minus evaporation and sublimation for the fjord area were combined with satellite-derived ice discharge and subglacial geothermal and frictional melting due to basal ice motion. A terrestrial freshwater flux of ~40.4×109 m3 y?1 was found for Sermilik Fjord, with an 11% contribution originated from surface runoff. For the Helheim glacier sub-catchment only 4% of the flux originated from terrestrial surface runoff.

  7. Environmental occurrence and biota concentration of phthalate esters in Epe and Lagos Lagoons, Nigeria.

    Science.gov (United States)

    Adeogun, Aina O; Ibor, Oju R; Omogbemi, Emmanuel D; Chukwuka, Azubuike V; Adegbola, Rachel A; Adewuyi, Gregory A; Arukwe, Augustine

    2015-07-01

    The high global occurrence of phthalates in different environmental matrixes has resulted in the detection of their metabolites in human urine, blood, and breast milk, indicating a widespread human exposure. In addition, the notorious endocrine disrupting effects of phthalates have shown that they mimic or antagonize the action of endogenous hormones, consequently producing adverse effects on reproduction, growth and development. Herein, we have studied the occurrence of phthalate esters (PEs) in water, sediment and biota of two lagoons (Epe and Lagos) in Nigeria. Two fish species (Tilapia guineensis, and Chrysichthys nigrodigitatus) and a crustacean (the African river prawn--Macrobrachium vollenhovenii) were analyzed for PEs levels using a HPLC method and the derived values were used for calculating bioconcentration factor (BCF), biota-sediment accumulation factor (BSAF) and phthalate pollution index (PPI) in the biota and environment. We observed that the growth and health condition of the fish species were normal with a k-factor of >1. Sediment PE levels were compared with water, at both lagoons showing concentration pattern that is characterized as DEHP = DEP > DBP. We observed that DBP was the predominant compound in T. guineensis, C. nigrodigitatus and African prawn, at both lagoons, showing organ-specific differences in bioconcentration (BCF and BSAF) patterns in the fish species. While there were no observed consistency in the pattern of PE concentration in fish organs, elevated DBP levels in different fish organs may be related to fish habitat and degradation level of phthalates. Low concentration of DEHP, compared with DBP and DEP, was measured in fish organs and whole prawn body. The BSAF values for DEHP were lowest, and highest for DBP for all species at both lagoons, and DEHP easily accumulated more in the sediment (sediment PPI = 0.28 and 0.16 for Epe and Lagos lagoon, respectively). Overall, our findings suggest a broader environmental and human health implication of the high PE levels in these lagoons since they represent significant sources of aquatic food resources for the neighboring communities. PMID:25935094

  8. Environmental assessment of water, sediment, and biota collected from the Bear Creek watershed, Colusa County, California

    Science.gov (United States)

    Rytuba, James J.; Hothem, Roger L.; Brussee, Brianne E.; Goldstein, Daniel; May, Jason T.

    2015-01-01

    The Cache Creek watershed lies within California's North Coast Range, an area with abundant geologic sources of mercury (Hg) and a long history of Hg contamination (Rytuba, 2000). Bear Creek, Cache Creek, and the North Fork of Cache Creek are the major streams of the Cache Creek watershed, encompassing 2978 km2. The Cache Creek watershed contains soils naturally enriched in Hg as well as natural springs (both hot and cold) with varying levels of aqueous Hg (Domagalski and others, 2004, Suchanek and others, 2004, Holloway and others 2009). All three tributaries are known to be significant sources of anthropogenically derived Hg from historic mines, both Hg and gold (Au), and associated ore storage/processing sites and facilities (Slotton and others, 1995, 2004; CVRWQCB, 2003; Schwarzbach and others, 2001; Gassel and others, 2005; Suchanek and others., 2004, 2008a, 2009). Historically, two of the primary sources of mercury contamination in the upper part of Bear Creek have been the Rathburn and Petray Hg Mines. The Rathburn Hg mine was discovered and initially mined in the early 1890s. The Rathburn and the more recently developed Petray open pit mines are localized along fault zones in serpentinite that has been altered and cut by quartz and chalcedony veins. Cold saline-carbonate springs are located perepheral to the Hg deposits and effluent from the springs locally has high concentrations of Hg (Slowey and Rytuba, 2008). Several ephemeral tributaries to Bear Creek drain the mine area which is located on federal land managed by the U.S. Bureau of Land Management (USBLM). The USBLM requested that the U.S. Geological Survey (USGS) measure and characterize Hg and other geochemical constituents in sediment, water, and biota to establish baseline information prior to remediation of the Rathburn and Petray mines. Samples sites were established in Bear Creek upstream and downstream from the mine area. This report is made in response to the USBLM request, the lead agency mandated to conduct a Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) - Removal Site Investigation (RSI). The RSI applies to the possible removal of Hg-contaminated mine waste from Bear Creek. This report summarizes data obtained from field sampling of water, sediment, and biota in Bear Creek, above input from the mine area and downstream from the Rathburn-Petray mine area to the confluence with Cache Creek. Our results permit a preliminary assessment of the chemical constituents that could elevate levels of monomethyl Hg (MMeHg) in Bear Creek and its uptake by biota and provide baseline information for comparison to conditions after mine remediation is completed.

  9. Tropical versus high latitude freshwater influence on the Atlantic circulation

    Energy Technology Data Exchange (ETDEWEB)

    Goelzer, Heiko; Levermann, Anders; Rahmstorf, Stefan [Potsdam Institute for Climate Impact Research, Potsdam (Germany); Mignot, Juliette [Institut Pierre Simon Laplace, Unite mixte de Recherche CNRS/IRD/UPMC, Laboratoire d' Oceanographie et du Climat, Experimentations et Approches Numeriques, Paris Cedex 05 (France)

    2006-12-15

    We investigate the model sensitivity of the Atlantic meridional overturning circulation (AMOC) to anomalous freshwater flux in the tropical and northern Atlantic. Forcing in both locations leads to the same qualitative response: a positive freshwater anomaly induces a weakening of the AMOC and a negative freshwater anomaly strengthens the AMOC. Strong differences arise in the temporal characteristics and amplitude of the response. The advection of the tropical anomaly up to the deep water formation area leads to a time delayed response compared to a northern forcing. Thus, in its transient response, the AMOC is less sensitive to a constant anomalous freshwater flux in the tropics than in the north. This difference decreases with time and practically vanishes in equilibrium with constant freshwater forcing. The equilibrium response of the AMOC shows a non-linear dependence on freshwater forcing in both locations, with a stronger sensitivity to positive freshwater forcing. As a consequence, competitive forcing in both regions is balanced when the negative forcing is about 1.5 times larger than the positive forcing. The relaxation time of the AMOC after termination of a freshwater perturbation depends significantly on the AMOC strength itself. A strong overturning exhibits a faster relaxation to its unperturbed state. By means of a set of complementary experiments (pulse-perturbations, constant and stochastic forcing) we quantify these effects and discuss the corresponding time scales and physical processes. (orig.)

  10. Dynamic model for the assessment of radiological exposure to marine biota

    International Nuclear Information System (INIS)

    A generic approach has been developed to simulate dynamically the uptake and turnover of radionuclides by marine biota. The approach incorporates a three-compartment biokinetic model based on first order linear kinetics, with interchange rates between the organism and its surrounding environment. Model rate constants are deduced as a function of known parameters: biological half-lives of elimination, concentration factors and a sample point of the retention curve, allowing for the representation of multi-component release. The new methodology has been tested and validated in respect of non-dynamic assessment models developed for regulatory purposes. The approach has also been successfully tested against research dynamic models developed to represent the uptake of technetium and radioiodine by lobsters and winkles. Assessments conducted on two realistic test scenarios demonstrated the importance of simulating time-dependency for ecosystems in which environmental levels of radionuclides are not in equilibrium

  11. Floodplain data: ecosystem characteristics and 137Cs concentrations in biota and soil

    International Nuclear Information System (INIS)

    Radiocesium (137Cs) distribution was determined in soil, roots, ground vegetation, overstory, litter, mammals, feces, and insects for a floodplain ecosystem contaminated by radioactive wastes from Manhattan Project operations in 1944. The 2-ha research site was located on the ERDA reservation, Oak Ridge, Tennessee, in a drained holding pond between Oak Ridge National Laboratory and White Oak Lake. Maximum 137Cs concentrations in soil occurred near the old retention pond dam (84,400 pCi/g) and at the upper portion of the floodplain boundary (70,500 pCi/g). This bimodal distribution pattern of 137Cs was evident for all samples collected. Large amounts of data have been collected since the summer of 1974. This report documents the data on ecosystem characteristics and 137Cs concentrations in biota and soil

  12. A well-preserved aneuretopsychid from the Jehol Biota of China (Insecta, Mecoptera,?Aneuretopsychidae

    Directory of Open Access Journals (Sweden)

    Dong Ren

    2011-09-01

    Full Text Available The Aneuretopsychidae is an unspeciose and enigmatic family of long-proboscid insects that presently consist of one known genus and three species from the Late Jurassic to Early Cretaceous of north-central Asia. In this paper, a new genus and species of fossil aneuretopsychid is described and illustrated, Jeholopsyche liaoningensis gen. et sp. n. Fossils representing this new taxon were collected from mid Early Cretaceous strata of the well known Jehol Biota in Liaoning Province, China. This finding documents the first formal record of fossil Aneuretopsychidae in China. In addition, this well-preserved and new material reveals previously unknown and detailed morphological structure of the mouthparts, antennae, head, thorax, legs and abdomen of this distinctive insect lineage.

  13. A well-preserved aneuretopsychid from the Jehol Biota of China (Insecta, Mecoptera, Aneuretopsychidae).

    Science.gov (United States)

    Ren, Dong; Shih, Chungkun; Labandeira, Conrad C

    2011-01-01

    The Aneuretopsychidae is an unspeciose and enigmatic family of long-proboscid insects that presently consist of one known genus and three species from the Late Jurassic to Early Cretaceous of north-central Asia. In this paper, a new genus and species of fossil aneuretopsychid is described and illustrated, Jeholopsyche liaoningensisgen. et sp. n. Fossils representing this new taxon were collected from mid Early Cretaceous strata of the well known Jehol Biota in Liaoning Province, China. This finding documents the first formal record of fossil Aneuretopsychidae in China. In addition, this well-preserved and new material reveals previously unknown and detailed morphological structure of the mouthparts, antennae, head, thorax, legs and abdomen of this distinctive insect lineage. PMID:21998553

  14. Fruit and seed floras from exceptionally preserved biotas in the European Paleogene

    Directory of Open Access Journals (Sweden)

    Hayes P

    2010-03-01

    Full Text Available Fossil fruit and seed assemblages from two exceptionally preserved biotas provide considerable information about systematics, diversity, dispersal biology and plant animal interactions in the European Paleogene. The first is from the Middle Eocene Messel oil shale in the Messel Pit near Darmstadt, Germany and occurs in association with exceptionally preserved flowers, insects and vertebrates. The second is from the latest Eocene Insect Limestone (Bembridge Marls Member, Solent Group from the northern coast of the Isle of Wight, UK and occurs in association with exceptionally preserved insects. These two assemblages of compressed fruits and seeds both preserve delicate structures including plumes, wings and a fruit with a long awn. The Messel site also has rare, completely preserved fruiting heads and other specimens with organic connections, preservation of soft tissues, and seeds found within animal gut contents. The Messel flora is especially important for understanding Middle Eocene dispersal biology, biogeography and floristic diversity.

  15. Abiotic causes of the great mass extinction of marine biota at the Triassic-Jurassic boundary

    Science.gov (United States)

    Barash, M. S.

    2015-05-01

    In the interval of the Triassic-Jurassic boundary up to 80% of marine species became extinct. The main hypotheses on the causes of this mass extinction are reviewed. The extinction was triggered by a powerful eruption of basalts in the Central Atlantic Magmatic Province. In addition, several impact craters have been found. Extraterrestrial factors resulted in two main sequences of events: terrestrial, leading to strong volcanism, and extraterrestrial (impact events). They produced similar effects: emissions of harmful chemical compounds and aerosols. Consequences included the greenhouse effect, darkening of the atmosphere (which prevented photosynthesis), stagnation of the oceans, and anoxia. Biological productivity decreased; food chains collapsed. As a result, all vital processes were disturbed, and a large portion of the biota went extinct.

  16. Isolation of microplastics in biota-rich seawater samples and marine organisms

    Science.gov (United States)

    Cole, Matthew; Webb, Hannah; Lindeque, Pennie K.; Fileman, Elaine S.; Halsband, Claudia; Galloway, Tamara S.

    2014-03-01

    Microplastic litter is a pervasive pollutant present in aquatic systems across the globe. A range of marine organisms have the capacity to ingest microplastics, resulting in adverse health effects. Developing methods to accurately quantify microplastics in productive marine waters, and those internalized by marine organisms, is of growing importance. Here we investigate the efficacy of using acid, alkaline and enzymatic digestion techniques in mineralizing biological material from marine surface trawls to reveal any microplastics present. Our optimized enzymatic protocol can digest >97% (by weight) of the material present in plankton-rich seawater samples without destroying any microplastic debris present. In applying the method to replicate marine samples from the western English Channel, we identified 0.27 microplastics m-3. The protocol was further used to extract microplastics ingested by marine zooplankton under laboratory conditions. Our findings illustrate that enzymatic digestion can aid the detection of microplastic debris within seawater samples and marine biota.

  17. Sensing of Scent, Fragrance, Smell, and Odor Emissions from Biota Sources

    Directory of Open Access Journals (Sweden)

    Ki-Hyun Kim

    2014-04-01

    Full Text Available People encounter enormous numbers of chemicals present in the outdoor atmosphere and/or in the various facilities they use daily. Despite such diversity, not many of them have necessarily the potential to draw human’s nasal attraction if their perception thresholds are in general not sufficiently low enough, regardless of abundance. In this sense, many types of scents, musks, fragrances, smells, odors, and pheromones are unique enough to draw a great deal of attention mainly by their presence at or near threshold levels which are far lower than those of common chemicals with poor odorant characteristics. It is known that most of the diverse characters of odor-related ingredients or expressions are commonly produced from various biota sources present in the biosphere, e.g., fauna, flora, bacteria, fruits, flowers, trees, meats, fresh/decaying foods, etc.

  18. Sediment erodability in sediment transport modelling: Can we account for biota effects?

    Science.gov (United States)

    Le Hir, P.; Monbet, Y.; Orvain, F.

    2007-05-01

    Sediment erosion results from hydrodynamic forcing, represented by the bottom shear stress (BSS), and from the erodability of the sediment, defined by the critical erosion shear stress and the erosion rate. Abundant literature has dealt with the effects of biological components on sediment erodability and concluded that sediment processes are highly sensitive to the biota. However, very few sediment transport models account for these effects. We provide some background on the computation of BSS, and on the classical erosion laws for fine sand and mud, followed by a brief review of biota effects with the aim of quantifying the latter into generic formulations, where applicable. The effects of macrophytes, microphytobenthos, and macrofauna are considered in succession. Marine vegetation enhances the bottom dissipation of current energy, but also reduces shear stress at the sediment-water interface, which can be significant when the shoot density is high. The microphytobenthos and secreted extracellular polymeric substances (EPS) stabilise the sediment, and an increase of up to a factor of 5 can be assigned to the erosion threshold on muddy beds. However, the consequences with respect to the erosion rate are debatable since, once the protective biofilm is eroded, the underlying sediment probably has the same erosion behaviour as bare sediment. In addition, the development of benthic diatoms tends to be seasonal, so that stabilising effects are likely to be minimal in winter. Macrofaunal effects are characterised by extreme variability. For muddy sediments, destabilisation seems to be the general trend; this can become critical when benthic communities settle on consolidated sediments that would not be eroded if they remained bare. Biodeposition and bioresuspension fluxes are mentioned, for comparison with hydrodynamically induced erosion rates. Unlike the microphytobenthos, epifaunal benthic organisms create local roughness and are likely to change the BSS generated by the flow. In this paper, we attempt to describe state-of-the-art sediment transport models accounting for biological processes. Such applications generally demonstrate a clear effect of the biota on erosion/deposition, but morphodynamic coupling is rarely achieved. In the present study, a modelling exercise of this type was run, based on a cross-shore morphodynamic model of an intertidal mudflat [Waeles, B., Le Hir, P., Silva Jacinto, R., 2004. Modélisation morphodynamique cross-shore d'un estran vaseux. Comptes Rendus Geoscience 336, 1025-1033] in which the equilibrium profile of the intertidal flat under tide and wave forcing is simulated. A seasonal presence of the microphytobenthos in late spring and summer, represented by a fourfold increase in the erosion threshold, generates sediment level changes of about 5 cm. However, these effects disappear in autumn and winter when the erosion threshold returns to its abiotic value, even when wave erosion is ignored. In contrast, the reduction of BSS in the upper flat to simulate the effect of a saltmarsh induces a spectacular seaward shift of the upper flat. The simulations show the strong, potential, long-term effect of vegetated beds, i.e. the protection of sediment from wave erosion. In contrast, local stabilisation by the microphytobenthos does not have a significant long-term effect. Some recommendations are given on the need to define experimental protocols for erosion tests and studies on biota effects. A stochastic approach is suggested to cope with the problem of patchiness and extreme variability of erodability patterns, combined with histograms of BSS.

  19. The Pipe Creek Sinkhole biota, a diverse late tertiary continental fossil assemblage from Grant County, Indiana

    Science.gov (United States)

    Farlow, J.O.; Sunderman, J.A.; Havens, J.J.; Swinehart, A.L.; Holman, J.A.; Richards, R.L.; Miller, N.G.; Martin, R.A.; Hunt, R.M., Jr.; Storrs, G.W.; Curry, B. Brandon; Fluegeman, R.H.; Dawson, M.; Flint, M.E.T.

    2001-01-01

    Quarrying in east-central Indiana has uncovered richly fossiliferous unconsolidated sediment buried beneath Pleistocene glacial till. The fossiliferous layer is part of a sedimentary deposit that accumulated in a sinkhole developed in the limestone flank beds of a Paleozoic reef. Plant and animal (mostly vertebrate) remains are abundant in the fossil assemblage. Plants are represented by a diversity of terrestrial and wetland forms, all of extant species. The vertebrate assemblage (here designated the Pipe Creek Sinkhole local fauna) is dominated by frogs and pond turtles, but fishes, birds; snakes and small and large mammals are also present; both extinct and extant taxa are represented. The mammalian assemblage indicates an early Pliocene age (latest Hemphillian or earliest Blancan North American Land Mammal Age). This is the first Tertiary continental biota discovered in the interior of the eastern half of North America.

  20. Pesticide Interactions with N source and Tillage: Effects on soil biota and ecosystem services

    DEFF Research Database (Denmark)

    Jensen, John; Petersen, SØren O

    Pesticide effects on soil biota must be interpreted in the context of the specific management practice, including rotation, fertilization, tillage, and pest control. Tillage, foe example, has been shown to reduce earthworm populations by up to 80%, depending on timing and specific tillage technique. Such disturbances may fully or partly obscure the effects of pesticides. The direct effects of pesticides and other management factors and their interactions must, therefore, be quantified before integrated pest management strategies that protect soil biodiversity and maintain soil functions can be identified. This study was planned to evaluate interactions between pesticide use and other soil management factors. The study was carried out within a long-term tillage experiment using two tillage practices (no-till (NT) and mouldboard ploughing (MP), two contrasting N sources (manure and mineral fertiliser), and two pesticides (the fungicide mancozeb and the insecticide alpha-cypermethrin) in a split-plot design.Results on earthworms and microarthropods will be shown and discussed.

  1. Comparing sediment equilibrium partitioning and passive sampling techniques to estimate benthic biota PCDD/F concentrations in Newark Bay, New Jersey (U.S.A.)

    International Nuclear Information System (INIS)

    Sediment and polyethylene sampler-based estimates of polychlorinated dibenzo-p-dioxin/dibenzofuran (PCDD/F) concentrations in Newark Bay, New Jersey (USA) benthic biota were compared. Biota concentrations based on sediment were estimated using an organic carbon (OC)-water partitioning model and an OC and black carbon (BC)-water dual model. Biota concentrations based on polyethylene were estimated from samplers deployed in the Newark Bay water column and samplers immersed in a sediment/porewater slurry in the laboratory. Porewater samplers provided the best estimates of biota concentrations (within 3.1×), with best results achieved for deposit-feeders (within 1.6×). Polyethylene deployed in deep water also provided good estimates of biota concentrations (within 4×). By contrast, OC-water partitioning overestimated biota concentrations by up to 7×, while OC and BC combined underestimated biota concentrations by up to 13×. We recommend passive samplers such as polyethylene for estimating concentrations of hydrophobic organic contaminants in field biota given its simplicity and relatively lower uncertainty compared to sediment equilibrium partitioning. -- Highlights: • PE samplers accurately estimate Newark Bay biota PCDD/F concentrations. • A traditional KOC partitioning model overestimated PCDD/F uptake by a factor of 4–7. • A dual KOC and KBC model underestimated biota PCDD/F uptake by a factor of 4–13. • Sediment- and depth-specific KBCs improved predictions of PCDD/F uptake. • Deposit feeder uptake switches from porewater control to ingestion at log KOW 6–7. -- Using polyethylene samplers to measure porewater concentrations is a more efficient approach for estimating site-specific bioavailable organic contaminants than equilibrium partitioning

  2. Screes as important landscape structures for xeric and psychrophilic biota conservation and monitoring environmental change in the Czech Republic.

    Czech Academy of Sciences Publication Activity Database

    Zacharda, Miloslav; Boucníková, Eva

    Sup.1/2005, ?. 24 (2005), s. 28-38. ISSN 1335-342X Institutional research plan: CEZ:AV0Z60870520 Keywords : scree * landscape diversity * biota * conservation * global change Subject RIV: EH - Ecology, Behaviour Impact factor: 0.085, year: 2005

  3. DETERMINATION OF ALKYLPHENOL AND ALKYLPHENOLETHOXYLATES IN BIOTA BY LIQUID CHROMATOGRAPHY WITH DETECTION BY TANDEM MASS SPECTROMETRY AND FLUORESCENCE SPECTROSCOPY

    Science.gov (United States)

    This paper presents a quantitative method for the simultaneous determination of octylphenol, nonylphenol and the corresponding ethoxylates (1 to 5) in biota. Extraction methods were developed for egg and fish matrices based on accelerated solvent extraction (ASE) followed by a solid-phase extractio...

  4. Radioactive cesium, cobalt and plutonium in biota, algae and sediments in the nonrestricted areas of the Russian Arctic Seas

    International Nuclear Information System (INIS)

    Biota, macroalgae and sediment samples were collected during scientific expeditions organized by the Murmansk Marine Biological Institute (MMBI) during 1993 - 1996 in the Barents, Petshora, Kara, Laptev and White seas and in the Kola Bay. The purpose of the expeditions was to study the levels of radioactive pollution in the Russian arctic seas

  5. Soil development and succession of soil biota in afforested and non-reclaimed sites in post mining landscape - preliminary results.

    Czech Academy of Sciences Publication Activity Database

    Frouz, Jan; Pižl, Václav; Tajovský, Karel; Balík, Vladimír; Hán?l, Ladislav; Starý, Josef; Lukešová, Alena; Nováková, Alena; Šourková, Monika; P?ikryl, I.

    Cagliari : DIGITA Facolta Ingegneria, 2002, s. 621-626. [Symposium on Environmental Issues and Waste Management of Mineral and Energy Production 2002. Cagliari (IT), 07.10.2002-10.10.2002] R&D Projects: GA ?R GA526/01/1055 Institutional research plan: CEZ:AV0Z6066911 Keywords : succession * soil biota * post mining landscape Subject RIV: EH - Ecology, Behaviour

  6. Concentrations and trophic magnification of cyclic siloxanes in aquatic biota from the Western Basin of Lake Erie, Canada

    International Nuclear Information System (INIS)

    We examine the concentrations and food web biomagnification of three cyclic volatile methylsiloxanes (cVMS) octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), and dodecamethylcyclohexasiloxane (D6) using aquatic biota collected from Lake Erie. Concentrations of cVMS in biota were within the range reported for other studies of cVMS in aquatic biota. Trophic magnification factors (TMF) were assessed in various food web configurations to investigate the effects of food web structure. TMF estimates were highly dependent on the inclusion/exclusion of the organisms occupying the highest and lowest trophic levels and were >1 for D4 and D5, indicating biomagnification, in only 1 of the 5 food web configurations investigated and were <1 in the remaining 4 food web configurations. TMF estimates for PCB180 were also dependant on food web configuration, but did not correspond with those obtained for cVMS materials. These differences may be attributed to environmental exposure and/or lipid partitioning differences between PCB180 and cVMS. -- Highlights: • We investigated trophic magnification of siloxanes in aquatic biota from Lake Erie. • Trophic magnification estimates were variable and sensitive to food web structure. • Lipid partitioning of siloxanes and PCBs differ and may contribute to variability. -- Biomagnification estimates for siloxanes in Lake Erie are sensitive to food web structure, contaminant exposure pathways, and lipid partitioning differences between PCBs and siloxanes

  7. Assessment of radiation impact on biota as a result of hypothetical accidents at small NPP

    International Nuclear Information System (INIS)

    Document available in abstract form only. Full text of publication follows: Breakthrough in the development of science and technology, caused by the creation of nuclear weapons, allowed expanding the scope of application of the energy of nuclear fission. Nuclear power plants, nuclear power installations for submarines and ships were created. The main factor of the competitiveness of nuclear energy is its success in areas of its industrial, scientific, technical application. Nuclear energy, as well as any other modern sophisticated technology used by people, is associated with a particular risk for the individuals, society and the environment. According to the classification adopted by the IAEA, small reactors are reactors with an equivalent electric power of <300 MW(e) and medium-sized reactors are reactors with an equivalent electric power of 300-700 MW(e). Russia has a unique experience in the creation and operation of reactor systems with lead-bismuth coolant for nuclear-powered submarines. Such is single unit nuclear power station with an experiment industrial power reactor installation with lead-bismuth coolant with an electric capacity of 100 MW (SVBR-100). The launch of the first power unit with the SVBR-100 is going to start up after 2017 in the city of Dimitrovgrad, Russia. After the Chernobyl and Fukushima accidents, the world community makes high demands to operation safety during running of NPPs. Due to this, the analysis of the consequences of non-routine and accidental events is the essential point of rationale for innovative nuclear technologies. In this regard, the evolution of modern radiation protection system considering the radiation protection of not only the population, but also non-human biota, cannot be disregarded. The aim of the current research was the assessment of radiological impact on biota caused by hypothetical accidents at NPP with lead-bismuth cooled small fast reactor SVBR-100. (authors)

  8. TENORM wastes and the potential alpha radiation dose to aquatic biota

    International Nuclear Information System (INIS)

    In the years seventies release-rates and derived limits for releasing radionuclides into the environment were adopted for each particular radionuclide and for a number of pathways. The release-rate limit adopted for alpha emitters was 1015 Bq.y-1 for a single site, but limited to 1014 Bq.y-1 for 226Ra and supported 210Po. In addition, to meet the requirements of the London Convention, a derived limit should be expressed in terms of concentration, which for alpha emitters was 1010 Bq.t-1 , but limited to 1014 Bq.t-1 for 226Ra and supported 210Po, assuming an upper limit to the mass dumping rate of 105 t per year at a single dumping site. New data on the radioactivity in the marine environment and biota, including plankton, indicated a potential alpha radiation dose to these aquatic organisms due to the release of technologically enhanced naturally occurring radioactive materials (TENORM) wastes. At the highest accumulation of 239Pu in the zooplankton Gammarus in Thule, Greenland, due to an accidental release associated with military activities, the dose rate reached about 0.14 ?Gy.h-1 . Such dose rate was similar to that received by the phytoplankton Chaetoceros and Rhizosolenia from Agulhas current, Africa, due to naturally occurring radioactive materials (NORM) supposedly enhanced for almost one century of gold mining at first, and subsequently because of heap-leaching uranium extraction from the tailings left behind by earlier gold miners. The paper will discuss the alpha radiation dose to aquatic biota, in general, and to plankton, in particular, due to potential releases of TENORM wastes in the aquatic environment. (author)

  9. Radurization of commercial freshwater fish species

    Science.gov (United States)

    Chuaqui-Offermanns, N.; McDougall, T. E.; Sprung, W.; Sullivan, V.

    The effect of radurization on the shelf life of fresh Whitefish obtained through ordinary commercial channels has been determined. Whitefish fillets irradiated at 1.2 kGy and stored at 3°C have a shelf life three times longer than the unirradiated fish. When the fish was irradiated at 0.82 kGy a two fold shelf-life extension was obtained. The shelf life was estimated by sensory, chemical and microbiological evaluations. Sensory evaluation involved organoleptic assessment of raw and cooked samples. Since freshwater fish do not contain trimethylamine oxide (TMAO), alternate tests for freshness were required. It was found the determination of hypoxanthine and total volatile acid number (VAN) are excellent tests for freshness and quality of freshwater fish; thus, these analyses were adopted. The degree of radiation-induced lipid oxidation was measured by the thiobarbituric acid test (TBA). It was found at doses of 0.82 and 1.2 kGy the TBA number remained within acceptable limits in all samples. Microbiological analyses consisted of the total microbial load assessment in the sample, as well as Pseudomonas and total psychrotrophic counts. The estimated shelf lives as determined by the three separate evaluations were in very good agreement.

  10. Monitoring endangered freshwater biodiversity using environmental DNA

    DEFF Research Database (Denmark)

    Thomsen, Philip Francis; Kielgast, Jos

    2012-01-01

    Freshwater ecosystems are among the most endangered habitats on Earth, with thousands of animal species known to be threatened or already extinct. Reliable monitoring of threatened organisms is crucial for data-driven conservation actions but remains a challenge owing to nonstandardized methods that depend on practical and taxonomic expertise, which is rapidly declining. Here, we show that a diversity of rare and threatened freshwater animals-representing amphibians, fish, mammals, insects and crustaceans-can be detected and quantified based on DNA obtained directly from small water samples of lakes, ponds and streams. We successfully validate our findings in a controlled mesocosm experiment and show that DNA becomes undetectable within 2 weeks after removal of animals, indicating that DNA traces are near contemporary with presence of the species. We further demonstrate that entire faunas of amphibians and fish can be detected by high-throughput sequencing of DNA extracted from pond water. Our findings underpin the ubiquitous nature of DNA traces in the environment and establish environmental DNA as a tool for monitoring rare and threatened species across a wide range of taxonomic groups.

  11. Radurization of commercial freshwater fish species

    International Nuclear Information System (INIS)

    The effect of radurization on the shelf life of fresh Whitefish obtained through ordinary commercial channels has been determined. Whitefish fillets irradiated at 1.2 kGy and stored at 30C have a shelf life three times longer than the unirradiated fish. When the fish was irradiated at 0.82 kGy a two fold shelf-life extension was obtained. The shelf life was estimated by sensory, chemical and microbiological evaluations. Sensory evaluation involved organoleptic assessment of raw and cooked samples. Since freshwater fish do not contain trimethylamine oxide (TMAO), alternate tests for freshness were required. It was found the determination of hypoxanthine and total volatile acid number (VAN) are excellent tests for freshness and quality of freshwater fish; thus, these analyses were adopted. The degree of radiation-induced lipid oxidation was measured by the thiobarbituric acid test (TBA). It was found at doses of 0.82 and 1.2 kGy the TBA number remained within acceptable limits in all samples. Microbiological analyses consisted of the total microbial load assessment in the sample, as well as Pseudomonas and total psychrotrophic counts. The estimated shelf lives as determined by the three separate evaluations were in very good agreement. (author)

  12. Heart Rate Sensor for Freshwater Mussels

    Science.gov (United States)

    Just, C. L.; Vial, D. P.; Kruger, A.; Niemeier, J. J.; Lee, H. W.; Schroer, H. W.

