WorldWideScience

Sample records for selected freshwater biota

  1. Toxicities of selected substances to freshwater biota

    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

    Evenset, Anita [Akvaplan-niva, Polar Environmental Centre, N-9296 Tromso (Norway)]. E-mail: ae@akvaplan.niva.no; Christensen, Guttorm N. [Akvaplan-niva, Polar Environmental Centre, N-9296 Tromso (Norway); Kallenborn, Roland [Norwegian Institute for Air Research, P.O. Box 100, N-2027 Kjeller (Norway)

    2005-08-15

    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. {delta}{sup 15}N-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. Selected chlorobornanes, polychlorinated naphthalenes and brominated flame retardants in Bjornoya (Bear Island) freshwater biota

    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. δ15N-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

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

    Evenset, Anita; Christensen, Guttorm N; Kallenborn, Roland

    2005-08-01

    Levels of selected sparsely investigated persistent organic pollutants (POPs) have been measured in organisms from two Arctic lakes on Bjørnøya (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 Ellasjøen. In Lake Øyangen, located only 5 km north of Ellasjøen, levels of these contaminants were significantly lower. delta(15)N-values were 7-10 per thousand higher in organisms from Ellasjøen as compared to Øyangen. 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 Ellasjøen 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. PMID:15862396

  5. Bioaccumulation factors for radionuclides in freshwater biota

    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

  6. Stratified distribution of nutrients and extremophile biota within freshwater ice covering the surface of Lake Baikal.

    Bondarenko, Nina A; Belykh, Olga I; Golobokova, Ludmila P; Artemyeva, Olga V; Logacheva, Natalia F; Tikhonova, Irina V; Lipko, Irina A; Kostornova, Tatyana Ya; Parfenova, Valentina V; Khodzher, Tamara V; Ahn, Tae-Seok; Zo, Young-Gun

    2012-02-01

    Biological entities and gradients of selected chemicals within the seemingly barren ice layers covering Lake Baikal were investigated. Ice cores 40-68 cm long were obtained from in shore and offshore sites of Southern Lake Baikal during the cold period of a year (March-April) in 2007 and 2008. In microscopic observations of the melted ice, both algae and bacteria were found in considerable numbers (>10(3) cells/L and >10(4) cells/ml, respectively). Among all organisms found, diatom was generally the most predominant taxon in the ice. Interestingly, both planktonic and benthic algae were present in considerable numbers (2-410(4) cells/L). Dominant phototrophic picoplankton were comprised of small green algae of various taxa and cyanobacteria of Synechococcus and Cyanobium. The bacterial community consisted mostly of short rod and cocci cells, either free-living or aggregated. Large numbers of yeast-like cells and actinomycete mycelium were also observed. Concentrations of silica, phosphorus, and nitrate were low by an order of magnitude where biota was abundant. The profile of the ice could be interpreted as vertical stratification of nutrients and biomass due to biological activities. Therefore, the organisms in the ice were regarded to maintain high activity while thriving under freezing conditions. Based on the results, it was concluded that the freshwater ice covering the surface of Lake Baikal is considerably populated by extremophilic microorganisms that actively metabolize and form a detritus food chain in the unique large freshwater ecosystem of Lake Baikal. PMID:22367932

  7. TOXIC EFFECT OF PESTICIDES ON THE BIOTA OF FRESHWATER RESERVOIRS OF UKRAINE (A REVIEW

    N. Kolesnyk

    2015-12-01

    Full Text Available Purpose. To analyze scientific sources on the studies of toxic and lethal concentrations of pesticides on phytoplankton, zooplankton, zoobenthos and fish in current conditions of Ukraine. Findings. A review of works of a variety of scientists showed that pesticides with different chemical origins have disastrous effects on everyone without the exception of freshwater biota organisms. The article highlights the peculiarities of the toxic effects of pesticides of major chemical groups, which are used or stored in Ukraine. Their toxic and lethal concentrations for the major species of phytoplankton, zooplankton, zoobenthos and ichthyofauna reservoirs are considered. The data on basic features of behavioral reactions of aquatic organisms on poisoning by pesticides are provided. The basic structural and systemic diosrders of homeostasis of the organisms of aquatic biota are described. The effect of pesticides on phytoplankton needs further research, however, is was found that they have common feature as the disturbace of photosynthesis process and accumulation. In turn, this provoques kills in water bodies and poisoning of phytoplanctivorous fish. Zooplanktonic organisms are highly sensitive to pesticides; hence they can be used as an indicator of the state of fresh water. It was found that, pesticides depending on their concentration have different toxic effects on zooplankton organisms. The effect of pesticides on benthic organisms was little investigated. It is known that benthic communities respond to the presence of pesticide by changes in species composition, number of species, abundance and biomass of benthos in general and individual taxonomic groups of benthic invertebrates. The toxicity of pesticides for fish depends on their chemical nature, the form of the preparation, dose, fish species and age, water temperature and the content of oxygen and salts. In particular, juvenile fish are much more sensitive to the chemicals, and an increase in water temperature and a decrease in oxygen content results in an increase in pesticide toxicity. Practical value. The array of the generalized information on the toxic and lethal effects of pesticides will be important for scientists who investigate the biological risk of pesticides and their impact on basic categories of freshwater biota and, in general, for ichthyological and environmental research. The information on the peculiarities of the toxic effects of pesticides on fish is important in the conditions of increasing demand for fish products as a source of valuable proteins for humans.

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

    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

  9. The use of geochemical speciation modelling to predict the impact of uranium to freshwater biota

    Uranium is the prime potential contaminant in mine waste waters that may be released from the Ranger Uranium Mine (RUM) into the receiving waters of the Magela Creek, Alligator Rivers Region, Northern Australia. The potential ecological impact of the migration of uranium, that would result from an elevation in its concentration above background, in the Magela Creek downstream of the RUM, has been experimentally investigated by integrating biomonitoring with geochemical speciation modelling. The freshwater bivalve Velesunio angasi, abundant throughout the Magela Creek catchment, was exposed to a variety of uranium concentrations in a synthetic Magela Creek water, at four pH levels (5.0, 5.3, 5.5 and 6.0), in the presence (3.05 and 7.50 mg l-1) and absence of a model fulvic acid (FA), and its behavioural response was measured. Speciation modelling, using the HARPHRQ code, provided evidence that UO2+2 and UO2OH+ are the uranium species most responsible (ca. 96%) for eliciting an adverse behavioural response when UO2+2 is assigned twice the toxic effect of UO2OH+. This finding rejects the notion that biota respond specifically to the sum total of inorganic uranyl species. (orig.)

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

    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

    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

    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

    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. The assessment of ionising radiation impact on the cooling pond freshwater ecosystem non-human biota from the Ignalina NPP operation beginning to shut down and initial decommissioning.

    Mazeika, J; Marciulioniene, D; Nedveckaite, T; Jefanova, O

    2016-01-01

    The radiological doses to non-human biota of freshwater ecosystem in the Ignalina NPP cooling pond - Lake Druksiai were evaluated for several cases including the plant's operation period and initial decommissioning activities, using the ERICA 1.2 code with IAEA SRS-19 models integrated approach and tool. Among the Lake Druksiai freshwater ecosystem reference organisms investigated the highest exposure dose rate was determined for bottom fauna - benthic organisms (mollusc-bivalves, crustaceans, mollusc-gastropods, insect larvae), and among the other reference organisms - for vascular plants. The mean and maximum total dose rate values due to anthropogenic radionuclide ionising radiation impact in all investigated cases were lower than the ERICA screening dose rate value of 10 μGy/h. The main exposure of reference organisms as a result of Ignalina NPP former effluent to Lake Druksiai is due to ionizing radiation of radionuclides (60)Co and (137)Cs, of predicted releases to Lake Druksiai during initial decommissioning period - due to radionuclides (60)Co, (134)Cs and (137)Cs, and as a result of predicted releases to Lake Druksiai from low- and intermediate-level short-lived radioactive waste disposal site in 30-100 year period - due to radionuclides (99)Tc and (3)H. The risk quotient expected values in all investigated cases were <1, and therefore the risk to non-human biota can be considered negligible with the exception of a conservative risk quotient for insect larvae. Radiological protection of non-human biota in Lake Druksiai, the Ignalina NPP cooling pond, is both feasible and acceptable. PMID:26397747

  15. Transitions in ancient inland freshwater resource management in Sri Lanka affect biota and human populations in and around coastal lagoons

    F. Dahdouh-Guebas; S. Hettiarachchi; Lo Seen, D; Batelaan, O.; Sooriyarachchi, S.; L. P. Jayatissa; Koedam, N.

    2005-01-01

    The increasing anthropogenic pressure on natural environments results in impacts that affect tropical forest areas and their biodiversity. Adverse impacts on terrestrial and oceanic environments often compound in the intertidal area, where mangrove forest ecosystems thrive. In tropical coastal areas of many developing countries where people depend on wood and other mangrove forest products and services, forest degradation leads to socioeconomic problems. At the same time, increasing freshwate...

  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)

    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)

    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)

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

    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.

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

    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.

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

    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

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

    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.

  2. Sustaining America's Aquatic Biodiversity. Selected Freshwater Fish Families

    Ney, John J.; Helfrich, Louis A.

    2005-01-01

    Provides a description of several common freshwater fish families - including minnows, perch, catfish, suckers, sunfish and bass, pike, salmon and trout, lamprey, eels, sturgeon, paddlefish, gar, and striped bass.

  3. Effects of selected silver nanoparticles on freshwater microbial communities

    Matzke, Marianne; Gallego, Julian; Hassellv, 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...

  4. NeoBiota

    2013-01-01

    NeoBiota is a peer-reviewed, open-access, rapid online journal launched to accelerate research on alien species and biological invasions: aquatic and terrestrial, animals, plants, fungi and micro-organisms.

  5. Selection of native freshwater microalgae and cyanobacteria for CO2 biofixation.

    Martínez, L; Otero, M; Morán, A; García, A I

    2013-01-01

    One of the technologies available for coping with problems related to the rise in atmospheric concentrations of carbon dioxide is CO2 biofixation with microalgae or cyanobacteria. The selection of native strains that grow well at the specific site where the technology is to be used will increase the success possibilities of such a technology. Thus, with the aim of finding a suitable local variety for use in a CO2 biofixation system, three recently isolated freshwater strains, Scenedesmus sp., Chlorogonium sp. and Synechocystis sp. were studied. Chlorella sorokiniana was used as a control strain. All the strains were grown under the same culture conditions for seven days of batch culture, and various growth and CO2 biofixation parameters were determined. Synechocystis sp. showed the highest specific growth rate at 1.75 per day (l/d). Results for CO2 biofixation ranged between 0.650 and 0.953 g of carbon dioxide per litre per day (g CO2/l/d), but differences among native strains were noted, although they were not statistically significant. However, Synechocystis sp. was selected as the most suitable strain for CO2 biofixation, owing to its good capacity to use light in dense cultures, an essential requirement for sustainable commercial systems. PMID:24617072

  6. Selective pressure of antibiotics on ARGs and bacterial communities in manure-polluted freshwater-sediment microcosms

    Xiong, Wenguang; Sun, Yongxue; Ding, Xueyao; Wang, Mianzhi; Zeng, Zhenling

    2015-01-01

    The aim of this study was to investigate selective pressure of antibiotics on antibiotic resistance genes (ARGs) and bacterial communities in manure-polluted aquatic environment. Three treatment groups were set up in freshwater-sediment microcosms: tetracyclines group, sulfonamides group and fluoroquinolones group. Sediment and water samples were collected on day 14 after treatment. Antibiotic concentrations, ARGs abundances and bacterial community composition were analyzed. Antibiotic concen...

  7. Baseline assessment of physical characteristics, aquatic biota, and selected water-quality properties at the reach and mesohabitat scale for reaches of Big Cypress, Black Cypress, and Little Cypress Bayous, Big Cypress Basin, northeastern Texas, 2010–11

    Braun, Christopher L.; Moring, James B.

    2013-01-01

    In 2010 and 2011, the U.S. Geological Survey (USGS), in cooperation with the Northeast Texas Municipal Water District and the Texas Commission on Environmental Quality, did a baseline assessment of physical characteristics and aquatic biota (fish and mussels) collected at the mesohabitat scale for reaches of Big Cypress, Black Cypress, and Little Cypress Bayous in the Big Cypress Basin in northeastern Texas, and measured selected water-quality properties in isolated pools in Black Cypress and Little Cypress. All of the data were collected in the context of prescribed environmental flows. The information acquired during the course of the study will support the long-term monitoring of biota in relation to environmental flow prescriptions for Big Cypress Bayou, Black Cypress Bayou, and Little Cypress Bayou. Data collection and analysis were done at mesohabitat- and reach-specific scales, where a mesohabitat is defined as a discrete area within a stream that exhibits unique depth, velocity, slope, substrate, and cover. Biological and physical characteristic data were collected from two sites on Big Cypress Bayou, and one site on both Black Cypress Bayou and Little Cypress Bayou. The upstream reach of Big Cypress Bayou (USGS station 07346015 Big Cypress Bayou at confluence of French Creek, Jefferson, Texas) is hereinafter referred to as the Big Cypress 02 site. The downstream site on Big Cypress Bayou (USGS station 07346017 Big Cypress Bayou near U.S. Highway 59 near Jefferson, Tex.) is hereinafter referred to as the Big Cypress 01 site and was sampled exclusively for mussels. The sites on Black Cypress Bayou (USGS station 07346044 Black Cypress Bayou near U.S. Highway 59 near Jefferson, Tex.) and Little Cypress Bayou (USGS station 07346071 Little Cypress Bayou near U.S. Highway 59 near Jefferson, Tex.) are hereinafter referred to as the Black Cypress and Little Cypress sites, respectively. A small range of streamflows was targeted for data collection, including a period of low flow during July and August 2010 and a period of very low flow during July 2011. This scenario accounts for variability in the abundance and distribution of fish and mussels and in the physical characteristics of mesohabitats present during different flow conditions. Mussels were not collected from the Little Cypress site. However, a quantitative survey of freshwater mussels was conducted at Big Cypress 01. Of the three reaches where physical habitat data were measured in 2010, Big Cypress 02 was both the widest and deepest, with a mean width of 62.2 feet (ft) and a mean depth of 5.5 ft in main-channel mesohabitats. Little Cypress was the second widest and deepest, with a mean width of 49.9 ft and a mean depth of 4.5 ft in main-channel mesohabitats. Black Cypress was by far the narrowest of the three reaches, with a mean width of 29.1 ft and a mean depth of 3.3 ft in main-channel mesohabitats but it had the highest mean velocity of 0.42 feet per second (ft/s). Appreciably more fish were collected from Big Cypress 02 (596) in summer 2010 compared to Black Cypress (273) or Little Cypress (359), but the total number of fish species collected among the three reaches was similar. Longear sunfish was the most abundant fish species collected from all three sites. The total number of fish species was largest in slow run mesohabitats at Big Cypress 02, fast runs at Black Cypress, and slow runs at Little Cypress. The catch-per-unit-effort of native minnows was largest in fast runs at Big Cypress 02. More species of native minnows, including the ironcolor and emerald shiner, were collected from Little Cypress relative to all other mesohabitats at all sites. Fifteen species and 182 individuals of freshwater mussels were collected, with 69.8 percent of the individual mussels collected from Big Cypress 02, 23.6 percent collected from Big Cypress 01, and 6.6 percent collected from Black Cypress. Big Cypress 01was the most species rich site with 13 species, and washboards were the most abundant species overall. Mussels were not collected from Little Cypress because there was no flow in this stream during the targeted sampling period in 2011. On July 30, 2010, when the estimated streamflow at the site (based on daily mean discharge measured at the upstream gage in conjunction with powerplant withdrawals) was 45 cubic feet per second (ft3/s), Big Cypress 02 had a mean width of 62.2 ft and a mean depth of 5.5 ft in main-channel mesohabitats. On July 27, 2011, when instantaneous streamflow at the site was 10 ft3/s, the mean width and mean depth in main-channel mesohabitats decreased to 49.6 ft and 3.1 ft, respectively. Mean velocity in 2010 (0.31 ft/s) was approximately twice as high as 2011 (0.17 ft/s) in main-channel mesohabitats. About 14 percent more fish were collected from Big Cypress 02 in 2010 relative to 2011, and about 18 percent fewer fish species were identified in 2011 at this site compared to 2010. Longear sunfish, which was the most abundant fish species collected in 2010, was second to western mosquitofish in 2011. In the absence of flow during fall 2011, the reach at Black Cypress was reduced to four isolated pools, and the reach at Little Cypress was reduced to three isolated pools. Dissolved oxygen, temperature, pH, and specific conductance data were collected from the pools because it was hypothesized that these conditions would be the most limiting with respect to aquatic life. Dissolved oxygen concentrations ranged from 0.58 milligrams per liter (mg/L) to 4.79 mg/L at Black Cypress and from 0.24 mg/L to 5.33 mg/L at Little Cypress; both sites exhibited a stratified pattern in dissolved oxygen concentrations along transect lines, but the pattern was less pronounced at Black Cypress.

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

    Hybel, Anne-Marie; Godskesen, Berit; Rygaard, Martin

    2015-01-01

    ) 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......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...

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

    Hybel, A-M; Godskesen, B; Rygaard, M

    2015-09-01

    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. PMID:26093102

  10. Pilot Freshwater

    Arrondeau, J.-P.; Penasso, A.; Ramos, M.-H.; Crochemore, L.; ., -

    2015-01-01

    The pilot Freshwater illustrate the experiences in realizing innovative technological measures for reservoir management in Brittany (France) to better manage droughts and combat water scarcity for freshwater supply.

  11. Baseline assessment of physical characteristics, aquatic biota, and selected water-quality properties at the reach and mesohabitat scale for three stream reaches in the Big Cypress Basin, northeastern Texas, 2010-11

    Braun, Christopher L.; Moring, James B.

    2013-01-01

    The U.S. Geological Survey (USGS), in cooperation with the Northeast Texas Municipal Water District and the Texas Commission on Environmental Quality, did a baseline assessment in 2010-11 of physical characteristics and selected aquatic biota (fish and mussels) collected at the mesohabitat scale for three stream reaches in the Big Cypress Basin in northeastern Texas for which environmental flows have been prescribed. Mesohabitats are visually distinct units of habitat within the stream with unique depth, velocity, slope, substrate, and cover. Mesohabitats in reaches of Big Cypress, Black Cypress, and Little Cypress Bayous were evaluated to gain an understanding of how fish communities and mussel populations varied by habitat. Selected water-quality properties were also measured in isolated pools in Black Cypress and Little Cypress. All of the data were collected in the context of the prescribed environmental flows. The information acquired during the study will support the long-term monitoring of biota in relation to the prescribed environmental flows.

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

    Ferchaud, Anne-Laure; Pedersen, Susanne H.; Bekkevold, Dorte; Jian, Jianbo; Niu, Yongchao; Hansen, Michael Møller

    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 s...

  13. Sources and pathways of selected organochlorine pesticides to the Arctic and the effect of pathway divergence on HCH trends in biota: a review

    Historical global usage and emissions for organochlorine pesticides (OCPs), including hexachlorocyclohexanes (HCHs), dichlorodiphenyltrichloroethane (DDT), toxaphene and endosulfan, are presented. Relationships between the air concentrations of these OCPs and their global emissions are also discussed. Differences between the pathways of ?- and ?-HCH to the Arctic Ocean are described in the context of environmental concentrating and diluting processes. These concentrating and diluting processes are shown to control the temporal and spatial loading of northern oceans and that the HCH burdens in marine biota from these oceans respond accordingly. The HCHs provide an elegant example of how hemispheric-scale solvent switching processes can alter the ocean into which an HCH congener partitions, how air-water partitioning controls the pathway for HCHs entering the Arctic, and how the various pathways impact spatial and temporal trends of HCH residues in arctic animals feeding out of marine and terrestrial foodwebs

  14. Stable and selective scintillating anion-exchange sensors for quantification of 99TcO4? in natural freshwaters

    New dual functionality scintillating anion-exchange resins were developed for selective determination of 99TcO4? in various natural freshwater samples. Stable scintillating particles were formed by preparing the vinyl monomer 2-[4-(4?-vinylbiphenylyl)]-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (vPBD), starting with the commercial organic flour TBut-PBD and its subsequent copolymerization with styrene, divinylbenzene, and p-chloromethylstyrene mixture. To integrate the radiochemical separation and radiometric detection steps within the same bead, the chloromethyl groups of the scintillating resins were subjected to amination reactions with dioctylamine (DOA) and trioctylamine (TOA). On-line quantification of 99TcO4? was achieved by packing the scintillating anion-exchange resin into Teflon tubing for quantification by a flow scintillation analyzer (FSA). The two functionalized resins were selective for pertechnetate over the common anions in natural freshwaters, especially Cl? and SO42? with up to 1000 ppm and with up to 10 ppm I? and Cr2O72?. The uptake efficiency of the TOA sensor decreased from 97.88% to 85.08% in well water and river water, respectively, while the counting efficiency was almost constant (69.50%). The DOA performance showed lower efficiency in the two water types relative to TOA. On the other hand, the DOA sensor could be regenerated by 5 M HNO3 for reuse at least four times without losing its chemical or optical performance. The detection limit was 1.45 Bq which could be achieved by loading 45 mL from well and tap water containing the maximum contaminant level (MCL) of 99Tc (33 Bq/L). -- Highlights: Two novel extractive scintillating sensors for monitoring 99TcO4? were developed. The resins are selective for pertechnetate over the common anions and chromate ions. The materials have high chemical and optical stability with good detection efficiency. 99TcO4? was determined in three freshwaters contain different radioactivity levels

  15. Extinction risk of soil biota

    Veresoglou, Stavros D.; Halley, John M.; Rillig, Matthias C

    2015-01-01

    Belowground soil biota play key roles in maintaining proper ecosystem functioning, but studies on their extinction ecology are sparse. Here, Veresoglou et al. review the risks to soil biota posed by global change, and highlight the technical challenges involved in identifying extinction events.

  16. Stable and selective scintillating anion-exchange sensors for quantification of 99TcO4- in natural freshwaters.

    Seliman, Ayman F; Helariutta, Kerttuli; Wiktorowicz, Szymon J; Tenhu, Heikki; Harjula, Risto

    2013-12-01

    New dual functionality scintillating anion-exchange resins were developed for selective determination of (99)TcO4(-) in various natural freshwater samples. Stable scintillating particles were formed by preparing the vinyl monomer 2-[4-(4'-vinylbiphenylyl)]-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (vPBD), starting with the commercial organic flour TBut-PBD and its subsequent copolymerization with styrene, divinylbenzene, and p-chloromethylstyrene mixture. To integrate the radiochemical separation and radiometric detection steps within the same bead, the chloromethyl groups of the scintillating resins were subjected to amination reactions with dioctylamine (DOA) and trioctylamine (TOA). On-line quantification of (99)TcO4(-) was achieved by packing the scintillating anion-exchange resin into Teflon tubing for quantification by a flow scintillation analyzer (FSA). The two functionalized resins were selective for pertechnetate over the common anions in natural freshwaters, especially Cl(-) and SO4(2-) with up to 1000 ppm and with up to 10 ppm I(-) and Cr2O7(2-). The uptake efficiency of the TOA sensor decreased from 97.88% to 85.08% in well water and river water, respectively, while the counting efficiency was almost constant (69.50%). The DOA performance showed lower efficiency in the two water types relative to TOA. On the other hand, the DOA sensor could be regenerated by 5 M HNO3 for reuse at least four times without losing its chemical or optical performance. The detection limit was 1.45 Bq which could be achieved by loading 45 mL from well and tap water containing the maximum contaminant level (MCL) of (99)Tc (33 Bq/L). PMID:24012764

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

    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.