    2014-12-01

    Researchers have long been interested the cardiac activity of mollusks. First, it is important as a basic measure of the animal's metabolism. Further, activities such as feeding and burrowing affect heart rate, as do environmental factors such as water salinity, water temperature, exposure, and predation. We have developed a small, noninvasive sensor for measuring freshwater mussel heart rate. Its working principle is as follows. An infrared (IR) light-emitting diode is placed in contact with the mussel shell. Some of the IR penetrates through the shell, reflects off internal organs, and traverses back. A photodetector detects this IR, and electronics condition the signal. The heartbeat of the animal modulates the IR, allowing one to measure the heart rate. The technique is widely-used in finger heart-rate monitors in humans. The sensors do not have to be positioned above the heart and several locations on the mussel shell work well. The sensor is small (8 mm × 10 mm) and consumes less than 1 mA, and has a simple one-wire interface that allows for easy integration into data acquisition hardware. We present heart rate measurements for the common pocketbook (lampsilis cardium) freshwater mussel.

  13. Baseline levels and trophic transfer of persistent organic pollutants in sediments and biota from the Congo River Basin (DR Congo).

    Science.gov (United States)

    Verhaert, Vera; Covaci, Adrian; Bouillon, Steven; Abrantes, Katya; Musibono, Dieudonné; Bervoets, Lieven; Verheyen, Erik; Blust, Ronny

    2013-09-01

    The present study aimed to evaluate the occurrence of persistent organic pollutants (POPs: (PCBs, PBDEs, DDTs, HCHs, CHLs and HCB) in sediments and biota from the middle Congo River Basin (CRB) and to investigate their trophic transfer through the aquatic food web using nitrogen stable isotope ratios. To our knowledge, no data on levels of POPs in sediment and biota from the CRB are present in the literature, and studies on trophic transfer and biomagnification profiles of POPs using ?(15)N are scarce in tropical regions. POP levels in the sediment and biota were low, with exception of total PCB levels found in fish from the Itimbiri River (1.4 to 44ng/g ww). Compared to concentrations found in fish from pristine to relatively industrial developed areas, the ?PCB levels in fish from the Itimbiri were high, indicating the presence of a local PCB contamination source in this catchment. Based on minimum risk level criteria formulated by ATSDR, the consumption of PCB contaminated fish from the Itimbiri river poses a potential risk for humans. The POP levels in biota were not significantly related to the POP levels in sediments, and the BSAF concept (Biota-Sediment Accumulation Factor) was found to be a poor predictor of the bioavailability and bioaccumulation of environmental pollutants in the present study. With increasing trophic levels, a significant increase in PCB 95, 101, 110, 138, 146, 149, 153, 174, 180 & 187 and p,p'-DDT in Itimbiri and BDE 47 & 99 in Itimbiri, Aruwimi & Lomami river basins was observed. Trophic magnification factors were higher than 1, indicating that biomagnification occurs through the tropical food web. PMID:23872388

  14. Molecular phylogeny and phylogeography of the Australian freshwater fish genus Galaxiella, with an emphasis on dwarf galaxias (G. pusilla).

    Science.gov (United States)

    Unmack, Peter J; Bagley, Justin C; Adams, Mark; Hammer, Michael P; Johnson, Jerald B

    2012-01-01

    The freshwater fauna of Southern Australia is primarily restricted to the southwestern and southeastern corners of the continent, and is separated by a large, arid region that is inhospitable to this biota. This geographic phenomenon has attracted considerable interest from biogeographers looking to explain evolutionary diversification in this region. Here, we employed phylogenetic and phylogeographic approaches to evaluate the effect of this barrier on a group of four galaxiid fish species (Galaxiella) endemic to temperate Southern Australia. We also tested if continental shelf width has influenced connectivity among populations during low sea levels when rivers, now isolated, could have been connected. We addressed these questions by sampling each species across its range using multiple molecular markers (mitochondrial cytochrome b sequences, nuclear S7 intron sequences, and 49 allozyme loci). These data also allowed us to assess species boundaries, to refine phylogenetic affinities, and to estimate species ages. Interestingly, we found compelling evidence for cryptic species in G. pusilla, manifesting as allopatric eastern and western taxa. Our combined phylogeny and dating analysis point to an origin for the genus dating to the early Cenozoic, with three of the four species originating during the Oligocene-Miocene. Each Galaxiella species showed high levels of genetic divergences between all but the most proximate populations. Despite extensive drainage connections during recent low sea levels in southeastern Australia, populations of both species within G. pusilla maintained high levels of genetic structure. All populations experienced Late Pleistocene-Holocene population growth, possibly in response to the relaxation of arid conditions after the last glacial maximum. High levels of genetic divergence and the discovery of new cryptic species have important implications for the conservation of this already threatened group of freshwater species. PMID:22693638

  15. Pre-assessment of dose rates of (134)Cs, (137)Cs, and (60)Co for marine biota from discharge of Haiyang Nuclear Power Plant, China.

    Science.gov (United States)

    Li, Jingjing; Liu, Senlin; Zhang, Yongxing; Chen, Ling; Yan, Yuan; Cheng, Weiya; Lou, Hailin; Zhang, Yongbao

    2015-09-01

    Haiyang Nuclear Power Plant to be built in China was selected as a case for the dose pre-assessment for marine biota in this study. The concentrations of Cs and Co in organisms (turbot, yellow croaker, swimming crab, abalone, sea cucumber, and sea lettuce), seawater, and bottom sediment sampled on-site were measured by neutron activation analysis, and the site-specific transfer parameters (concentration ratios and distribution coefficients) of Cs and Co were calculated. (134)Cs, (137)Cs, and (60)Co activity concentrations in the organisms and the sediment at the site were calculated with the site-specific transfer parameters and the anticipated activity concentrations in the liquid effluent of the nuclear power plant. The ERICA tool was used to estimate the dose rates of (134)Cs, (137)Cs, and (60)Co to the selected organisms based on the biological models developed. The total dose rates of (134)Cs, (137)Cs, and (60)Co to the six organisms were all <0.001 ?Gy h(-1). PMID:26005771

  16. The role of vegetation on freshwater lens sustainability in small coral islands facing climate change

    Science.gov (United States)

    Comte, Jean-Christophe; Join, Jean-Lambert; Banton, Olivier; Nicolini, Eric

    2015-04-01

    Small islands are commonly densely vegetated despite a near absence of surface water and a limited fresh groundwater resource (freshwater lenses) subjected to widespread seawater intrusion. Due to both the shallow depth of the water table, and the low water storage capacity of the soils, vegetation roots abstract water directly from groundwater. Where groundwater contains dissolved salt, roots selectively uptake freshwater which results in salt concentration in groundwater. Groundwater dynamics and salt transport are therefore coupled with vegetation activity and dynamics. However, roots cannot tolerate high levels of dissolved salt due to its phytotoxicity. This results in a buffer mechanism where vegetation regresses, and therefore groundwater uptake decreases, with increased salinization. A numerical groundwater model is applied to a monitored small coral island in the western Indian Ocean to simulate the freshwater lens behaviour and its response to climate changes. A phytotoxicity model is coupled with the groundwater model. Simulations assessed against field observations show the major control currently exerted by the vegetation with regards to the freshwater lens morphology. In particular, thinnest lenses and seawater intrusions observed in the island depressions can be explained by high vegetation activity due to the shallowest water table. Simulation of the response to predicted long-term changes in both groundwater recharge and sea level shows general lens regression by salinization associated with a simultaneous decrease in vegetation activity. Interestingly, the salinization is far less important than when omitting phytotoxicity processes. This demonstrates the need to couple groundwater and ecohydrological models when modelling the impact of climate changes on groundwater resources in small islands.

  17. Freshwater ecotoxicity characterisation factor for metal oxide nanoparticles: A case study on titanium dioxide nanoparticle

    DEFF Research Database (Denmark)

    Salieri, Beatrice; Righi, Serena

    2015-01-01

    The Life Cycle Assessment (LCA) methodology is widely applied in several industrial sectors to evaluate the environmental performance of processes, products and services. Recently, several reports and studies have emphasized the importance of LCA in the field of engineered nanomaterials. However, to date only a few LCA studies on nanotechnology have been carried out, and fewer still have assessed aspects relating to ecotoxicity. This is mainly due to the lack of knowledge in relation on human and environmental exposure and effect of engineered nanoparticles (ENPs). This bottleneck is continued when performing Life Cycle Impact Assessment, where characterization models and consequently characterization factors (CFs) for ENPs are missing. This paper aims to provide the freshwater ecotoxicity CF for titanium dioxide nanoparticles (nano-TiO2). The USEtox™ model has been selected as a characterisation model. An adjusted multimedia fate model has been developed which accounts for nano-specific fate process descriptors (i.e. sedimentation, aggregation with suspended particle matter, etc.) to estimate the fate of nano-TiO2 in freshwater. A literature survey of toxicity tests performed on freshwater organism representative of multiple trophic levels was conducted, including algae, crustaceans and fish in order to collect relevant EC50 values. Then, the toxic effect of nano-TiO2 was computed on the basis of the HC50 value. Thus, following the principle of USEtox™ model and accounting for nano-specific descriptors a CF for the toxic impact of freshwater ecotoxicity of 0.28PAFdaym3kg-1 is proposed.

  18. Cultivation of macroscopic marine algae and freshwater aquatic weeds. Progress report, May 1--December 31, 1976

    Energy Technology Data Exchange (ETDEWEB)

    Ryther, J. H.

    1977-01-01

    Research was divided between basic physiological studies of the growth and nutrient-uptake kinetics of macroscopic marine algae and the more applied problems involved in the selection of species and the development of inexpensive, non-energy intensive culture methods for growing seaweeds and freshwater plants as a biomass source for conversion to energy. Best growth of the seaweeds occurs at low (0.1 to 1.0 ..mu..molar) concentration of major nutrients, with ammonia as a nitrogen source, with rapid exchange of the culture medium (residence time of 0.05 days or less). Of 43 species of seaweeds evaluated, representatives of the large red alga genus Gracilaria appear most promising with potential yields, in a highly intensive culture system under optimal conditions, of some 129 metric dry tons per hectare per year (about half of which is organic). Non-intensive culture methods have yielded one-third to one-half that figure. Unexplained periodicity of growth and overgrowth by epiphytes remain the most critical constraint to large-scale seaweed culture. Freshwater weed species in culture include water hyacinth (Eichhornia crassipes), duckweed (Lemna minor), and Hydrilla vertecillata, with yields to date averaging 15, 4, and 8 g dry wt/m/sup 2//day, respectively. However, these plants have not yet been grown through the winter, so average annual yields are expected to be lower. In contrast to the seaweeds, the freshwater plants grow well at high nutrient concentrations and slow culture volume exchange rates (residence time ca. 20 days or more). Experiments were initiated on the recycling of digester residues from the fermentation of the freshwater and marine plants as a possible nutrient source for growth of the same species.

  19. Effects of cadmium stress and sorption kinetics on tropical freshwater periphytic communities in indoor mesocosm experiments

    International Nuclear Information System (INIS)

    Understanding the cause and effect relationship between stressors and biota is crucial for the effective management, restoration and preservation of aquatic systems. The objective of the present study was to assess the effects of five Cd concentrations on tropical periphyton community growth, Cd accumulation kinetics, as well as the effects of Cd on diatom community structure and composition. Natural periphyton communities were transferred to artificial stream chambers and exposed to Cd concentrations of 0.005, 0.01, 0.03, 0.05 and 0.1 mg.L?1. Metal accumulation (total and intracellular) in biofilms, dry weight and ash-free dry mass, growth rate, algal cell density and diatom community composition were analysed on samples collected after 1, 2 and 4 weeks of colonization. Periphyton growth and development were significantly lowered by Cd concentrations > 0.03 mg.L?1. High Cd accumulation capacity by periphyton was demonstrated with total and intracellular Cd content in biofilms reflecting the effects of concentrations of Cd in the culture media and exposure duration. Total and intracellular Cd content generally increased in treatments in the order 0.005 ?1 at any sampling time with increasing level of accumulated Cd with duration of exposure in all the systems. Shifts in species composition (development of more resistant species like Achnanthidium minutissimum and reduction of sensitive ones like Diatoma vulgare, Navicula viridula and Navicula cryptocephala), decreases in species richness and diversity and morphological alterations (deformities) of diatom cells with increasing Cd concentration and exposure duration were observed. The results give valuable information on Cd impact of freshwater biofilms. -- Highlights: ? We investigated toxicity and sorption kinetics of Cd on periphyton communities. ? [Cd] > 0.03 mg.L?1 lowers growth. ? Absorbed Cd was a function of duration of exposure and [Cd]. ? Changes in community composition were recorded. ? Biofilms are potential monitors of metal pollution in aquatic systems.

  20. Spatial heterogeneity in the Mediterranean Biodiversity Hotspot affects barcoding accuracy of its freshwater fishes.

    Science.gov (United States)

    Geiger, M F; Herder, F; Monaghan, M T; Almada, V; Barbieri, R; Bariche, M; Berrebi, P; Bohlen, J; Casal-Lopez, M; Delmastro, G B; Denys, G P J; Dettai, A; Doadrio, I; Kalogianni, E; Kärst, H; Kottelat, M; Kova?i?, M; Laporte, M; Lorenzoni, M; Mar?i?, Z; Özulu?, M; Perdices, A; Perea, S; Persat, H; Porcelotti, S; Puzzi, C; Robalo, J; Šanda, R; Schneider, M; Šlechtová, V; Stoumboudi, M; Walter, S; Freyhof, J

    2014-11-01

    Incomplete knowledge of biodiversity remains a stumbling block for conservation planning and even occurs within globally important Biodiversity Hotspots (BH). Although technical advances have boosted the power of molecular biodiversity assessments, the link between DNA sequences and species and the analytics to discriminate entities remain crucial. Here, we present an analysis of the first DNA barcode library for the freshwater fish fauna of the Mediterranean BH (526 spp.), with virtually complete species coverage (498 spp., 98% extant species). In order to build an identification system supporting conservation, we compared species determination by taxonomists to multiple clustering analyses of DNA barcodes for 3165 specimens. The congruence of barcode clusters with morphological determination was strongly dependent on the method of cluster delineation, but was highest with the general mixed Yule-coalescent (GMYC) model-based approach (83% of all species recovered as GMYC entity). Overall, genetic morphological discontinuities suggest the existence of up to 64 previously unrecognized candidate species. We found reduced identification accuracy when using the entire DNA-barcode database, compared with analyses on databases for individual river catchments. This scale effect has important implications for barcoding assessments and suggests that fairly simple identification pipelines provide sufficient resolution in local applications. We calculated Evolutionarily Distinct and Globally Endangered scores in order to identify candidate species for conservation priority and argue that the evolutionary content of barcode data can be used to detect priority species for future IUCN assessments. We show that large-scale barcoding inventories of complex biotas are feasible and contribute directly to the evaluation of conservation priorities. PMID:24690331

  1. Finding patterns of distribution for freshwater phytoplankton, zooplankton and fish, by means of parsimony analysis of endemicity Encontrando patrones de distribución para fitoplancton, zooplancton y peces dulceacuícolas por medio de análisis de parsimonia de endemismos

    Directory of Open Access Journals (Sweden)

    J. PABLO OYANEDEL

    2008-06-01

    Full Text Available During the last decades, limnological studies on Chilean systems have contributed to know the species composition and main environmental variables of many water bodies distributed over a wide latitudinal interval, from 18º to 53º S. However, we still lack of a comprehensive view about the structure and functioning of regional freshwaters. In this work we review the available information about pelagic biota from Chilean basins, in order to reveal patterns of species distribution and their possible association with environmental variables. We built presence-absence matrices for phytoplankton, zooplankton and fish over lakes and basins. From this database, we performed parsimony analysis of endemicity as a tool for determining fundamental distribution patterns of freshwater biota. Also, we assessed the relationship between species occurrences and some available site-related variables. Our results indicated that latitude exerted the strongest influence on species distribution, although altitude, longitude, and area also exerted significant effects for some groups. On the other hand, our results suggest a relationship between the degree of vagility of the groups and the degree of metacommunity structuring, related to the number of endemicity areas.Durante las últimas décadas, los estudios limnológicos en sistemas chilenos han contribuido al conocimiento de la composición de especies y de las principales variables ambientales de muchos cuerpos de agua distribuidos sobre un amplio intervalo latitudinal, desde los 18º a los 53º S. Asimismo, aún carecemos de una visión comprensiva acerca de la estructura y funcionamiento de las aguas dulces regionales. En este trabajo revisamos la información sobre la biota pelágica de las cuencas de Chile, con el propósito de revelar patrones de distribución de especies y su posible asociación con variables ambientales. Construimos matrices de presencia-ausencia para fitoplancton, zooplancton y peces en lagos y cuencas. Desde esta base de datos, realizamos análisis de parsimonia de endemismo, como medio para determinar patrones fundamentales de distribución de la biota dulceacuícola. También, determinamos la relación entre la presencia de especies y algunas variables relevantes de los sitios. Nuestros resultados sugieren que la latitud ejerce una fuerte influencia en la distribución de especies, aunque también la altitud, longitud y el área ejercen efectos significativos en algunos grupos. Por otro lado, los resultados sugieren una relación entre el grado de vagilidad de los grupos y el grado de estructuración de la metacomunidad, relacionada con el número de áreas de endemismos.

  2. Finding patterns of distribution for freshwater phytoplankton, zooplankton and fish, by means of parsimony analysis of endemicity / Encontrando patrones de distribución para fitoplancton, zooplancton y peces dulceacuícolas por medio de análisis de parsimonia de endemismos

    Scientific Electronic Library Online (English)

    J. PABLO, OYANEDEL; CAREN, VEGA-RETTER; SERGIO, SCOTT; LUIS FELIPE, HINOJOSA; RODRIGO, RAMOS-JILIBERTO.

    2008-06-01

    Full Text Available Durante las últimas décadas, los estudios limnológicos en sistemas chilenos han contribuido al conocimiento de la composición de especies y de las principales variables ambientales de muchos cuerpos de agua distribuidos sobre un amplio intervalo latitudinal, desde los 18º a los 53º S. Asimismo, aún [...] carecemos de una visión comprensiva acerca de la estructura y funcionamiento de las aguas dulces regionales. En este trabajo revisamos la información sobre la biota pelágica de las cuencas de Chile, con el propósito de revelar patrones de distribución de especies y su posible asociación con variables ambientales. Construimos matrices de presencia-ausencia para fitoplancton, zooplancton y peces en lagos y cuencas. Desde esta base de datos, realizamos análisis de parsimonia de endemismo, como medio para determinar patrones fundamentales de distribución de la biota dulceacuícola. También, determinamos la relación entre la presencia de especies y algunas variables relevantes de los sitios. Nuestros resultados sugieren que la latitud ejerce una fuerte influencia en la distribución de especies, aunque también la altitud, longitud y el área ejercen efectos significativos en algunos grupos. Por otro lado, los resultados sugieren una relación entre el grado de vagilidad de los grupos y el grado de estructuración de la metacomunidad, relacionada con el número de áreas de endemismos. Abstract in english During the last decades, limnological studies on Chilean systems have contributed to know the species composition and main environmental variables of many water bodies distributed over a wide latitudinal interval, from 18º to 53º S. However, we still lack of a comprehensive view about the structure [...] and functioning of regional freshwaters. In this work we review the available information about pelagic biota from Chilean basins, in order to reveal patterns of species distribution and their possible association with environmental variables. We built presence-absence matrices for phytoplankton, zooplankton and fish over lakes and basins. From this database, we performed parsimony analysis of endemicity as a tool for determining fundamental distribution patterns of freshwater biota. Also, we assessed the relationship between species occurrences and some available site-related variables. Our results indicated that latitude exerted the strongest influence on species distribution, although altitude, longitude, and area also exerted significant effects for some groups. On the other hand, our results suggest a relationship between the degree of vagility of the groups and the degree of metacommunity structuring, related to the number of endemicity areas.

  3. CHARACTERIZATION AND IDENTIFICATION OF FRESHWATER MICROALGAL STRAINS TOWARD BIOFUEL PRODUCTION

    Directory of Open Access Journals (Sweden)

    Xun Yang,

    2011-12-01

    Full Text Available Fifty-three algal cultures were isolated from freshwater lakes in Hainan, China. Four microalgal isolates were selected because they could be successfully cultivated at high density and demostrated a strong fluorescence after being stained with nile red. These cultures were identified as strains of Chlorella sp. C11, Chlamydomonas reinhardtii C22, Monoraphidium dybowskii C29, and Chlorella sp. HK12 through microscopic and 18S rDNA analysis. Under similar conditions, the lipid productivity of Chlorella sp. C11, Chla. reinhardtii C22, M. dybowskii C29 , and Chlorella sp. HK12 were 1.88, 2.79, 2.00, and 3.25 g L-1, respectively. Chla. reinhardtii C22 yielded a higher lipid content (51%, with a lower biomass concentration (5.47 g dwt L-1. Chlorella sp. HK12 reached a growth rate of 0.88 day-1 at OD540nm and yielded a biomass concentration of 7.56 g dwt L-1, with a high lipid content of 43%. Gas chromatography/ mass spectrometry analysis indicated that lipid fraction mainly comprises hydrocarbons including palmitic acid, stearic acid, oleic acid, linoleic acid, and linolenic acids. Our results suggest that Chlorella sp. HK12 is a promising species for biodiesel production, because of its high lipid productivity and a relatively high content of oleic acid.

  4. Screening of perfluorinated compounds in water, sediment and biota of the Llobregat River basin (NE Spain)

    Science.gov (United States)

    Campo, Julian; Perez, Francisca; Pico, Yolanda; Farre, Marinella; Barcelo, Damia; Andreu, Vicente

    2014-05-01

    PFCs present significant thermal and chemical stability being persistent in the environment, where they can bio-accumulate and adversely affect humans and wildlife (Llorca et al., 2012). Human exposure to PFCs is of concern since PFCs tend to be associated with fatty acid binding proteins in the liver or albumin proteins in blood, and have been detected in human serum, urine, saliva, seminal plasma and breast milk (Sundstrom et al., 2011). This study is aimed at the screening of 21 perfluorinated compounds (PFCs) in environmental samples by high-performance liquid chromatography tandem mass spectrometry (LC-MS/MS). The main objective is to identify target compounds at low levels in water, sediments and biota of the Llobregat River (2010), second longest river in Catalonia and one of Barcelona's major drinking water resources. PFCs were extracted from water samples by Solid Phase Extraction (SPE); from sediment by ultrasonication with acidified methanol followed by an off-line SPE procedure (Picó et al., 2012), and from biota (fish) with alkaline digestion, clean-up by TurboFlow™ on line technology coupled to LC-MS/MS (Llorca et al., 2012). The limits of detection (LODs) and limits of quantification (LOQs) of the method were calculated by analysis of spiked river water, sediment, and biota with minimum concentrations of each individual compound at a signal-to-noise ratio of 3 and 10, respectively. The LODs and LOQs of the method in river water ranged between 0.004 and 0.8 ng L-1 and between 0.01 and 2 ng L-1, respectively. In sediment LODs were 0.013-2.667 ng g-1 dry weight (dw) and LOQs were 0.04-8 ng g-1 dw, meanwhile in biota these were 0.006-0.7 pg ?L-1 and 0.02-2.26 pg ?L-1, respectively. Recoveries ranged between 65% and 102% for all target compounds. The method was applied to study the spatial distribution of these compounds in the Llobregat River basin. For this, a total of 40 samples were analysed (14 water, 14 sediments, 12 fishes). Of the 21 target compounds, 13 were identified in water samples (PFBA, PFDA, PFHpA, PFHxA, PFHxDA, PFNA, PFOA, PFPeA, PFTrDA, PFUdA, L-PFBS, L-PFHxS and L-PFOS), and their concentrations ranged between 0. 1 ng L-1 (PFNA) and 2709 ng L-1 (L-PFOS). Similarly, PFBA, PFDA, PFDoA, PFHpA, PFNA, PFOA, PFPeA, PFTrDA, PFUdA, L-PFBS, L-PFHxS, L-PFOS and PFOSA were identified in sediments samples, with concentrations ranging from 0.147 ng g-1 dw (L-PFOS) to 13 ng g-1 dw (PFBA). In biota similar PFC were detected, with values between 0.03 and 1738.06 ng g-1. According to this study, PFCs were detected in different compartments of the ecosystem where they are bio-accumulating and, potentially, would produce adverse effects on humans. Acknowledgements This work has been supported by the Spanish Ministry of Economy and Competitiveness through the projects Consolider-Ingenio 2010 CSD2009-00065 and CGL2011-29703-C02-02. We also thank the persons of IDAEA for taking the samples. References Llorca, M., Farre, M., Pico, Y., Muller, J., Knepper, T. P., Barcelo, D., 2012. Analysis of perfluoroalkyl substances in waters from Germany and Spain. Sci. Total Environ. 431, 139-150. Llorca, M., Pérez, F., Farre, M., Agramunt, S., Kogevinas, M., Barceló, D., 2012. Analysis of perfluoroalkyl substances in cord blood by turbulent flow chromatography coupled to tandem mass spectrometry. Sci. Total Environ. 433, 151-160. Pico, Y., Blasco, C., Farre, M., Barcelo, D., 2012. Occurrence of perfluorinated compounds in water and sediment of L'Albufera Natural Park (Valencia, Spain). Environ.Sci.Pollut.Res. 19, 946-957. Sundstrom, M., Ehresman, D. J., Bignert, A., Butenhoff, J. L., Olsen, G. W., Chang, S. C., Bergman, A., 2011. A temporal trend study (1972-2008) of perfluorooctanesulfonate, perfluorohexanesulfonate, and perfluorooctanoate in pooled human milk samples from Stockholm, Sweden. Environ. Inter. 37, 178-183.

  5. Freshwater algae of the Nevada Test Site

    International Nuclear Information System (INIS)

    Fifty-two species of freshwater algae were identified in samples collected from the eight known natural springs of the Nevada Test Site. Although several species were widespread, 29 species were site specific. Diatoms provided the greatest variety of species at each spring. Three-fifths of all algal species encountered were diatoms. Well-developed mats of filamentous green algae (Chlorophyta) were common in many of the water tanks associated with the springs and accounted for most of the algal biomass. Major nutrients were adequate, if not abundant, in most spring waters - growth being limited primarily by light and physical habitat. There was some evidence of cesium-137 bioconcentration by algae at several of the springs

  6. Investigation of strength properties of freshwater ice

    Directory of Open Access Journals (Sweden)

    Bragov A.

    2015-01-01

    Full Text Available A study of the strength and deformation properties of freshwater ice under compression, tension and shear in a wide range of strain rates (10?4 ? 3 ? 103?s?1 and temperatures of ? 5??C, ? 20??C, ? 40??C and ? 60??C was performed. Static stress-strain curves of ice under compression were obtained on which the identified strength properties of ice as well as compressive modulus. To determine the mechanical properties of ice at high-speed loading the Kolsky method was used with various embodiments of split Hopkinson bar. The deformation curves were obtained at various loading conditions. Thereon breaking points were defined as well as their dependence on the strain rate and temperature. Also static and dynamic strength properties of ice at splitting and circular shear were defined. Increase in the dynamic strength properties upon the static ones for all loading conditions was marked.

  7. Investigation of strength properties of freshwater ice

    Science.gov (United States)

    Bragov, A.; Igumnov, L.; Konstantinov, A.; Lomunov, A.; Filippov, A.; Shmotin, Yu.; Didenko, R.; Krundaeva, A.

    2015-09-01

    A study of the strength and deformation properties of freshwater ice under compression, tension and shear in a wide range of strain rates (10-4 - 3 ? 103 s-1) and temperatures of - 5? C, - 20? C, - 40? C and - 60? C was performed. Static stress-strain curves of ice under compression were obtained on which the identified strength properties of ice as well as compressive modulus. To determine the mechanical properties of ice at high-speed loading the Kolsky method was used with various embodiments of split Hopkinson bar. The deformation curves were obtained at various loading conditions. Thereon breaking points were defined as well as their dependence on the strain rate and temperature. Also static and dynamic strength properties of ice at splitting and circular shear were defined. Increase in the dynamic strength properties upon the static ones for all loading conditions was marked.