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

    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

  19. Radiation weighting factors for biota

    Dosimetry models are needed to assess the impact of environmental radioactivity on biota and to demonstrate compliance with biota radiation dose guidelines. Realistic dosimetry models for biota are much less well developed compared to human dosimetry. A number of factors contribute to uncertainty in biota dosimetry, among them, organism, population relevant end point(s), the range of doses under consideration and the choice of a modifying factor for application to absorbed dose used to account for the relative effectiveness of different types of radiation. This modifying factor is alternatively referred to as radiation weighting factor, relative biological effectiveness (RBE), and ecodosimetric weighting factor among others. It remains to be decided whether this modified dose should be called 'dose equivalent' or something else; also whether it should be measured in grays, sieverts, or some new unit specific to biota. Reference or guidance doses (or dose rates) for the protection of biota are generally based on exposures to X rays or gamma rays as the reference radiation. If an organism were exposed to a source radiation of a different quality, say high LET radiation, then the absorbed dose to the organism would be multiplied by a radiation weighting factor to determine if the dose guideline has been exceeded. This paper describes the basis for biota radiation weighting factors, reviews of available data, and suggests ranges of alpha radiation weighting factors for use in environmental evaluations. (author)

  20. Accumulation of polychlorinated biphenyls in the freshwater fish, crucian, from the Han river and the Kum river, Korea

    Jeong, G.H.; Kim, Y.B.; Moon, J.Y.; Lee, S.I.; Kim, H.; Song, H. [Pusan National Univ. (Korea)

    2004-09-15

    Even though polychlorinated biphenyls(PCBs) were prohibited from producing and using for a long time, it is still identified in the every environmental media including biota. Since PCBs are lipophilic and persistent, they concentrate readily in the tissue and accumulate exponentially as they move through the food chain. Crucian (Carassius auratus) is most widely living freshwater fish in Korea. So crucian was selected as a representative freshwater fish in this study to determine the accumulation level and distribution characteristics of PCBs. In this study, we attempted to investigate the accumulation profile of individual PCB congeners in the muscle of freshwater fish crucian from the two major rivers, the Han River and Kum River, in Korea.

  1. Supporting Documentation Used in the Derivation of Selected Freshwater Tier 2 ESBs

    Compilation of toxicity data used to derive secondary chronic values (SCVs) and tier 2 equilibrium partitioning sediment benchmarks (ESBs) for a selection of nonionic organic chemicals. The values are used in the following U.S. EPA document: U.S. EPA. 2008. Procedures for th...

  2. Influence of cadmium exposure on selected hematological parameters in freshwater teleost, Notemigonus crysoleucas

    Benson, W.H.; Baer, K.N.; Stackhouse, R.A.; Watson, C.F.

    1987-02-01

    The use of hematological parameters for assessing the acute toxicity of heavy metals to mammals has shown considerable promise. These parameters include the measurement of blood glucose, hematocrit, and a variety of enzymes. The present investigation was undertaken to evaluate the use of selected hematological parameters in aquatic organisms. Exposure of Notemigonus crysoleucas to cadmium resulted in a 96-hr /sup LC/50 value of 3.15 mg Cd/liter. The influence of cadmium on selected hematological parameters was examined following 96 hr of exposure to 0, 1.35, and 2.40 mg Cd/liter. Cadmium exposure produced significant alterations in the levels of glucose, aspartate aminotransaminase, and alanine aminotransaminase. Hematocrit was not altered by exposure to cadmium. These results indicate that glucose and transaminases may be useful as diagnostic tests for cadmium exposure in aquatic organisms.

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

    Šimek, Karel; Chrzanowski, Thomas H.

    1992-01-01

    Size-selective grazing of three heterotrophic nanoflagellates (with cell sizes of 21, 44, and 66 μm3) 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...

  4. Short-term bioconcentration studies of Np in freshwater biota

    Short-term laboratory exposures were conducted to determine the potential accumulation of Np in aquatic organisms. Concentration factors were highest in green algae. Daphnia magna, a filter-feeding crustacean, accumulated Np at levels one order of magnitude greater than the amphipod Gammarus sp., an omnivorous substrate feeder. Accumulation of Np in juvenile rainbow trout (Oncorhynchus mykiss) was highest in carcass (generally greater than 78% of the total body burden) and lowest in fillets. Recommended concentration factors for Np, based on fresh weight, were 300 for green algae, 100 for filter-feeding invertebrates, for nonfilter-feeding invertebrates, 10 for whole fish, and one for fish flesh

  5. Isotope and ion selectivity in reverse osmosis desalination: geochemical tracers for man-made freshwater.

    Kloppmann, Wolfram; Vengosh, Avner; Guerrot, Catherine; Millot, Romain; Pankratov, Irena

    2008-07-01

    A systematic measurement of ions and 2H/1H, 7Li/6Li, 11B/10B, 18O/ 16O, and 87Sr/86Sr isotopes in feed-waters, permeates, and brines from commercial reverse osmosis (RO) desalination plants in Israel (Ashkelon, Eilat, and Nitzana) and Cyprus (Larnaca) reveals distinctive geochemical and isotopic fingerprints of fresh water generated from desalination of seawater (SWRO) and brackish water (BWRO). The degree of isotope fractionation during the passage of water and solutes through the RO membranes depends on the medium (solvent-water vs. solutes), chemical speciation of the solutes, their charge, and their mass difference. O, H, and Sr isotopes are not fractionated during the RO process. 7Li is preferentially rejected in low pH RO, and B isotope fractionation depends on the pH conditions. Under low pH conditions, B isotopes are not significantly fractionated, whereas at high pH, RO permeates are enriched by 20 per thousand in 11B due to selective rejection of borate ion and preferential permeation of 11B-enriched boric acid through the membrane. The specific geochemical and isotopic fingerprints of SWRO provide a unique tool for tracing "man-made" fresh water as an emerging recharge component of natural water resources. PMID:18677997

  6. Effects of selected organic compounds on radionuclide adsorption to sediments in freshwater systems

    The roles of selected organic compounds on K/sub d/ (distribution coefficients) values of radionuclides in laboratory sediment-water systems was evaluated. The radionuclides 57Co, 106Ru, 137Cs, and 241Am were used as tracers in the experiments. Five organic compounds: 1)1-nitroso-2-naphthol; 2)1,10-phenanthroline; 3)acetic acid; 4)salicylic acid; and 5)EDTA were evaluated for their effects on the distribution coefficients of the four radionuclides. The results of the study confirmed that organic compounds can affect sediment-water distribution coefficients of radionuclides, however, the magnitudes and directions of these K/sub d/ effects are functions of both the physico-chemical properties of the radionuclide and the specific interactions of the radionuclide and organic compound within a given sediment-water system. The results emphasize the complex variety of interacting factors that can effect sediment-water distributions of radionuclides. Therefore, it is necessary in any adsorption study to characterize, as fully as possible, the chemical parameters of water and sediment that can contribute to the eventual results in any given system

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

    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.

  8. Biota-Sediment Accumulation Factor Data

    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...

  9. Computerizing marine biota: a rational approach

    Chavan, V.S.; Chandramohan, D.; Parulekar, A.H.

    Data on marine biota while being extensive are also patchy and scattered; thus making retrieval and dissemination of information time consuming. This emphasise the need for computerizing information on marine biota with the objective to collate...

  10. Alpha radiation weighting factors for biota

    It is well know that the potential for radiation effects on living organisms depends not only on the absorbed dose and dose-rate, in the tissue or organ of interest, but also on the type and energy of the radiation causing the dose among other factors. For example, alpha particles and neutrons can produce observable damage at lower absorbed doses than gamma radiation. This observation has lead to the practice of multiplying the absorbed dose by a modifying factor commonly referred to as relative biological effectiveness or RBE, and other terms such as quality factor, radiation weighting factor and for non-human biota, ecodosimetry weighting factor. For human dosimetry, ICRP 60 recommends radiation weighting factors of 1 for beta and gamma rays, 10 for neutrons and 20 for alpha radiation. To distinguish from the radiation weighting factors for humans, we adopt the provisional term 'ecodosimetry radiation weighting factor' eR for application to non-human biota. The selection of an ecological relevant eR must not be considered in isolation but rather, it must be the consequence of an integrated evaluation which includes the selection of the relevant biological endpoint, the approach to calculating relevant dose, and the selection of the most appropriate ecodosimetry radiation weighting factor. This paper reviews the selection of ecologically relevant endpoints for alpha radiation, the corresponding estimation of dose, and the selection of ecodosimetry radiation weighting factors. Overall, a nominal eR of about 10 for population relevant deterministic endpoints, with a range from about 5 to about 20 is recommended. Sources of uncertainty in this estimate are discussed. (author)

  11. Bioaccumulation and depuration of chromium in the selected organs and whole body tissues of freshwater fish Cirrhinus mrigala individually and in binary solutions with nickel.

    Palaniappan, P L R M; Karthikeyan, S

    2009-01-01

    Contamination of aquatic ecosystems with heavy metals has been receiving increased worldwide attention due to their harmful effects on human health and other organisms in the environment. Most of the studies dealing with toxic effects of metals deal with single metal species, while the aquatic organisms are typically exposed to mixtures of metals. Hence, in order to provide data supporting the usefulness of freshwater fish as indicators of heavy metal pollution, it has been proposed in the present study to investigate the bioaccumulation and depuration of chromium in the selected organs of freshwater fingerlings Cirrhinus mrigala, individually and in binary solutions with nickel. The results show that the kidney is a target organ for chromium accumulation, which implies that it is also the "critical" organ for toxic symptoms. The results further show that accumulation of nickel in all the tissues of C. mrigala is higher than that of chromium. In addition, the metal accumulations of the binary mixtures of chromium and nickel are substantially higher than those of the individual metals, indicating synergistic interactions between the two metals. Theoretically the simplest explanation for an additive joint action of toxicants in a mixture is that they act in a qualitatively similar way. The observed data suggest that C. mrigala could be suitable monitoring organisms to study the bioavailability of water-bound metals in freshwater habitats. PMID:19402427

  12. Ediacaran biota from Sonora, Mexico.

    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...

  13. Investigation of metal toxicity to tropical biota. Recommendations for revision of Australian water quality guidelines

    The specific objectives of this study were to: review available data on the toxicity of metals to aquatic biota in tropical Australia; identify metals considered to be priority toxicants to aquatic biota in tropical Australia; and employ previously developed toxicity testing protocols for two tropical freshwater species to obtain preliminary toxicity data for two priority metals. From the literature review, it was concluded that insufficient metal toxicity data exist for Australian tropical species. Data were absent for a range of metals (eg Ag, As, Al, Cr, Hg, Ni, Sb and Se) listed in the current Australian water quality guidelines. Aluminium, Cd, Co, Cu, Ni, Mn, Pb, U, V and Zn were identified as priority metals of potential ecotoxicological concern in aquatic ecosystems of tropical Australia, largely as a consequence of mining activities, but also from urban impacts. Instead of testing the toxicity of the priority metals for which data do not currently exist (ie Al, Co, Ni and V), it was deemed more important to conduct further experimental work on Cu and U, in the context of elucidating the relatively high variability in the toxic response of these two metals. As a result, Cu and U were selected and toxicity tests conducted using two tropical freshwater species (green hydra (Hydra viridissima) and gudgeon fish (Mogurnda mogurnda)) from the Australian wet/dry tropics using test protocols designed to maximise the greatest sensitivity of metal response in the shortest period of time. Hydra viridissima was about eight times more sensitive to Cu than U, whereas M. mogurnda was about twenty times more sensitive. Once differences between the sublethal and lethal endpoints of the two organisms were corrected by statistical extrapolation, H. viridissima was approximately seven times more sensitive than M. mogurnda to U, but only about three times more sensitive to Cu. Both species were more sensitive to Cu than U. These results are generally consistent with those from previous studies when differences in key water quality variables, including water hardness, alkalinity, pH and dissolved organic carbon (DOC) are considered

  14. Freshwater Wetlands.

    Naturescope, 1986

    1986-01-01

    Provides descriptions about freshwater wetlands, such as marshes, swamps, and bogs. Contains three learning activities which deal with unusual wetland plants, the animals and plants in a typical marsh, and the effects of a draught on a swamp. Included are reproducible handouts and worksheets for two of the activities. (TW)

  15. Environmental pathways and radiological dosimetry for biota

    Radionuclides entering the environment as a result man's activities may be transported, cycled, and/or concentrated in the biotic and abiotic compartments of the ecosystem. Organisms in an environment contaminated with radioactive waste may be irradiated externally by radionuclides in air, water, vegetation, soil or sediment and internally by radionuclides accumulated within their bodies by inhalation or by direct absorption through their skin. The purpose of this paper is to examine the pathways in which biota are exposed to radioactive releases to the environment and to review the methods used to calculate radiation doses to the biota. In general, the methodology for estimating radiation doses to biota in their natural environment is better developed for aquatic biota than for terrestrial biota. The different methodologies which have been used for calculating radiation doses to aquatic biota were reviewed. If the protection of non-human biota is an issue in addressing environmental assessments of nuclear facilities, then the methodology for estimating radiation doses to biota should be improved. It is recommended that dose calculations should be simplified and standardized by developing dose conversion factors for a number of generic aquatic and terrestrial organisms. (author)