  8. Fouling and corrosion of freshwater heat exchangers

    International Nuclear Information System (INIS)

    Fouling in freshwater heat exchangers (HX) costs the Canadian nuclear power industry millions of dollars annually in replacement energy and capital equipment. The main reasons are loss of heat transfer and corrosion. Underdeposit pitting is the predominant corrosion mechanism. Erosion corrosion has also been observed. Failure analyses, field studies, and laboratory research have provided us with information to help explain the reasons for reduced performance. Newly installed HX tubing immediately becomes colonized with a complex community of bacteria in a slimey organic matrix. The biofilm itself produces corrosive species and in addition it promotes the attachment of sediment particles and the deposition of calcareous material. The result is a thick, adherent deposit which creates crevices, concentrates aggressive species and alters the system's hydrodynamics

  9. The use of biota sampling for environmental contaminant analysis for characterization of benthic communities in the Aleutians

    International Nuclear Information System (INIS)

    It is increasingly clear that the public, native tribes, and governmental agencies are interested in assessing the well-being of natural resources and ecosystems. This may take the form of understanding species presence, monitoring population status and trends, measuring behavior, or quantifying physiology, biological stresses, or chemical/radiological exposure through biomarkers. Often there is a separation between understanding the biological aspects of species well-being and assessing exposure to contaminants. In this paper we examine the applicability of using scuba sampling aimed primarily at specimen collection for radionuclide analysis to assess species presence/absence and to compare among sampling sites and depths. We were especially interested in whether dive transects could provide information on species presence and potential exposure to environmental contaminants. In June/July 2004 we sampled at 49 depth stations along 19 transects at Amchitka and Kiska Islands in the western Aleutian Islands in the Northern Pacific/Bering Sea region. Amchitka Island, a former World War II U.S. Navy base, was the site of three underground nuclear test shots from 1965 to 1971. Four to six transects were established at three Amchitka sites and two Kiska Sites, and 2 to 4 stations were sampled on each transect. Bottom conditions, weather and currents prevented a complete sampling of all stations. There were interspecific differences in the percent of stations where biota were found and collected, in their occurrence near the three test shots on Amchitka, and in the depth where they were found. There were no significant differences between Amchitka and Kiska Island in the percent of stations where species were found. These data suggest that information gathered incidentally to the collection of specimens for chemical/radiological analysis can prove useful for understanding the presence of benthic organisms along particular transects, at given depths, and at different geographical locations. This information also provides a baseline for the range of organisms that could be exposed to future physical or chemical/radiological stressors. The data are useful for developing future biomonitoring plans to assess biological well-being and chemical/radiological exposure only if they are published and available to the public, public policy makers, and managers. Just as it is critical to select endpoints and bioindicators that are of interest for assessing both human and ecological health, specimens should be collected using a protocol that is useful for both chemical/radiological analysis and biological information

  10. Assessment of heavy metal concentrations in water, sediment and biota (fish and crabs) samples from the Densu Delta

    International Nuclear Information System (INIS)

    The aim of the study was assess the concentration of some selected heavy metals in water, sediments and biota (fish and crab) sampled from the Densu Delta. In situ and laboratory based analysis were carried out to measure the following physicochemical properties of surface water from the delta; temperature, pH, electrical conductivity (EC), salinity, total dissolved solids (TDS), alkalinity, sodium ion concentration (Na+), potassium ion concentration (K+), chloride ion concentration (Cl), bicarbonate concentration, phosphate concentration, nitrate concentration, sulphate concentration and biochemical oxygen demand (BOD). Heavy metal (Fe, Zn, Cu, Ni, Cd, Cr, Pb and Hg) concentrations in water, sediments, fish and crab sampled at six sites from the Densu Delta wetland in the month of December, 2009 were analysed using VARIAN Fast Sequential Atomic Absorption Spectrophotometer (AAS) model AA240 FS. Two fish species; Blackchin tilapia (Sarotherodon melanotheron), White mullet (Mugil curema) and one species of crab; Blue swimming crab (Callinectes amnicola) were collected from the Densu Delta wetland and analysed. Heavy metal contents in the fish were higher in gill tissue than muscle tissue while in crabs concentrations were higher in the soft tissue than the shell. Levels of Fe, Zn and Cu in the muscle tissue of S. melanotheron were greater than the levels detected in the muscle tissue of M. curema. Cd, Ni and Hg were detected in gill tissue but not in the muscle tissue of S. melanotheron, M. curema on the other hand contained these metals in both gill and muscle tissue. The maximum level of Fe (34.98 mg/L), Zn (25.08 mg/L) in the muscle of S. melanotheron was observed at Bortianor and Zn (2.70 mg/L) was observed at Tetegu. In the M. curema, the maximum level of Fe (34.66 mg/L), Zn (15.9 mg/L) and Cu (1.43 mg/L) was detected at Aplaku, Tetegu and Faana respectively. Heavy metal concentrations were higher in sediment than water. The presence of elevated levels of Cd and Ni in the muscle tissue of the white mullet fish from Tetegu and Faana, is a potential public health hazard to the inhabitants of these two communities and other neighbouring communities who depend on fish from the delta as their source of protein. (au)

  11. Freshwater reservoir effect variability in Northern Germany

    DEFF Research Database (Denmark)

    Philippsen, Bente; Heinemeier, Jan

    The freshwater reservoir effect is a potential problem when radiocarbon dating fishbones, shells, human bones or food crusts on pottery from sites next to rivers or lakes. The reservoir age in rivers containing considerable amounts of dissolved 14C-free carbonates can be up to several thousand years and may be highly variable. For accurate radiocarbon dating of freshwater-based samples, the order of magnitude of the reservoir effect as well as the degree of variability has to be known. The initial problem in this case was the accurate dating of food crusts on pottery from the Mesolithic sites Kayhude at the river Alster and Schlamersdorf at the river Trave, both in Schleswig-Holstein, Northern Germany. Measurements on modern materials from these rivers may not give a single reservoir age correction that can be applied to archaeological samples, but they will show the order of magnitude and variability that can also be expected for the past. Water DIC from different seasons, and from the same season in different years, has been dated because it is the carbon source in photosynthesis and thus at the basis of the rivers’ food webs. The radiocarbon ages of underwater plants and different parts (underwater or floating) of emerging water plants are compared, as it might be expected that the reservoir age is higher for plants that assimilate DIC as for plants or parts of plants that assimilate atmospheric CO2. Mollusc shells as well as flesh and bone collagen of fish are dated as well. Radiocarbon datings of archaeological samples from the two Mesolithic sites will be analysed, considering the insights provided by the study of modern material.

  12. Survival strategies of freshwater insects in cold environments

    Directory of Open Access Journals (Sweden)

    Valeria LENCIONI

    2004-09-01

    Full Text Available At high latitudes and altitudes, ice formation is a major variable affecting survival of freshwater fauna and hence the abundance and composition of invertebrate communities. Freezing, but also desiccation and anoxia, are lethal threats to all life stages of aquatic insects, from the eggs to the adults. During cold periods, the aquatic stages commonly remain in or move to a portion of the water body that will not freeze or dry (e.g., deep waters of lakes, springs and hyporheic zone where they can remain active. Less frequently they migrate to habitats that will freeze at the onset of winter. Insects have developed a complex of strategies to survive at their physiological temperature minimum, comprising (a morphological (melanism, reduction in size, hairiness/pubescence, brachyptery and aptery, (b behavioural (basking in the sun, changes in feeding and mating habit, parthenogenesis, polyploidy, ovoviviparity, habitat selection and cocoon building, (c ecological (extension of development to several years by quiescence or diapause and reduction of the number of generations per year, (d physiological and biochemical (freezing tolerance and freezing avoidance adaptations. Most species develop a combination of these survival strategies that can be different in the aquatic and terrestrial phase. Freezing avoidance and freezing tolerance may be accompanied by diapause. Both cold hardiness and diapause manifest during the unfavourable season and: (i involve storage of food resources (commonly glycogen and lipids; (ii are under hormonal control (ecdysone and juvenile hormone; (iii involve a depression or suppression of the oxidative metabolism with mitochondrial degradation. However, where the growing season is reduced to a few weeks, insects may develop cold hardiness without entering diapause, maintaining in the haemolymph a high concentration of Thermal Hysteris Proteins (THPs for the entire year and a slow but continuous growth. A synthesis of literature regarding adaptation strategies in aquatic insects is presented, highlighting the scarcity of information on freshwater insects from Alpine regions. Most references are on Diptera Chironomidae from North America and North Europe. Some recent findings on aquatic insects from Italian Alpine streams are also presented.

  13. Community structure and decadal changes in macrozoobenthic assemblages in Lake Poyang, the largest freshwater lake in China

    Directory of Open Access Journals (Sweden)

    Cai Y. J.

    2014-01-01

    Full Text Available Lake Poyang is the largest freshwater lake in China and contains unique and diverse biota within the Yangtze floodplain ecosystem. However, knowledge of its macrozoobenthic assemblages remains inadequate. To characterize the current community structure of these assemblages and to portray their decadal changes, quarterly investigations were conducted at 15 sites from February to November 2012. A total of 42 taxa were recorded, and Corbicula fluminea, Limnoperna fortunei, Gammaridae sp., Nephtys polybranchia, Polypedilum scalaenum and Branchiura sowerbyi were found to dominate the community in terms of abundance. The bivalves Corbicula fluminea, Lamprotula rochechouarti, Arconaia lanceolata and Lamprotula caveata dominated the community in biomass due to their large body size. The mean abundance of the total macrozoobenthos varied from 48 to 920 ind·m-2, the mean biomass ranged from 28 to 428 g·m-2. The substrate type affected strongly the abundance, biomass, and diversity of the macrozoobenthos, with muddy sand substrates showing the highest values. Compared with historical data, remarkable changes were observed in the abundance of macrozoobenthos and the identity of the dominant species. The mean total abundance decreased from 724 ind·m-2 in 1992 to 228 ind·m-2 in 2012. The dominant species have shifted dramatically. Large unionids were dominant before 1998, whereas pollution-tolerant species (e.g., Branchiura sowerbyi increased in dominance after 2008. Our findings should have implications for the conservation of the benthic biodiversity of this large Yangtze-connected lake.

  14. Transfer of radionuclides in aquatic ecosystems - Default concentration ratios for aquatic biota in the Erica Tool

    Energy Technology Data Exchange (ETDEWEB)

    Hosseini, A.; Thorring, H. [Norwegian Radiation Protection Authority, Department of Emergency Preparedness and Environmental Radioactivity, Grini naeringspark 13, P.O. Box 55, No-1332 Osteras (Norway); Brown, J.E. [Norwegian Radiation Protection Authority, Department of Emergency Preparedness and Environmental Radioactivity, Grini naeringspark 13, P.O. Box 55, No-1332 Osteras (Norway)], E-mail: justin.brown@nrpa.no; Saxen, R.; Ilus, E. [Radiation and Nuclear Safety Authority (STUK), Laippatie 4, P.O. Box 14, 00881 Helsinki (Finland)

    2008-09-15

    The process of assessing risk to the environment following a given release of radioactivity requires the quantification of activity concentrations in environmental media and reference organisms. The methodology adopted by the ERICA Integrated Approach involves the application of concentration ratios (CR values) and distribution coefficients (K{sub d} values) for aquatic systems. Within this paper the methodologies applied to derive default transfer parameters, collated within the ERICA Tool databases, are described to provide transparency and traceability in the documentation process. Detailed information is provided for the CR values used for marine and freshwater systems. Of the total 372 CR values derived for the marine ecosystem, 195 were identified by literature review. For the freshwater system, the number of values based on review was less, but still constituted 129 from a total of 372 values. In both types of aquatic systems, 70-80% of the data gaps have been filled by employing 'preferable' approaches such as those based on substituting values from taxonomically similar organisms or biogeochemically similar elements.

  15. Transfer of radionuclides in aquatic ecosystems - Default concentration ratios for aquatic biota in the Erica Tool

    International Nuclear Information System (INIS)

    The process of assessing risk to the environment following a given release of radioactivity requires the quantification of activity concentrations in environmental media and reference organisms. The methodology adopted by the ERICA Integrated Approach involves the application of concentration ratios (CR values) and distribution coefficients (Kd values) for aquatic systems. Within this paper the methodologies applied to derive default transfer parameters, collated within the ERICA Tool databases, are described to provide transparency and traceability in the documentation process. Detailed information is provided for the CR values used for marine and freshwater systems. Of the total 372 CR values derived for the marine ecosystem, 195 were identified by literature review. For the freshwater system, the number of values based on review was less, but still constituted 129 from a total of 372 values. In both types of aquatic systems, 70-80% of the data gaps have been filled by employing 'preferable' approaches such as those based on substituting values from taxonomically similar organisms or biogeochemically similar elements

  16. Uptake, turnover and distribution of chlorinated fatty acids in aquatic biota

    Energy Technology Data Exchange (ETDEWEB)

    Bjoern, Helena

    1999-09-01

    Chlorinated fatty acids (CIFAs) are the major contributors of extractable, organically bound chlorine in fish lipids. A known anthropogenic source of CIFAs is chlorine bleached pulp production. Additional anthropogenic sources may exist, e.g., chlorine-containing discharge from industrial and household waste and they may also occur naturally. CIFAs have a wide geographic distribution. They have, for instance, been identified in fish both from Alaskan and Scandinavian waters. In toxicological studies of CIFAs, the most pronounced effects have been found in reproductive related processes. CIFAs have also been shown to disrupt cell membrane functions. The present study was carried out to further characterise the ecotoxicological properties of CIFAs and their presence in biota. To investigate the biological stability of CIFAs, two experiments were carried out using radiolabelled chlorinated and non-chlorinated fatty acids. In both experiments, CIFAs were taken up from food by fish and assimilated to lipids. From the first experiment it was concluded that the chlorinated fatty acid investigated was turned over in the fish to a lower degree than the non-chlorinated analogue. In the second experiment, the transfer of a chlorinated fatty acid was followed over several trophic levels and the chlorinated fatty acid was transferred to the highest trophic level. In samples with differing loads of persistent organic pollutants (POPs) from both fish and marine mammals, high concentrations and diversity of CIFAs were detected. This was also observed in samples with low POP concentration. Chlorohydroxy fatty acids made up a considerable portion of the CIFAs in certain samples, both from limnic fish and marine mammals. CIFAs in fish were found to be bound in complex lipids such as triacylglycerols (storage lipids) and phospholipids, as well as in acyl sterols (membrane lipids). In the marine mammals investigated, high concentrations of CIFAs were mainly bound in phospholipids. If CIFAs are assimilated like `normal` fatty acids, are incorporated into membrane lipids, and are recalcitrant to catabolism, they may thus give rise to ecotoxicological effects when released to the environment and accumulated in biota 55 refs, 1 fig

  17. Freshwater aquaculture in the United States: Complying with environmental protection law and policy

    OpenAIRE

    Noble, M.

    1993-01-01

    The author deal with the relations between the freshwater fish culture and the many regulations of the environmental protection in USA. The author develops the federal and state administrative frameworks (federal government administration of aquaculture, the state government administration of aquaculture), the freshwater aquaculture and water rights, the freshwater aquaculture and wetlands regulation, the freshwater aquaculture and water quality regulation, the freshwater aquaculture and wild...

  18. Potential Risks of Freshwater Aquifer Contamination with Geosequestration

    Energy Technology Data Exchange (ETDEWEB)

    Jackson, Robert

    2013-09-30

    Substantial leakage of CO{sub 2} from deep geological strata to shallow potable aquifers is likely to be rare, but chemical detection of potential leakage nonetheless remains an integral component of any safe carbon capture and storage system. CO{sub 2} that infiltrates an unconfined freshwater aquifer will have an immediate impact on water chemistry by lowering pH in most cases and by altering the concentration of total dissolved solids. Chemical signatures in affected waters provide an important opportunity for early detection of leaks. In the presence of CO{sub 2}, trace elements such as Mn, Fe, and Ca can increase by an order of magnitude or more above control concentrations within 100 days. Therefore, these and other elements should be monitored along with pH as geochemical markers of potential CO{sub 2} leaks. Dissolved inorganic carbon and alkalinity can also be rapidly responsive to CO{sub 2} and are stable indicators of a leak. Importantly, such changes may be detectable long before direct changes in CO{sub 2} are observed. The experimental results also suggest that the relative severity of the impact of leaks on overlying drinking-water aquifers should be considered in the selection of CO{sub 2} sequestration sites. One primary selection criteria should be metal and metalloid availability, such as uranium and arsenic abundance, to carefully monitor chemical species that could trigger changes above maximum contaminant levels (MCLs). Overall, the risks of leakage from underground CO{sub 2} storage are real but appear to be manageable if systems are closely monitored.

  19. Comparative toxicity of metals to freshwater life in tropical Australia

    International Nuclear Information System (INIS)

    At present, there is a paucity of internally consistent datasets on the toxicity of metals (and other contaminants) in the tropics, relative to the cool and warm temperate regions of the world. Such information is considered mandatory before a proper comparison of the toxicity of metals to aquatic life between tropical and temperate regions is possible. As part of a larger study to investigate whether the toxicity of metals to aquatic life differs between the tropical and temperate regions of Australia, several species of tropical freshwater organisms, comprising a molluscs, fish, hydra, Daphnia and an alga were employed to obtain an internally consistent data set on the comparative toxicity of selected metals, such as U and Cu, that are of potential concern in the wet-dry tropics of Australia as a result of man's activities. Both acute and chronic ecologically relevant sublethal endpoints, such as growth and reproduction (EC50, BEC10) were measured for the five species, which cover a variety of trophic levels. A synthetic water quality that closely resembled the inorganic composition of the natural waters in which the organisms inhabit, was used in all experiments. This facilitated the use of the geochemical modelling code, HARPHRQ, to predict the speciation, and hence, bioavailability of the selected metals. A knowledge of the bioavailable fraction of a metal is necessary for setting up national water quality guidelines for the protection of aquatic life. The results from this study are discussed and related to the derivation of both site-specific and national water quality-guidelines for metals

  20. Freshwater Microcosms-Based Assessment of Eco-toxicological Effects of a Chemical Effluent from the Pilcam Industry in Cameroon

    Directory of Open Access Journals (Sweden)

    J. E. Djomo

    2004-09-01

    Full Text Available We studied the acute toxicity of a raw effluent from a battery manufacturing plant (Pilcam in Douala, Cameroon, to a freshwater fish (Oreochromis niloticus, and subsequently evaluated its sub-acute effects on water quality and the biota in freshwater microscosms. The acute toxicity test was based on 96 hrs static renewal bioassays that resulted in 96-h LC50 and LC90 values of 16 and 20.7% (v/v, respectively. The sub-acute experiments were conducted by exposing several species of aquatic organisms (plankton, macro-invertebrates and mollusks to lower effluent concentrations [1.6%, 8.0%, 16% (v/v] for six weeks, and monitoring their survival rates, as well as the physical and chemical characteristics of water. These concentrations were based on 10%, 50%, and 100% of the 96 h - median lethal concentrations (LC50 of the effluent to the freshwater fish, Oreochromis niloticus. Significant effects on functional parameters, such as, chlorophyll-a and total protein could not be demonstrated. However, the activity of alkaline phosphatase was significantly inhibited at all concentrations tested. Phytoplankton, zooplankton, macro-invertebrate communities and snails were negatively affected by the effluent application at concentrations ≥ 8% (v/v, with chlorophyta, ciliates, ostracoda, annelida, planaria and snails being the most sensitive groups. The snails were eliminated after 24 h exposure from microcosms treated with effluent at concentration ≥ 8% (v/v. Effluent exposure also caused significant effects on water quality parameters (DO, pH, hardness, conductivity, color, turbidity, ammonia in general at concentrations ≥ 8% (v/v. Temperature and alkalinity were not significantly affected. Overall, data from this research indicate that a dilution of the Pilcam effluent down to 1.6% does not provide protection against chronic toxicity to aquatic organisms. Further studies are needed to determine the no observable adverse effect level (NOAEL, as well as a chronic reference concentration for this effluent.

  1. Bibliography on cycling of trace metals in freshwater ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    LaRiviere, M.G.; Scott, A.J.; Woodfield, W.G.; Cushing, C.E.

    1978-07-01

    This bibliography is a listing of pertinent literature directly addressing the cycling of trace metals in freshwater ecosystems. Data on cycling, including the influences of environmental mediators, are included. 151 references.

  2. Imperiled Freshwater and Diadromous Fishes of North America

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — List of imperiled freshwater and diadromous fishes of North America as determined by the 2008 American Fisheries Society (AFS) Endangered Species Committee (ESC) on...

  3. Caernarvon freshwater diversion: Contaminants monitoring study (interim report)

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Caernarvon Freshwater Diversion Structure was completed in January 1991 by the U.S. Army Corps of Engineers. The purpose of the structure is to divert...

  4. Methods for freshwater riverine input into regional ocean models

    Science.gov (United States)

    Herzfeld, M.

    2015-06-01

    The input of freshwater at the coast in regional models is a non-trivial exercise that has been studied extensively in the past. Several issues are of relevance; firstly, estuaries process water properties along their length, so that while freshwater may enter at the estuary head, it is no longer fresh at the mouth. Secondly, models create a numerical response that results in excessive upstream or offshore transport compared to what is typically observed. The cause of this has been traced to the lack of landward flow at the coast where freshwater is input. In this study we assess the performance of various methods of freshwater input in coarse resolution regional models where the estuary cannot be explicitly resolved, and present a formulation that attempts to account for upstream flow in the salt wedge and in-estuary mixing that elevates salinity at the mouth.

  5. Ecobiological studies of the freshwater lakes at Schirmacher Oasis, Antarctica

    Digital Repository Service at National Institute of Oceanography (India)

    Verlecar, X.N.; Dhargalkar, V.K.; Matondkar, S.G.P.

    Ecological studies of the freshwater lakes at the Schirmacher Oasis have been reported. Physical variables such as atmospheric temperature, solar radiation, winds, etc. showed that the environment at Schirmacher Oasis is less extreme than near...

  6. FRESHWATER FISHERY OF THE REPUBLIC OF CROATIA

    Directory of Open Access Journals (Sweden)

    Zlatko Homen

    1999-09-01

    Full Text Available As fishery, including freshwater, is very important for economy of the Republic of Croatia, the aim of this paper is to show its condition from 1995 to 1998. and also to draw a plan for fish production in 1999. The period from 1998-1999. is more stressed in order to have a total and detailed view into the present condition of the freshwater fishery and into the direction in wish that production is going. Data about carp ponds and also about trout ponds is presented. Twentynine fish-ponds are processed out of which 20 are carp ponds and 9 trout ponds. Data was delivered to the Ministry of Agriculture and Forestry Fisheries Directorate. An assessment of the condition is made for 3 fish-ponds as the desired data was not provided. As to the number of employees on fish-ponds, a slight decline could be percived in the period from 1995 to 1997. In 1998 a number of employees considerably increased for 10.07% in relation to 1997. qualification of the employees in 1998. show that the most of them are unqualified what is in accord with the requirements of a job on a fish-pond. Overall surface of the carp ponds in 1998 was 12,708 and the production surface was 9,782 ha. The most of the fish-ponds have up to 500 ha of total surface (45.45%, while 50% of the fish-ponds have production surface from 500-100 ha. The production in the trout ponds is made on 165,905 m 2 of the overall surface of the ponds, and only 40,538 m 2 are the production surface of the ponds. The production of fish in that period was in constant increase and that increasing trend in expected in 1999, and it will be an 28.30 % increase in relation to 1998. The increase is expected for all kids of fish except for big head carps, silver carps and tinch fishs. As a part of the production of tinch fishs an increase in production of consumption tinch fish is expected, but a decrease in production of one-year and two-year old fishs and two-year old fish. Out of all kinds of fish, the most produced in 1998. was carp (80.93%, then trout (8.30 %, herbivorous kinds of fish (8.01% and all other fish (2.76% out of which sheat fish was the most produced. Only slightly changed structure of the production is expected in 1999. Carp production will still be the most prolific and slightly increased - 81.97%, trout - production - 6.68 %, herbivorous fish - 7.69% and other kinds of fish - 3.69% which in increased percentage in relation to 1998. Taking into consideration production surfaces of the fish ponds and the realized production in 1998., it can be conciuded that the average amount in carp fish ponds was 710.37 kg/ha which is substantially under desired amount of about 1000 kg/ha. Surely, it should be stressed that some fish ponds managed to attain that number and even to exceed it. In trout fish ponds the average amount was 133.17 t/ha. The increased production requires an increased need for food. It is expected that the largest expenditure for fish feeding will be that of corn (60.59%, wheat (14.91%, mixture (10.36%, barley (8.38%, and soya shot (3.29%, meat-bone flour (0.48, fish flour (0.51%, medicines, medicinal food and aditives (0.68% and other food (0.81%. Fish in carp ponds are sold on the domestic market and abroad, while trouts are sold only on the domestic market. Total realization on the freshwater fish market was 45 milions kunas in 1998. As one of the mesaures for improvement of fishery and aquaculture in general are stimuli for production of freshwater fish. On the grounds of the law of monetary incentive in agriculture and fishery. During 1998. A monetary incentive for growing of freshwater fish was payed and it was 5,623,957.01 kunas which is an increase of 77.57% in relation to 1997.

  7. Technical report: Metal concentrations in sediments, and selected biota from mine tailings in Gastineau Channel, Juneau, Alaska [Draft

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Hardrock gold mining occurred in Juneau from 1880 to 1944. Tailings and waste rock from the mines were deposited into Gastineau Channel and formed beaches along...

  8. Dynamics of radiation exposure to marine biota in the area of the Fukushima NPP in March–May 2011

    International Nuclear Information System (INIS)

    Estimates of radiation dose rates are presented for marine biota in March–May 2011 in the coastal zone near Fukushima NPP, and in the open sea. Calculations of fish contamination were made using two methods: a concentration factor approach, and a dynamic model. For representative marine organisms (fish and molluscs) the radiation dose rates did not exceed the reference level of 10 mGy/day. At a distance 30 km from the NPP, in the open sea the radiation doses for marine biota were much lower than those in the coastal zone near the NPP. Comparative estimates are presented for radiation doses to aquatic organisms in the exclusion zones of the Eastern Urals Radioactive Trail, and the Chernobyl NPP.

  9. The role of regional information in the dose rate estimation of biota: from the view point of stakeholder involvement

    International Nuclear Information System (INIS)

    A dose evaluation system developed to judge environmental radiation safety was proposed in order to evaluate the effect on environmental flora and fauna. However, it was noted that large differences exist between biota doses based on the regional data and those determined by the dose evaluation system developed. In order to realize successful mutual communication among stakeholders, information needed for environmental radiation protection has been investigated in various kinds of exposure situations, because the Japanese tend to act following the standards set by them to get the most appropriate results in the situations they are faced with. It became clear from the investigation on beliefs about environmental issues that the Japanese are concerned about regional characteristics of natural environments and biota through which they observe variations in their living conditions. Furthermore, the systematic approach for compilation of the regional environmental parameters and data becomes important to accomplish a social agreement on environmental safety. (author)

  10. Deep-ocean origin of the freshwater eels

    OpenAIRE

    Inoue, Jun G.; Miya, Masaki; Miller, Michael J.; Sado, Tetsuya; Hanel, Reinhold; Hatooka, Kiyotaka; Aoyama, Jun; Minegishi, Yuki; Nishida, Mutsumi; Tsukamoto, Katsumi

    2010-01-01

    Of more than 800 species of eels of the order Anguilliformes, only freshwater eels (genus Anguilla with 16 species plus three subspecies) spend most of their lives in freshwater during their catadromous life cycle. Nevertheless, because their spawning areas are located offshore in the open ocean, they migrate back to their specific breeding places in the ocean, often located thousands of kilometres away. The evolutionary origin of such enigmatic behaviour, however, remains elusive because of ...

  11. Nucleus Pearl Coating Process of Freshwater Mussel Anodonta woodiana (Unionidae)

    OpenAIRE

    WASMEN MANALU; DEDY DURYADI SOLIHIN; SATA YOSHIDA SRIE RAHAYU; RIDWAN AFFANDI

    2013-01-01

    The limiting factor which is a weakness of sea water pearl production are high costs, the risk of major business failures and a long coating time. From the issue of freshwater pearls appear to have prospects of alternative substitution for sea water pearl. This present study aimed to evaluate effect of loads (the number and diameter nucleus) on freshwater pearl coating process and the number and size of the appropriate nucleus diameter, to produce the optimum coating thickness of half-round p...

  12. Genetic calibration of species diversity among North America's freshwater fishes

    OpenAIRE

    April, Julien; Mayden, Richard L; Hanner, Robert H.; Bernatchez, Louis

    2011-01-01

    Freshwater ecosystems are being heavily exploited and degraded by human activities all over the world, including in North America, where fishes and fisheries are strongly affected. Despite centuries of taxonomic inquiry, problems inherent to species identification continue to hamper the conservation of North American freshwater fishes. Indeed, nearly 10% of species diversity is thought to remain undescribed. To provide an independent calibration of taxonomic uncertainty and to establish a mor...

  13. The fossil record and evolution of freshwater plants: A review

    OpenAIRE

    Martin-Closas, Carles

    2003-01-01

    Palaeobotany applied to freshwater plants is an emerging field of palaeontology. Hydrophytic plants reveal evolutionary trends of their own, clearly distinct from those of the terrestrial and marine flora. During the Precambrian, two groups stand out in the fossil record of freshwater plants: the Cyanobacteria (stromatolites) in benthic environments and the prasinophytes (leiosphaeridian acritarchs) in transitional planktonic environments. During the Palaeozoic, green algae (Chlorococcales, Z...

  14. The fossil recordand evolution of freshwater plants : a review

    OpenAIRE

    Martín-Closas, C.

    2003-01-01

    Palaeobotany applied to freshwater plants is an emerging field of palaeontology. Hydrophytic plants reveal evolutionary trends of their own, clearly distinct from those of the terrestrial and marine flora. During the Precambrian, two groups stand out in the fossil record of freshwater plants: the Cyanobacteria (stromatolites) in benthic environments and the prasinophytes (leiosphaeridian acritarchs) in transitional planktonic environments. During the Palaeozoic, green algae (Chlorococcales, Z...

  15. A sinemydid turtle from the Jehol Biota provides insights into the basal divergence of crown turtles.

    Science.gov (United States)

    Zhou, Chang-Fu; Rabi, Márton

    2015-01-01

    Morphological phylogenies stand in a major conflict with molecular hypotheses regarding the phylogeny of Cryptodira, the most diverse and widely distributed clade of extant turtles. However, molecular hypotheses are often considered a better estimate of phylogeny given that it is more consistent with the stratigraphic and geographic distribution of extinct taxa. That morphology fails to reproduce the molecular topology partly originates from problematic character polarization due to yet another contradiction around the composition of the cryptodiran stem lineage. Extinct sinemydids are one of these problematic clades: they have been either placed among stem-cryptodires, stem-chelonioid sea turtles, or even stem-turtles. A new sinemydid from the Early Cretaceous Jehol Biota (Yixian Formation, Barremian-Early Aptian) of China, Xiaochelys ningchengensis gen. et sp. nov., allows for a reassessment of the phylogenetic position of Sinemydidae. Our analysis indicates that sinemydids mostly share symplesiomorphies with sea turtles and their purported placement outside the crown-group of turtles is an artefact of previous datasets. The best current phylogenetic estimate is therefore that sinemydids are part of the stem lineage of Cryptodira together with an array of other Jurassic to Cretaceous taxa. Our study further emphasises the importance of using molecular scaffolds in global turtle analyses. PMID:26553740

  16. Technetium-99 in biota samples collected along the Finnish coast in 1999

    Energy Technology Data Exchange (ETDEWEB)

    Ilus, E.; Vartti, V.-P.; Ikaeheimonen, T.K.; Mattila, J.; Klemola, S. [Radiation and Nuclear Safety Authority, Helsinki (Finland)

    2002-07-01

    The aim of the study was to develop a method for analysing {sup 99}Tc at STUK (Radiation and Nuclear Safety Authority in Finland), and to establish whether {sup 99}Tc can be detected in Finnish coastal waters. Samples of Fucus vesiculosus, Myriophyllum spp., Macoma baltica, Mytilus edulis, Saduria entomon and seawater were collected at more than 30 stations along the western and southern coasts of Finland for {sup 99}Tc analysis. Small amounts of {sup 99}Tc were observed in all the Fucus samples collected; the activity concentrations ranged from 1.6 to 11.6 Bq kg{sup -1} dry wt. The highest concentrations were found in two samples taken from the northernmost stations in the Quark, probably for biological reasons. Due to the low salinity of the water, Fucus vesiculosus is very slow-growing and small in this area, which is at the extreme limit of its permanent distribution range in the Baltic Sea. In seawater and in all the other biota samples, the concentration of {sup 99}Tc was below the detection limit, which supports the use of Fucus as an indicator organism for {sup 99}Tc in the marine environment. Global fallout from atmospheric nuclear weapons tests carried out in the 1950s and 1960s is certainly the most important source of {sup 99}Tc detected in Fucus on the Finnish coast. In addition, the samples were analysed for gamma- emitting radionuclides. (orig.)