  16. Temporal trends of legacy POPs in Arctic biota, an update.

    Rigét, Frank; Bignert, Anders; Braune, Birgit; Stow, Jason; Wilson, Simon

    2010-07-01

    A statistically robust method was applied to 316 time-series of 'legacy' persistent organic pollutants (POPs) in Arctic biota from marine, freshwater and terrestrial ecosystems with the purpose of generating a 'meta-analysis' of temporal trend data collected over the past two to three decades for locations from Alaska in the west to northern Scandinavian in the east. Information from recently published temporal trend studies was tabulated and comparisons were also drawn with trends in arctic air. Most of the analysed time-series of legacy POP compounds showed decreasing trends, with only a few time-series showing significantly increasing trends. Compounds such as alpha-HCH, gamma-HCH and SigmaDDT had a relatively high proportion of time-series showing significantly decreasing trends; SigmaCHL had the lowest proportion. beta-HCH was an exception, where long-range transport through the ocean, and not the atmosphere, may explain several increasing trends that were detected in the Canadian Arctic. Moving east from the Canadian Arctic there was a trend towards a greater proportion of significantly decreasing trends. Several time-series for DDE and SigmaDDT showed significantly non-exponential trends, most often with a period of relative stability followed by a decrease. The median 'minimum detectable annual change within a 10-year period' for all of the time-series considered was 12% which did not meet the desirable level of statistical power capable of detecting a 5% annual change with a significance level of 5% within a 10-year period. The trends observed in the biota were consistent with decreasing trends of legacy POPs reported for Arctic air which appear to follow historic decreases in emissions. However, recent decreases in air are also starting to show signs of levelling off which may be an indication that atmospheric concentrations and, consequently those in the biota, are being less driven by primary sources and more by environmental processes and degradation. PMID:19686961

  17. Diastereomeric and enantiomeric selective accumulation of cypermethrin in the freshwater mussel Unio gibbus and its effects on biochemical parameters.

    Khazri, Abdelhafidh; Sellami, Badreddine; Dellali, Mohamed; Corcellas, Cayo; Eljarrat, Ethel; Barceló, Damià; Beyrem, Hamouda; Mahmoudi, Ezzeddine

    2016-05-01

    Synthetic pyrethroids are a family of chiral pesticides with a large number of stereoisomers. Cypermethrin (CYP) is used in a variety of agricultural crops, but also has public health and veterinary uses. In this work, the freshwater mussel (Unio gibbus) was chosen to evaluate the stereoselectivity of CYP through the use of gas chromatography with mass-spectrometry. The effects of CYP on mussels were examined by measuring neurotoxicity and oxidative stress biomarkers during its uptake. The investigation was performed under laboratory conditions using nominal CYP concentrations C1=100μg/L and C2=150μg/L over 96h. Preferential bioaccumulation of cis-CYP isomers was observed. Furthermore, enantiomeric characterization revealed enantioselective accumulation, most probably related to mussel metabolism. Antioxidant enzyme activities (superoxide dismutase (SOD), and catalase (CAT)), and levels of reduced glutathione (GSH) and malondialdehyde (MDA) were determined in digestive gland after 4days of exposure. CYP significantly inhibited acetylcholine esterase activity, by 51% and 57%, respectively, in mussels treated with 100 and 150μg/L doses. The highest and lowest CYP concentrations elicited an increase of 67 and 63%, respectively, in SOD activity compared to the controls, while CAT activity was increased by 65 and 73%. A statistically significant decrease in GSH levels (40%) was observed only with the highest CYP concentration tested (150μg/L). In addition, lipid peroxidation was significantly higher (67%) than in controls. These results provided information on CYP-enantioselective uptake and potential biomarkers that could be effectively applied for the biomonitoring of freshwater ecosystem. PMID:27017886

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

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

    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...

  19. Proposed Release Guides to Protect Aquatic Biota

    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.

  20. Capture efficiency and size selectivity of sampling gears targeting red-swamp crayfish in several freshwater habitats

    Paillisson J.-M.

    2011-05-01

    Full Text Available The ecological importance of the red-swamp crayfish (Procambarus clarkii in the functioning of freshwater aquatic ecosystems is becoming more evident. It is important to know the limitations of sampling methods targeting this species, because accurate determination of population characteristics is required for predicting the ecological success of P. clarkii and its potential impacts on invaded ecosystems. In the current study, we addressed the question of trap efficiency by comparing population structure provided by eight trap devices (varying in number and position of entrances, mesh size, trap size and construction materials in three habitats (a pond, a reed bed and a grassland in a French marsh in spring 2010. Based on a large collection of P. clarkii (n = 2091, 272 and 213 respectively in the pond, reed bed and grassland habitats, we found that semi-cylindrical traps made from 5.5 mm mesh galvanized steel wire (SCG were the most efficient in terms of catch probability (96.7–100% compared to 15.7–82.8% depending on trap types and habitats and catch-per-unit effort (CPUE: 15.3, 6.0 and 5.1 crayfish·trap-1·24 h-1 compared to 0.2–4.4, 2.9 and 1.7 crayfish·trap-1·24 h-1 by the other types of fishing gear in the pond, reed bed and grassland respectively. The SCG trap was also the most effective for sampling all size classes, especially small individuals (carapace length \\hbox{$\\leqslant 30$} ⩽ 30 mm. Sex ratio was balanced in all cases. SCG could be considered as appropriate trapping gear to likely give more realistic information about P. clarkii population characteristics than many other trap types. Further investigation is needed to assess the catching effort required for ultimately proposing a standardised sampling method in a large range of habitats.

  1. Comparative analysis of doses to aquatic biota in water bodies impacted by radioactive contamination

    Comparative analysis of doses to the reference species of freshwater biota was performed for the following water bodies in Russia or former USSR: Chernobyl NPPs cooling pond, Lakes Uruskul and Berdenish located in the Eastern Urals Radioactive Trace, Techa River, Yenisei River. It was concluded that the doses to biota were considerably different in the acute and chronic periods of radioactive contamination. The most vulnerable part of all considered aquatic ecosystems was benthic trophic chain. A numerical scale on the “dose rate – effects” relationships for fish was formulated. Threshold dose rates above which radiation effects can be expected in fish were evaluated to be the following: 1 mGy d−1 for appearance of the first morbidity effects in fish; 5 mGy d−1 for the first negative effects on reproduction system; 10 mGy d−1 for the first effects on life shortening of fish. The results of dose assessment to biota were compared with the scale “dose rate – effects” and the literature data on the radiobiological effects observed in the considered water bodies. It was shown that in the most contaminated water bodies the dose rates were high enough to cause the radiobiological effects in fish. - Highlights: ► Comparative analysis of dose rates to biota in different water bodies was performed. ► A numerical scale on the dose rates – effects relationships for fish was formulated. ► Results of assessment of exposure to biota were compared with the dose rates – effects scale. ► In the most contaminated water bodies the doses were high enough to cause radiobiological effects in fish. ► Current dose rates to biota in all considered water bodies are below the safety level of 1 mGy/day.

  2. Assessment of the impact of the Chernobyl Reactor accident on the Biota of Swedeish Streams and Lakes

    The Chernobyl reactor accident resulted in elevated levels of radionuclides in the air space above Sweden, which were then washed into Swedish lakes and streams. Before suspended particles stripped the water column, the concentration of /sp137/Cs in small Swedish lakes was in the order of 10-40 Bq/l. This level of radioactivity should result in a negligible increase in the external exposure rate. However, by August 1986 increased levels of radioactivity were found at all trophic levels of freshwater ecosystems from algae to top carnivore, and from the available data the levels of radioactivity are still increasing. The calculated dose rate for the aquatic biota caused by the two cesium isotopes, /sp134/Cs and /sp137/Cs, is about 25 times higher than natural levels. While acute effectrs of the Chernobyl fallout on freshwater biota are unlikely, the long term ecological effects bear watching

  3. A method for calculation of dose per unit concentration values for aquatic biota

    A dose per unit concentration database has been generated for application to ecosystem assessments within the FASSET framework. Organisms are represented by ellipsoids of appropriate dimensions, and the proportion of radiation absorbed within the organisms is calculated using a numerical method implemented in a series of spreadsheet-based programs. Energy-dependent absorbed fraction functions have been derived for calculating the total dose per unit concentration of radionuclides present in biota or in the media they inhabit. All radionuclides and reference organism dimensions defined within FASSET for marine and freshwater ecosystems are included. The methodology has been validated against more complex dosimetric models and compared with human dosimetry based on ICRP 72. Ecosystem assessments for aquatic biota within the FASSET framework can now be performed simply, once radionuclide concentrations in target organisms are known, either directly or indirectly by deduction from radionuclide concentrations in the surrounding medium

  4. New evidence suggests pyroclastic flows are responsible for the remarkable preservation of the Jehol biota

    Jiang, Baoyu; Harlow, George E.; Wohletz, Kenneth; Zhou, Zhonghe; Meng, Jin

    2014-02-01

    The lower Cretaceous Yixian and Jiufotang formations contain numerous exceptionally well-preserved invertebrate, vertebrate and plant fossils that comprise the Jehol Biota. Freshwater and terrestrial fossils of the biota usually occur together within some horizons and have been interpreted as deposits of mass mortality events. The nature of the events and the mechanisms behind the exceptional preservation of the fossils, however, are poorly understood. Here, after examining and analysing sediments and residual fossils from several key horizons, we postulate that the causal events were mainly phreatomagmatic eruptions. Pyroclastic density currents were probably responsible for the major causalities and for transporting the bulk of the terrestrial vertebrates from different habitats, such as lizards, birds, non-avian dinosaurs and mammals, into lacustrine environments for burial. Terrestrial vertebrate carcasses transported by and sealed within the pyroclastic flows were clearly preserved as exceptional fossils through this process.

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

    Říha, Milan; Jůza, Tomáš; Prchalová, Marie; Mrkvička, Tomáš; Čech, Martin; Draštík, Vladislav; Muška, Milan; Kratochvíl, Michal; Peterka, Jiří; Tušer, Michal; Vašek, Mojmír; Kubečka, Jan

    2012-01-01

    Roč. 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

  6. Part 7: Monitoring of biota

    The present state of the biota, in respect to the previous state and in respect to the development after the realised technical measures on both sides, was evaluated according to the data included in the Slovak-Hungarian joint monitoring covering the period from 1992 to 1996. The river branch water supply on the Slovak side was introduced in May 1993 through the intake structure at Dobrohost. On the Hungarian side the water supply is accomplished by the underwater weir put into operation in June 1995. The biological monitoring on the Slovak side was performed at six monitoring areas, where all the groups agreed in the joint monitoring were monitored. On the Hungarian side each group were monitored on different monitoring sites. The water supply introduced on the Hungarian side by the underwater weir operation has no impact on the Slovak side. Similar impact as it is now observed on the Hungarian side has been observed on the Slovak side since introduction of water supply in 1993. The increased amount of water discharged to the Danube was reflected by changes of the habitat of aquatic communities. The water supply on the Hungarian side was accomplished by the construction of the underwater weir and therefore a connection of the river branch system with the Danube at two factors have had very significant influence on the bio-tops existing in the river branch system and subsequently to the fauna and flora. Generally large amount of water became available, which was reflected in change of stagnant or slowly flowing water into water flow with higher velocity or in increase of the water surface. In some locations the water level returned to the state before damming, in others new bio-tops were created, and in some locations the previous bio-tops disappeared. To these changed conditions the aquatic fauna reacted the most rapidly.The terrestrial communities prove the necessity of flooding and raising of ground water level on some of the inundation areas, because in spite of the good soil moisture conditions on some of the monitoring area gradual changes in terrestrial communities were observed

  7. Freshwater fish of the Wilderness National Park

    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.

  8. New record of a freshwater crab Phricotelphusa callianira (De Man, 1887 (Decapoda: Brachyura: Gecarcinucidae from Thailand

    V. Lheknim

    2009-09-01

    Full Text Available An expedition by scientists participating in a Plant Genetic Conservation Project under the Royal Initiative of Her Royal Highness Princess Maha Chakri Sirindhorn to Tachai Island, off the coast of Changwat Phangnga, Andaman Sea, southern Thailand in April 1999, revealed a new record of the freshwater crab Phricotelphusa callianira (De Man 1887. The new distribution data is considered indicative of a lack of freshwater biota surveys in the area studied, and emphasizes the need for further biogeographical studies.

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

    Veraart, J.A.; Groot, R.S.; Perell, 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...

  10. Assessment of marine biota doses arising from radioactive discharges to the sea by the COGEMA La Hague facility: A comprehensive case study

    The paper presents an assessment of radiation doses to marine biota arising from the radioactive sea discharges (as liquid effluents) of the COGEMA La Hague facility. The primary objective of this study was to select a representative set of marine biota for the study area (i.e. the Nord-Cotentin Peninsula coast) and to assess the potential radiological impacts, in terms of biota dose rates and their related potential health effects on marine biota, arising from the radioactive sea discharges of the COGEMA La Hague facility. For assessing potential effects to biota, the predicted biota dose rates were compared to the available guidance for the protection of populations of non-human biota. The guidance values are based on published data by international organizations (e.g. UNSCEAR and IAEA) and on a screening review of a recent database (by FASSET) on biological effects of ionizing radiation on non-human biota. The major conclusion of the case study was that the predicted dose rates to marine biota attributable to radioactive sea discharges from the La Hague facility are small, and in general, well below comparison guidance levels at which deleterious and observable health effects to populations of marine biota might, according to current knowledge, be expected. The predicted incremental dose rates arising from the La Hague facility are also, in general, well below those caused by the background radioactivity in the region. (author)

  11. Solid-phase/supercritical-fluid extraction for liquid chromatography of phenolic compounds in freshwater microalgae and selected cyanobacterial species.

    Klejdus, B; Kopecký, J; Benesová, L; Vacek, J

    2009-01-30

    In the present paper a new extraction technique based on the combination of solid-phase/supercritical-fluid extraction (SPE/SFE) with subsequent reversed-phase HPLC is described. The SPE/SFE extractor was originally constructed from SPE-cartridge incorporated into the SFE extraction cell. Selected groups of benzoic acid derivatives (p-hydroxybenzoic, protocatechuic, gallic, vanillic and syringic acid), hydroxybenzaldehydes (4-hydroxybenzaldehyde and 3,4-dihydroxybenzaldehyde) and cinnamic acid derivatives (o-coumaric, p-coumaric, caffeic, ferulic, sinapic and chlorogenic acid) were extracted. Cyclic addition of binary extraction solvent system based on methanol:water (1:1, v/v) and methanol/ammonia aqueous solution was used for extraction at 40MPa and 80 degrees C. The p-hydroxybenzoic, protocatechuic, vanillic, syringic, caffeic and chlorogenic acid; 4-hydroxybenzaldehyde and 3,4-dihydroxybenzaldehyde were identified by HPLC-electrospray mass spectrometry in SPE/SFE extracts of acid hydrolyzates of microalga (Spongiochloris spongiosa) and cyanobacterial strains (Spirulina platensis, Anabaena doliolum, Nostoc sp., and Cylindrospermum sp.). For the identification and quantification of the compounds the quasi-molecular ions [M-H](-) and specific fragments were analysed by quadrupole mass spectrometry analyzer. Our analysis showed that the microalgae and cyanobacteria usually contained phenolic acids or aldehydes at microg levels per gram of lyophilized sample. The proposed SPE/SFE extraction method would be useful for the analysis of different plant species containing trace amount of polar fraction of phenols. PMID:19111311

  12. Spatial distribution and partitioning behavior of selected poly- and perfluoroalkyl substances in freshwater ecosystems: a French nationwide survey.

    Munoz, Gabriel; Giraudel, Jean-Luc; Botta, Fabrizio; Lestremau, Franois; Dvier, Marie-Hlne; Budzinski, Hlne; Labadie, Pierre

    2015-06-01

    The spatial distribution and partitioning of 22 poly- and perfluoroalkyl substances (PFASs) in 133 selected rivers and lakes were investigated at a nationwide scale in mainland France. ?PFASs was in the rangeurban, rural or industrial sites. Although perfluorooctane sulfonate (PFOS) was found to be the prevalent compound on average, a multivariate analysis based on neural networks revealed noteworthy trends for other compounds at specific locations and, in some cases, at watershed scale. For instance, several sites along the Rhne River displayed a peculiar PFAS signature, perfluoroalkyl carboxylates (PFCAs) often dominating the PFAS profile (e.g., PFCAs>99% of ?PFASs in the sediment, likely as a consequence of industrial point source discharge). Several treatments for data below detection limits (non-detects) were used to compute descriptive statistics, differences among groups, and correlations between congeners, as well as log Kd and log Koc partition coefficients; in that respect, the Regression on Order Statistics (robust ROS) method was preferred for descriptive statistics computation while the Akritas-Theil-Sen estimator was used for regression and correlation analyses. Multiple regression results suggest that PFAS levels in the dissolved phase and sediment characteristics (organic carbon fraction and grain size) may be significant controlling factors of PFAS levels in the sediment. PMID:25721143

  13. Spatial distribution and partitioning behavior of selected poly- and perfluoroalkyl substances in freshwater ecosystems: A French nationwide survey

    The spatial distribution and partitioning of 22 poly- and perfluoroalkyl substances (PFASs) in 133 selected rivers and lakes were investigated at a nationwide scale in mainland France. ΣPFASs was in the range < LOD–725 ng L−1 in the dissolved phase (median: 7.9 ng L−1) and < LOD–25 ng g−1 dry weight (dw) in the sediment (median: 0.48 ng g−1 dw); dissolved PFAS levels were significantly lower at “reference” sites than at urban, rural or industrial sites. Although perfluorooctane sulfonate (PFOS) was found to be the prevalent compound on average, a multivariate analysis based on neural networks revealed noteworthy trends for other compounds at specific locations and, in some cases, at watershed scale. For instance, several sites along the Rhône River displayed a peculiar PFAS signature, perfluoroalkyl carboxylates (PFCAs) often dominating the PFAS profile (e.g., PFCAs > 99% of ΣPFASs in the sediment, likely as a consequence of industrial point source discharge). Several treatments for data below detection limits (non-detects) were used to compute descriptive statistics, differences among groups, and correlations between congeners, as well as log Kd and log Koc partition coefficients; in that respect, the Regression on Order Statistics (robust ROS) method was preferred for descriptive statistics computation while the Akritas–Theil–Sen estimator was used for regression and correlation analyses. Multiple regression results suggest that PFAS levels in the dissolved phase and sediment characteristics (organic carbon fraction and grain size) may be significant controlling factors of PFAS levels in the sediment. - Highlights: • A large-scale survey of PFASs in 133 French rivers and lakes is reported. • Descriptive statistics, correlations and partitioning coefficients were determined. • Non-detects were taken into account using functions from the NADA R-package. • Hot spots of PFAS contamination were found near large urban and industrial areas. • Sediment levels were partly controlled by grain size and organic carbon content

  14. Spatial distribution and partitioning behavior of selected poly- and perfluoroalkyl substances in freshwater ecosystems: A French nationwide survey

    Munoz, Gabriel; Giraudel, Jean-Luc [University of Bordeaux, EPOC, UMR 5805, LPTC, 351 Cours de la Libération, F-33400 Talence, France. (France); Botta, Fabrizio; Lestremau, François [INERIS, Parc Technologique Alata, BP2, 60550 Verneuil-en-Halatte, France. (France); Dévier, Marie-Hélène [University of Bordeaux, EPOC, UMR 5805, LPTC, 351 Cours de la Libération, F-33400 Talence, France. (France); Budzinski, Hélène [CNRS, EPOC, UMR 5805, LPTC, 351 Cours de la Libération, F-33400 Talence, France. (France); Labadie, Pierre, E-mail: pierre.labadie@u-bordeaux.fr [CNRS, EPOC, UMR 5805, LPTC, 351 Cours de la Libération, F-33400 Talence, France. (France)

    2015-06-01

    The spatial distribution and partitioning of 22 poly- and perfluoroalkyl substances (PFASs) in 133 selected rivers and lakes were investigated at a nationwide scale in mainland France. ΣPFASs was in the range < LOD–725 ng L{sup −1} in the dissolved phase (median: 7.9 ng L{sup −1}) and < LOD–25 ng g{sup −1} dry weight (dw) in the sediment (median: 0.48 ng g{sup −1} dw); dissolved PFAS levels were significantly lower at “reference” sites than at urban, rural or industrial sites. Although perfluorooctane sulfonate (PFOS) was found to be the prevalent compound on average, a multivariate analysis based on neural networks revealed noteworthy trends for other compounds at specific locations and, in some cases, at watershed scale. For instance, several sites along the Rhône River displayed a peculiar PFAS signature, perfluoroalkyl carboxylates (PFCAs) often dominating the PFAS profile (e.g., PFCAs > 99% of ΣPFASs in the sediment, likely as a consequence of industrial point source discharge). Several treatments for data below detection limits (non-detects) were used to compute descriptive statistics, differences among groups, and correlations between congeners, as well as log K{sub d} and log K{sub oc} partition coefficients; in that respect, the Regression on Order Statistics (robust ROS) method was preferred for descriptive statistics computation while the Akritas–Theil–Sen estimator was used for regression and correlation analyses. Multiple regression results suggest that PFAS levels in the dissolved phase and sediment characteristics (organic carbon fraction and grain size) may be significant controlling factors of PFAS levels in the sediment. - Highlights: • A large-scale survey of PFASs in 133 French rivers and lakes is reported. • Descriptive statistics, correlations and partitioning coefficients were determined. • Non-detects were taken into account using functions from the NADA R-package. • Hot spots of PFAS contamination were found near large urban and industrial areas. • Sediment levels were partly controlled by grain size and organic carbon content.

  15. Disjunct distributions of freshwater snails testify to a central role of the Congo system in shaping biogeographical patterns in Africa

    Schultheiss, Roland; Van Bocxlaer, Bert; Riedel, Frank; von Rintelen, Thomas; Albrecht, Christian

    2014-01-01

    Background: The formation of the East African Rift System has decisively influenced the distribution and evolution of tropical Africa's biota by altering climate conditions, by creating basins for large long-lived lakes, and by affecting the catchment and drainage directions of river systems. However, it remains unclear how rifting affected the biogeographical patterns of freshwater biota through time on a continental scale, which is further complicated by the scarcity of molecular data from ...

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

    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.

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

    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

  18. Biota - Elwha River salmon carcass addition experiment

    National Oceanic and Atmospheric Administration, Department of Commerce — Dam removal and other fish-barrier removal projects in western North America are assumed to boost freshwater productivity via the transport of marine-derived...

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

    Ricardo A. Castro-Huerta

    2015-03-01

    Full Text Available 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 intensities: naturalized grasslands, recent agriculture, and intensive agriculture fields. During five months, litterbags of each mesh size were collected once a month per system with five replicates. The remaining mass was measured and decomposition rates calculated. Differences were found for the different biota groups, and they were dependant on soil use. Within systems, the results show that in the naturalized grasslands, the macrofauna had the highest contribution to decomposition. In the recent agricultural system it was the combined activity of the macro- and mesofauna, and in the intensive agricultural use it was the mesofauna activity. These results underscore the relative importance and activity of the different groups of the edaphic biota and the effects of different soil uses on soil biota activity.

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

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

    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 intensities: naturalized grasslands, recent agriculture, and intensive agriculture fields. During five months, litterbags of each mesh size were collected once a month per system with five replicates. The remaining mass was measured and decomposition rates calculated. Differences were found for the different biota groups, and they were dependant on soil use. Within systems, the results show that in the naturalized grasslands, the macrofauna had the highest contribution to decomposition. In the recent agricultural system it was the combined activity of the macro- and mesofauna, and in the intensive agricultural use it was the mesofauna activity. These results underscore the relative importance and activity of the different groups of the edaphic biota and the effects of different soil uses on soil biota activity. PMID:25780777

  1. Preliminary Study on Coral Reef and Its Associated Biota in Qatari Waters, Arabian Gulf

    Al Ansi, Mohsin A. [???? ??? ???? ??????

    1999-01-01

    Coral reef grounds and their associated biota m Qatari waters were investigated by Scuba diving. Four selected reef-sites were studied. Coral was presented by 17 species. Descriptive notes of each site and an initial list of associated fauna and flora were presented. The associated biota composed mainly of Algae 23 sp, Porifera 5 sp, Bryozoa 4 sp, Polychaeta 17 sp, Echinodermata 21 sp, Mollusca 102 sp, Chordata 4 sp, and Crustacea 15 sp. Mollusca was the predominant group in all visited sites...