  17. Novel brominated flame retardants and dechlorane plus in Greenland air and biota.

    Science.gov (United States)

    Vorkamp, Katrin; Bossi, Rossana; Riget, Frank F; Skov, Henrik; Sonne, Christian; Dietz, Rune

    2015-01-01

    Following the ban of polybrominated diphenyl ethers, other halogenated flame retardants (FRs) might be used increasingly. This study has analyzed hexabromocyclododecane (HBCD), 1,2-bis(2,4,6-tribromophenoxy)-ethane (BTBPE), 2,3-dibromopropyl-2,4,6-tribromophenyl ether (DPTE) and dechloraneplus (DP) in Greenland air over the course of a year. Moreover, BTBPE, DPTE, DP, 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (TBB), bis(2-ethylhexyl) tetrabromophthalate (TBPH) and decabromodiphenylethane (DBDPE) were analyzed in samples of polar bear, ringed seal, black guillemot and glaucous gull from Greenland. HBCD in air appeared low, while mean concentrations of syn- and anti-DP were 2.3 and 5.2 pg/m(3), respectively. BTBPE and DPTE were undetectable in air. Detection frequencies in biota were <50% for BTBPE, TBPH and DBDPE, but near 100% for the remaining compounds. Ringed seals from East Greenland had highest mean concentrations of TBB, DPTE, syn- and anti-DP (1.02, 0.078, 0.096 and 0.42 ng/g wet weight, respectively). Our study documents the long-range transport and, to some extent, bioaccumulation of these novel FRs. PMID:25463724

  18. Contrasting food web factor and body size relationships with Hg and Se concentrations in marine biota.

    Science.gov (United States)

    Karimi, Roxanne; Frisk, Michael; Fisher, Nicholas S

    2013-01-01

    Marine fish and shellfish are primary sources of human exposure to mercury, a potentially toxic metal, and selenium, an essential element that may protect against mercury bioaccumulation and toxicity. Yet we lack a thorough understanding of Hg and Se patterns in common marine taxa, particularly those that are commercially important, and how food web and body size factors differ in their influence on Hg and Se patterns. We compared Hg and Se content among marine fish and invertebrate taxa collected from Long Island, NY, and examined associations between Hg, Se, body length, trophic level (measured by ?(15)N) and degree of pelagic feeding (measured by ?(13)C). Finfish, particularly shark, had high Hg content whereas bivalves generally had high Se content. Both taxonomic differences and variability were larger for Hg than Se, and Hg content explained most of the variation in Hg:Se molar ratios among taxa. Finally, Hg was more strongly associated with length and trophic level across taxa than Se, consistent with a greater degree of Hg bioaccumulation in the body over time, and biomagnification through the food web, respectively. Overall, our findings indicate distinct taxonomic and ecological Hg and Se patterns in commercially important marine biota, and these patterns have nutritional and toxicological implications for seafood-consuming wildlife and humans. PMID:24019976

  19. Distribution of hexabromocyclododecane diastereomers in marine biota in the Western Scheldt Estuary

    Energy Technology Data Exchange (ETDEWEB)

    Janak, K. [Norwegian Institute of Public Health, Oslo (Norway). Div. of Environmental Medicine; Covaci, A.; Voorspoels, S. [Antwerp Univ., Wilrijk (Belgium). Toxicological Centre

    2004-09-15

    Hexabromocyclododecane (HBCD) is one of the most common additive flame retardant mainly used in polystyrene foams with the global market consumption in 2001 at about 16 700 tons.1 HBCD production results in a technical product consisting mostly of three diastereomers, {alpha}-, {beta}-, and {gamma}-HBCD, with the {gamma}-isomer being the predominant one. HBCD has a high bioaccumulation potential and bioavailability and has been found in increasing concentrations in environmental samples and in biota. Diastereoisomer-specific analysis of HBCD was achieved by reversed phase HPLC4 and consistently higher concentrations of the {alpha}-isomer compared to {gamma}-isomer have recently been reported, while the {beta}-isomer was non-detected in the majority of samples. The Western Scheldt Estuary is subjected to a variety of suspected brominated flame retardants (BFR) sources such as a BFR manufacturing plant (Terneuzen, The Netherlands), the Antwerp harbour and textile industry located further upstream the river. Recently, polybrominated diphenyl ethers (PBDEs) were investigated in marine species of different trophic levels collected from the Scheldt Estuary. In Europe, HBCD is more widely used than PBDEs and high levels of HBCD have already been reported in sediments from the Scheldt. So far, there is very little known about differences in toxicity, bioavailability and bioaccumulation of HBCD diastereoisomers. In this paper, we report on the levels of the HBCD diastereomers in various marine species and sediment from the Western Scheldt.

  20. Proposal of a weight factor for alpha radiation aiming biota radioprotection

    International Nuclear Information System (INIS)

    Several proposals based on the environmental radioprotection of calculating the absorbed dose in biota have been suggested. The absorbed dose expresses the deposition of energy per mass unit. The differences in biological effects of the absorbed dose can be quantified by applying a correction factor to the absorbed dose. The correction factor for radiation is easier to establish, because radiations exist in smaller number (alpha, beta, neutrons and photons) and can be set for groups of organisms. This work aims to propose a correction factor for radiation, in order to adequate the concept of absorbed dose currently used to the concept of equivalent dose. A survey of the literature on correction factors proposed for alpha radiation was carried out and, when possible, the biological endpoint was identified, as well as the radionuclide and the biological target. A variation of the weight factor for alpha radiation from 1 to 377 was observed and a number of biological endpoints, biological target and alpha emitter radionuclide were identified. Finally we propose a weight value for alpha radiation of 40, and we propose also the name of correction factor for radiation alpha as being ecological radiation weighting factor (WRE) the name 'equivalent dose for flora and fauna' (HTFF) to name of the new dose. (author)

  1. The distribution and speciation of antimony in river water, sediment and biota in Yodo River, Japan.

    Science.gov (United States)

    Kawamoto, Y; Morisawa, S

    2003-11-01

    In 1993, the Japanese government set the guideline concentration of 2 microg l(-1) for antimony in natural water and drinking water as an item for precautionary monitoring in consideration of its chronic toxicity, however in 1999 the guideline value was tentatively canceled to examine the health risk of antimony through the accumulation of more information and data for detailed risk assessment. In this study, the distribution of antimony in the river water environment including water, sediment, aquatic plants and fishes was surveyed in the Yodo River basin. The characteristics of antimony distribution between river water and sediment were determined by the batch sorption experiments, focusing on the difference in oxidation state. This study suggests that biota in the Yodo River basin have antimony at concentrated levels. Some of the sewage treatment plants seemed to influence the concentration of antimony in river water. It was shown that the pentavalent antimony is dominant in river water and especially paramount downstream of the sewage treatment plants, though the trivalent antimony is dominant in industrial use. According to the sorption experiments of antimony on river sediment, the trivalent antimony is sorbed faster and more in partition than the pentavalent antimony. PMID:14733388

  2. Comparison and unification of carbon stable isotope ratios in specific aquatic biota

    Science.gov (United States)

    Wang, N.; Wu, Y.; Zhang, J.

    2009-05-01

    Stable isotope analysis has become a convenient tool for aquatic food web research in recent years. However, one controversial point on using stable isotope analysis for food web is whether to extract lipids or not before stable isotope analysis due to strong discrimination against 13C and more negative 13C in lipid-rich tissues independent of diet that can be induced by the key step of endogenous lipid synthesis. Lipid extraction may result in the loss of non-lipid compounds that alters ?15N, which urged the development of arithmetic correction techniques for ?13C, although the techniques as well as their underlying assumptions were seldom systematically verified. A novel lipid normalizing model for different aquatic biota was therefore established and applied to the East China Sea (ECS). According to the experimentally measured ?13C values of dorsal muscle of 11 common fish species, organs and whole-body of Japanese Anchovy (Engraulis japonicas), the proposed model is verified to be appropriate to the food web research on the East China Sea.

  3. [Fungal biota in manned space environment and impact on human health].

    Science.gov (United States)

    Makimura, Koichi; Satoh, Kazuo; Sugita, Takashi; Yamazaki, Takashi

    2011-01-01

    It is important to promote microbiological research essential for long-term manned space activities under microgravity and in a completely closed environment in space craft in relation to long-duration space expeditions on the International Space Station (ISS) or to the moon and Mars in the future. Environmental monitoring data from the space shuttle, the Mir, and the ISS have already shown that microorganisms isolated from air and on inner surfaces of space craft were generally carried by crew members. The Japanese Experiment Module (JEM) "KIBO" was attached to the ISS and started its operation from 2008. It is an invaluable opportunity to begin the survey of the transition of microbiota, particularly fungal biota, in JEM from "brand-new" to "well-used" condition at various periods. Therefore, we are preparing the on-board analyzing systems for microbiota in air and on inner surfaces of ISS/JEM and normal microbiota of the astronauts themselves. In this paper, we introduce the current status and future plans on fungal research on ISS/JEM to protect flight crew members and flight hardware from potentially hazardous microorganisms from the environmental and biomedical aspects of Japan Aerospace Exploration Agency (JAXA). PMID:21358138

  4. Plant Diversity Surpasses Plant Functional Groups and Plant Productivity as Driver of Soil Biota in the Long Term

    OpenAIRE

    Eisenhauer, Nico; Milcu, Alexandru; Sabais, Alexander C. W.; Bessler, Holger; Brenner, Johanna; Engels, Christof; Klarner, Bernhard; Maraun, Mark; Partsch, Stephan; Roscher, Christiane; Schonert, Felix; Temperton, Vicky M.; Thomisch, Karolin; Weigelt, Alexandra; Weisser, Wolfgang W

    2011-01-01

    Background: One of the most significant consequences of contemporary global change is the rapid decline of biodiversity in many ecosystems. Knowledge of the consequences of biodiversity loss in terrestrial ecosystems is largely restricted to single ecosystem functions. Impacts of key plant functional groups on soil biota are considered to be more important than those of plant diversity; however, current knowledge mainly relies on short-term experiments. Methodology/Principal Findi...

  5. Assessment of radiological risk for marine biota and human consumers of seafood in the coast of Qingdao, China.

    Science.gov (United States)

    Yang, Baolu; Ha, Yiming; Jin, Jing

    2015-09-01

    This paper reports the levels of (226)Ra, (232)Th, (40)K and (137)Cs in the edible parts of 11 different marine species collected from the Qingdao coast of China. The activities of (226)Ra, (232)Th and (40)K ranged from 0.08±0.03 to 1.65±0.60 Bq kg(-1) w.w., 0.09±0.02 to 1.44±0.10 Bq kg(-1) w.w., 26.89±1.25 to 219.25±5.61 Bq kg(-1) w.w., respectively. Artificial (137)Cs was undetectable or close to the detection limit in the biota sampled. To link radioactivity to possible impact on health, we calculated radiation doses to both the marine biota and human beings. We showed that doses in all cases were dominated by naturally occurring (40)K and that (137)Cs doses were negligible compared with (40)K-derived doses. The total doses to marine biota ranged between 16.55 and 62.41 nGy h(-1) among different biota species, which were below the benchmark level of aquatic organism. The committed effective dose to humans through seafood consumption varied from 10.55 to 36.17 ?Sv y(-1), and the associated lifetime cancer risks ranged from 5.93E-05 to 9.49E-05 for different age and gender groups. Both the dose and cancer risk to humans were at the acceptable range. Despite the significant amount of radionuclides released as a result of the Fukushima accident, their impact on the seafood in Qingdao coast appears to be negligible based on our measurements of concentrations of radionuclide activity and internal dose estimates. PMID:25985213

  6. Assessment of doses to non-human biota: Review of developments and demonstration assessment for Olkiluoto repository

    Energy Technology Data Exchange (ETDEWEB)

    Smith, K. [Carol Robinson Enviros Consulting Ltd, Edinburgh (United Kingdom)

    2006-12-15

    This report provides a summary of work commissioned by Posiva Oy and undertaken by Enviros Consulting Ltd to support the development of a strategy for the assessment of environmental impacts from ionising radiation associated with the Olkiluoto waste repository, Finland, as part of the development of the Posiva Safety Case Portfolio. This project included a review of the development of international policies and standards related to protection of biota from the effects of ionizing radiation and of biota assessment methodologies, paying particular attention to those that have been applied to waste repository performance assessments. On the basis of this review, recommendations were developed on the most appropriate methodology to apply in order to assess the impact of radioactive releases from the planned spent fuel repository in Olkiluoto. A test-case was developed, in collaboration with staff from Posiva and Facilia AB, and an assessment was performed. The results and experience of which were analysed and summarised to develop recommendations for a future strategy. The test case highlighted some significant data gaps related to the assessment of impacts to both generic biota types and to interest species. In particular, concentration ratios for generic carnivorous mammals and migratory species such as moose that may consume food from multiple ecosystems and dose conversion factors for large burrowing (i.e. hibernating) mammals. However, in general terms, the dose rates predicted for all organism types were several orders of magnitude below those at which population effects would be expected to be observed and those at which effects on the individual may be anticipated. There would therefore be scope for simplifying the approach applied, although there would be value in performing a sensitivity analysis to ensure that the simplification is applied appropriately. There would also be value in ensuring consistency of the developing approach for non-human biota with that applied for human protection. (orig.)

  7. Assessment of doses to non-human biota: Review of developments and demonstration assessment for Olkiluoto repository

    International Nuclear Information System (INIS)

    This report provides a summary of work commissioned by Posiva Oy and undertaken by Enviros Consulting Ltd to support the development of a strategy for the assessment of environmental impacts from ionising radiation associated with the Olkiluoto waste repository, Finland, as part of the development of the Posiva Safety Case Portfolio. This project included a review of the development of international policies and standards related to protection of biota from the effects of ionizing radiation and of biota assessment methodologies, paying particular attention to those that have been applied to waste repository performance assessments. On the basis of this review, recommendations were developed on the most appropriate methodology to apply in order to assess the impact of radioactive releases from the planned spent fuel repository in Olkiluoto. A test-case was developed, in collaboration with staff from Posiva and Facilia AB, and an assessment was performed. The results and experience of which were analysed and summarised to develop recommendations for a future strategy. The test case highlighted some significant data gaps related to the assessment of impacts to both generic biota types and to interest species. In particular, concentration ratios for generic carnivorous mammals and migratory species such as moose that may consume food from multiple ecosystems and dose conversion factors for large burrowing (i.e. hibernating) mammals. However, in general terms, the dose rates predicted for all organism types were several orders of magnitude below those at which population effects would be expected to be observed and those at which effects on the individual may be anticipated. There would therefore be scope for simplifying the approach applied, although there would be value in performing a sensitivity analysis to ensure that the simplification is applied appropriately. There would also be value in ensuring consistency of the developing approach for non-human biota with that applied for human protection. (orig.)

  8. Bacterial community response to petroleum hydrocarbon amendments in freshwater, marine, and hypersaline water-containing microcosms.

    Science.gov (United States)

    Jurelevicius, Diogo; Alvarez, Vanessa Marques; Marques, Joana Montezano; de Sousa Lima, Laryssa Ribeiro Fonseca; Dias, Felipe de Almeida; Seldin, Lucy

    2013-10-01

    Hydrocarbon-degrading bacterial communities from freshwater, marine, and hypersaline Brazilian aquatic ecosystems (with water salinities corresponding to 0.2%, 4%, and 5%, respectively) were enriched with different hydrocarbons (heptadecane, naphthalene, or crude oil). Changes within the different microcosms of bacterial communities were analyzed using cultivation approaches and molecular methods (DNA and RNA extraction, followed by genetic fingerprinting and analyses of clone libraries based on the 16S rRNA-coding gene). A redundancy analysis (RDA) of the genetic fingerprint data and a principal component analysis (PCA) of the clone libraries revealed hydrocarbon-enriched bacterial communities specific for each ecosystem studied. However, within the same ecosystem, different bacterial communities were selected according to the petroleum hydrocarbon used. In general, the results demonstrated that Acinetobacter and Cloacibacterium were the dominant genera in freshwater microcosms; the Oceanospirillales order and the Marinobacter, Pseudomonas, and Cycloclasticus genera predominated in marine microcosms; and the Oceanospirillales order and the Marinobacter genus were selected in the different hydrocarbon-containing microcosms in hypersaline water. Determination of total petroleum hydrocarbons (TPHs) in all microcosms after 32 days of incubation showed a decrease in the hydrocarbon concentration compared to that for the controls. A total of 50 (41.3%) isolates from the different hydrocarbon-contaminated microcosms were associated with the dominant operational taxonomic units (OTUs) obtained from the clone libraries, and their growth in the hydrocarbon contaminating the microcosm from which they were isolated as the sole carbon source was observed. These data provide insight into the general response of bacterial communities from freshwater, marine, and hypersaline aquatic ecosystems to petroleum hydrocarbon contamination. PMID:23872573

  9. Analysis of Selenium Concentrations in Biota and Sediment from Stewart Lake and the Middle Green River, 1995-1999: Evaluation of Phase IV Remediation

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report presents the analytical results and analysis of selenium concentrations in biota and sediment samples collected by the U.S. Fish and Wildlife Service...

  10. Radioactivity of plutonium isotopes, 137Cs and their ratio in sediment, seawater and biota from the east coast of Peninsular Malaysia

    International Nuclear Information System (INIS)

    This study with sampling expeditions of marine sediment, seawater and biota were performed at 30 stations within Malaysian Exclusive Economic Zone (EEZ). A total of >400 samples were collected to determine the activity concentration of anthropogenic radionuclides (239+240Pu, 137Cs) and their activity ratio (239+240Pu/137Cs) in sediments, seawater and biota. The purpose of this study was to determine the concentration levels for these radionuclides and to evaluate any occurrence of radioactive contamination. Sediment cores were obtained using multicorer device, while water samples via co-precipitation techniques and biota was purchased from local fishermen. The activity concentrations of 239+240Pu in sediment, seawater and biota were ranged 0.21-0.45 Bq/kg fresh wt., respectively. Meanwhile, the values of 137Cs were ranged 3 in seawater and 239+240Pu to 137Cs obtained seem to confirm that these artificial radioactivities were mainly due to global nuclear fallout. (author)

  11. Review of research on impacts to biota of discharges of naturally occurring radionuclides in produced water to the marine environment.

    Science.gov (United States)

    Hosseini, Ali; Brown, Justin E; Gwynn, Justin P; Dowdall, Mark

    2012-11-01

    Produced water has been described as the largest volume waste stream in the exploration and production process of oil and gas. It is accompanied by discharges of naturally occurring radionuclides raising concerns over the potential radiological impacts of produced water on marine biota. In the Northern European marine environment, radioactivity in produced water has received substantial attention owing to the OSPAR Radioactive Substances Strategy which aims at achieving 'concentrations in the environment near background values for naturally occurring radioactive substances'. This review provides an overview of published research on the impacts to biota from naturally occurring radionuclides discharged in produced water by the offshore oil and gas industry. In addition to summarising studies and data that deal directly with the issue of dose and effect, the review also considers studies related to the impact of added chemicals on the fate of discharged radionuclides. The review clearly illustrates that only a limited number of studies have investigated possible impacts on biota from naturally occurring radionuclides present in produced water. Hence, although these studies indicate that the risk to the environment from naturally occurring radionuclides discharged in produced water is negligible, the substantial uncertainties involved in the assessments of impact make it difficult to be conclusive. With regard to the complexity involved in the problem under consideration there is a pressing need to supplement existing data and acquire new knowledge. Finally, the present work identifies some knowledge gaps to indicate future research requirements. PMID:23022586

  12. Radiological benchmarks for screening contaminants of potential concern for effects on aquatic biota at Oak Ridge National Laboratory, Oak Ridge, Tennessee

    International Nuclear Information System (INIS)

    A hazardous waste site may contain hundreds of contaminants; therefore, it is important to screen contaminants of potential concern for the ecological risk assessment. Often this screening is done as part of a screening assessment, the purpose of which is to evaluate the available data, identify data gaps, and screen contaminants of potential concern. Screening may be accomplished by using a set of toxicological benchmarks. These benchmarks are helpful in determining whether contaminants warrant further assessment or are at a level that requires no further attention. Unlike exposures to chemicals, which are expressed as the concentration in water or sediment, exposures to radionuclides are expressed as the dose rate received by the organism. The recommended acceptable dose rate to natural populations of aquatic biota is 1 rad d-1. Blaylock, Frank, and O'Neal provide formulas and exposure factors for estimating the dose rates to representative aquatic organisms. Those formulas were used herein to calculate the water and sediment concentrations that result in a total dose rate of 1 rad d-1 to fish for selected radionuclides. These radiological benchmarks are intended for use at the US Department of Energy's (DOE's) Oak Ridge Reservation and at the Portsmouth and Paducah gaseous diffusion plants as screening values only to show the nature and extent of contamination and identify the need for additional site-specific investigation

  13. Baseline survey on air, water, soil quality, radioactivity and aquatic biota in and around the project site on new uranium mining site, Tummalapalle, Andhra Pradesh

    International Nuclear Information System (INIS)

    In this study four ecological parameters of the environment ie. water, air, soil and biota were monitored at the new uranium mining site of Tummalapalle, Andhra Pradesh. The water quality was assessed by estimating trace metals, natural uranium, physical and chemical parameters. Air quality was assessed through PM10, TSP, PM2.5, SOx and NOx parameters. Soil samples were analysed for trace metals, metal oxides and natural radionuclides. Similarly biota samples were analysed for trace metals and radionuclides

  14. RADIATION DOSE ASSESSMENT FOR THE BIOTA OF TERRESTRIAL ECOSYSTEMS IN THE SHORELINE ZONE OF THE CHERNOBYL NUCLEAR POWER PLANT COOLING POND

    Energy Technology Data Exchange (ETDEWEB)

    Farfan, E.; Jannik, T.

    2011-10-01

    Radiation exposure of the biota in the shoreline area of the Chernobyl Nuclear Power Plant Cooling Pond was assessed to evaluate radiological consequences from the decommissioning of the Cooling Pond. The article addresses studies of radioactive contamination of the terrestrial faunal complex and radionuclide concentration ratios in bodies of small birds, small mammals, amphibians, and reptiles living in the area. The data were used to calculate doses to biota using the ERICA Tool software. Doses from {sup 90}Sr and {sup 137}Cs were calculated using the default parameters of the ERICA Tool and were shown to be consistent with biota doses calculated from the field data. However, the ERICA dose calculations for plutonium isotopes were much higher (2-5 times for small mammals and 10-14 times for birds) than the doses calculated using the experimental data. Currently, the total doses for the terrestrial biota do not exceed maximum recommended levels. However, if the Cooling Pond is allowed to drawdown naturally and the contaminants of the bottom sediments are exposed and enter the biological cycle, the calculated doses to biota may exceed the maximum recommended values. The study is important in establishing the current exposure conditions such that a baseline exists from which changes can be documented following the lowering of the reservoir water. Additionally, the study provided useful radioecological data on biota concentration ratios for some species that are poorly represented in the literature.

  15. Radiation dose assessment for the biota of terrestrial ecosystems in the shoreline zone of the Chernobyl nuclear power plant cooling pond.

    Science.gov (United States)

    Oskolkov, Boris Ya; Bondarkov, Mikhail D; Gaschak, Sergey P; Maksimenko, Andrey M; Hinton, Thomas G; Coughlin, Daniel; Jannik, G Timothy; Farfán, Eduardo B

    2011-10-01

    Radiation exposure of the biota in the shoreline area of the Chernobyl Nuclear Power Plant Cooling Pond was assessed to evaluate radiological consequences from the decommissioning of the Cooling Pond. This paper addresses studies of radioactive contamination of the terrestrial faunal complex and radionuclide concentration ratios in bodies of small birds, small mammals, amphibians, and reptiles living in the area. The data were used to calculate doses to biota using the ERICA Tool software. Doses from 90Sr and 137Cs were calculated using the default parameters of the ERICA Tool and were shown to be consistent with biota doses calculated from the field data. However, the ERICA dose calculations for plutonium isotopes were much higher (2-5 times for small mammals and 10-14 times for birds) than the doses calculated using the experimental data. Currently, the total doses for the terrestrial biota do not exceed maximum recommended levels. However, if the Cooling Pond is allowed to draw down naturally and the contaminants of the bottom sediments are exposed and enter the biological cycle, the calculated doses to biota may exceed the maximum recommended values. The study is important in establishing the current exposure conditions such that a baseline exists from which changes can be documented following the lowering of the reservoir water. Additionally, the study provided useful radioecological data on biota concentration ratios for some species that are poorly represented in the literature. PMID:21878760

  16. Radiation Dose Assessment For The Biota Of Terrestrial Ecosystems In The Shoreline Zone Of The Chernobyl Nuclear Power Plant Cooling Pond

    International Nuclear Information System (INIS)

    Radiation exposure of the biota in the shoreline area of the Chernobyl Nuclear Power Plant Cooling Pond was assessed to evaluate radiological consequences from the decommissioning of the Cooling Pond. The article addresses studies of radioactive contamination of the terrestrial faunal complex and radionuclide concentration ratios in bodies of small birds, small mammals, amphibians, and reptiles living in the area. The data were used to calculate doses to biota using the ERICA Tool software. Doses from 90Sr and 137Cs were calculated using the default parameters of the ERICA Tool and were shown to be consistent with biota doses calculated from the field data. However, the ERICA dose calculations for plutonium isotopes were much higher (2-5 times for small mammals and 10-14 times for birds) than the doses calculated using the experimental data. Currently, the total doses for the terrestrial biota do not exceed maximum recommended levels. However, if the Cooling Pond is allowed to drawdown naturally and the contaminants of the bottom sediments are exposed and enter the biological cycle, the calculated doses to biota may exceed the maximum recommended values. The study is important in establishing the current exposure conditions such that a baseline exists from which changes can be documented following the lowering of the reservoir water. Additionally, the study provided useful radioecological data on biota concentration ratios for some species that are poorly represented in the literature.

  17. Actinide behavior in a freshwater pond

    International Nuclear Information System (INIS)

    Long-term investigations of solution chemistry in an alkaline freshwater pond have revealed that actinide oxidation state behavior, particularly that of plutonium, is complex. The Pu(V,VI) fraction was predominant in solution, but it varied over the entire range reported from other natural aquatic environments, in this case, as a result of intrinsic biological and chemical cycles (redox and pH-dependent phenomena). A strong positive correlation between plutonium (Pu), but not uranium (U), and hydroxyl ion over the observation period, especially when both were known to be in higher oxidation states, was particularly notable. Coupled with other examples of divergent U and Pu behavior, this result suggests that Pu(V), or perhaps a mixture of Pu(V,VI), was the prevalent oxidation state in solution. Observations of trivalent actinide sorption behavior during an algal bloom, coupled with the association with a high-molecular weight (nominally 6000 to 10,000 mol wt) organic fraction in solution, indicate that solution-detritus cycling of organic carbon, in turn, may be the primary mechanism in amercium-curium (Am-Cm) cycling. Sorption by sedimentary materials appears to predominate over other factors controlling effective actinide solubility and may explain, at least partially, the absence of an expected strong positive correlation between carbonate and dissolved U. 49 references, 6 figures, 12 tables

  18. Biofouling problems in freshwater cooling systems

    International Nuclear Information System (INIS)

    In aqueous environments, microorganisms (bacteria, algae, fungi etc.,) are attracted towards surfaces, which they readily colonise resulting in the formation of biofilms. The implications of biofouling are energy losses due to increased fluid frictional resistance and increased heat transfer resistance. The temperatures prevalent inside the condenser system provide a favorable environment for the rapid growth of microorganisms. This results in thick slime deposit, which is responsible for heat transfer losses, thereby enhancing aggregation of deposits on the material surface and induces localised corrosion. There have been instances of increased capital costs due to premature replacement of equipment caused by severe under deposit corrosion due to biofouling. Moreover, fouling of service water systems of nuclear power plants is of concern, because it reduces the heat transfer capacity during an emergency or an accident. The growth of microbial films (slimes) a few tens of microns thick, in a condenser tube is sufficient to induce microbiologically influenced corrosion and cause irreparable damage to the condenser tubes and other structural materials. The down time costs to power plant due to condenser fouling and corrosion are quite large. This paper presents the author's experience in biofouling and corrosion problems in various power plants cooled by freshwater. (author)

  19. 2007 NWFSC Tidal Freshwater Genetics Results

    Energy Technology Data Exchange (ETDEWEB)

    David Teel

    2008-03-18

    Genetic Analysis of Juvenile Chinook Salmon for inclusion in 'Ecology of Juvenile Salmonids in Shallow Tidal Freshwater Habitats in the Vicinity of the Sandy River Delta, lower Columbia River, 2007. Final report submitted to the Bonneville Power Administration, Contract DE-AC05-76RLO1830.' Genotypic data were collected for 108 Chinook salmon and used in the genetic stock identification analysis. Results of the mixture analysis are presented in Table 1. Percentage estimates for four genetic stock groups (West Cascade Tributary Fall, Willamette River Spring, Deschutes River Fall, and Upper Columbia River Summer/Fall) ranged from 11% to 43%, all with non-zero lower 95% confidence intervals. Small contributions were also estimated for the West Cascade Tributary Spring (3%) and Snake River Fall (6%) stock groups. Results of individual fish probability assignments were summed by collection date (Figure 1) and site (Figure 2). Assignment probabilities for the most likely stock group for each individual ranged from 0.51 to 1.00 with approximately 60% of the assignments greater than 0.90 (data not shown). Nearly all of the low probability assignments were fish with assignments split between the Deschutes River Fall and Upper Columbia River Summer/Fall groups.

  20. Photosynthetic carbon metabolism in freshwater phytoplankton

    International Nuclear Information System (INIS)

    Photosynthetic carbon metabolism of natural assemblages of freshwater phytoplankton was measured by following the flow of inorganic 14C into the photosynthetic end products polysaccharide protein, lipid, and soluble metabolites. Data were collected from a wide range of physical, chemical, and trophic conditions in six southern United States reservoirs, with the primary environmental variables of interest being light intensity and nutrient supply. Polysaccharide and protein were consistently the primary products of photosynthetic carbon metabolism, comprising an average of 70% of the total carbon fixation over a wide range of light intensities. Polysaccharide was quantitatively more important at higher light intensities, and protein at lower light intensities, as light intensity varied both with depth within the water column and over diurnal cycles. Polysaccharide synthesis was more variable over the diurnal period than was protein synthesis. Phytoplankton in the downlake epilimnion of Normandy Lake, a central Tennessee reservoir, responded to summer nitrogen (N) deficiency by increasing relative rates of lipid synthesis from 10-15% to 20-25% of the total photosynthetic carbon fixation. Phytoplankton in more nitrogen-sufficient areas of the reservoir maintained lower rates of lipid synthesis throughout the summer. These results document the occurrence in nature of a relationship between N-deficiency and increased lipid synthesis previously observed only in laboratory algal culture studies

  1. Simulation of radioactive cesium transfer in the southern Fukushima coastal biota using a dynamic food chain transfer model

    International Nuclear Information System (INIS)

    The Fukushima Dai-ichi Nuclear Power Plant (1F NPP) accident occurred on 11 March 2011. The accident introduced 137Cs into the coastal waters which was subsequently transferred to the local coastal biota thereby elevating the concentration of this radionuclide in coastal organisms. In this study, the radioactive cesium levels in coastal biota from the southern Fukushima area were simulated using a dynamic biological compartment model. The simulation derived the possible maximum radioactive cesium levels in organisms, indicating that the maximum 137Cs concentrations in invertebrates, benthic fish and predator fish occurred during late April, late May and late July, respectively in the studied area where the source was mainly the direct leakage of 137Cs effluent from the 1F NPP. The delay of a 137Cs increase in fish was explained by the gradual food chain transfer of 137Cs introduced to the ecosystem from the initial contamination of the seawater. The model also provided the degree of radionuclide depuration in organisms, and it demonstrated the latest start of the decontamination phase in benthic fish. The ecological half-lives, derived both from model simulation and observation, were 1–4 months in invertebrates, and 2–9 months in plankton feeding fish and coastal predator fish from the studied area. In contrast, it was not possible to similarly calculate these parameters in benthic fish because of an unidentified additional radionuclide source which was deduced from the biological compartment model. To adequately reconstruct the in-situ depuration of radiocesium in benthic fish in the natural ecosystem, a contamination source associated with the bottom sediments is necessary. -- Highlights: • Cs-137 in the southern Fukushima coastal biota were simulated using a dynamic biological compartment model. • Simulation derived contamination phase of marine biota was completed until late April to July 2011. • The delay of Cs-137 concentration increase in fish was explained by the gradual food chain transfer. • The ecological half-lives during model derived depuration period were 1–9 months in coastal biota. • Additional source is necessary to reconstruct observed delay of Cs-137 depuration in benthic fish

  2. Chemical analysis and genotoxicity of high molecular mass PAH in sediment samples and biota

    International Nuclear Information System (INIS)

    A normal phase liquid chromatography (NPLC) method was used to fractionate the organic extracts of prepared from coal tar-contaminated sediments from hamilton Harbor in Ontario and from Sydney Harbor in Nova Scotia into molecular mass classes. Each PAH fraction up to 302 amu was analyzed by GC-MS and fractions containing PAH with molecular masses greater than 302 amu were analyzed by atmospheric pressure chemical ionization (APCI) LC-MS.Each fraction was also subjected to Ames bioassays using a TA100-like strain of Salmonella typhimurium (YG1025 + S9). The 300/302 amu, 326/328 and 350/352 amu PAH fractions accounted for 25% of the total genotoxic response of the extract; these PAH constitute a substantial genotoxic burden. A number of 300, 302, 326, 350, 374 and 400 amu PAH were identified using APCI LC-MS and comparison with authentic standards. The non-polar aromatic extracts of bottom sediments, suspended sediments and zebra mussels from Hamilton Harbor were also examined by GC-MS, APCI LC-MS and genotoxicity bioassays. The profiles of the priority and high mass PAH in these samples were identical showing that all PAH up to and exceeding 400 amu were readily bioavailable to biota such as Zebra mussels. In addition, the pseudo faeces of the Zebra mussels and amphipod detritivores which fed on the pseudo faeces had chemical profiles identical to the Zebra mussels. Since many sport fish prize amphipods as food, this observation demonstrates a pathway for organic contan demonstrates a pathway for organic contaminants adsorbed to suspended sediments to enter the food chain of non-bottom-feeding fish in areas infested by Zebra musselsA normal phase liquid chromatography (NPLC) method was used to fractionate the organic extracts of prepared from coal tar-contaminated sediments from hamilton Harbor in Ontario and from Sydney Harbor in Nova Scotia into molecular mass classes. Each PAH fraction up to 302 amu was analyzed by GC-MS and fractions containing PAH with molecular masses greater than 302 amu were analyzed by atmospheric pressure chemical ionization (APCI) LC-MS.Each fraction was also subjected to Ames bioassays using a TA100-like strain of Salmonella typhimurium (YG1025 + S9). The 300/302 amu, 326/328 and 350/352 amu PAH fractions accounted for 25% of the total genotoxic response of the extract; these PAH constitute a substantial genotoxic burden. A number of 300, 302, 326, 350, 374 and 400 amu PAH were identified using APCI LC-MS and comparison with authentic standards. The non-polar aromatic extracts of bottom sediments, suspended sediments and zebra mussels from Hamilton Harbor were also examined by GC-MS, APCI LC-MS and genotoxicity bioassays. The profiles of the priority and high mass PAH in these samples were identical showing that all PAH up to and exceeding 400 amu were readily bioavailable to biota such as Zebra mussels. In addition, the pseudo faeces of the Zebra mussels and amphipod detritivores which fed on the pseudo faeces had chemical profiles identical to the Zebra mussels. Since many sport fish prize amphipods as food, this observation demonstrates a pathway for organic cont

  3. New Zealand Freshwater Management: Changing Policy for a Changing World

    Science.gov (United States)

    Rouse, H. L.; Norton, N.

    2014-12-01

    Fresh water is essential to New Zealand's economic, environmental, cultural and social well-being. In line with global trends, New Zealand's freshwater resources are under pressure from increased abstraction and changes in land-use which contribute contaminants to our freshwater systems. Recent central government policy reform introduces greater national direction and guidance, to bring about a step-change in freshwater management. An existing national policy for freshwater management introduced in 2011 requires regional authorities to produce freshwater management plans containing clear freshwater objectives (measurable statements about the desired environmental state for water bodies) and associated limits to resource use (such as environmental flows and quantity allocation limits, and loads of contaminants to be discharged). These plans must integrate water quantity and quality management, consider climate change, and incorporate tangata whenua (New Zealand m?ori) roles and interests. In recent (2014) national policy amendments, the regional authorities are also required to implement national 'bottom-line' standards for certain attributes of the system to be managed; undertake accounting for all water takes and all sources of contaminants; and to develop and implement their plans in a collaborative way with communities. This rapid change in national policy has necessitated a new way of working for authorities tasked with implementation; many obstacles lie in their path. The scientific methods required to help set water quantity limits are well established, but water quality methods are less so. Collaborative processes have well documented benefits but also raise many challenges, particularly for the communication of complex and often uncertain scientific information. This paper provides background on the national policy changes and offers some early lessons learned by the regional authorities implementing collaborative freshwater management in New Zealand.

  4. A Standardised Vocabulary for Identifying Benthic Biota and Substrata from Underwater Imagery: The CATAMI Classification Scheme

    Science.gov (United States)

    Jordan, Alan; Rees, Tony; Gowlett-Holmes, Karen

    2015-01-01

    Imagery collected by still and video cameras is an increasingly important tool for minimal impact, repeatable observations in the marine environment. Data generated from imagery includes identification, annotation and quantification of biological subjects and environmental features within an image. To be long-lived and useful beyond their project-specific initial purpose, and to maximize their utility across studies and disciplines, marine imagery data should use a standardised vocabulary of defined terms. This would enable the compilation of regional, national and/or global data sets from multiple sources, contributing to broad-scale management studies and development of automated annotation algorithms. The classification scheme developed under the Collaborative and Automated Tools for Analysis of Marine Imagery (CATAMI) project provides such a vocabulary. The CATAMI classification scheme introduces Australian-wide acknowledged, standardised terminology for annotating benthic substrates and biota in marine imagery. It combines coarse-level taxonomy and morphology, and is a flexible, hierarchical classification that bridges the gap between habitat/biotope characterisation and taxonomy, acknowledging limitations when describing biological taxa through imagery. It is fully described, documented, and maintained through curated online databases, and can be applied across benthic image collection methods, annotation platforms and scoring methods. Following release in 2013, the CATAMI classification scheme was taken up by a wide variety of users, including government, academia and industry. This rapid acceptance highlights the scheme’s utility and the potential to facilitate broad-scale multidisciplinary studies of marine ecosystems when applied globally. Here we present the CATAMI classification scheme, describe its conception and features, and discuss its utility and the opportunities as well as challenges arising from its use. PMID:26509918

  5. Climate change and Southern Ocean ecosystems I: how changes in physical habitats directly affect marine biota.

    Science.gov (United States)

    Constable, Andrew J; Melbourne-Thomas, Jessica; Corney, Stuart P; Arrigo, Kevin R; Barbraud, Christophe; Barnes, David K A; Bindoff, Nathaniel L; Boyd, Philip W; Brandt, Angelika; Costa, Daniel P; Davidson, Andrew T; Ducklow, Hugh W; Emmerson, Louise; Fukuchi, Mitsuo; Gutt, Julian; Hindell, Mark A; Hofmann, Eileen E; Hosie, Graham W; Iida, Takahiro; Jacob, Sarah; Johnston, Nadine M; Kawaguchi, So; Kokubun, Nobuo; Koubbi, Philippe; Lea, Mary-Anne; Makhado, Azwianewi; Massom, Rob A; Meiners, Klaus; Meredith, Michael P; Murphy, Eugene J; Nicol, Stephen; Reid, Keith; Richerson, Kate; Riddle, Martin J; Rintoul, Stephen R; Smith, Walker O; Southwell, Colin; Stark, Jonathon S; Sumner, Michael; Swadling, Kerrie M; Takahashi, Kunio T; Trathan, Phil N; Welsford, Dirk C; Weimerskirch, Henri; Westwood, Karen J; Wienecke, Barbara C; Wolf-Gladrow, Dieter; Wright, Simon W; Xavier, Jose C; Ziegler, Philippe

    2014-10-01

    Antarctic and Southern Ocean (ASO) marine ecosystems have been changing for at least the last 30 years, including in response to increasing ocean temperatures and changes in the extent and seasonality of sea ice; the magnitude and direction of these changes differ between regions around Antarctica that could see populations of the same species changing differently in different regions. This article reviews current and expected changes in ASO physical habitats in response to climate change. It then reviews how these changes may impact the autecology of marine biota of this polar region: microbes, zooplankton, salps, Antarctic krill, fish, cephalopods, marine mammals, seabirds, and benthos. The general prognosis for ASO marine habitats is for an overall warming and freshening, strengthening of westerly winds, with a potential pole-ward movement of those winds and the frontal systems, and an increase in ocean eddy activity. Many habitat parameters will have regionally specific changes, particularly relating to sea ice characteristics and seasonal dynamics. Lower trophic levels are expected to move south as the ocean conditions in which they are currently found move pole-ward. For Antarctic krill and finfish, the latitudinal breadth of their range will depend on their tolerance of warming oceans and changes to productivity. Ocean acidification is a concern not only for calcifying organisms but also for crustaceans such as Antarctic krill; it is also likely to be the most important change in benthic habitats over the coming century. For marine mammals and birds, the expected changes primarily relate to their flexibility in moving to alternative locations for food and the energetic cost of longer or more complex foraging trips for those that are bound to breeding colonies. Few species are sufficiently well studied to make comprehensive species-specific vulnerability assessments possible. Priorities for future work are discussed. PMID:24802817

  6. Fukushima-derived radionuclides in the ocean and biota off Japan.

    Science.gov (United States)

    Buesseler, Ken O; Jayne, Steven R; Fisher, Nicholas S; Rypina, Irina I; Baumann, Hannes; Baumann, Zofia; Breier, Crystaline F; Douglass, Elizabeth M; George, Jennifer; Macdonald, Alison M; Miyamoto, Hiroomi; Nishikawa, Jun; Pike, Steven M; Yoshida, Sashiko

    2012-04-17

    The T?hoku earthquake and tsunami of March 11, 2011, resulted in unprecedented radioactivity releases from the Fukushima Dai-ichi nuclear power plants to the Northwest Pacific Ocean. Results are presented here from an international study of radionuclide contaminants in surface and subsurface waters, as well as in zooplankton and fish, off Japan in June 2011. A major finding is detection of Fukushima-derived (134)Cs and (137)Cs throughout waters 30-600 km offshore, with the highest activities associated with near-shore eddies and the Kuroshio Current acting as a southern boundary for transport. Fukushima-derived Cs isotopes were also detected in zooplankton and mesopelagic fish, and unique to this study we also find (110 m)Ag in zooplankton. Vertical profiles are used to calculate a total inventory of ~2 PBq (137)Cs in an ocean area of 150,000 km(2). Our results can only be understood in the context of our drifter data and an oceanographic model that shows rapid advection of contaminants further out in the Pacific. Importantly, our data are consistent with higher estimates of the magnitude of Fukushima fallout and direct releases [Stohl et al. (2011) Atmos Chem Phys Discuss 11:28319-28394; Bailly du Bois et al. (2011) J Environ Radioact, 10.1016/j.jenvrad.2011.11.015]. We address risks to public health and marine biota by showing that though Cs isotopes are elevated 10-1,000× over prior levels in waters off Japan, radiation risks due to these radionuclides are below those generally considered harmful to marine animals and human consumers, and even below those from naturally occurring radionuclides. PMID:22474387

  7. In situ evaluation of wastewater discharges and the bioavailability of contaminants to marine biota.

    Science.gov (United States)

    Maranho, L A; André, C; DelValls, T A; Gagné, F; Martín-Díaz, M L

    2015-12-15

    Marine sediment quality of wastewater discharges areas was determined by using in situ caged clams Ruditapes philippinarum taking into account the seasonality. Clams were caged in sediment directly affected by wastewater discharges at four sites (P1, P2, P3, P4) at the Bay of Cádiz (SW, Spain), and one reference site (P6). Exposure to contaminated sediments was confirmed by measurement of metals and As, PAH, pharmaceutical products and surfactants (SAS) in bottom sediments. Biological effects were determined by following biomarkers of exposure (activities of 7-ethoxyresorufin O-deethylase - EROD, dibenzylfluorescein dealkylase - DBF, glutathione S-transferase - GST, glutathione peroxidase - GPX, glutathione reductase - GR and acetylcholinesterase - AChE), effects (lysosomal membrane stability - LMS, DNA damage and lipid peroxidation - LPO), energy status (total lipids - TLP and mitochondrial electron transport - MET), and involved in the mode of action of pharmaceutical products (monoamine oxidase activity - MAO, alkali-labile phosphates - ALP levels and cyclooxygenase activity - COX). In winter, urban effluents were detoxified by phase I biotransformation (CYP3A-like activity), phase II (GST), and the activation of antioxidant defence enzymes (GR). Urban effluents lead to the detoxification metabolism (CYP1A-like), oxidative effects (LPO and DNA damage), neurotoxicity (AChE) and neuroendocrine disruption (COX and ALP levels) involved in inflammation (P1 and P2) and changes in reproduction as spawning delay (P3 and P4) in clams exposed in summer. Adverse effects on biota exposed to sediment directly affected by wastewater discharges depend on the chemical contamination level and also on the reproductive cycle according to seasonality. PMID:26356994

  8. The effect of native and introduced biofuel crops on the composition of soil biota communities

    Science.gov (United States)

    Hed?nec, Petr; Ustak, Sergej; Novotný, David; Frouz, Jan

    2015-04-01

    Biofuel crops are an accepted alternative to fossil fuels, but little is known about the ecological impact of their production. The aim of this contribution is to study the effect of native (Salix viminalis and Phalaris arundinacea) and introduced (Helianthus tuberosus, Reynoutria sachalinensis and Silphium perfoliatum) biofuel crop plantations on the soil biota in comparison with cultural meadow vegetation used as control. The study was performed as part of a split plot field experiment of the Crop Research Institute in the city of Chomutov (Czech Republic). The composition of the soil meso- and macrofauna community, composition of the cultivable fraction of the soil fungal community, cellulose decomposition (using litter bags), microbial biomass, basal soil respiration and PLFA composition (incl. F/B ratio) were studied in each site. The C:N ratio and content of polyphenols differed among plant species, but these results could not be considered significant between introduced and native plant species. Abundance of the soil meso- and macrofauna was higher in field sites planted with S. viminalis and P. arundinacea than those planted with S. perfoliatum, H. tuberosus and R. sachalinensis. RDA and Monte Carlo Permutation Test showed that the composition of the faunal community differed significantly between various native and introduced plants. Significantly different basal soil respiration was found in sites planted with various energy crops; however, this difference was not significant between native and introduced species. Microbial biomass carbon and cellulose decomposition did not exhibit any statistical differences among the biofuel crops. The largest statistically significant difference we found was in the content of actinobacterial and bacterial (bacteria, G+ bacteria and G- bacteria) PLFA in sites overgrown by P. arundinacea compared to introduced as well as native biofuel crops. In conclusion, certain parameters significantly differ between various native and introduced species of biofuel crops; however, the functional importance of these differences requires further research.

  9. Comparing measured and predicted PCB concentrations in Arctic seawater and marine biota

    International Nuclear Information System (INIS)

    When a mechanistic food web model was parameterized for the Arctic marine ecosystem, it predicted PCB concentrations in zooplankton and fish that were two orders of magnitude lower than measured. PCB concentrations measured in zooplankton and fish were within the laboratory's accredited quality assured criteria, and were comparable to other Arctic regions. Although on a different scale, the predicted and measured PCB concentrations were highly correlated. As sensitivity analyses indicated water concentrations as the most sensitive parameter for the model output, dissolved water concentrations were predicted using measured zooplankton and air PCB concentrations, and empirical and mechanistic models. The food web model and the empirical relationship between bioaccumulation factor and octanol-water partitioning coefficient predicted mean dissolved water concentrations of 28 and 29 pg/L ?PCB6 (PCB-28, -52, -105, -118, -138, -153), respectively. Mean dissolved water concentration predicted from measured air concentrations in 1996 was 7.6 pg/L ?PCB5 (PCB-28 was not analysed). Mean dissolved water concentration measured in Barents Sea water sampled simultaneously as the biota in 1999 was 0.3 pg/L ?PCB6. The dissolved water concentrations predicted from zooplankton PCB concentrations were comparable to water concentrations measured in 1996, whereas the dissolved water concentrations measured in 1999 were comparable to measurements from 2001. If the present high empirically derived bioaccumulation factors (log BAF 7.3-9.0) were realistic, this suggests that bioaccumulation in Arctic zooplankton is more efficient that previously assumed. The present study illustrates and discusses some of the difficulties encountered when different approaches to study environmental distribution of contaminants are compared

  10. THE STEPPE RIVERS OF KUBAN, STATE OF THEIR BIOTA AND PROSPECTS OF DEVELOPMENT

    Directory of Open Access Journals (Sweden)

    Belyuchenko I. S.

    2015-02-01

    Full Text Available The steppe rivers of Kuban, which form their landscapes in the space between the basins of the rivers Don and Kuban, are divided into two subtypes: the rivers of internal flow which flow into the small ponds (Panura, Kirpili et al., and the rivers of external flow which flow into the Sea of Azov (Eja, Beysug, Chelbas; direction of flow of these rivers is defined slightly downward from the high right bank of the Kuban (up to 50m and the eastern slopes (altitude up to 50-170m of Stavropol Upland; shores of rivers are heavily deforested, subjected to strong anthropogenic pressure and water systems contaminated of organic substances. Plowing of catchment areas to foreshore and plowing dry beams, as well as cutting of forests caused huge harm of river systems. The qualitative composition of microorganisms is not very varied. Polluted rivers and bottom sediments are dominated by saprotrophic microorganisms, spore-bearing and other rod-shaped bacteria. In the samples of sludge we marked high titer thiobacteria and sulfate-reducing bacteria. Complex of actinomycetes was investigated. The species composition of vascular plants includes 135 species from 48 families, most numerous asteraceae, cereals and legumes. The dominant plant of many floodplains steppe rivers is common reed, which contributes to the process of silting soil particles from the fields and the destruction of the sod with overgrazing. Among phytocenoses there is a domination of reed grass-forb deposits on moist soils, mesophilic couch grass-forb and grass-forb xerophytic. In soil biota of floodplains it is dominated by oligochaetes, bottom fauna molluscs and oligochaetes, water - rotifers and cladocerans

  11. Investigating salt and naphthenic acids interactions in the toxicity of oil sands process water to freshwater invertebrates

    Energy Technology Data Exchange (ETDEWEB)

    Turcotte, D.; Kautzman, M.; Wojnarowicz, P.; Cutter, J.; Bird, E.; Liber, K. [Saskatchewan Univ., Regina, SK (Canada)

    2010-07-01

    The hot water extraction process used to produce bitumens from oil sands produces a large volume of oil sands process water (OSPW) that contain elevated concentrations of naphthenic acids (NA) and salts. Many oil sands reclamation projects are proposing the use of OSPW as part of reconstructed wetlands projects. This study investigated the toxicity of OSPW to freshwater invertebrates. The toxic interactions between NA and salinity on freshwater invertebrates were assessed. Bioassays with laboratory-cultured Ceriodaphnia dubia were conducted to determine the toxicity of OSPW from selected water bodies. The study showed that while the concentrations of NAs and salinity were elevated in OSPW waters that caused toxic responses, the concentrations of salinity ions varied greatly among the OSPW samples. Results of the study suggested that ion composition may be a factor in toxicity. Interactions between NAs and salinity were then assessed by performing bioassays with mixtures representing major ion combinations in OSPW.

  12. Various voltage productions by microbial fuel cells with sedimentary inocula taken from different sites in one freshwater lake.

    Science.gov (United States)

    Song, Tian-Shun; Cai, Hai-Yuan; Yan, Zai-Sheng; Zhao, Zhi-Wei; Jiang, He-Long

    2012-03-01

    In this study, single-chamber microbial fuel cells (MFCs) were inoculated with sedimentary samples taken from one freshwater shallow lake. After 98 days of operation, it was found that sedimentary inocula had strong effect on MFC performances, and Fe(III) contents in sediments were significantly related to voltage values produced from MFCs. Inoculation of the sedimentary sample from the site with the highest Fe(III) content led to the production of the highest voltage with a value of 580 mV, while voltage from the MFC inoculated with sediments from the site with the lowest Fe(III) concentration was less than 30 mV at the end of the experiments. In addition, microbial communities of anode biofilms from the MFCs with the highest and lowest voltages showed significant difference. This study will help enable scientific decisions to be made regarding the selection of freshwater sediments as MFC inoculum, and survey exoelectrogenic microorganisms within sediments. PMID:22264430

  13. Investigating salt and naphthenic acids interactions in the toxicity of oil sands process water to freshwater invertebrates

    International Nuclear Information System (INIS)

    The hot water extraction process used to produce bitumens from oil sands produces a large volume of oil sands process water (OSPW) that contain elevated concentrations of naphthenic acids (NA) and salts. Many oil sands reclamation projects are proposing the use of OSPW as part of reconstructed wetlands projects. This study investigated the toxicity of OSPW to freshwater invertebrates. The toxic interactions between NA and salinity on freshwater invertebrates were assessed. Bioassays with laboratory-cultured Ceriodaphnia dubia were conducted to determine the toxicity of OSPW from selected water bodies. The study showed that while the concentrations of NAs and salinity were elevated in OSPW waters that caused toxic responses, the concentrations of salinity ions varied greatly among the OSPW samples. Results of the study suggested that ion composition may be a factor in toxicity. Interactions between NAs and salinity were then assessed by performing bioassays with mixtures representing major ion combinations in OSPW.

  14. Freshwater biodiversity: importance, threats, status and conservation challenges.

    Science.gov (United States)

    Dudgeon, David; Arthington, Angela H; Gessner, Mark O; Kawabata, Zen-Ichiro; Knowler, Duncan J; Lévêque, Christian; Naiman, Robert J; Prieur-Richard, Anne-Hélène; Soto, Doris; Stiassny, Melanie L J; Sullivan, Caroline A

    2006-05-01

    Freshwater biodiversity is the over-riding conservation priority during the International Decade for Action - 'Water for Life' - 2005 to 2015. Fresh water makes up only 0.01% of the World's water and approximately 0.8% of the Earth's surface, yet this tiny fraction of global water supports at least 100000 species out of approximately 1.8 million - almost 6% of all described species. Inland waters and freshwater biodiversity constitute a valuable natural resource, in economic, cultural, aesthetic, scientific and educational terms. Their conservation and management are critical to the interests of all humans, nations and governments. Yet this precious heritage is in crisis. Fresh waters are experiencing declines in biodiversity far greater than those in the most affected terrestrial ecosystems, and if trends in human demands for water remain unaltered and species losses continue at current rates, the opportunity to conserve much of the remaining biodiversity in fresh water will vanish before the 'Water for Life' decade ends in 2015. Why is this so, and what is being done about it? This article explores the special features of freshwater habitats and the biodiversity they support that makes them especially vulnerable to human activities. We document threats to global freshwater biodiversity under five headings: overexploitation; water pollution; flow modification; destruction or degradation of habitat; and invasion by exotic species. Their combined and interacting influences have resulted in population declines and range reduction of freshwater biodiversity worldwide. Conservation of biodiversity is complicated by the landscape position of rivers and wetlands as 'receivers' of land-use effluents, and the problems posed by endemism and thus non-substitutability. In addition, in many parts of the world, fresh water is subject to severe competition among multiple human stakeholders. Protection of freshwater biodiversity is perhaps the ultimate conservation challenge because it is influenced by the upstream drainage network, the surrounding land, the riparian zone, and - in the case of migrating aquatic fauna - downstream reaches. Such prerequisites are hardly ever met. Immediate action is needed where opportunities exist to set aside intact lake and river ecosystems within large protected areas. For most of the global land surface, trade-offs between conservation of freshwater biodiversity and human use of ecosystem goods and services are necessary. We advocate continuing attempts to check species loss but, in many situations, urge adoption of a compromise position of management for biodiversity conservation, ecosystem functioning and resilience, and human livelihoods in order to provide a viable long-term basis for freshwater conservation. Recognition of this need will require adoption of a new paradigm for biodiversity protection and freshwater ecosystem management - one that has been appropriately termed 'reconciliation ecology'. PMID:16336747

  15. Groundwater Exploration in Freshwater/Saline Layered Aquifers - Southern Bangladesh.

    Science.gov (United States)

    McKelvey, P. A.; Rahman, M.

    2001-05-01

    A major urban water supply and sanitation project is being implemented in the southern coastal districts of Bangladesh, by the Governments of Bangladesh and Denmark (DPHE/DANIDA). Due to the poor quality and reliability of surface water in the coastal districts, the source for these schemes will be groundwater. However, the abstraction of large quantities of water is complicated by the fact that the shallow aquifers are thin and of poor hydraulic quality. In addition, there is saline water underlying the shallow aquifer and, in recent years, arsenic has been discovered in many shallow wells throughout Bangladesh. Over the majority of the coastal districts, a thick freshwater sand underlies the saline aquifers, at depths below 200 m. This freshwater unit is bounded by thick clays which protect it from overlying and underlying saline water. The deep aquifer has been exploited in some of the project towns but in a few areas no freshwater aquifers had been located. An exploration programme was undertaken in each of these towns to prove the location of the freshwater sands and to help plan the location and depth of production well drilling. The first exploration stage was to locate any existing deep hand pumped wells and to carry out a water quality survey. Generally, this was sufficient to prove the existence of a thick freshwater aquifer. However, exact well depths and geological data were usually lacking and an exploration well was usually required. In three of the project towns, no deep aquifers had been exploited by existing hand pumped wells and geophysical surveys were undertaken to identify the locations of freshwater aquifers. These surveys comprised resistivity sounding both within the towns and in outlying areas within a feasible pumping distance. In two cases, freshwater aquifers were inferred from the geophysical surveys and exploration drilling was undertaken to prove the resource. Exploration drilling was undertaken by local contractors using hand drilling techniques. In most cases, a hand drilled borehole could be drilled to 300 m within ten days, in the unconsolidated sands and clays. A hand operated downhole geophysical unit was then used to run a resistivity log to locate freshwater sands. Where thick freshwater units were identified, the main production rig was mobilised to construct high capacity wells. In total, 33 production wells have been installed in the nine towns over Southern Bangladesh. Pumping tests were undertaken to establish well and aquifer properties. These data have been used to establish strict operating rules for the wellfields to minimise the risks of saline intrusion.

  16. Behavior of technetium in freshwater environments

    International Nuclear Information System (INIS)

    In a previous study, /sup 95m/Tc, as a pertechnetate, was released to a small, experimental, freshwater pond, and the concentrations were determined in biotic and abiotic components of the pond ecosystem. A simple mathematical model was developed to predict the concentration of /sup 95m/Tc in fish and snails. Results from this study indicated that uptake through the food chain was an important source of technetium to the higher trophic levels (i.e., fish). In the current study, an experimental pond was spiked with /sup 95m/Tc in the pertechnetate form, and the concentrations of /sup 95m/Tc were measured in the lower trophic levels. Emphasis was placed on measuring the concentration of /sup 95m/Tc in zooplankton, benthic invertebrates, and the aquatic macrophyte Elodea canadensis. Fish were excluded from the pond to allow the development of a large zooplankton population. The concentration of /sup 95m/Tc in water decreased from 0.75 Bq/mL 1 h after the pond was spiked, to 0.21 Bq/mL at 20 d. Throughout the experiment, at least 98% of the /sup 95m/Tc in the water was in the dissolved fraction (0.4 ?m). Zooplankton accumulated /sup 95m/Tc rapidly, having concentration factors (Bq/g sample wet wt. divided by Bq/g water) ranging from 3 at 4 h to 36 at 20 d. Concentration factors ranged from 3 to 8 for benthic insects and from 1 to 62 for the aquatic macrophyte

  17. Flavobacterium buctense sp. nov., isolated from freshwater.

    Science.gov (United States)

    Feng, Xiao-Min; Tan, Xu; Jia, Li; Long, Ping-Ping; Han, Lu; Lv, Jie

    2015-11-01

    A gram-negative, non-gliding motile, aerobic bacterium, designated as strain T7(T), was isolated from freshwater of Chishui River flowing through Maotai town, Guizhou Province, southwest of China. Based on the 16S rRNA gene sequence analysis, the isolate was identified as a member of the genus Flavobacterium and that shared less than 97 % sequence similarities with recognized Flavobacterium species. Its closest phylogenetic relative was Flavobacterium dankookense (96.9 %), followed by Flavobacterium cheonhonense (96.8 %) and Flavobacterium macrobrachii (96.7 %). The strain formed smooth yellow colonies on R2A plates, and cells were observed to be short rods. Strain T7(T) was found to be able to grow at 15-30 °C (optimum 25 °C), at NaCl concentration of 0-0.5 % (optimum 0 %) and at pH 6.5-9.5 (optimum pH 7.5). Catalase and oxidase tests were positive. Polar lipids of strain T7(T) included phosphatidylethanolamine, four unidentified polar lipids, one unidentified phospholipid and one unidentified aminolipid. Chemotaxonomic analysis revealed menaquinone-6 as the dominant respiratory quinone and C15:0, iso-C15:0 and iso-C15:1 as the major fatty acids. The DNA G+C content of strain T7(T) was determined to be 38.2 mol%. On the basis of phylogenetic, phenotypic and genetic data obtained in this study, strain T7(T) represents a novel species of the genus Flavobacterium, for which the name Flavobacterium buctense sp. nov. is proposed. The type strain is T7(T) (=JCM 30750=CGMCC 1.15216). PMID:26374244

  18. Behavior of technetium in freshwater environments

    Energy Technology Data Exchange (ETDEWEB)

    Blaylock, B.G.; Frank, M.L.; Hoffman, F.O.; DeAngelis, D.L.

    1984-01-01

    In a previous study, /sup 95m/Tc, as a pertechnetate, was released to a small, experimental, freshwater pond, and the concentrations were determined in biotic and abiotic components of the pond ecosystem. A simple mathematical model was developed to predict the concentration of /sup 95m/Tc in fish and snails. Results from this study indicated that uptake through the food chain was an important source of technetium to the higher trophic levels (i.e., fish). In the current study, an experimental pond was spiked with /sup 95m/Tc in the pertechnetate form, and the concentrations of /sup 95m/Tc were measured in the lower trophic levels. Emphasis was placed on measuring the concentration of /sup 95m/Tc in zooplankton, benthic invertebrates, and the aquatic macrophyte Elodea canadensis. Fish were excluded from the pond to allow the development of a large zooplankton population. The concentration of /sup 95m/Tc in water decreased from 0.75 Bq/mL 1 h after the pond was spiked, to 0.21 Bq/mL at 20 d. Throughout the experiment, at least 98% of the /sup 95m/Tc in the water was in the dissolved fraction (0.4 ..mu..m). Zooplankton accumulated /sup 95m/Tc rapidly, having concentration factors (Bq/g sample wet wt. divided by Bq/g water) ranging from 3 at 4 h to 36 at 20 d. Concentration factors ranged from 3 to 8 for benthic insects and from 1 to 62 for the aquatic macrophyte.