  2. The RESRAD-BIOTA code for application in biota dose evaluation

    The RESRAD-BIOTA code was developed through a partnership among U.S. Department of Energy, the U.S. Environmental Protection Agency, and the U.S. Nuclear Regulatory Commission. RESRAD-BIOTA provides a full spectrum of analysis capabilities, from cost-effective conservative screening methods (using biota concentration guides) to realistic, organism-specific dose assessment. A beta version of the RESRAD-BIOTA code is currently available for use and testing. Continued coordination and partnerships with U.S. agencies and international organizations is providing opportunities for the inclusion of additional evaluation approaches and capabilities, such as (1) development of biota concentration guides for additional radionuclides, (2) additional flexibility for specifying and expanding organism options, (3) improvements to parameter datasets of environmental transfer factors, (4) inclusion of additional ''reference organism geometries'' (e.g., dose conversion factors for ellipsoids of appropriate size and shielding properties for different sized organisms, appropriate for specific ecosystem types), and (5) the capability to perform sensitivity and uncertainty analyses for calculated dose estimates

  3. High-precision 40Ar/39Ar age for the Jehol Biota

    Chang, S.; Zhang, H.; Renne, P. R.; Fang, Y.

    2008-12-01

    Abundant fossils of the terrestrial Jehol Biota, including plants, insects, dinosaurs, birds, mammals and freshwater invertebrates, were discovered from the Yixian Formation and the overlying Jiufotang Formation in Inner Mongolia, Hebei Province and Liaoning Province, northeastern China. Because of the exceptional preservation of fossils, the Jehol Biota is one of the most important Mesozoic fossil outcrops and referred to as a "Mesozoic Pompeii". The Jehol Biota has provided a rare opportunity to address questions about the origin of birds, the evolution of feathers and flight, the early diversification of angiosperms and the timing of the radiation of placental mammals. The Tuchengzi Formation, which lies unconformably just below the Yixian Formation and consists mainly of variegated sandstones, is less fossiliferous than the two overlying formations. However, dinosaur tracks, silicified wood and compressed plants are found in this formation. A systematic 40Ar/39Ar dating of the Yixian and the Jiufotang formations was undertaken to provide a framework for understanding the timing and duration of the Jehol Biota and evolutionary events represented within it. Furthermore, determining the absolute age of the Tuchengzi Formation provides information to interpret abundant dinosaur tracks within and provide better age constrains for the beginning of the Jehol Biota. Here we present robust high-precision 40Ar/39Ar data for six tuff samples and two basalt samples collected from the Tuchengzi, the Yixian and the Jiufotang formations near the classic outcrops in western Liaoning, NE China. We obtain an age of 139.5 ± 1.0 Ma for the uppermost Tuchengzi Formation, an age of 129.7 ± 0.5 Ma for a basaltic lava from the bottom of the Yixian Formation and an age of 122.1 ± 0.3 Ma for a tuff from the base of the overlying Jiufotang Formation. Our data indicate that the Yixian Formation was deposited during the Early Cretaceous, the Barremian to early Aptian, within a time span of 7 Ma. Because of the systematic sampling and the high quality of our data, these results contribute the most accurate age calibration yet of the Jehol Biota within the Yixian Formation and the overlying Jiufotang Formation, providing significant calibration for the evolution of early angiosperms, primitive birds and feathered dinosaurs.

  4. New record of a freshwater crab Phricotelphusa callianira (De Man, 1887) (Decapoda: Brachyura: Gecarcinucidae) from Thailand

    V. Lheknim; P. Leelawathanagoon

    2009-01-01

    An expedition by scientists participating in a Plant Genetic Conservation Project under the Royal Initiative of Her Royal Highness Princess Maha Chakri Sirindhorn to Tachai Island, off the coast of Changwat Phangnga, Andaman Sea, southern Thailand in April 1999, revealed a new record of the freshwater crab Phricotelphusa callianira (De Man 1887). The new distribution data is considered indicative of a lack of freshwater biota surveys in the area studied, and emphasizes the need for further b...

  5. Freshwater crabs in Africa

    Dobson, Michael

    2004-01-01

    Freshwater crabs are a strangely neglected component of the world's inland aquatic ecosystems. Despite their wide distribution throughout the tropical and warm temperate zones of the world, and their great diversity, their role in the ecology of freshwaters is very poorly understood. This is nowhere more true than in Africa, where crabs occur in almost every freshwater system, yet even fundamentals such as their higher taxonomy are yet to be determined. This review will attempt to stimulate i...

  6. Redistribution of soil biota by rainfall erosion

    Baxter, Craig; Rowan, John; McKenzie, Blair; Neilson, Roy

    2013-04-01

    Soil is central to the provision of multiple ecosystem services that sustain life through a myriad of chemical, physical and biological processes. One of the greatest threats to soil is erosion, a natural process accelerated by human activities. Elevated erosion rates are common in agro-ecosystems causing both direct physical impacts (e.g. soil loss), and indirect biogeochemical consequences, which ultimately leads to impaired ecosystem functioning. The consequences of erosion on soil biota have hitherto been ignored, yet biota have fundamental roles in the provision of soil ecosystem services. To our knowledge few studies have addressed the gap between erosion and impacts on soil biota. Here we use soil nematodes as a model organism for assessing erosion impacts on soil (micro) fauna in temperate agro-ecosystems. Soil nematodes are ubiquitous, abundant, are represented at all levels in soil food webs and can be categorised into a range of trophic or functional groups. To quantify transport of nematodes and gain a better understanding of erosive mechanisms responsible, we measured their export from small erosion plots (0.0625m2) under a fixed-intensity design rainstorm (6mm min-1 duration: 3 min) over six slope angles (4° - 24°) and three soil texture classes (sandy silt, silty sand, silt). Runoff and eroded sediment were collected for each plot (four replicate runs), and a suite of biological and physico-chemical parameters measured. Results confirmed that, similar to soil particles, nematodes were exported at rates influenced by slope angle and soil texture. These experiments, linked with field and catchment-scale equivalents, are designed to elucidate the links between soil erosion and provision of ecosystem services and to inform biodiversity-sensitive soil and water conservation practices.

  7. A Silurian soft-bodied biota

    Mikulic, Donald G.; Briggs, D.E.G.; Kluessendorf, Joanne

    1985-01-01

    A new Silurian (Llandoverian) biota from Wisconsin with a significant soft-bodied and lightly sclerotized component is dominated by arthropods and worms. The fauna includes the earliest well-preserved xiphosure, a possible marine uniramian, three new arthropods of uncertain affinity, and possibly the first Paleozoic leech. This may be only the second locality to yield a conodont animal. Lack of a normal shelly fauna suggests an unusual environment. The discovery adds significantly to the few such exceptionally preserved faunas known from Lower Paleozoic rocks.

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

    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)

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

    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 137Cs 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 137Cs 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 137Cs 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)

  10. The U.S. Department of Energy's graded approach for evaluating radiation doses to aquatic and terrestrial biota

    The United States Department of Energy (DOE) currently has in place a radiation dose limit for the protection of aquatic organisms, and has considered dose limits for terrestrial biota. These limits 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 and other proposed limits for protection of biota is needed. In response to this need, we have developed methods, models and guidance within a graded approach for evaluating radiation doses to biota. DOE's multi-tiered process is described in a technical standard document. Methods are encoded in a series of electronic spreadsheets termed the RAD-BCG Calculator to assist the user in progressing through the evaluation process. A key component of the graded approach is a screening methodology that provides limiting concentrations of radionuclides, termed Biota Concentration Guides (BCGs), for use in screening water, sediment, and soil media to determine if dose limits for biota are likely to be exceeded. The graded approach provides flexibility and the ability to iterate through the evaluation process. User-selected biota dose limits can be entered in place of default dose limits. Parameter values, radiation weighting factors, and organism residence times can be modified within site-specific screening and site-specific analysis phases of the graded approach. The methodology, available since 2000, was developed using an interdisciplinary team approach that included both 'developers' and 'users' through the Department's Biota Dose Assessment Committee (BDAC). DOE's graded approach framework provides a practical and effective tool for demonstrating protection of biota relative to Dose Rate Guidelines, and for conducting ecological screening assessments of radiological impact. It provides a needed evaluation tool that can be employed within an international framework for protection of the environment. (author)

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

    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 measured at about 56 million metric tons, valued at a minimum of US$ 280 million per year. The forest is rich in biodiversity, where over 65 species of mangroves and about 1136 wildlife species occur. The BSMF acts as a natural wall, saving property as well as millions of lives from natural disasters, the value of which is between 273 and 714 million US$. A 15 to 20 km band impact zone exists to the north and east of the BSMF, with a human settlement of about 3.5 million that is partly dependent on the forests. Three wildlife sanctuaries are to the south of the BSMF, the home of the great royal Bengal tigers, covering a total area of about 1397 km2. Construction of a coal-fired power plant at Rampal will be the largest threat to the Sundarbans. It is a reserve forest, declared as a Ramsar site of international importance and a UNESCO natural world heritage site.

  12. U.S. department of energy's graded approach for evaluating radiation doses to aquatic and terrestrial biota

    The United States Department of Energy (DOE) has been active in the development of requirements, methods and guidance for protection of the environment (biota and ecosystems) from the effects of ionising radiation since the late 1980's. This oral presentation provided an overview of: (1) DOE's requirements and strategic objectives for the evaluation of doses to biota at DOE sites and facilities; (2) a practical screening tool provided within DOE's graded approach to biota dose evaluation; (3) lessons learned from the first year of the graded approach methodology's implementation at DOE sites; and (4) thoughts for International Commission on Radiological Protection (ICRP) activities on radiological protection of the environment. Practical and cost-effective methods are needed for demonstrating protection of biota. Through its Biota Dose Assessment Committee (BDAC), the DOE has developed screening methods, models, and guidance within a graded approach for evaluating radiation impacts to biota (Figure 1). DOE's graded approach is described in the DOE Technical Standard, 'A Graded Approach for Evaluating Radiation Doses to Aquatic and Terrestrial Biota'. A series of electronic spread-sheets for conducting an evaluation are contained in a 'RAD-BCG Calculator'.' A practical screening methodology provides limiting concentrations of radionuclides, termed Biota Concentration Guides (BCGs), for use in screening water, sediment, and soil media to determine if dose limits for biota might be exceeded. Methods and models for site-specific screening and detailed analysis, if needed, are also provided (Table 1). Four reference organisms were selected as the basis for methods development. Internal and external exposure assumptions and default parameters used provide for conservative screening values. Users can modify the biota dose limits and parameter values to account for site-specific receptors and exposure scenarios. DOE's proactive outreach and co-ordination with other U.S. agencies (through the Interagency Steering Committee on Radiation Standards) and with international organisations has resulted in opportunities for partnerships and methods advancement. DOE's approach for evaluating radiation doses to biota is proving useful as a sensible and cost-effective tool that could be employed within an overall framework for protection of the environment from the effects of ionising radiation. (author)

  13. Interactions of radionuclides with marine biota

    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)

  14. A Computerized Database for Freshwater Algae Recorded in Turkey

    Şen, Bülent; ALP, Mehmet Tahir; Sönmez, Feray; AYKULU, Güler; YILDIZ, Kazım

    2006-01-01

    A computer-based database for freshwater algae recorded in Turkey has been established. The first phase of the project involved the selecting of data types available for freshwater algal species occurring in Turkey. Such data were obtained from algal studies previously carried out in various freshwater bodies of the country. Data were then standardized in accordance with "The Central Database of Turkish Herbaria". The database program Access was used for entering data, as this progr...

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

    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.

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

    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)

  17. Preliminary study on radiological impact assessment of radioactive liquid effluent to aquatic biota

    RESRAD-BIOTA is a computer code recommended by U.S. Department of Energy (DOE) for assessing the radiological close of aquatic biota. RESRAD-BIOTA code is briefly introduced, and an example is given. The existing problems, further improvement and research directions of RESRAD-BIOTA code applied to radiological impact of aquatic biota are pointed out in the end. (authors)

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

    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

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

    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

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

    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 129I into the atmosphere and coastal waters. To study 129I behaviour in brackish Lake Obuchi, which is adjacent to the plant, 129I concentrations in aquatic biota were measured by accelerator mass spectrometry. Owing to 129I discharge from the plant, the 129I concentration in the biota started to rise from the background concentration in 2006 and was high during 2007-08. The 129I concentration has been rapidly decreasing after the fuel cutting and chemically processing were finished. The 129I 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 129I concentration in the biota samples was 2.8 nSv y-1. (authors)

  1. ACCUMULATION OF HEAVY METALS IN BIOTA OF VYRLYTSA LAKE

    Bilyk, Tetiana; Tsurkan, Katerina; Koren, Lyudmila

    2011-01-01

    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.