  19. Management of freshwater lenses on small Pacific islands

    Science.gov (United States)

    White, Ian; Falkland, Tony

    2010-02-01

    The nature of shallow aquifers and the impacts of seawater intrusion in small islands within the Pacific Ocean are reviewed. Many Pacific islands rely on shallow fresh groundwater lenses in highly permeable aquifers, underlain and surrounded by seawater, as their principal freshwater source. It is argued here that, in small islands, the nature of fresh groundwater lenses and their host aquifers coupled with frequent natural and ever-present anthropogenic threats make them some of the most vulnerable aquifer systems in the world. A simple steady-state approximation is used to provide insight into the key climatic, hydrogeological, physiographic, and management factors that influence the quantity of, and saline intrusion into freshwater lenses. Examples of the dynamic nature of freshwater lenses as they respond to these drivers are given. Natural and human-related threats to freshwater lenses are discussed. Long dry periods strongly coupled to sea surface temperatures impact on the quantity and salinity of fresh groundwater. The vulnerability of small island freshwater lenses dictates careful assessment, vigilant monitoring, appropriate development, and astute management. Strategies to aid future groundwater sustainability in small islands are presented and suggested improvements to donor and aid programs in water are also advanced.

  20. Taking High Conservation Value from Forests to Freshwaters

    Science.gov (United States)

    Abell, Robin; Morgan, Siân K.; Morgan, Alexis J.

    2015-07-01

    The high conservation value (HCV) concept, originally developed by the Forest Stewardship Council, has been widely incorporated outside the forestry sector into companies' supply chain assessments and responsible purchasing policies, financial institutions' investment policies, and numerous voluntary commodity standards. Many, if not most, of these newer applications relate to production practices that are likely to affect freshwater systems directly or indirectly, yet there is little guidance as to whether or how HCV can be applied to water bodies. We focus this paper on commodity standards and begin by exploring how prominent standards currently address both HCVs and freshwaters. We then highlight freshwater features of high conservation importance and examine how well those features are captured by the existing HCV framework. We propose a new set of freshwater `elements' for each of the six values and suggest an approach for identifying HCV Areas that takes out-of-fence line impacts into account, thereby spatially extending the scope of existing methods to define HCVs. We argue that virtually any non-marine HCV assessment, regardless of the production sector, should be expanded to include freshwater values, and we suggest how to put those recommendations into practice.

  1. Ammonia-oxidizing Bacteria and Archaea in the Rhizosphere of Freshwater Macrophytes

    DEFF Research Database (Denmark)

    Herrmann, Martina; Schramm, Andreas

    2007-01-01

    AMMONIA-OXIDIZING ARCHAEA AND BACTERIA IN THE RHIZOSPHERE OF FRESHWATER MACROPHYTES Martina Herrmann and Andreas Schramm Department of Biological Sciences, Microbiology, University of Aarhus, Denmark Aquatic macrophytes such as Littorella uniflora and Lobelia dortmanna release oxygen from their roots and thereby stimulate nitrification and coupled nitrification-denitrification in their rhizosphere. However, oxygen release and inorganic nitrogen concentrations differ markedly between macrophyte species. We therefore propose (i) that the rhizosphere of freshwater macrophytes harbours a species-specific microbial community distinct from that of unvegetated sediment and (ii) that aquatic macrophytes have an impact on abundance and activity of nitrifying and denitrifying bacteria in freshwater sediment. The goal of this study was to test these hypotheses for the key functional group for coupled nitrification-denitrification, the ammonia-oxidizing prokaryotes. Six different sites and three macrophyte species with contrasting root systems and rhizosphere microenvironments, i.e. Littorella uniflora, Juncus bulbosus, and Myriophyllum alterniflorum, were selected for comparative investigations. Porewater analyses and potential rate measurements revealed clear differences in ammonia oxidation rates. The diversity of ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) was assessed using the ammonia monooxygenase (amoA) gene as functional marker. Both AOA and AOB could be detected in the rhizosphere of all three plant species, whereas AOA were absent in some unvegetated sediments. Distribution patterns of AOA and AOB phylotypes suggest that plant species as well as site-dependant sediment properties influence nitrifier community composition. Preliminary quantitative results from fluorescence in situ hybridization and PCR indicate higher abundances of nitrifying prokaryotes in the rhizosphere compared to unvegetated sediment, and a dominance of AOA over AOB in most rhizospheres. Whether AOA also dominate ammonia oxidation activity remains to be investigated.    

  2. A freshwater biodiversity hotspot under pressure – assessing threats and identifying conservation needs for ancient Lake Ohrid

    Directory of Open Access Journals (Sweden)

    G. Kostoski

    2010-12-01

    Full Text Available Immediate conservation measures for world-wide freshwater resources are of eminent importance. This is particularly true for so-called ancient lakes. While these lakes are famous for being evolutionary theatres, often displaying an extraordinarily high degree of biodiversity and endemism, in many cases these biota are also experiencing extreme anthropogenic impact.

    Lake Ohrid, a major European biodiversity hotspot situated in a trans-frontier setting on the Balkans, is a prime example for a lake with a magnitude of narrow range endemic taxa that are under increasing anthropogenic pressure. Unfortunately, evidence for a "creeping biodiversity crisis" has accumulated over the last decades, and major socio-political changes have gone along with human-mediated environmental changes.

    Based on field surveys, monitoring data, published records, and expert interviews, we aimed to (1 assess threats to Lake Ohrids' (endemic biodiversity, (2 summarize existing conservation activities and strategies, and (3 outline future conservation needs for Lake Ohrid. We compiled threats to both specific taxa (and in cases to particular species as well as to the lake ecosystems itself. Major conservation concerns identified for Lake Ohrid are: (1 watershed impacts, (2 agriculture and forestry, (3 tourism and population growth, (4 non-indigenous species, (5 habitat alteration or loss, (6 unsustainable exploitation of fisheries, and (7 global climate change.

    Among the major (well-known threats with high impact are nutrient input (particularly of phosphorus, habitat conversion and silt load. Other threats are potentially of high impact but less well known. Such threats include pollution with hazardous substances (from sources such as mines, former industries, agriculture or climate change. We review and discuss institutional responsibilities, environmental monitoring and ecosystem management, existing parks and reserves, biodiversity and species measures, international conservation activities, and ongoing research on conservation and raising of public awareness. Following this summary, we evaluate the status quo and future of Lake Ohrid and its biota. A comprehensive conservation strategy should include measures that result in an immediate reduction of nutrient input, particularly with phosphorus, in order to slow down the ongoing eutrophication process. The existing watershed management should become more effective. Implementation and particularly with a view to the enforcement of national laws should be enhanced. Increased research on the lakes' limnology, biodiversity, and conservation management practices are necessary. The latter research should identify conservation priorities. Public awareness should be enhanced. Facing these parallel needs to protect the unique biodiversity of Lake Ohrid, we suggest urging (a implementation and enforcement of the General Management Plan that would ensure long-term integrated and sustainable use of the lake and its watershed, (b scientific studies on ecology, biodiversity and effects of human impact, (c the establishment of Core Conservation areas (CCA, including underwater reserves, and (d Coastal Zone Management (CZM areas that would constitute buffer zones for the CCAs around the lake. Given the number of identified threats, it is clear that only concerted international action can stop or at least slow down further degradation of Lake Ohrid and the creeping biodiversity crisis already evident. All conservation activities should, among others, ultimately lead to a trans-boundary major conservation area of the Ohrid-Prespa region that would allow long-term integration of both humans and nature.

  3. A freshwater biodiversity hotspot under pressure - assessing threats and identifying conservation needs for ancient Lake Ohrid

    Science.gov (United States)

    Kostoski, G.; Albrecht, C.; Trajanovski, S.; Wilke, T.

    2010-12-01

    Immediate conservation measures for world-wide freshwater resources are of eminent importance. This is particularly true for so-called ancient lakes. While these lakes are famous for being evolutionary theatres, often displaying an extraordinarily high degree of biodiversity and endemism, in many cases these biota are also experiencing extreme anthropogenic impact. Lake Ohrid, a major European biodiversity hotspot situated in a trans-frontier setting on the Balkans, is a prime example for a lake with a magnitude of narrow range endemic taxa that are under increasing anthropogenic pressure. Unfortunately, evidence for a "creeping biodiversity crisis" has accumulated over the last decades, and major socio-political changes have gone along with human-mediated environmental changes. Based on field surveys, monitoring data, published records, and expert interviews, we aimed to (1) assess threats to Lake Ohrids' (endemic) biodiversity, (2) summarize existing conservation activities and strategies, and (3) outline future conservation needs for Lake Ohrid. We compiled threats to both specific taxa (and in cases to particular species) as well as to the lake ecosystems itself. Major conservation concerns identified for Lake Ohrid are: (1) watershed impacts, (2) agriculture and forestry, (3) tourism and population growth, (4) non-indigenous species, (5) habitat alteration or loss, (6) unsustainable exploitation of fisheries, and (7) global climate change. Among the major (well-known) threats with high impact are nutrient input (particularly of phosphorus), habitat conversion and silt load. Other threats are potentially of high impact but less well known. Such threats include pollution with hazardous substances (from sources such as mines, former industries, agriculture) or climate change. We review and discuss institutional responsibilities, environmental monitoring and ecosystem management, existing parks and reserves, biodiversity and species measures, international conservation activities, and ongoing research on conservation and raising of public awareness. Following this summary, we evaluate the status quo and future of Lake Ohrid and its biota. A comprehensive conservation strategy should include measures that result in an immediate reduction of nutrient input, particularly with phosphorus, in order to slow down the ongoing eutrophication process. The existing watershed management should become more effective. Implementation and particularly with a view to the enforcement of national laws should be enhanced. Increased research on the lakes' limnology, biodiversity, and conservation management practices are necessary. The latter research should identify conservation priorities. Public awareness should be enhanced. Facing these parallel needs to protect the unique biodiversity of Lake Ohrid, we suggest urging (a) implementation and enforcement of the General Management Plan that would ensure long-term integrated and sustainable use of the lake and its watershed, (b) scientific studies on ecology, biodiversity and effects of human impact, (c) the establishment of Core Conservation areas (CCA), including underwater reserves, and (d) Coastal Zone Management (CZM) areas that would constitute buffer zones for the CCAs around the lake. Given the number of identified threats, it is clear that only concerted international action can stop or at least slow down further degradation of Lake Ohrid and the creeping biodiversity crisis already evident. All conservation activities should, among others, ultimately lead to a trans-boundary major conservation area of the Ohrid-Prespa region that would allow long-term integration of both humans and nature.

  4. Extinction rates in North American freshwater fishes, 1900-2010

    Science.gov (United States)

    Burkhead, Noel M.

    2012-01-01

    Widespread evidence shows that the modern rates of extinction in many plants and animals exceed background rates in the fossil record. In the present article, I investigate this issue with regard to North American freshwater fishes. From 1898 to 2006, 57 taxa became extinct, and three distinct populations were extirpated from the continent. Since 1989, the numbers of extinct North American fishes have increased by 25%. From the end of the nineteenth century to the present, modern extinctions varied by decade but significantly increased after 1950 (post-1950s mean = 7.5 extinct taxa per decade). The modern extinction rate for North American freshwater fishes is conservatively estimated to be 877 times greater than the background extinction rate for freshwater fishes (one extinction every 3 million years). Reasonable estimates project that future increases in extinctions will range from 53 to 86 species by 2050.

  5. Research Progress on Biomineralization Mechanism of Freshwater Pearl

    Directory of Open Access Journals (Sweden)

    MA Yu-Fei, QIAO Li, FENG Qing-Ling

    2013-01-01

    Full Text Available Calcium carbonate exists widely in many kinds of biominerals, and is one of the most widespread biominerals on the earth. The main component of the shell and pearl is calcium carbonate. In China, the majority of the freshwater pearls originated from Hyriopsis cumingii (Zhuji, Zhejiang Province is with excellent quality and has outstanding pearly luster. The inorganic phase of this luster pearl is aragonite crystal and is regarded as aragonite pearl. Recently, the vaterite is observed in the freshwater cultured pearls, which is responsible for the lack luster and poor quality of the pearls. In the present paper, microstructure and property of the freshwater aragonite and vaterite pearl are introduced. In addition, in vitro growth of calcium carbonate crystal related to the pearl is reviewed. At last, the future research of nacre biomineralization is expected.

  6. Estimating freshwater flows from tidally affected hydrographic data

    Science.gov (United States)

    Pagendam, D. E.; Percival, D. B.

    2015-03-01

    Detiding end-of-catchment flow data are an important step in determining the total volumes of freshwater (and associated pollutant loads) entering the ocean. We examine three approaches for separating freshwater and tidal flows from tidally affected data: (i) a simple low-pass Butterworth filter (BWF); (ii) a robust, harmonic analysis with Kalman smoothing (RoHAKS) which is a novel approach introduced in this paper; and (iii) dynamic harmonic regression (DHR). Using hydrographic data collected in the Logan River, Australia, over a period of 452 days, we judge the accuracy of the three methods based on three criteria: consistency of freshwater flows with upstream gauges; consistency of total discharge volumes with the raw data over the event; and minimal upstream flow. A simulation experiment shows that RoHAKS outperforms both BWF and DHR on a number of criteria. In addition, RoHAKS enjoys a computational advantage over DHR in speed and use of freely available software.

  7. Sensitivity test of food chain model of temporal 137Cs distribution in coastal biota in case of short term introduction

    International Nuclear Information System (INIS)

    Because of the criticality accident occurred at JCO Co. Ltd. on September 30, 1999 in Tokai, Japan, short term estimation of released radionuclides behavior will be required for decision-making in emergent action. To predict radionuclide concentrations in marine organisms under short term radionuclide introduction to coastal water such as accidental situation, models of nuclide transfer both from seawater and food chain to marine organisms are studied by TATEDA (1994, 1997), TATEDA et al. (1997, 2001). The model was developed for typical Japanese coastal water including benthic food chain and planktonic food chain, with transfer parameter data set, such as uptake rate constant, excretion rate constants, gut transfer rates, food ingestion rates of 137Cs, those collected by many tracer experiment studies. Using the model verified by (calculated equilibrated concentrations)/ (observed concentrations) in biota and (calculated decrease curves of 137Cs concentrations)/(observed curves) in biota under the Chernobyl fallout introduction in Japan, we estimate the period for decontamination time of 137Cs in organisms of marine food chain under several imaginable cases. However, prediction by this model still contains uncertainty because of the variation of transfer parameters used in the model. In this study, we tested the model sensitivity for the different combinations of varied transfer parameters reported, and predicted the temporal and special distribution of 137Cs in biota in the coastal area of future nuclear fuel reprocessing plant site at Rokkasho, Aomori, Japan. The result of sensitivity analyses suggested that the effects of the variation of transfer parameters to the output of model calculations are within a range of 3 - 10 times in temporal 137Cs concentrations in coastal organisms. (author)

  8. Paleoecology of an early Holocene faunal and floral assemblage from the Dows Local Biota of north-central Iowa

    Science.gov (United States)

    Hudak, Curtis M.

    1984-05-01

    The faunas and floras from the Dows Local Biota provide an opportunity to compare Holocene taxa without a cultural bias. The Dows Local Biota is located in a large depression on the back side (north) of the Altamont I Moraine complex within the Des Moines Lobe. The Dows Silt Fauna/Flora ( = DSF; ca. 9380 ± 130 yr B.P.), one horizon of the Dows Local Biota, was collected for plant macrofossils, mollusks, and micromammals. DSF terrestrial gastropods are upland mesic forest dwellers although one species, Strobilops affinis, is characteristic of more xeric forests and may represent open woods. The aquatic gastropods reflect both permanent and periodic waters. DSF micromammals prefer an open, mesic, deciduous forest. The micromammal sympatry is restricted to a small area within the tension zone and deciduous forest belt of west-central Wisconsin. DSF plants are characteristic of upland forests, moist meadowlands or disturbed areas, and aquatic habitats. The DSF plant sympatry is large but restricted to the conifer-hardwood and deciduous forests along the Great Lakes-New England regions. Quantitative climatic data for the combined DSF sympatries suggest that Dows (ca. 9380 yr B.P.) was cooler than at present, and is nearly identical to that achieved by pollen analyses at the Cherokee Sewer-Lake West Okoboji sites (ca. 9000 yr B.P.) in northwest Iowa. Based on common habitat interpretations and sympatries, about 9380 yr B.P. north-central Iowa was cooler and moister than at present and was occupied by an open deciduous forest.

  9. Dose estimation and prediction of radiation effects on aquatic biota resulting from radioactive releases from the nuclear fuel cycle

    International Nuclear Information System (INIS)

    Aquatic organisms are exposed to radionuclides released to the environment during various steps of the nuclear fuel cycle. Routine releases from these processes are limited in compliance with technical specifications and requirements of federal regulations. These regulations reflect I.C.R.P. recommendations which are designed to provide an environment considered safe for man. It is generally accepted that aquatic organisms will not receive damaging external radiation doses in such environments; however, because of possible bioaccumulation of radionuclides there is concern that aquatic organisms might be adversely affected by internal doses. The objectives of this paper are: to estimate the radiation dose received by aquatic biota from the different processes and determine the major dose-contributing radionuclides, and to assess the impact of estimated doses on aquatic biota. Dose estimates are made by using radionuclide concentration measured in the liquid effluents of representative facilities. This evaluation indicates the potential for the greatest radiation dose to aquatic biota from the nuclear fuel supply facilities (i.e., uranium mining and milling). The effects of chronic low-level radiation on aquatic organisms are discussed from somatic and genetic viewpoints. Based on the body of radiobiological evidence accumulated up to the present time, no significant deleterious effects are predicted for populations of aquatic organisms exposed to the estimated dose rates resulting from routine releases from conversion, enrichment, fabrication, reactors and reprocessing facilities. At the doses estimated for milling and mining operations it would be difficult to detect radiation effects on aquatic populations; however, the significance of such radiation exposures to aquatic populations cannot be fully evaluated without further research on effects of chronic low-level radiation. (U.S.)

  10. Occurrence, distribution and bioaccumulation of endocrine disrupting compounds in water, sediment and biota samples from a European river basin.

    Science.gov (United States)

    Salgueiro-González, N; Turnes-Carou, I; Besada, V; Muniategui-Lorenzo, S; López-Mahía, P; Prada-Rodríguez, D

    2015-10-01

    The occurrence, distribution and bioaccumulation of five endocrine disrupting compounds (4-tert-octylphenol, 4-n-octylphenol, 4-n-nonylphenol, nonylphenol and bisphenol A) in water, sediment and biota (Corbicula fluminea) collected along the Minho River estuary (NW Iberian Peninsula) were examined. Samples were collected in two campaigns (May and November, 2012) and analyzed by different extraction procedures followed by liquid chromatography tandem mass spectrometry determination. The presence of linear isomers (4-n-octylphenol and 4-n-nonylphenol) was scarcely observed whereas branched isomers (4-tert-octylphenol and nonylphenol) were measured in almost all samples. Wastewater treatment plant effluents and nautical, fishing and agricultural activities are considered the primary source of pollution of the river by alkylphenols. The presence of bisphenol A in the river could be mainly associated to punctual sources of contamination from industrial discharges. A decrease in the total concentration of phenolic compounds in water was observed from spring to autumn (from 0.888 ?g L(-1) in May to 0.05 ?g L(-1) in November), while similar values were shown in C. fluminea samples from the two campaigns (1388 and 1228 ng g(-1) dw in spring and autumn, respectively). In sediments, the total concentration of the target compounds varied between 13 and 4536 ng g(-1) dw (average of 1041 ng g(-1) dw). Sediment-water partition coefficient (Kd), bioaccumulation factor (BAF) and biota-sediment accumulation factor (BSAF) were estimated and highest values were obtained for nonylphenol. Calculated risk quotients showed low and moderate risk for the aquatic environment from the presence of the target compounds at all sampling points. The estimation of the daily intake of the studied compounds via water and biota ingestion indicated no risk for human health. PMID:26005755

  11. Oil spill in the Rio de la Plata estuary, Argentina: 1. Biogeochemical assessment of waters, sediments, soils and biota

    International Nuclear Information System (INIS)

    Aliphatic (ALI) and aromatic (ARO) hydrocarbon concentrations, composition and sources were evaluated in waters, sediments, soils and biota to assess the impact of ?1000 tons of oil spilled in Rio de la Plata coastal waters. Total ALI levels ranged from 0.4-262 ?g/l in waters, 0.01-87 ?g/g in sediments, 5-39 ?g/g in bivalves, 12-323 ?g/g in macrophytes to 948-5187 ?g/g in soils. ARO varied from non-detected 10 ?g/l, 0.01-1.3 ?g/g, 1.0-16 ?g/g, 0.5-6.9 ?g/g to 22-67 ?g/g, respectively. Offshore (1, 5, 15 km) waters and sediments were little affected and contained low background hydrocarbon levels reflecting an effective wind-driven transport of the slick to the coast. Six months after the spill, coastal waters, sediments, soils and biota still presented very high levels exceeding baseline concentrations by 1-3 orders of magnitude. UCM/resolved aliphatic ratio showed a clear trend of increasing decay: coastal waters (3.3)n-C23) and petrogenic/pyrogenic relationship (methylated/unsubstitued PAH) discriminated the samples according to the different degree of impact. The following paper present the results of the study of the progress of hydrocarbon disappearance in sediments and soils 13 and 42 months after the spill. - The Oil spill impact the Rio de la Plata was evaluated by HRGC and multivariate techniques applied to waters, sediments and biota

  12. Filling the gaps: Predicting the distribution of temperate reef biota using high resolution biological and acoustic data

    Science.gov (United States)

    Hill, Nicole A.; Lucieer, Vanessa; Barrett, Neville S.; Anderson, Tara J.; Williams, Stefan B.

    2014-06-01

    Management of the marine environment is often hampered by a lack of comprehensive spatial information on the distribution of diversity and the bio-physical processes structuring regional ecosystems. This is particularly true in temperate reef systems beyond depths easily accessible to divers. Yet these systems harbor a diversity of sessile life that provide essential ecosystem services, sustain fisheries and, as with shallower ecosystems, are also increasingly vulnerable to anthropogenic impacts and environmental change. Here we use cutting-edge tools (Autonomous Underwater Vehicles and ship-borne acoustics) and analytical approaches (predictive modelling) to quantify and map these highly productive ecosystems. We find the occurrence of key temperate-reef biota can be explained and predicted using standard (depth) and novel (texture) surrogates derived from multibeam acoustic data, and geographic surrogates. This suggests that combinations of fine-scale processes, such as light limitation and habitat complexity, and broad-scale processes, such as regional currents and exposure regimes, are important in structuring these diverse deep-reef communities. While some dominant habitat forming biota, including canopy algae, were widely distributed, others, including gorgonians and sea whips, exhibited patchy and restricted distributions across the reef system. In addition to providing the first quantitative and full coverage maps of reef diversity for this area, our modelling revealed that offshore reefs represented a regional diversity hotspot that is of high ecological and conservation value. Regional reef systems should not, therefore, be considered homogenous units in conservation planning and management. Full-coverage maps of the predicted distribution of biota (and associated uncertainty) are likely to be increasingly valuable, not only for conservation planning, but in the ongoing management and monitoring of these less-accessible ecosystems.

  13. Patterns of Freshwater Species Richness, Endemism, and Vulnerability in California.

    Science.gov (United States)

    Howard, Jeanette K; Klausmeyer, Kirk R; Fesenmyer, Kurt A; Furnish, Joseph; Gardali, Thomas; Grantham, Ted; Katz, Jacob V E; Kupferberg, Sarah; McIntyre, Patrick; Moyle, Peter B; Ode, Peter R; Peek, Ryan; Quiñones, Rebecca M; Rehn, Andrew C; Santos, Nick; Schoenig, Steve; Serpa, Larry; Shedd, Jackson D; Slusark, Joe; Viers, Joshua H; Wright, Amber; Morrison, Scott A

    2015-01-01

    The ranges and abundances of species that depend on freshwater habitats are declining worldwide. Efforts to counteract those trends are often hampered by a lack of information about species distribution and conservation status and are often strongly biased toward a few well-studied groups. We identified the 3,906 vascular plants, macroinvertebrates, and vertebrates native to California, USA, that depend on fresh water for at least one stage of their life history. We evaluated the conservation status for these taxa using existing government and non-governmental organization assessments (e.g., endangered species act, NatureServe), created a spatial database of locality observations or distribution information from ~400 data sources, and mapped patterns of richness, endemism, and vulnerability. Although nearly half of all taxa with conservation status (n = 1,939) are vulnerable to extinction, only 114 (6%) of those vulnerable taxa have a legal mandate for protection in the form of formal inclusion on a state or federal endangered species list. Endemic taxa are at greater risk than non-endemics, with 90% of the 927 endemic taxa vulnerable to extinction. Records with spatial data were available for a total of 2,276 species (61%). The patterns of species richness differ depending on the taxonomic group analyzed, but are similar across taxonomic level. No particular taxonomic group represents an umbrella for all species, but hotspots of high richness for listed species cover 40% of the hotspots for all other species and 58% of the hotspots for vulnerable freshwater species. By mapping freshwater species hotspots we show locations that represent the top priority for conservation action in the state. This study identifies opportunities to fill gaps in the evaluation of conservation status for freshwater taxa in California, to address the lack of occurrence information for nearly 40% of freshwater taxa and nearly 40% of watersheds in the state, and to implement adequate protections for freshwater taxa where they are currently lacking. PMID:26147215

  14. Geochemistry, biota and natural background levels in an arsenic naturally contaminated volcanic aquifer

    Science.gov (United States)

    Preziosi, Elisabetta; Amalfitano, Stefano; Di Lorenzo, Tiziana; Parrone, Daniele; Rossi, David; Ghergo, Stefano; Lungarini, Silvia; Zoppini, Anna Maria

    2015-04-01

    The tight links between chemical and ecological status are largely acknowledged as for surface water bodies, while aquifers are still considered as hidden groundwater reservoirs, rather than ecosystems to be preserved. Geochemical and biological interactions play a key role in all subterranean processes, including the dynamics of the fate of anthropogenic contaminants. Studies on groundwater dependent ecosystems (GDE) were mainly focused on karst aquifers so far, but an increased awareness on the importance of water-rock interactions and methodological improvements in microbial ecology are rapidly increasing the level of characterization of groundwater ecosystems in various hydrogeological contexts. Similarly, knowledge about groundwater biodiversity is still limited, especially if porous habitats are concerned. Yet, groundwater and GDEs are populated by a diverse and highly adapted biota, dominated by crustaceans, which provide important ecosystem services and act as biological indicators of chemical and quantitative impact on groundwater resources. In a previous research (Amalfitano et al. 2014), we reported that the microbial community heterogeneity may reflect the lithological and hydrogeological complexity within volcanic and alluvial facies transition in a groundwater body. The quantitative tracking of the microbial community structure allowed disentangling the natural biogeochemical processes evolving within the aquifer flow path. The analyses of groundwater crustaceans assemblages may contribute to shed more light upon the state and dynamics of such ecosystems. In the present research, a comprehensive study of a water table aquifer flowing through a quaternary volcanic district is being performed, including the geochemical (inorganic) composition, the microbial composition, and the analysis of crustacean assemblages . Groundwater samples are periodically collected from private wells and springs under a low anthropic impact. The key issues within the sampling area are related to occurrence of arsenic from natural sources, fluoride and coliforms, which make the water resource unsuitable for human consumption. The aim of this work is to present the first outcomes of this activity. References Amalfitano S, Del Bon A, Zoppini AM, Ghergo S, Fazi S, Parrone D, Casella P, Stano F, Preziosi E (2014) Groundwater geochemistry and microbial community structure in the aquifer transition from volcanic to alluvial areas. Water Research, 65 (2014) 384-394. Doi http://dx.doi.org/10.1016/j.watres.2014.08.004

  15. High levels of natural radioactivity in biota from deep sea hydrothermal vents

    International Nuclear Information System (INIS)

    Hydrothermal vent ecosystems are associated with areas of tectonic activities throughout the deep sea and are thus enriched in natural primitive radionuclides characterizing the magma source i.e. uranium-thorium series. However, the amount of data on radionuclide content in hydrothermal vent biota is very scarce. Here we present data from various archived biological samples collected on several hydrothermal vent site. Samples were collected by manned or unmanned submersibles on the East Pacific Rise (EPR) in 1996 and 2002 and on the Mid Atlantic Ridge (MAR) in 2001. Their concentrations in uranium and thorium isotopes were determined by isotope dilution mass spectrometry. Measurements were performed with a Sector field ICP-MS, the Axiom single collector from VG Elemental (Winsford, Cheshire, UK). 210Po was determined through alpha spectrometry. Results in Table II underline that high levels in uranium isotopes are found in polychaetes from the East Pacific Rise. The highest contents characterize their tubes plus mucus samples. On the contrary, the deep-sea amphipod sample (Orchomenella) collected outside hydrothermal vent areas exhibits the lowest values though direct comparison is difficult due to variability between species. 238U contents in coastal marine organisms are generally in the range 1 to 5 Bq kg-1 dry weight. Comparison between sites (Atlantic vs Pacific) is not obvious since different species have been sampled on MAR and EPR but the highest levels characterize the samples from EPR. Some samples demonstrate 234U/238U ratios very close to the mean value for seawater (1.1 - 1.2) but four present lower ratios (i.e. one sample of Bathymodiolus, Paralvinella, Riftia and Orchomenella). This is certainly to be linked to an uptake of particulate uranium. 210Po contents are very high in polychaetes tubes and mucus and are almost entirely supported by 210Pb. This in agreement with what has been reported by Cherry et al. (1992) for polychaetes (Alvinella and Paralvinella) from EPR. These authors also reported highest levels for these elements in Paralvinella (i.e. 15113 and 19038 Bq kg-1 dry weight for 210Pb and 210Po respectively). We are aware that this work is still based on too few data. A major work has to be done on this topic but these first results appear to be promising. The determination of vent organism concentrations for key elements in the uranium-thorium families has to be carried out in order to precisely determine the radiation exposure they are subject to. This appears especially important at the time where international bodies aim at promoting the development of criteria on the protection of the environment from effects arising from exposures to ionizing radiation

  16. Multiple drivers of decline in the global status of freshwater crayfish (Decapoda: Astacidea)

    OpenAIRE

    Richman, Nadia I.; Böhm, Monika; Adams, Susan B.; Alvarez, Fernando; Bergey, Elizabeth A.; Bunn, John J. S.; Burnham, Quinton; Cordeiro, Jay; Coughran, Jason; Crandall, Keith A; Dawkins, Kathryn L.; DiStefano, Robert J.; Doran, Niall E.; EDSMAN Lennart; Eversole, Arnold G.

    2015-01-01

    Rates of biodiversity loss are higher in freshwater ecosystems than in most terrestrial or marine ecosystems, making freshwater conservation a priority. However, prioritization methods are impeded by insufficient knowledge on the distribution and conservation status of freshwater taxa, particularly invertebrates. We evaluated the extinction risk of the world's 590 freshwater crayfish species using the IUCN Categories and Criteria and found 32% of all species are threatened with extinction. Th...

  17. Introduced guppies being the first record of freshwater fish on the Cape Verdean archipelago

    OpenAIRE

    Kay Lucek; Mélissa Lemoine

    2013-01-01

    The Cape Verdean islands form a distinct aquatic freshwater ecoregion characterised by mainly temporal water bodies with an adapted invertebrate community. Freshwater fish were not yet recorded from the archipelago. During a non-exhaustive screen of freshwater bodies on five islands of the archipelago, the first presence of freshwater fish was recorded in an artificial reservoir. Using barcoding sequences, the species was identified to be introduced guppies (Poecilia reticulata), a highly inv...

  18. The impact of the Fukushima nuclear accident on marine biota: Retrospective assessment of the first year and perspectives

    Energy Technology Data Exchange (ETDEWEB)

    Vives i Batlle, Jordi, E-mail: jordi.vives.i.batlle@sckcen.be [Biosphere Impact Studies Unit, Belgian Nuclear Research Centre SCK-CEN, Boeretang 200, 2400 Mol (Belgium); Aono, Tatsuo [National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Brown, Justin E.; Hosseini, Ali [Norwegian Radiation Protection Authority, Grini næringspark 13, 1332 Østerås (Norway); CERAD Centre of Excellence, Grini næringspark 13, 1332 Østerås (Norway); Garnier-Laplace, Jacqueline [Institute for Radioprotection and Nuclear Safety, Department for research and expertise in environmental risks, PRP-ENV/SERIS, Cadarache, Building 159, 13115 Saint-Paul-Lez-Durance Cedex (France); Sazykina, Tatiana [State Institution Research and Production Association Typhoon, 4 Pobedy Str., Obninsk, Kaluga Region 249038 (Russian Federation); Steenhuisen, Frits [Arctic Centre, University of Groningen, Groningen (Netherlands); Strand, Per [Norwegian Radiation Protection Authority, Grini næringspark 13, 1332 Østerås (Norway); CERAD Centre of Excellence, Grini næringspark 13, 1332 Østerås (Norway)

    2014-07-01

    An international study under the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) was performed to assess radiological impact of the nuclear accident at the Fukushima-Daiichi Nuclear Power Station (FDNPS) on the marine environment. This work constitutes the first international assessment of this type, drawing upon methodologies that incorporate the most up-to-date radioecological models and knowledge. To quantify the radiological impact on marine wildlife, a suite of state-of-the-art approaches to assess exposures to Fukushima derived radionuclides of marine biota, including predictive dynamic transfer modelling, was applied to a comprehensive dataset consisting of over 500 sediment, 6000 seawater and 5000 biota data points representative of the geographically relevant area during the first year after the accident. The dataset covers the period from May 2011 to August 2012. The method used to evaluate the ecological impact consists of comparing dose (rates) to which living species of interest are exposed during a defined period to critical effects values arising from the literature. The assessed doses follow a highly variable pattern and generally do not seem to indicate the potential for effects. A possible exception of a transient nature is the relatively contaminated area in the vicinity of the discharge point, where effects on sensitive endpoints in individual plants and animals might have occurred in the weeks directly following the accident. However, impacts on population integrity would have been unlikely due to the short duration and the limited space area of the initially high exposures. Our understanding of the biological impact of radiation on chronically exposed plants and animals continues to evolve, and still needs to be improved through future studies in the FDNPS marine environment. - Highlights: • UNSCEAR assessment of the Fukushima accident impact on the marine environment. • The study covers the period from March 2011 to August 2012. • Doses to marine organisms are generally below levels for effects on populations. • The only exception is {sup 131}I in macroalgae near the plant early after the accident. • Exposures to biota in the late phase are below the thresholds for population effects. • Further away from the plant, potential effects on biota will be significantly lower.

  19. The impact of the Fukushima nuclear accident on marine biota: Retrospective assessment of the first year and perspectives

    International Nuclear Information System (INIS)

    An international study under the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) was performed to assess radiological impact of the nuclear accident at the Fukushima-Daiichi Nuclear Power Station (FDNPS) on the marine environment. This work constitutes the first international assessment of this type, drawing upon methodologies that incorporate the most up-to-date radioecological models and knowledge. To quantify the radiological impact on marine wildlife, a suite of state-of-the-art approaches to assess exposures to Fukushima derived radionuclides of marine biota, including predictive dynamic transfer modelling, was applied to a comprehensive dataset consisting of over 500 sediment, 6000 seawater and 5000 biota data points representative of the geographically relevant area during the first year after the accident. The dataset covers the period from May 2011 to August 2012. The method used to evaluate the ecological impact consists of comparing dose (rates) to which living species of interest are exposed during a defined period to critical effects values arising from the literature. The assessed doses follow a highly variable pattern and generally do not seem to indicate the potential for effects. A possible exception of a transient nature is the relatively contaminated area in the vicinity of the discharge point, where effects on sensitive endpoints in individual plants and animals might have occurred in the weeks directly following the accident. However, impacts on population integrity would have been unlikely due to the short duration and the limited space area of the initially high exposures. Our understanding of the biological impact of radiation on chronically exposed plants and animals continues to evolve, and still needs to be improved through future studies in the FDNPS marine environment. - Highlights: • UNSCEAR assessment of the Fukushima accident impact on the marine environment. • The study covers the period from March 2011 to August 2012. • Doses to marine organisms are generally below levels for effects on populations. • The only exception is 131I in macroalgae near the plant early after the accident. • Exposures to biota in the late phase are below the thresholds for population effects. • Further away from the plant, potential effects on biota will be significantly lower

  20. Potential Impacts of Food Production on Freshwater Availability

    Science.gov (United States)

    Yano, Shinjiro; Hanasaki, Naota; Itsubo, Norihiro; Kim, Hyungjun; Oki, Taikan

    2014-05-01

    The sustainability of freshwater use is often evaluated based on the total volume of water consumption or withdrawal. However, the renewable freshwater resource and potential impacts of water depletion differ with location and water source. In addition, most estimates of the environmental impacts of water use have focused on depletion from a single-source perspective without separating geographically different water sources. Therefore, comprehensive potential impacts from multiple water sources remain unclear. In this study, we quantified the potential impacts of the global food production on freshwater availability (water availability footprint), applying the Water Availability Factor (fwa). Each water source including rainfall, surface water, and groundwater had individual fwa, which is calculated based on the geophysical hydrological cycle, to reflect the differences among renewable freshwater resources by place and source. The fwa for each water source was estimated based on land area or time period required to obtain the reference volume of freshwater. The reference volume was regarded as 1 m3 of rainfall over an area of 1.0 m2 (1,000 mm/year), based on the global mean annual precipitation. This concept is consistent with the Ecological Footprint (EF), which measures how much biologically productive land area is required to provide the resources consumed. The EF concept is measured in global hectares, a standardized unit equal to one hectare with global average bioproductivity. We found that the current agriculture consumes freshwater resources at 1.3 times the rapid rate than sustainable water use. This rate can also indicate environmental water scarcity. Among environmentally water-scarce countries, well-financed countries tend to import cereal products as virtual water to compensate for their domestic water resources. Among water-abundant countries, well-financed countries tend to export cereal products by exploiting their freshwater availability. The fwa concept provides a non-conventional approach to compare and integrate the potential impacts of freshwater use from various sources and climatic conditions. The results should focus attention on the need to address not only physical but also social and environmental water-scarcity issues.

  1. Freshwater biodiversity and conservation in mediterranean climate streams of Chile.

    OpenAIRE

    Figueroa, Ricardo; Bonada, Núria; Guevara, Meyer; Pedreros, Pablo; Correa-Araneda, Francisco; Díaz, María E.; Ruiz, Victor H.

    2013-01-01

    In Chile, mediterranean climate conditions only occur in the Central Zone (ChMZ). Despite its small area, this mediterranean climate region (med-region) has been recognised as a hotspot for biodiversity. However, in contrast to the rivers of other med-regions, the rivers in the ChMZ have been studied infrequently, and knowledge of their freshwater biodiversity is scarce and fragmented. We gathered information on the freshwater biodiversity of ChMZ, and present a review of the current knowledg...

  2. Ammonium transformation in a nitrogen-rich tidal freshwater marsh

    DEFF Research Database (Denmark)

    Gribsholt, B.; Andersson, M.; Boschker, H.T.S.; Brion, N.; De Brabandere, Loreto; Dehairs, F.; Meire, P.; Middelburg, J.J.; Struyf, E.; Tramper, A.; Van Damme, S.

    2006-01-01

    The fate and transport of watershed-derived ammonium in a tidal freshwater marsh fringing the nutrient rich Scheldt River, Belgium, was quantified in a whole ecosystem 15N labeling experiment. In late summer (September) we added 15N-NH4+ to the flood water entering a 3477 m2 tidal freshwater marsh area, and traced the ammonium processing and retention in four subsequent tide cycles. In this paper we present the results for the water-phase components of the marsh system and compare them to a simi...

  3. A dynamic model to estimate the dose rate of marine biota (K-BIOTADYN- M) and its application to the Fukushima accident

    International Nuclear Information System (INIS)

    This paper describes a dynamic compartment model, K-BIOTA-DYN-M, to assess the activity concentration and dose rate of marine biota when the seawater activity varies with time, which is likely for the early phase after an accident. The model consists of seven compartments, phytoplankton, zooplankton, prey fish, benthic fish, crustacean, mollusk, and macro-algae. The phytoplankton compartment is assumed to be instantaneously in equilibrium with the seawater owing to the huge mass of the plankton in sea, and thus the activity of the phytoplankton is estimated using the equilibrium concentration ratio. The other compartments intake the radioactivity from both water and food, and lose the radioactivity by the biological elimination and radioactivity decay. Given the seawater activity, a set of ordinary differential equations representing the activity balance for biota is solved to obtain the time-variant activity concentration of biota, which is subsequently used to calculate the internal dose rate. The key parameters include the water intake rate, the daily feeding rate, the assimilation efficiency of radionuclides from food, the occupancy factor, and so on. The model has been applied to predict the activity concentration and dose rate of marine biota as a result the Fukushima nuclear accident on March 11, 2011. Using the seawater activities measured at three locations near the Fukushima NPPs, the time-variant activity concentration and dose rate during a few months after an accident for the seven model biota have been estimated. The preliminary results showed that the activity concentration of 137Cs in fish inhabiting the sea close to the Fukushima Daiichi NPP increased up to tenth-thousands of Bq/kg around the peak time of the seawater activity. This level is much higher than the food consumption restriction level for human protection; however, the estimated total dose rates (internal + external) for biota during the entire simulation time were all much less than the UNSCEAR's benchmark level to protect the aquatic biota from the ionizing radiation, indicating that the integrity of marine ecosystem would be maintained. In addition, the simulation results will be compared with the measured activity concentration of the biota as well as the results predicted by the equilibrium model. (authors)

  4. A dynamic model to estimate the dose rate of marine biota (K-BIOTADYN- M) and its application to the Fukushima accident

    Energy Technology Data Exchange (ETDEWEB)

    Keum, Dong-Kwon; Jun, In; Kim, Byeong-Ho; Lim, Kwang-Muk; Choi, Yong-ho [Nuclear Environmental Safety Research Division, Korea Atomic Energy Research Institute, 989-111 Daedeodaero, Yuseong, Daejeon, 305-353 (Korea, Republic of)

    2014-07-01

    This paper describes a dynamic compartment model, K-BIOTA-DYN-M, to assess the activity concentration and dose rate of marine biota when the seawater activity varies with time, which is likely for the early phase after an accident. The model consists of seven compartments, phytoplankton, zooplankton, prey fish, benthic fish, crustacean, mollusk, and macro-algae. The phytoplankton compartment is assumed to be instantaneously in equilibrium with the seawater owing to the huge mass of the plankton in sea, and thus the activity of the phytoplankton is estimated using the equilibrium concentration ratio. The other compartments intake the radioactivity from both water and food, and lose the radioactivity by the biological elimination and radioactivity decay. Given the seawater activity, a set of ordinary differential equations representing the activity balance for biota is solved to obtain the time-variant activity concentration of biota, which is subsequently used to calculate the internal dose rate. The key parameters include the water intake rate, the daily feeding rate, the assimilation efficiency of radionuclides from food, the occupancy factor, and so on. The model has been applied to predict the activity concentration and dose rate of marine biota as a result the Fukushima nuclear accident on March 11, 2011. Using the seawater activities measured at three locations near the Fukushima NPPs, the time-variant activity concentration and dose rate during a few months after an accident for the seven model biota have been estimated. The preliminary results showed that the activity concentration of {sup 137}Cs in fish inhabiting the sea close to the Fukushima Daiichi NPP increased up to tenth-thousands of Bq/kg around the peak time of the seawater activity. This level is much higher than the food consumption restriction level for human protection; however, the estimated total dose rates (internal + external) for biota during the entire simulation time were all much less than the UNSCEAR's benchmark level to protect the aquatic biota from the ionizing radiation, indicating that the integrity of marine ecosystem would be maintained. In addition, the simulation results will be compared with the measured activity concentration of the biota as well as the results predicted by the equilibrium model. (authors)

  5. Multi proxy chemical properties of freshwater sapropel

    Science.gov (United States)

    Stankevica, Karina; Rutina, Liga; Burlakovs, Juris; Klavins, Maris

    2014-05-01

    Freshwater sapropel is organic rich lake sediment firstly named "gyttja" by Hampus van Post in 1862. It is composed of organic remains such as shell detritus, plankton, chitin of insects, spores of higher plants and mineral part formed in eutrophic lake environments. The most appropriate environments for the formation of sapropel are in shallow, overgrown post-glacial lakes and valleys of big rivers in boreal zone, while thick deposits of such kind of organic sediments rarely can be found in lakes on permafrost, mountainous regions or areas with increased aridity. Organic lake sediments are divided in 3 classes according the content of organic matter and mineral part: biogenic, clastic and mixed. The value of sapropel as natural resource increases with the content of organic matter and main applications of sapropel are in agriculture, medicine, cosmetic and chemical industry. The research of sapropel in Latvia has shown that the total amount of this natural resource is close to 2 billion m3 or ~500 million tons. Sapropel has fine, dispersed structure and is plastic, but colour due to the high natural content of phosphorus usually is dark blue, later after drying it becomes light blue. Main research of the sapropel nowadays is turned to investigation of interactions among organic and mineral part of the sapropel with living organisms thus giving the inside look in processes and biological activity of the formation. From the chemical point of view sapropel contains lipids (bitumen), water-soluble substances that are readily hydrolyzed, including humic and fulvic acids, cellulose and the residual part, which does not hydrolyze. In this work we have analyzed the class of organic sapropel: peaty, cyanobacterial and green algal types, as well as siliceous sapropel, in order to determine the presence of biologically active substances, including humic substances, proteins and enzymes as well as to check free radical scavenging activity. Samples were collected from lakes which are recognized as promising for sapropel extraction and the study may benefit the use of sapropel for soil amendments, feed additives and chemical processing.

  6. Exposure dose response relationships of the freshwater bivalve Hyridella australis to cadmium spiked sediments

    Energy Technology Data Exchange (ETDEWEB)

    Marasinghe Wadige, Chamani P.M., E-mail: chamani.marasinghe.wadige@canberra.edu.au; Maher, William A.; Taylor, Anne M.; Krikowa, Frank

    2014-07-01

    Highlights: • The exposure–dose–response approach was used to assess cadmium exposure and toxicity. • Accumulated cadmium in H. australis reflected the sediment cadmium exposure. • Spill over of cadmium into the biologically active pool was observed. • Increased cadmium resulted in measurable biological effects. • H. australis has the potential to be a cadmium biomonitor in freshwater environments. - Abstract: To understand how benthic biota may respond to the additive or antagonistic effects of metal mixtures in the environment it is first necessary to examine their responses to the individual metals. In this context, laboratory controlled single metal-spiked sediment toxicity tests are useful to assess this. The exposure–dose–response relationships of Hyridella australis to cadmium-spiked sediments were, therefore, investigated in laboratory microcosms. H. australis was exposed to individual cadmium spiked sediments (<0.05 (control), 4 ± 0.3 (low) and 15 ± 1 (high) ?g/g dry mass) for 28 days. Dose was measured as cadmium accumulation in whole soft body and individual tissues at weekly intervals over the exposure period. Dose was further examined as sub-cellular localisation of cadmium in hepatopancreas tissues. The biological responses in terms of enzymatic and cellular biomarkers were measured in hepatopancreas tissues at day 28. H. australis accumulated cadmium from spiked sediments with an 8-fold (low exposure organisms) and 16-fold (high exposure organisms) increase at day 28 compared to control organisms. The accumulated tissue cadmium concentrations reflected the sediment cadmium exposure at day 28. Cadmium accumulation in high exposure organisms was inversely related to the tissue calcium concentrations. Gills of H. australis showed significantly higher cadmium accumulation than the other tissues. Accumulated cadmium in biologically active and biologically detoxified metal pools was not significantly different in cadmium exposed organisms, which suggests that H. australis has some tolerance to cadmium. The metallothionein like protein fraction played an important role in the sequestration and detoxification of cadmium and the amount sequestered in this fraction increased with increased cadmium exposure. The highest percentage of biologically active cadmium was associated with the lysosome + microsome and mitochondrial fractions. Cadmium concentrations in these two fractions of cadmium exposed organisms were significantly higher with respect to controls. Total antioxidant capacity decreased with increased cadmium exposure and tissue dose. Lipid peroxidation increased and lysosomal membrane stability decreased significantly with increased cadmium exposure and tissue dose. Based on exposure–dose–response analysis in this study, H. australis would be a suitable organism for assessing cadmium sediment exposure and toxicity.

  7. Effects of cadmium stress and sorption kinetics on tropical freshwater periphytic communities in indoor mesocosm experiments

    Energy Technology Data Exchange (ETDEWEB)

    Bere, Taurai, E-mail: taubere@yahoo.com [Instituto Internacional de Ecologia, Rua Bento Carlos, 750, Centro, Sao Carlos, Sao Paulo (Brazil); Universidade Federal De Sao Carlosm, Programa de Pos-Graduacao em Ecologia e Recursos Naturais, Rodovia Washington Luis, km 235, SP-310, Sao Carlos, Sao Paulo (Brazil); Tundisi, Jose Galizia [Instituto Internacional de Ecologia, Rua Bento Carlos, 750, Centro, Sao Carlos, Sao Paulo (Brazil)

    2012-08-15

    Understanding the cause and effect relationship between stressors and biota is crucial for the effective management, restoration and preservation of aquatic systems. The objective of the present study was to assess the effects of five Cd concentrations on tropical periphyton community growth, Cd accumulation kinetics, as well as the effects of Cd on diatom community structure and composition. Natural periphyton communities were transferred to artificial stream chambers and exposed to Cd concentrations of 0.005, 0.01, 0.03, 0.05 and 0.1 mg.L{sup -1}. Metal accumulation (total and intracellular) in biofilms, dry weight and ash-free dry mass, growth rate, algal cell density and diatom community composition were analysed on samples collected after 1, 2 and 4 weeks of colonization. Periphyton growth and development were significantly lowered by Cd concentrations > 0.03 mg.L{sup -1}. High Cd accumulation capacity by periphyton was demonstrated with total and intracellular Cd content in biofilms reflecting the effects of concentrations of Cd in the culture media and exposure duration. Total and intracellular Cd content generally increased in treatments in the order 0.005 < 0.01 < 0.03 < 0.05 < 0.1 mg.L{sup -1} at any sampling time with increasing level of accumulated Cd with duration of exposure in all the systems. Shifts in species composition (development of more resistant species like Achnanthidium minutissimum and reduction of sensitive ones like Diatoma vulgare, Navicula viridula and Navicula cryptocephala), decreases in species richness and diversity and morphological alterations (deformities) of diatom cells with increasing Cd concentration and exposure duration were observed. The results give valuable information on Cd impact of freshwater biofilms. -- Highlights: Black-Right-Pointing-Pointer We investigated toxicity and sorption kinetics of Cd on periphyton communities. Black-Right-Pointing-Pointer [Cd] > 0.03 mg.L{sup -1} lowers growth. Black-Right-Pointing-Pointer Absorbed Cd was a function of duration of exposure and [Cd]. Black-Right-Pointing-Pointer Changes in community composition were recorded. Black-Right-Pointing-Pointer Biofilms are potential monitors of metal pollution in aquatic systems.

  8. Chemical Footprint Method for Improved Communication of Freshwater Ecotoxicity Impacts in the Context of Ecological Limits

    DEFF Research Database (Denmark)

    BjØrn, Anders; Diamond, Miriam

    2014-01-01

    The ecological footprint method has been successful in communicating environmental impacts of anthropogenic activities in the context of ecological limits. We introduce a chemical footprint method that expresses ecotoxicity impacts from anthropogenic chemical emissions as the dilution needed to avoid freshwater ecosystem damage. The indicator is based on USEtox characterization factors with a modified toxicity reference point. Chemical footprint results can be compared to the actual dilution capacity within the geographic vicinity receiving the emissions to estimate whether its ecological limit has been exceeded and hence whether emissions can be expected to be environmentally sustainable. The footprint method was illustrated using two case studies. The first was all inventoried emissions from European countries and selected metropolitan areas in 2004, which indicated that the dilution capacity was likely exceeded for most European countries and all landlocked metropolitan areas. The second case study indicated that peak application of pesticides alone was likely to exceed Denmark's freshwater dilution capacity in 1999-2011. The uncertainty assessment showed that better spatially differentiated fate factors would be useful and pointed out other major sources of uncertainty and some opportunities to reduce these.

  9. Common Ancestry Is a Poor Predictor of Competitive Traits in Freshwater Green Algae

    Science.gov (United States)

    Narwani, Anita; Alexandrou, Markos A.; Herrin, James; Vouaux, Alaina; Zhou, Charles; Oakley, Todd H.; Cardinale, Bradley J.

    2015-01-01

    Phytoplankton species traits have been used to successfully predict the outcome of competition, but these traits are notoriously laborious to measure. If these traits display a phylogenetic signal, phylogenetic distance (PD) can be used as a proxy for trait variation. We provide the first investigation of the degree of phylogenetic signal in traits related to competition in freshwater green phytoplankton. We measured 17 traits related to competition and tested whether they displayed a phylogenetic signal across a molecular phylogeny of 59 species of green algae. We also assessed the fit of five models of trait evolution to trait variation across the phylogeny. There was no significant phylogenetic signal for 13 out of 17 ecological traits. For 7 traits, a non-phylogenetic model provided the best fit. For another 7 traits, a phylogenetic model was selected, but parameter values indicated that trait variation evolved recently, diminishing the importance of common ancestry. This study suggests that traits related to competition in freshwater green algae are not generally well-predicted by patterns of common ancestry. We discuss the mechanisms by which the link between phylogenetic distance and phenotypic differentiation may be broken. PMID:26348482

  10. "Key to Freshwater Algae": A Web-Based Tool to Enhance Understanding of Microscopic Biodiversity

    Science.gov (United States)

    Shayler, Hannah A.; Siver, Peter A.

    2006-01-01

    The Freshwater Ecology Laboratory at Connecticut College has developed an interactive, Web-based identification key to freshwater algal genera using the Lucid Professional and Lucid 3 software developed by the Centre for Biological Information Technology at the University of Queensland, Brisbane, Australia. The "Key to Freshwater Algae" was funded…

  11. Benthic macroinvertebrate based indices for assessing the ecological status of freshwaters on oceanic islands

    OpenAIRE

    Raposeiro, Pedro M.; Costa, Ana C.

    2009-01-01

    Following the Water Framework Directive (2000/60/EC), macroinvertebrates are required biological elements for monitoring European aquatic ecosystems. Several efforts have been made towards establishing a biomonitoring programme for the Azores freshwater systems using benthic macroinvertebrates. However, little was previously known concerning Azorean freshwater macroinvertebrate fauna. Data from a major ongoing survey of macroinvertebrate freshwater fauna for two islands are pre...

  12. [Freshwater fish freshness on-line detection method based on near-infrared spectroscopy].

    Science.gov (United States)

    Huang, Tao; Li, Xiao-Yu; Peng, Yi; Tao, Hai-Long; Li, Peng; Xiong, Shan-Bai

    2014-10-01

    In the present study, the near infrared spectrum of freshwater fish was used to detect the freshness on line, and the near infrared spectra on-line acquisition device was built to get the fish spectrum. In the process of spectrum acquisition, experiment samples move at a speed of 0.5 m · s(-1), the near-infrared diffuse reflection spectrum (900-2,500 nm) could be got for the next analyzing, and SVM was used to build on-line detection model. Sample set partitioning based on joint X-Y distances algo- rithm (SPXY) was used to divide sample set, there were 111 samples in calibration set (57 fresh samples and 54 bad samples), and 37 samples in test set (19 fresh samples and 18 bad samples). Seven spectral preprocessing methods were utilized to prepro- cess the spectrum, and the influences of different methods were compared. Model results indicated that first derivative (FD) with autoscale was the best preprocessing method, the model recognition rate of calibration set was 97.96%, and the recognition rate of test set was 95.92%. In order to improve the modeling speed, it is necessary to optimize the spectra variables. Therefore genetic algorithm (GA), successive projection algorithm (SPA) and competitive adaptive reweighed sampling (CARS) were adopted to select characteristic variables respectively. Finally CARS was proved to be the optimal variable selection method, 10 characteristic wavelengths were selected to develop SVM model, recognition rate of calibration set reached 100%, and recognition rate of test set was 93.88%. The research provided technical reference for freshwater fish freshness online detection. PMID:25739217

  13. MOIRA: a computerised decision support system for the restoration of radionuclide contaminated freshwater ecosystems

    International Nuclear Information System (INIS)

    The radiation dose resulting from contamination of freshwater ecosystems due to the release of radioactive substances into the environment may be reduced by applying suitable countermeasures. The options for intervention are wide-ranging and can be broadly grouped into three main categories: chemical, physical and social countermeasures. In some cases, a combination of actions -or even the no action- may be the optimal strategy. Despite their benefits, intervention strategies may have detrimental effects of economic, ecological and social nature. Thus, it is of paramount importance to assess, by objective criteria, the global cost-benefit balance of different options. The MOIRA project (A MOdel based computerised system for management support to Identity optimal remedial strategies for Restoring radionuclide contaminated Aquatic ecosystems, European Commission contract FI4P-CT96-0036) has developed a user-friendly, computerised tool that will allow decision makers to choose optimal intervention strategies for freshwater ecosystems with different contamination scenarios. To achieve that goal, the MOIRA software system -apart from a user-friendly interface- incorporates several innovative aspects: - eographical information system (GIS) and databases to get to get the values of the model parameters at different locations in Europe. - redictive ecosystem models for the behaviour of radionuclides (namely Cs-137 and Sr-90) in catchments, lakes and rivers, complemented with models of the effect of the countermeasures on the environmental contamination levels. These models are based on an extensive use of aggregate parameters' that summarise, in single quantities, the effects of a variety of environmental processes. Methods for critical model testing, sensitivity and uncertainty analyses have been applied to them getting a high reliability. - cosystem index (EI) to handle the influence chemical remedial measures may have on the structure, reproduction and biomass of key functional groups of aquatic organisms. Radiation dose to fish (prey and predator) is also assessed as another threat to ecosystem biota. - se assessment model for individual and collective dose that takes into account different external and internal exposure pathways, including the use of water for irrigation of pasture and crops. The dose model is also used to assess the impact of 'social' countermeasures, like bans or restrictions on water and fish consumption, on irrigation of crops, or on accusing contaminated areas, which may directly change the dose received. - Suitable models for evaluation of the economic impact of countermeasures. - Multi-Attribute Analysis (MAA) module, fully interactive, that makes the process of decision making as easy and efficient as possible for the user. MAA is a methodology for rationally analysing complex decision problems. An organic set of MAA procedures has been developed for the specific goals of the MOIRA project (evaluation of the global effectiveness of the intervention strategies). Such procedures account for the most important environmental, social and economic factors previously quantified by the system models. The aim of the paper is to briefly describe the main principles of the MOIRA system and to demonstrate its application using real case based scenarios. (author)

  14. Effects of sodium chloride exposure on ion regulation in larvae (glochidia) of the freshwater mussel Lampsilis fasciola.

    Science.gov (United States)

    Nogueira, Lygia S; Bianchini, Adalto; Wood, Chris M; Loro, Vania L; Higgins, Sarah; Gillis, Patricia L

    2015-12-01

    The salinization of freshwater can have negative effects on ecosystem health, with heightened effects in salt-sensitive biota such as glochidia, the larvae of freshwater mussels. However, the toxicological mechanism underlying this sensitivity is unknown. Therefore, Lampsilis fasciola glochidia were exposed to NaCl (nominally 0.25 and 1.0g/L) prepared in reconstituted moderately-hard water (control), as well as to a dilution of that water (1:4) with ultrapure reference water (diluted control). Unidirectional Na(+) influx (measured with (22)Na) was evaluated after 1, 3 and 48h of exposure. In addition, unidirectional Cl(-) influx (measured with (36)Cl), whole-body ion (Cl(-) and Na(+)) concentrations, and glochidia viability (measured as the ability to close valves) were assessed after 48h of exposure. Significantly reduced glochidia viability (56%) was observed after exposure to 1.0g/L NaCl. Na(+) influx was significantly higher in glochidia exposed to both 0.25 and 1.0g/L NaCl for 1h than in those kept under control conditions. After 3 and 48h of exposure, differences in Na(+) influx rate between salt-exposed and control glochidia were generally reduced, indicating that larvae may be able to, at least temporarily, recover their ability to regulate Na(+) influx when exposed to elevated NaCl concentration. Compared to the moderately-hard water control, whole-body Na(+) and Cl(-) concentrations were relatively unchanged in glochidia exposed to 0.25g/L NaCl, but were significantly elevated in glochidia exposed to 1.0g/L NaCl and the diluted control. While Na(+) influx rate had recovered to the control level after 48h of exposure to 1.0g/L NaCl, Cl(-) influx rate remained elevated, being ~7-fold higher than the Na(+) influx rate. These findings suggest that the loss of viability observed when glochidia were exposed to a high NaCl concentration (1.0g/L) could be caused by ionoregulatory disturbances mainly associated with an elevated Cl(-) influx. PMID:26410192

  15. Evaluation of lethality and genotoxicity in the freshwater mussel Utterbackia imbecillis (Bivalvia: Unionidae) exposed singly and in combination to chemicals used in lawn care.

    Science.gov (United States)

    Conners, Deanna E; Black, Marsha C

    2004-04-01

    Many chemicals, including fertilizers, herbicides, and insecticides, are routinely applied to turf in the care and maintenance of lawns. These chemicals have the potential to leach into nearby surface waters and adversely affect aquatic biota. In this study, we evaluated the lethal and genotoxic effects of chemicals used in lawn care on an early life stage of freshwater mussels (Utterbackia imbecillis). The chemicals tested were copper and commercial formulations of atrazine, glyphosate, carbaryl, and diazinon. Mussel glochidia were exposed to chemicals singly or in combination (equitoxic and environmentally realistic mixtures) for 24 h and toxic interactions were evaluated with Marking's additive index. Genotoxicity was quantified with the alkaline single-cell gel electrophoresis assay (Comet assay). In acute tests, copper was the most toxic of all chemicals evaluated (LC50 = 37.4 microg/L) and carbaryl was the most toxic of all pesticides evaluated (LC50 = 7.9 mg/L). In comparison to other aquatic organisms commonly used in toxicity tests (e.g., amphipods, cladocerans, and chironomids), mussel glochidia were as or more sensitive to the chemicals evaluated with the exception of diazinon, where mussels were observed to be less sensitive. The combined toxicity of equitoxic and environmentally realistic mixtures to mussels was additive. Genotoxic responses were observed in mussels exposed to copper, atrazine and diazinon at levels below their respective no-observed-effect concentrations. Together, these data indicate that freshwater mussels are among the most sensitive aquatic organisms tested for some chemicals commonly used in lawn care and that DNA damage may be useful as a screening tool to evaluate potential sublethal effects of lawn care products on non-target aquatic organisms. PMID:15195808

  16. Enantioselectivity of polychlorinated biphenyl atropisomers in sediment and biota from the Turtle/Brunswick River estuary, Georgia, USA.