  2. Decline of radionuclides in Columbia River biota

    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

  3. Decline of radionuclides in Columbia River biota

    Cushing, C.E.; Watson, D.G.; Scott, A.J.; Gurtisen, J.M.

    1980-03-01

    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.

  4. A study on the radioactivity profile of Polonium-210 in different freshwater habitats

    The present study is an attempt to understand the distribution pattern of Polonium-210, a natural alpha emitter in three distinct freshwater systems namely lotic (running water), lentic (standing water) and semi-lentic (impounded water) of the Kaveri river system, Tiruchirappalli (10.48 degN latitude and 78.42 degE longitude). Measurements were made on the 210Po levels of water, sediment and selected biota (net plankton, weed, snail, bivalve, prawn and fish) collected from the three different habitats. Analysis of the results indicate that a lentic system tends to accumulate 210Po at a relatively higher level compared to a lotic system in all environmental matrices tested. The semi-lentic system maintained an intermediate level between the lotic and the lentic habitat. In water, dissolved concentrations of 210Po ranged from 0.77 mBq.l-1 (lotic system) to 1.8 mBq.l-1 (lentic system). As in water, 210Po concentration in sediment was also significantly higher in lentic habitat (59.9 Bq.kg-1 dry wt.) than in lotic habitat (20.8 Bq.kg-1 dry wt.). The aquatic organisms demonstrated differential accumulation of 210Po with enhanced bioaccumulation in soft tissues and muscle. The 210Po activity in the biota fell within the range 1.6 to 140.1 Bq.kg-1 wet wt. The bivalve mollusca, Parrevsia favidens was identified to concentrate higher levels of 210Po in their soft tissues, suggesting, that these organisms could serve as sentinel organisms for 210Po in a riverine system. The significance of the results of 210Po in the abiotic and biotic components are discussed. (author)

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

    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.

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

    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)

  7. Pesticide toxicity index for freshwater aquatic organisms

    Munn, Mark D.; Gilliom, Robert J.

    2001-01-01

    The U.S. Geological Survey's National Water-Quality Assessment (NAWQA) Program is designed to assess current water-quality conditions, changes in water quality over time, and the effects of natural and human factors on water quality for the Nation's streams and ground-water resources. For streams, one of the most difficult parts of the assessment is to link chemical conditions to effects on aquatic biota, particularly for pesticides, which tend to occur in streams as complex mixtures with strong seasonal patterns. A Pesticide Toxicity Index (PTI) was developed that combines pesticide exposure of aquatic biota (measured concentrations of pesticides in stream water) with toxicity estimates (standard endpoints from laboratory bioassays) to produce a single index value for a sample or site. The development of the PTI was limited to pesticide compounds routinely measured in NAWQA studies and to toxicity data readily available from existing databases. Qualifying toxicity data were found for one or more types of test organisms for 75 of the 83 pesticide compounds measured in NAWQA samples, but with a wide range of bioassays per compound (1 to 65). There were a total of 2,824 bioassays for the 75 compounds, including 287 48-hour EC50 values (concentration at which 50 percent of test organisms exhibit a nonlethal response) for freshwater cladocerans, 585 96-hour LC50 values (concentration lethal to 50 percent of test organisms) for freshwater benthic invertebrates, and 1,952 96-hour LC50 values for freshwater fish. The PTI for a particular sample is the sum of toxicity quotients (measured concentration divided by the median toxicity concentration from bioassays) for each detected pesticide. The PTI can be calculated for specific groups of pesticides and for specific taxonomic groups.While the PTI does not determine whether water in a sample is toxic, its values can be used to rank or compare the toxicity of samples or sites on a relative basis for use in further analysis or additional assessments. The PTI approach may be useful as a basis for comparing the potential significance of pesticides in different streams on a common basis, for evaluating relations between pesticide exposure and observed biological conditions, and for prioritizing where further studies are most needed.

  8. Effects of the new wildlife transfer factors on RESRAD-BIOTA's screening Biota Concentration Guides and previous model comparison studies

    The RESRAD-BIOTA Level 1 default Biota Concentration Guides (BCGs) are generic screening environmental medium concentrations based on reasonably conservative concentration ratios (CRs). These CRs had been identified from available literature for a variety of biota organisms. The International Atomic Energy Agency (IAEA) Technical Report Series (TRS) handbook on radionuclide transfer to wildlife was recently published with data that can be compared with the RESRAD-BIOTA values. In addition, previous IAEA Environmental Modeling for Radiation Safety (EMRAS) II Biota Working Group model comparison results are examined by comparing them with those obtained using the new TRS CR values for wildlife. Since the CR affects only internal doses, the effect on the overall dose depends on the relative contribution from internal and external exposure pathways

  9. A method for estimating radiation dose rates to aquatic biota

    Compared with terrestrial biota, aquatic biota have simpler biological structure and living environment, and the density of organisms is very close to that of environment medium. Therefore, doses to aquatic biota are generally obtained by calculating the absorption fraction of different particles on organisms. Taking Chinese Sturgeon as an example, this paper uses MCNP 4C to simulate the transportation of particles emitted by 60Co and 51Cr in the organisms, and calculates radiation doses to individuals resulting from these two radionuclides of unit concentration. (authors)

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

    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

  11. Central Northwest Pacific biota and their radioactivity

    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

  12. Effects of thermal discharges on aquatic biota

    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

  13. Enhanced activities of organically bound tritium in biota samples

    Světlík, Ivo; Fejgl, Michal; Malátová, I.; Tomášková, Lenka

    2014-01-01

    Roč. 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

  14. Help from under ground: soil biota facilitate knotweed invasion

    Parepa, Madalin; Schaffner, Urs; Bossdorf, Oliver

    2013-01-01

    Soil biota can be important drivers of plant community structure. Depending on the balance between antagonistic and mutualistic interactions, they can limit or promote the success of plant species. This is particularly important in the context of exotic plant invasions where soil biota can either increase the biotic resistance of habitats, or they can shift the balance between exotic and native plants towards the exotics and thereby greatly contribute to their dominance. Here, we explored the...

  15. Plant communtiy development is affected by nutrients and soil biota

    De Deyn, G.B.; Raaijmakers, C.E.; van der Putten, W.H.

    2004-01-01

    Plant community development depends to a great extent on the availability of soil nutrients, but recent studies underline the role of symbiotic, herbivorous and pathogenic soil biota. We tested for interactions between these biotic and abiotic factors by studying the effects of additional nutrients and the removal of soil biota on the replacement of grassland plant species typical of different successional stages. Species representing each of the early, mid and target phases of secondary ...

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

    Heinemann, M.; Timmermann, A.; Feudel, U.

    2011-01-01

    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 m...

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

    Heinemann, M.; Timmermann, A.; Feudel, U.

    2011-01-01

    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 ...

  18. Freshwater and fish

    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)

  19. Freshwater and fish

    Saxen, R. [Finnish Centre for Radiation and Nuclear Safety (Finland)

    1997-10-01

    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 {sup 90}Sr 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). 18 refs.

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

    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)

  1. TOXICITY AND METABOLISM STUDIES WITH EPA (ENVIRONMENTAL PROTECTION AGENCY) PRIORITY POLLUTANTS AND RELATED CHEMICALS IN FRESHWATER ORGANISMS

    Twenty-two chemicals from the EPA priority pollutant list were studied for their acute and/or chronic toxicity to selected freshwater organisms. Freshwater species tested included the fathead minnow (Pimephales promelas), rainbow trout (Salmo gairdneri), bluegill sunfish (Lepomis...

  2. Water hardness reduces the accumulation and toxicity of uranium in a freshwater macrophyte (Ceratophyllum demersum)

    There is a lack of good quality data and mechanistic understanding on the effects of true water hardness (calcium (Ca) and magnesium (Mg)) on the bioavailability and toxicity of uranium (U) to freshwater biota. This study determined the effect of true water hardness (20, 75, 150, 275 and 400 mg CaCO3 L−1) on the cell surface binding affinity (log K), accumulation and toxicity (growth inhibition) of U in a submerged, rootless, macrophyte (Ceratophyllum demersum) in a synthetic freshwater with constant alkalinity (13 mg CaCO3 L−1) and pH (6.2) over 7 days. A 20-fold increase in water hardness resulted in a 4-fold decrease in U toxicity (median effect concentration (EC50) = 134 μg L−1 U at 20 mg CaCO3 L−1 hardness, increasing to 547 μg L−1 U at 400 mg CaCO3 L−1 hardness), cell surface binding affinity (log K = 6.25 at 20 mg CaCO3 L−1 hardness, decreasing to log K = 5.64 at 400 mg CaCO3 L−1 hardness) and accumulation (the concentration factor decreased from 63 at 20 mg CaCO3 L−1 hardness to 15 at 400 mg CaCO3 L−1 hardness) of U. Calcium provided a 4-fold greater protective effect against U accumulation and toxicity compared to Mg. Speciation calculations indicated negligible differences in the percentages of key U species (UO22+, UO2OH+, UO2(OH)2) over the range of water hardness tested. The inhibition of U binding at the cell surface, and subsequent uptake, by C. demersum, with increasing Ca and/or Mg concentration, may be explained in terms of (i) competition between Ca2+/Mg2+ and UO22+ (and/or UO2OH+) for physiologically active sites at the cell surface, and/or (ii) reduced negative charge (electrical potential) at the cell surface, resulting in a decrease in the activity of UO22+ (and/or UO2OH+) at the plant/water interface (boundary layer), and consequently, less U bound to physiologically active cell surface sites. In the absence of a biotic ligand model for U, the results of this study (together with previous work) reinforce the need for a more flexible, hardness-dependent, U guideline for the protection of selected freshwater biota. - Highlights: ► Effect of water hardness on U toxicity and accumulation in a freshwater macrophyte was studied. ► A 20-fold increase in water hardness resulted in a 4-fold decrease in U toxicity and accumulation. ► Ca provided a 4-fold greater protective effect against U toxicity and accumulation than Mg. ► Negligible differences in the percentages of key U species with increased water hardness ► Mechanisms of competition and/or electrostatic effects at the cell surface are proposed

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

    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)

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

    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.

  5. Reviewing the serotonin reuptake inhibitors (SSRIs) footprint in the aquatic biota: Uptake, bioaccumulation and ecotoxicology

    Selective serotonin re-uptake inhibitors (SSRIs) antidepressants are amongst the most prescribed pharmaceutical active substances throughout the world. Their presence, already described in different environmental compartments such as wastewaters, surface, ground and drinking waters, and sediments, and their remarkable effects on non-target organisms justify the growing concern about these emerging environmental pollutants. A comprehensive review of the literature data with focus on their footprint in the aquatic biota, namely their uptake, bioaccumulation and both acute and chronic ecotoxicology is presented. Long-term multigenerational exposure studies, at environmental relevant concentrations and in mixtures of related compounds, such as oestrogenic endocrine disruptors, continue to be sparse and are imperative to better know their environmental impact. - Highlights: • Current knowledge of uptake and bioaccumulation of SSRIs. • Ecotoxicology and effects of SSRIs in the aquatic biota. • Identification of existing knowledge gaps. - A comprehensive review focussing SSRIs antidepressants footprint in the aquatic biota, namely their uptake, bioaccumulation, and both acute and chronic ecotoxicology is presented

  6. Relationship of Freshwater Aquaculture Production to Renewable Freshwater Resources

    Boyd, Claude E.; Li, Li; Brummett, Randall

    2012-01-01

    At the country-level, freshwater aquaculture production was correlated (P 1,000 ton/km3 (n = 12). Most renewable freshwater isin countries with no freshwater aquaculture or low AFR; countries with high AFR contain 11.1% of global renewable freshwater. By FAO region, AFR values were: Oceania,1.56 ton/km3; Latin America and Caribbean, 31.1 ton/km3; North America, 50.0 ton/km3; Europe, 68.7 ton/km3; Africa, 84.1 ton/km3; and Asia, 2,409 ton/km3. Renewable freshwater appears adequate for consider...