    Science.gov (United States)

    Ross, Matthew S; Pulster, Erin L; Ejsmont, Malgorzata B; Chow, Elaine A; Hessel, Colin M; Maruya, Keith A; Wong, Charles S

    2011-01-01

    To investigate the potential for enantioselective transformation and accumulation, the enantiomer distributions of seven polychlorinated biphenyl (PCB) atropisomers were measured in the sediment and biota from a sub-tropical estuary heavily contaminated with Aroclor 1268, a technical mixture of highly chlorinated PCB congeners. Enantiomer fractions (EFs) of PCBs 91, 95, 136, 149, 174, 176, and 183 in marsh sediment, invertebrate, forage and predatory fish species, and bottlenose dolphins were determined. Non-racemic EFs greater than 0.75 were found in sediments for PCBs 136 and 174, likely the result of microbial dechlorination. Although enantiomer fractions in grass shrimp (Palaemonetes spp.) mirrored those of sediment, fish species had EFs that differed significantly from sediment or grass shrimp. Similarly, bottlenose dolphins were also found to contain non-racemic quantities of PCBs 91, 136, 174, 176, and 183. Non-racemic EFs in these biota were likely a result of both uptake of non-racemic proportions of PCBs from the diet and enantioselective biotransformation. PMID:21392808

  17. Aquatic biota of different karst habitats in epigean and subterranean systems of Central Brazil – visibility versus relevance of taxa

    Directory of Open Access Journals (Sweden)

    Luiza Simões

    2013-10-01

    Full Text Available The karstic area of São Domingos, central Brazil, holds extensive drainage systems. In order to understand its biodiversity, various volumes of water were filtered with planktonic nets in stretches of subterranean and superficial rivers on five different occasions. We sampled four drips (152L, three calcite pools (368L, two subterranean rivers fed mainly by percolation water (6,395L, two subterranean rivers fed mainly by water coming from a sinkhole (4,175L along different caves, one resurgence (158L, and four epigean rivers (101,690L. Physical and chemical variables were measured at some sites. Canonical Correlation Analysis was used to verify relationships between taxa and environment. The degree of similarity of the biota was assessed by cluster analysis (Sorensen, single linkage. There were records of exclusive taxa in epigean and subterranean samples, mainly in drips, which harbour the most unique fauna. The high richness of taxa presently recorded reveals the potential of the vadose zone biota in the tropical region, which was neglected in studies on Brazilian subterranean biodiversity. According to our results, the unsaturated zone tropical fauna may have different composition compared to that from temperate habitats. The studied communities were dominated by rotifers, while crustacean are predominant in the latter. The hypothesis can be clarified with the increase of long term studies and taxa identification at species level, besides the use of complementary sampling methods.

  18. Improvements and application of a modified gas chromatography atomic fluorescence spectroscopy method for routine determination of methylmercury in biota samples.

    Science.gov (United States)

    Gorecki, Jerzy; Díez, Sergi; Macherzynski, Mariusz; Kalisinska, El?bieta; Golas, Janusz

    2013-10-15

    Improvements to the application of a combined solid-phase microextraction followed by gas chromatography coupled to pyrolysis and atomic fluorescence spectrometry method (SPME-GC-AFS) for methylmercury (MeHg) determination in biota samples are presented. Our new method includes improvements in the methodology of determination and the quantification technique. A shaker instead of a stirrer was used, in order to reduce the possibility of sample contamination and to simplify cleaning procedures. Then, optimal rotation frequency and shaking time were settled at 800 rpm and 10 min, respectively. Moreover, the GC-AFS system was equipped with a valve and an argon heater to eliminate the effect of the decrease in analytical signal caused by the moisture released from SPME fiber. For its determination, MeHg was first extracted from biota samples with a 25% KOH solution (3h) and then it was quantified by two methods, a conventional double standard addition method (AC) and a modified matrix-matched calibration (MQ) which is two times faster than the AC method. Both procedures were successfully tested with certified reference materials, and applied for the first time to the determination of MeHg in muscle samples of goosander (Mergus merganser) and liver samples of white-tailed eagle (Haliaeetus albicilla) with values ranging from 1.19 to 3.84 mg/kg dry weight (dw), and from 0.69 to 6.23 mg kg(-1) dw, respectively. PMID:24054647

  19. Fate of a broad spectrum of perfluorinated compounds in soils and biota from Tierra del Fuego and Antarctica

    International Nuclear Information System (INIS)

    In this study, the presence of 18 perfluorinated compounds was investigated in biota and environmental samples from the Antarctica and Tierra de Fuego, which were collected during a sampling campaign carried out along February and March 2010. 61 samples were analysed including fish, superficial soils, guano, algae, dung and tissues of Papua penguin by liquid chromatography coupled to tandem mass spectrometry. The concentrations of PFCs were ranging from 0.10 to 240 ng/g for most of the samples except for penguin dung, which presented levels between 95 and 603 ng/g for perfluorooctane sulfonate, and guano samples from Ushuaia, with concentration levels of 1190–2480 ng/g of perfluorohexanoic acid. PFCs acids presented, in general, the highest levels of concentration and perfluorooctanesulfonate was the most frequently found compound. The present study provides a significant amount of results, which globally supports the previous studies, related to the transport, deposition, biodegradation and bioaccumulation patterns of PFCs. - Highlights: ? 61 samples from the Antarctica and Tierra de Fuego analysed for the presence of 18 perfluorinated compounds. ? Acid compounds presented the highest levels of concentration and perfluorooctane sulfonate was the most frequently found. ? Concentrations in algae much higher than those in soils. ? Data supporting existing models for the transport, deposition, biodegradation and bioaccumulation patterns are presented. - 18 perfluorinated compounds assessed in biota and environmental samples from Tierra del Fuego and the Antarctica. Concentrations related to Compounds properties.

  20. Low-level tritium measurement in freshwater sources in the Philippines using electrolytic enrichment and liquid scintillation spectrometry

    International Nuclear Information System (INIS)

    The procedure for low-level tritium analysis of freshwater sources via electrolytic enrichment system and low-level liquid scintillation spectrometry in the Philippine Nuclear Research Institute (PNRI) is described. The working conditions for electrolytic enrichment as well as for liquid scintillation counting were optimized and were applied to the analysis of freshwater samples, dead water blanks and spiked standards. The minimum detectable activity, MDA, using the described procedure was found to be 0.3 TU. This detection limit was obtained with an enrichment factor of 28, a counting efficiency of 16%, and a sample to scintillant ratio of 10:10 (w/v). The established procedure was validated through PNRI's participation in the inter-laboratory comparison exercise, TRIC 2008 organized by the Isotope Hydrology Laboratory of the IAEA to assure accurate and precise measurements. The PNRI results were in good agreement with the IAEA reference values; the absolute relative bias was <5% for the tritium activity ranging from 1-15 TU and 19% for <1 TU. The PNRI optimized procedure for tritium determination, after suitable improvements to the sample preparation and counting protocols, was applied in the analysis of environmental tritium in freshwater sources in selected areas in the country. The range of tritium concentration in freshwater samples were found to be 0.7 - 3.0 TU for rain water, 0.8 - 3.9 TU for river waters, 0.8 - 1.7 TU for springs, from <0.3 - 1.7 for deep groundwater (100 - 200m), and from <0.3 - 1.6 TU for shallow groundwater (20 - 50m). The data gathered will be useful in the assessment of groundwater residence time and vulnerability to contamination of groundwater in these areas. (author)

  1. Assessing radiation impact at a protected coastal sand dune site: an intercomparison of models for estimating the radiological exposure of non-human biota

    International Nuclear Information System (INIS)

    This paper presents the application of three publicly available biota dose assessment models (the ERICA Tool, R and D128/SP1a and RESRAD-BIOTA) to an assessment of the Drigg coastal sand dunes. Using measured 90Sr, 99Tc, 137Cs, 238Pu, 239+240Pu and 241Am activity concentrations in sand dune soil, activity concentration and dose rate predictions are made for a range of organisms including amphibians, birds, invertebrates, mammals, reptiles, plants and fungi. Predicted biota activity concentrations are compared to measured data where available. The main source of variability in the model predictions is the transfer parameters used and it is concluded that developing the available transfer databases should be a focus of future research effort. The value of taking an informed user approach to investigate the way in which models may be expected to be applied in practice is highlighted and a strategy for the future development of intercomparison exercises is presented.

  2. Optimization of the microwave-assisted saponification and extraction of organic pollutants from marine biota using experimental design and artificial neural networks

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez-Borges, J.; Rodriques-Delgado, M.A.; Garcia-Montelongo, F.J. [Laguna Univ., Tenerife (Spain). Dept. of Analytical Chemistry, Nutrition and Food Science

    2006-02-15

    Several improvements in sample pretreatment for the determination of organic pollutants (i.e. n-alkanes, polycyclic aromatic hydrocarbons, PAHs) in marine biota (mussels) are presented. The use of liquid nitrogen and homogenization of the samples are shown to be an alternative to the time consuming liophilization step required for the analysis of biota samples. Microwave-assisted hydrolysis and extraction are combined to isolate organic pollutants (19 n-alkanes and 27 PAHs) from biota matrices. Experimental design (ES) and artificial neural networks (ANNs) were used to optimize the experimental conditions. NIST-CRM 2978 was used to test the validity of the developed method which shows a good agreement with certified values. (orig.)

  3. Phage Specificity of the Freshwater Fish Pathogen Flavobacterium columnare?

    OpenAIRE

    Laanto, Elina; Sundberg, Lotta-Riina; Bamford, Jaana K. H.

    2011-01-01

    Flavobacteria and their phages were isolated from Finnish freshwaters and fish farms. Emphasis was placed on finding phages infecting the fish pathogen Flavobacterium columnare for use as phage therapy agents. The host ranges of the flavobacterial phages varied, phages infecting F. columnare being more host specific than the other phages.

  4. Helminth parasites of freshwater fish in Chiapas, Mexico.

    Czech Academy of Sciences Publication Activity Database

    Salgado-Maldonado, G.; Caspeta-Mandujano, J. M.; Moravec, František; Soto-Galera, E.; Rodiles-Hernández, R.; Cabanas-Carranza, G.; Montoya-Mendoza, J.

    2011-01-01

    Ro?. 108, ?. 1 (2011), s. 31-59. ISSN 0932-0113 Institutional research plan: CEZ:AV0Z60220518 Keywords : Helminth parasites * freshwater fish * Chiapas Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 2.149, year: 2011

  5. Effects of pollution on freshwater fish and amphibians

    International Nuclear Information System (INIS)

    A literature review is presented dealing with studies on the effects of pollution on freshwater fish and amphibians. The pollutants studied included acid mine drainage, PCBs, cadmium, lead, naphthalene, plutonium, in addition to several studies dealing with pH effects

  6. The freshwater fishes of the middle and lower Orange river

    OpenAIRE

    J.A. Cambray; Skelton, P.H.

    1981-01-01

    The occurrence and distribution of freshwater fishes of the middle and lower Orange River in the Republic of South Africa is presented, based on a survey conducted in September 1980. Particular attention is paid to the Augrabies Falls region including the Augrabies Falls National Park. Comments on the distribution and conservation status of the fishes are given.

  7. Limnology of freshwater lakes of Schirmacher Oasis, East Antarctica

    Digital Repository Service at National Institute of Oceanography (India)

    Ingole, B.S; Parulekar, A.H

    Ten freshwater lakes in the Schirmacher Oasis, Antarctica, with water temperature varying from 1.0 to 7.9 degrees; dissolved oxygen from 10.4 to 13.8 mg l/1 and pH from 7.6 to 8.8, were studied biologically during January-February of 1985 and 1987...

  8. There and back again: migration in freshwater fishes

    DEFF Research Database (Denmark)

    Brönmark, C.; Hulthén, K.

    2013-01-01

    Animal migration is an amazing phenomenon that has fascinated humans for long. Many freshwater fishes also show remarkable migrations, whereof the spectacular mass migrations of salmonids from the spawning streams are the most well known and well studied. However, recent studies have shown that migration occurs in a range of freshwater fish taxa from many different habitats. In this review we focus on the causes and consequences of migration in freshwater fishes. We start with an introduction of concepts and categories of migration, and then address the evolutionary causes that drive individuals to make these migratory journeys. The basis for the decision of an individual fish to migrate or stay resident is an evaluation of the costs and benefits of different strategies to maximize its lifetime reproductive effort. We provide examples by discussing our own work on the causes behind seasonal migration in a cyprinid fish, roach (Rutilus rutilus (L., 1758)), within this framework. We then highlight different adaptations that allow fish to migrate over sometimes vast journeys across space, including capacity for orientation, osmoregulation, and efficient energy expenditure. Following this we consider the consequences of migration in freshwater fish from ecological, evolutionary, and conservation perspectives, and finally, we detail some of the recent developments in the methodologies used to collect data on fish migration and how these could be used in future research

  9. Value-chain analysis of freshwater apple snail (Pila globosa) used for on-farm feeds in the freshwater prawn farming sector in Bangladesh

    OpenAIRE

    S.A.A. Nahid

    2013-01-01

    Growth of the freshwater prawn (Macrobrachium rosenbergii) sector in Bangladesh since 1970s has been supported by natural availability of freshwater apple snail (Pila globosa), used for on-farm prawn feeds. The present study identified the current configuration of the value-chain benefits and constraints of freshwater apple snail in south-western Bangladesh in August 2011, based upon Rapid Market Appraisal (RMA) approach. The site of snail collection was Chanda Beel in Gopalganj district, whi...

  10. Ecotoxicity of engineered nanoparticles to freshwater organisms

    DEFF Research Database (Denmark)

    Hartmann, Nanna Isabella Bloch

    2011-01-01

    A large variety of societal benefits are expected from the development and use of engineered nanoparticles. At present, the majority of ‘nano-products’ put on the market can be classified as consumer products, whereas future applications are expected to have more widespread and societal benefits in areas as diverse as cancer treatment, groundwater remediation and industrial coatings. Nanoparticles are used to give the products new and improved characteristics. Yet exactly these new and nano-specific properties might be a cause of concern in a health and environment context. In order to ensure adequate protection of humans and the environment, a pro-active effort to understand, identify and minimise potential risks is needed at an early stage in the innovation process. However, due to the fundamentally different nature of nanoparticles as discrete entities, compared to ‘conventional’ water soluble chemicals, many aspects of commonly used test methods for evaluation of potential adverse environmental effects make their applicability to nanoparticles questionable. For this reason the overarching aim of this PhD project has been to acquire information, which can be disseminated and applied in relation to appropriate test methods for identifying potential adverse effects of nanoparticles; this is of great relevance from both a scientific and regulatory point of view. An important aspect of this project was the acquisition of experience in testing nanoparticles in aqueous test systems – both through practical lab-based studies as well as literature studies. The process of testing nanoparticles in aquatic ecotoxicity tests has been as important in the project approach as the test outcomes. Applied test methods have included acute and chronic toxicity tests as well as bioaccumulation studies with freshwater filter feeder Daphnia magna, sediment feeder Lumbriculus variegatus and green alga Pseudokirchneriella subcapitata. The results made it possible to identify major scientific and methodological challenges in the testing of nanoparticles compared to ‘conventional’ chemicals. It has been highlighted that while it is possible to obtain dose-response relationships for nanoparticles, such tests often raise as many questions as they answer. Issues requiring further attention include nonlinear concentration-aggregation relationships, adhesion of nanoparticles to the cell and organism surfaces, problems of relating effects directly to properties of the primary nanoparticles, dynamic two-way interactions between nanoparticles and organisms as well as how to best quantify and qualify exposure in a dynamic system. Particularly for algal growth inhibition tests, methodological issues were raised related to biomass quantification methods. Here, a combination of several techniques is recommended. The combination of visual inspection, cell counting and fluorescence measurement of acetone-extracted pigments was found to give additional insight into the nature of the observed effects. A separate task was to explore the role of nanoparticles in chemical mixtures, elucidated through experimental and conceptual studies. Interaction between nanoparticles and co-contaminants in chemical mixtures may result in changes in the bioavailability and toxicity of the individual compounds. A conceptual model for interaction scenarios between nanoparticles and co-existing environmental pollutants was developed. Experimental results showed that several types of nanoparticles (e.g. TiO2 and C60) have a large adsorption capacity for some heavy metals and organic chemicals. Nonetheless, cadmium adsorbed to TiO2 nanoparticles was found to be bioavailable to D. magna, L. variegatus and P. subcapitata. TiO2 nanoparticles were seen to attach to the surface of P. subcapitata and to mainly be located in the gut of D. magna. In D. magna the presence of TiO2 resulted in increased uptake of cadmium but not in overall increased toxicity. Interaction studies (especially binary multiple-dose studies) may be considered premature at present due to the additional

  11. HAZARD ANALYSIS OF EXOTIC PATHOGENS OF POTENTIAL THREAT TO EUROPEAN FRESHWATER CRAYFISH.

    Directory of Open Access Journals (Sweden)

    EDGERTON B. F.

    2002-07-01

    Full Text Available Managers, scientists, fishermen and farmers who work with freshwater crayfish understand clearly the severe affects that the introduction of an exotic pathogen can have on freshwater crayfish populations. This acute awareness is due to the severe impact on native European freshwater crayfish of the introduction of crayfish plague fungus Aphanomyces astaci. This issue has been thoroughly covered in previous reviews. The potential impact of other pathogens on European freshwater crayfish has not been addressed. This paper presents a hazard analysis of pathogens of freshwater crayfish exotic to Europe, which is the first step of import risk analysis.

  12. Worldwide Laboratory Comparison on the Determination of Trace Elements in IAEA-452 Biota Sample

    International Nuclear Information System (INIS)

    The Marine Environmental Studies Laboratory (MESL) of the International Atomic Energy Agency's Environment Laboratories (IAEA-NAEL) has the programmatic responsibility to provide assistance to Member States' laboratories in maintaining and improving the reliability of analytical measurement results, both in trace elements and organic pollutants. This is accomplished through the provision of reference materials of marine origin, validated analytical procedures, training in the implementation of internal quality control, and through the evaluation of measurement performance by the organization of worldwide and regional interlaboratory comparison exercises. For nearly thirty years, the MESL has conducted worldwide laboratory performance studies, also known as interlaboratory comparison. The results have been used to evaluate laboratory performance with respect to a wide range of organic and inorganic pollutants, including methyl mercury. This work has been conducted in collaboration with the UNEP Regional Seas Programme. The goal of interlaboratory comparison is to demonstrate the measurement capabilities of laboratories participating in interlaboratory comparisons (ILCs) and proficiency tests (PTs). The results from ILCs or PTs are of crucial interest for laboratories as these provide clear information of its measurement capabilities. It should be pointed out that the participation is either voluntary or forced by external requirements (e.g. legal, accreditation, control bodies). NAEL's interlaboratory comparison (ILC) and proficiency test (PT) schemes involve comparison of participant's results with an assigned value, which usually is delivered as a consensus value from the overall population of test results. Those exercises are designed to monitor and demonstrate the performance and analytical capabilities of the participating laboratories, and to identify gaps and problem areas where further development is needed. Continued membership has benefits in training and educational opportunities, enhanced mutual trust in results and methodology and objective evidence for accreditation purposes The present ILC was designed in order to evaluate the measurement performance of participating laboratories for the analysis of trace elements in biota samples. The test material was distributed to 150 laboratories worldwide and the results from 143 laboratories in 59 countries were received by the end 2009. The data reported by the laboratories, together with the technical and statistical evaluations of the results for each element, are included in this report. The performance of the participant laboratories was assessed through evaluating Z-scores in accordance with ISO 13528 and the International Harmonised Protocol for the Proficiency Testing of Analytical Chemistry Laboratories. On the basis of the outcome from previous ILCs, organised by NAEL for the same population of laboratories, the standard deviation for proficiency assessment (also called target standard deviation) was fixed to 12.5%. Z-scores obtained from this ILC results should assist chemists to make appropriate modifications in their laboratory analytical procedures in order to improve data quality. All results were treated confidentially and each laboratory was identified with a code number for anonymity.

  13. Assessment of impact to non-human biota from a generic waste repository in the UK

    International Nuclear Information System (INIS)

    The UK Nuclear Decommissioning Authority Radioactive Waste Management Directorate (NDA RWMD, formerly Nirex UK Ltd), has played a leading role in establishing knowledge on geological disposal of radioactive waste in the UK. In 2001, a study was commissioned of the potential impact of releases of radio-nuclides from a generic repository on plants and animals). More recently, the NDA commissioned Enviros Consulting to report on developments in policy and in approaches for assessing impacts of radioactivity on non-human biota, that have occurred since the previous study. A trial application of the ERICA assessment tool, to reassess the impact of releases from a generic deep repository using similar source data as used previously (Nirex, 2003), formed part of this work. This paper summarizes the results of the reassessment exercise; key differences between the two assessments are identified and explored. The applicability and capabilities of the ERICA tool to assessments of releases from a waste repository are discussed and priorities for future work are identified. Conclusions: The peak activity concentrations predicted to arise from releases from a generic repository would not lead to a significant increase in environmental risk. Indeed, a substantial proportion of the calculated dose rates are due to natural series radio-nuclides at concentrations that are well below typical background levels. In the previous study, the highest (weighted) absorbed dose rate in an aquatic system was predicted to be around 6.5 micoGy h-1, which is of the same order of magnitude as those predicted in the current study; the significance of the contribution of natural series radionuclides is also common to both studies. However, previously, the authors concluded that it was not possible to undertake a detailed assessment for the terrestrial system, due to the paucity of data on concentration ratios. While the derivation of default concentration factors, as part of the ERICA project, has now made assessment in this system possible, it should be noted that many of the concentration ratio values have been based on extrapolation, for example from data for similar organisms or from nuclides that are considered to be biogeochemically similar. This exercise also revealed some drawbacks with use of the ERICA methodology and tool for this type of assessment, in addition to the lack of flexibility (discussed above) to deal with the type of complex time series of data that arise from a repository performance assessment. While it was not an issue for this assessment, the exclusion of some important ecosystems from the ERICA tool may restrict its application inn other circumstances, for example where an existing or future ecosystem may include wetlands or mires. Changes in climate, and the associated ecosystems, are also not easily accommodated. However, it is also questionable whether existing data, particularly on concentration ratios, are sufficiently robust to allow differentiation between different climates. In this study, concentration ratios for the user defined organism - the fox - were derived from an alternative data source. The consistency of these data within the default range and their relevance to a particular climate and ecosystem type would merit further consideration. The robustness of individual concentration ratios is clearly dependent upon the derivation approach and the need for further sensitivity analysis was identified. A study to evaluate the pedigree of these data and the sensitivity of assessments of the long-term releases of long-lived radio-nuclides to these values would be valuable. Such a study has been proposed to take place as part of the BIOPROTA programme (author)(tk)

  14. Gulf-Wide Information System, Environmental Sensitivity Index Freshwater Fish Database, Geographic NAD83, LDWF (2001) [esi_freshwater_fish_LDWF_2001

    Data.gov (United States)

    Louisiana Geographic Information Center — This data set contains sensitive biological resource data for freshwater (inland) fish species in coastal Louisiana. Vector polygons represent water-bodies and...

  15. Biogeography of freshwater fishes from the Northeastern Mata Atlântica freshwater ecoregion: distribution, endemism, and area relationships

    Scientific Electronic Library Online (English)

    Priscila, Camelier; Angela M., Zanata.

    2014-12-01

    Full Text Available A ecorregião Mata Atlântica Nordeste (NMAF) inclui parte das drenagens costeiras do leste do Brasil, tem alto grau de endemismo de peixes e grande significado biogeográfico. Um levantamento taxonômico da ictiofauna de água doce de 25 drenagens da ecorregião NMAF e uma análise biogeográfica utilizand [...] o o método de Análise de Parcimônia de Endemismo (PAE) foram realizados. Um total de 192 espécies nativas foi listado. O método PAE foi aplicado a 24 bacias e 37 espécies, resultando em cinco diagramas de áreas igualmente parcimoniosos. O diagrama de consenso estrito indica a existência de dois grupos de bacias principais ao longo da ecorregião NMAF. Estes grupos foram denominados: Grupo Norte e Grupo Centro-Sul. O Grupo Centro-Sul apresenta uma politomia basal composta por dois grupos (Grupo Centro e Grupo Sul) mais a bacia do rio Itapemirim. O Grupo Norte é formado por oito drenagens entre o rio Sergipe e o rio Paraguaçu, o Grupo Centro por cinco drenagens entre o rio Cachoeira e o rio Jequitinhonha e o Grupo Sul por nove drenagens entre o rio Buranhém e rio Doce. Comentários sobre a distribuição das espécies e a fauna compartilhada com ecorregiões adjacentes são fornecidos. Apresentamos também uma comparação da hipótese de relação aqui obtida com filogenias publicadas para alguns táxons relevantes ao presente estudo. Abstract in english The Northeastern Mata Atlântica freshwater ecoregion (NMAF) includes part of the eastern Brazilian coastal drainages, has high level of fish endemism and great biogeographic significance. A taxonomic inventory of freshwater fishes from 25 drainages of the NMAF ecoregion and a biogeographic analysis [...] using the Parsimony Analysis of Endemicity (PAE) method were carried out. A total of 192 native species was listed. The PAE method was applied to 24 basins and 37 species, resulting in five equally parsimonious area diagrams. The strict consensus diagram indicates the existence of two main groups of basins throughout the NMAF ecoregion. These groups were denominated: North Group and Central-South Group. The Central-South Group shows a basal polytomy composed by two Groups (Central Group and South Group) plus the rio Itapemirim basin. The North Group is composed by eight drainages from the rio Sergipe to the rio Paraguaçu, the Central Group by five drainages from the rio Cachoeira to the rio Jequitinhonha, and the South Group by nine drainages from the rio Buranhém to the rio Doce. Comments about the species distribution and the fish fauna shared with adjacent ecoregions are provided. We also present a comparison of the hypothesis of river relationships proposed herein with published phylogenetic hypotheses that include taxa relevant to this study.

  16. Comparison of the respiratory metabolism of juvenile Litopenaeus vannamei cultured in seawater and freshwater

    Science.gov (United States)

    Ding, Sen; Wang, Fang; Dong, Shuanglin; Li, Ying

    2013-11-01

    Litopenaeus vannamei, a euryhaline species, can be cultured at a wide range of salinities. The emergence of freshwater pond-culture of L. vannamei is an important prelude to the continued development of shrimp culture in China. In this study, we compared the respiratory metabolism of juvenile L. vannamei cultured in freshwater and saltwater by measuring their oxygen consumption rate (OCR), ammonium-type nitrogen excretion rate (AER) and pyruvate kinase (PK) and lactate dehydrogenase (LDH) activities at different molting stages in order to physiecologically characterize juvenile L. vannamei under freshwater conditions. The results showed that OCR was significantly higher in saltwater than in freshwater at all stages of molting cycle. However, variation of OCR among molting stages in saltwater was similar with that in freshwater, and the highest OCR was observed at post-molting stage. At all stages of molting cycle, AER was significantly higher in freshwater than in saltwater, and the highest was observed at post-molting stage. The activity of PK was significantly higher in saltwater than in freshwater. Conversely, the activity of LDH was higher in freshwater than in saltwater in general. Significant variation of PK and LDH activities in molting cycle was observed in saltwater and freshwater. The results indicated that aerobic metabolism of juvenile L. vannamei was more active in saltwater than in freshwater; while its protein metabolism was more active in freshwater than in saltwater.

  17. Doses due to naturally occurring radionuclides to wildlife terrestrial and freshwater species in South Africa

    International Nuclear Information System (INIS)

    Contamination of soil and fresh water systems by naturally occurring radionuclides in South Africa have existed in mining and mineral processing areas for more than a hundred years. The gold deposits of the Witwatersrand Basin gave rise to huge quantities of historical residues, many of them exhibiting elevated concentration of natural radionuclides. This contamination has chronically exposed wildlife species and this paper attempts to present some results, based on available database of contaminated areas, regarding doses received by selected terrestrial and freshwater species. The results obtained indicate that doses received by the majority of species considered in the paper are below the presently recommended guideline levels, however, doses to some species (mammalian herbivores, benthic molluscs) are above these levels and could be of concern. It should also be taken into consideration that the obtained results are likely underestimated due to limited data available. (author)

  18. Acute toxic effects of two lampricides on twenty-one freshwater invertebrates

    Science.gov (United States)

    Rye, Robert P., Jr.; King, Everett Louis, Jr.

    1976-01-01

    We conducted laboratory static bioassays to determine acute toxicity of two lampricides -- a 70% 2-aminoethanol salt of 5,2'dichloro-4'-nitrosalicylanilide (Bayer 73) and a mixture containing 98% 3-trifluoromethyl-4-nitrophenol (TFM) and 2% Bayer 73 (TFM-2B) -- to 21 freshwater invertebrates. LC50 values were determined for 24-h exposure periods at 12.8 C. Organisms relatively sensitive to Bayer 73 were a turbellarian (Dugesia tigrina), aquatic earthworms (Tubifex tubifex and Lumbriculus inconstans), snails (Physa sp.) and (Pleurocera sp.), a clam (Eliptio dilatatus), blackflies (Simulium sp.), leeches (Erpobdellidae), and a daphnid (Daphnia pulex). The invertebrates most sensitive to TFM-2B were turbellarians, aquatic earthworms (Tubifex), snails (Physa), blackflies, leeches, and burrowing mayflies (Hexagenia sp.). Bayer 73 was generally much more toxic to the test organisms than TFM-2B. At lampricidal concentrations, TFM-2B was more highly selective than Bayer 73 against larval sea lampreys (Petromyzon marinus).

  19. Comparative Analysis of Japanese Three-Spined Stickleback Clades Reveals the Pacific Ocean Lineage Has Adapted to Freshwater Environments while the Japan Sea Has Not

    OpenAIRE

    Ravinet, Mark; Takeuchi, Naoko; Kume, Manabu; Mori, Seiichi; Kitano, Jun

    2014-01-01

    Divergent selection and adaptive divergence can increase phenotypic diversification amongst populations and lineages. Yet adaptive divergence between different environments, habitats or niches does not occur in all lineages. For example, the colonization of freshwater environments by ancestral marine species has triggered adaptive radiation and phenotypic diversification in some taxa but not in others. Studying closely related lineages differing in their ability to diversify is an excellent m...

  20. Enzymes of energy metabolism in hatchlings of amazonian freshwater turtles (Testudines, Podocnemididae) Enzimas do metabolismo energético em quelônios amazônicos (Testudines, Podocnemididae) recém-eclodidos

    OpenAIRE

    WP. Duncan; JL. Marcon

    2009-01-01

    The metabolic profiles of selected tissues were analyzed in hatchlings of the Amazonian freshwater turtles Podocnemis expansa, P. unifilis and P. sextuberculata. Metabolic design in these species was judged based on the key enzymes of energy metabolism, with special emphasis on carbohydrate, lipid, amino acid and ketone body metabolism. All species showed a high glycolytic potential in all sampled tissues. Based on low level