  7. Approaches to estimating the transfer of radionuclides to arctic biota

    There is increasing concern over potential radioactive contamination of the Arctic due to the wide range of nuclear sources. Environmental characteristics of the Arctic also suggest that it may be comparatively vulnerable to contaminants. Here we review collated data and available models for estimating the transfer of radionuclides to terrestrial biota within the Arctic. The most abundant data are for radiocaesium and radiostrontium although many data for natural radionuclides were available from studies in the Arctic. For some radionuclides no data are available for describing transfer to Arctic biota. Allometric-kinetic models have been used to provide estimates of transfer for radionuclide biota combinations for which data were lacking. Predicted values were in good agreement with observed data for some radionuclides (e.g. Cs, U) although less so for others. However, for some radionuclides where comparison appeared poor there were relatively little observed data with which to compare and the models developed were simplistic excluding some potentially important transfer pathways (e.g. soil ingestion). There are no bespoke models to enable the dynamic prediction of radionuclide transfer to Arctic biota. A human food chain model is available which includes limited parameterization for Cs and Sr transfer in Arctic ecosystems. This has been relatively easily adapted to estimate 137Cs and 90Sr transfer to some Arctic biota and could be readily adapted to other radionuclide-biota combinations. There are many factors of Arctic ecosystems which may influence radionuclide behaviour including short growing seasons, prolonged freezing of soil, and effects of low temperatures on biological rates. However, these are not included within existing predictive models (for human or biota exposure). If exposure to ionising radiation within Arctic ecosystems is to be robustly predicted such factors must be fully understood and properly incorporated into models. (author)

  8. Plutonium in biota from an east Tennessee floodplain forest

    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)

  9. The use of reference gene selection programs to study the silvering transformation in a freshwater eel Anguilla australis: a cautionary tale

    Lokman P Mark

    2010-09-01

    Full Text Available Abstract Background Quantitative real-time PCR (qPCR has been the method of choice for the quantification of mRNA. Due to the various artifactual factors that may affect the accuracy of qPCR, internal reference genes are most often used to normalize qPCR data. Recently, many studies have employed computer programs such as GeNorm, BestKeeper and NormFinder in selecting reference genes, but very few statistically validate the outcomes of these programs. Thus, in this study, we selected reference genes for qPCR of liver and ovary samples of yellow (juvenile, migratory (silver and 11-KT treated juveniles of New Zealand shortfinned eels (Anguilla australis using the three computer programs and validate the selected genes statistically using REST 2009 software and the Mann-Whitney test. We also tested for the repeatability of use for the best reference genes by applying them to a data set obtained in a similar experiment conducted the previous year. Results Out of six candidate genes, the combination of 18 s and eef1 was found to be the best statistically validated reference for liver, while in ovary it was l36. However, discrepancies in gene rankings were found between the different programs. Also, statistical validation procedures showed that several genes put forward as being the best by the programs were in fact, regulated, making them unsuitable as reference genes. Additionally, eef1 which was found to be a suitable - though not the top ranked - reference gene for liver tissues in one year, was regulated in another. Conclusions Our study highlights the need for external validations of reference gene selections made by computer programs. Researchers need to be vigilant in validating and reporting the rationale for the use of reference gene in published studies.

  10. Fatty Acid Composition and Levels of Selected Polyunsaturated Fatty Acids in Four Commercial Important Freshwater Fish Species from Lake Victoria, Tanzania

    Agnes Robert; Prosper Mfilinge; Samwel M. Limbu; Mwita, Chacha J.

    2014-01-01

    Fatty acids (FAs) particularly ?3 and ?6 polyunsaturated fatty acids (PUFAs) play important role in human health. This study aimed to investigate the composition and levels of selected ?3 PUFAs in four commercial fish species, Nile perch (Lates niloticus), Nile tilapia (Oreochromis niloticus), Tilapia zillii, and dagaa (Rastrineobola argentea) from Mwanza Gulf in Lake Victoria. The results indicated that 36 types of FAs with different saturation levels were detected. These FAs were dominated ...

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

    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.

  12. Combined ecological risks of nitrogen and phosphorus in European freshwaters

    Eutrophication is a key water quality issue triggered by increasing nitrogen (N) and phosphorus (P) levels and potentially posing risks to freshwater biota. We predicted the probability that an invertebrate species within a community assemblage becomes absent due to nutrient stress as the ecological risk (ER) for European lakes and streams subjected to N and P pollution from 1985 to 2011. The ER was calculated as a function of species-specific tolerances to NO3− and total P concentrations and water quality monitoring data. Lake and stream ER averaged 50% in the last monitored year (i.e. 2011) and we observed a decrease by 22% and 38% in lake and stream ER (respectively) of river basins since 1985. Additionally, the ER from N stress surpassed that of P in both freshwater systems. The ER can be applied to identify river basins most subjected to eutrophication risks and the main drivers of impacts. - Highlights: • Ecological risk was estimated as response additions of N and P. • The risk posed by N stress is higher than that by P in European freshwaters. • Ecological risks have remained unchanged in most European river basins. - Quantifying the ecological risk of invertebrate losses due to N and P pollution

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

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

    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. The problem of permissible doses of irradiation for biota

    The dose of acute irradiation or of chronic irradiation under which the biota's functioning is not disturbed is suggested as a permissible dose of irradiation for biota. On the basis of many separate experiments and observations, doses of chronic irradiation 1-3 gy/year are supposed to be permissible for higher plants and animals. The irradiation tolerance of microorganisms is considerably higher. The permissible doses of irradiation for the biota and for human beings are compared. The accepted maximum tolerance dose of irradiation of 10-3 gy/year for humans is determined to be groundless. We propose substituting the term open-quotes permissible dose.close quotes 28 refs., 3 figs

  15. Radioactive radium and lead isotopes determinations in biota samples

    210Pb and radium's isotopes were determined in biota samples by two different radiochemical techniques-Fe(OH)3 co-precipitation and calcium phosphate precipitation. The applied procedures were adapted for very small amount (0.25 g) of sample material and were checked in actual biota samples. Measurements were made by liquid scintillation counting, ?- and ?-spectrometry. All the results show that Ca3(PO4)2 precipitation technique is better for determination of trace radionuclide concentrations in biota. The procedure of separation is stable with significant yield for the both 210Pb and radium's isotopes and can be successfully used for assessment of environmental stressors in field of bio-monitoring. (author)

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

    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. Ecodosimetry weighting factor (eR) for non-human biota

    The ICRP's radiological protection guidance for humans recognizes that equal absorbed doses of different types of radiation can have different biological effects in humans. ICRP publication 60 thus prescribes radiation weighting factors, wR values, to modify the absorbed dose (Gy) to effective dose (Sv) to enable the risk from different types of radiation to be compared on an equivalent basis. The wR values are selected on the basis of various considerations, including the linear energy transfer of the radiation and relative biological effectiveness (RBE) values (which are the ratios of the absorbed dose of reference to test radiation that produce an equivalent level of effect, for a given endpoint, system and dose level). There is no similar factor for non-human biota. It would be useful to have one: assessment of possible impacts on non-human biota (particularly from alpha-emitters and tritium beta-rays) is important for Canadian nuclear facilities. We propose a radiation equivalency factor 'eR' for biota to fulfill a role equivalent to that occupied by wR in human radiation protection. RBE values for deterministic effects such as reproduction, fecundity and survival in biota are the critical bases for selection of eR values. These deterministic effects in populations are far more relevant to the assessment endpoints in ecological risk assessment than are stochastic effects, to which RBE values in human radiation protection relate. For tritium β-rays, most determinations support RBE values of 2-3 for deterministic effects when referenced to gamma radiation but little more than unity when x-rays are the reference radiation. This is because x-rays themselves have RBE -2 if referenced to gamma rays. Despite this, the ICRP assigns a wR of 1 to all electrons and all photons, including tritium beta-rays. Therefore, if eR is constrained to an integer, 1 is more appropriate than a value of 2 for tritium beta-rays. An RBE factor of 200-300 for alpha particles in radiation protection of non-human biota has been suggested in Canada, but in two studies that reported RBE values of about 250, the dosimetry for alpha particles was uncertain. Furthermore, RBE value of 20 for non-human biota is indefensible because it relates to stochastic effects in individuals. For deterministic effects, most animal studies report RBE values (for population-based endpoints) in the range of 5-10. Since ecological risk to biota generally appears only when doses are moderately high, the most logical and reasonable choice of eR for α-emitters is not the larger, limiting value of RBE value observed at low doses, but rather a value around 5. (author)

  18. Implementation and validation of the USDOE graded approach for evaluating radiation impacts on biota at long-term stewardship sites

    The DOE Technical Standard, 'A Graded Approach for Evaluating Radiation Doses to Aquatic and Terrestrial Biota' (the Graded Approach) was used to evaluate two geographically discrete DOE sites, Bear Creek Valley (BCV) in Oak Ridge, Tennessee and the Test Reactor Area (TRA) ponds in Idaho Falls, Idaho. The first step entailed reviewing existing ecological risk assessments (ERAs) of contaminated waste sites and selecting the most appropriate sites for testing the Graded Approach, based on the existence of measurable radiological contamination and biological data. Ambient media (soil) data were evaluated using the initial (conservative) screening protocol in the Graded Approach. The next step entailed comparing the results from the Graded Approach with those of the existing ERAs for each site, which were used as the primary standard of performance. The default (conservative) screening protocol correctly classified the positive control site (TRA) as posing potential risks to biota and the negative control site (BCV) as not posing potential risks to biota, based on exposures to ionizing radiation. Future evaluations will use both ambient media and the available biota data to test the more realistic tiers (i.e., the Analysis Phase) of the Graded Approach. (author)

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

    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

    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...... 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....

  20. The New Zealand biota: Historical background and new research.

    Cooper, R A; Millener, P R

    1993-12-01

    New Zealand's origin as part of Gondwana, the composition of its ancestral biota, its geographic isolation for 80 million years, its tectonic history of changing shorelines and mountain building, and its changing climate, have all influenced the composition and distribution of its plant and animal communities, and thus its ecology and evolutionary biology. Recent DNA-sequencing studies combined with palaeogeographic analysis suggest that an Oligocene marine transgression had a major genetic bottle-neck effect on the biota and, together with recent advances in avian biogeography and paleontology, are leading to new hypotheses on the origin of many bird groups. PMID:21236222

  1. Radio biophysical studies on some fresh water biota

    The present study includes biophysical measurements of uptake and release of Co-60 by aquatic biota, water hyacinth plant (Eichhronia Crassipes ) and biomphalaria alexandrina snails placed in ismailia canal water. The uptake of co-60 was studied under different experimental conditions, namely the effect of contact time, variation of p H of the cobalt solution, the presence of competing ions and variation of cobalt carrier concentration. The experimental results of Co-60 uptake and release by the aquatic biota are described using the compartmental model, and also using the well known freudlich isotherm equation model

  2. Artificial radionuclides in aquatic biota of major european rivers

    Studies on the content of radionuclides in water, suspended particles, bed sediment and aquatic biota of different trophic levels relate to different periods and regions and suggest that our knowledge of the radiological situation in Europe's largest rivers varies considerably. Radioactive contamination of the Danube has been studied in greatest detail -a corollary of the intensive development of nuclear energy and of international interest in radioecological problems in this region. Here we present the results of studies of Sr-90 and Cs-137 - the ecologically most significant artificial radionuclides - in aquatic biota of different trophic levels in the Volga, Danube and Dnieper. The studies were carried out in 1988. (author)

  3. Invasive species and habitat degradation in Iberian streams: an analysis of their role in freshwater fish diversity loss

    Hermoso, Virgilio; Clavero, Miguel; Blanco-Garrido, F.; Prenda, J.

    2011-01-01

    Mediterranean endemic freshwater fish are among the most threatened biota in the world. Distinguishing the role of different extinction drivers and their potential interactions is crucial for achieving conservation goals. While some authors argue that invasive species are a main driver of native species declines, others see their proliferation as a co-occurring process to biodiversity loss driven by habitat degradation. It is difficult to discern between the two potential causes given that fe...

  4. Radiation protection of humans and biota in the environment

    An increase in the natural radiation background, development of nuclear power engineering, heavy radiation accidents with the release of radionuclides into the environment, need for the remediation of areas affected by previous anthropogenic activity (both military and peaceful) all made the problem of the environmental protection against radiation extremely urgent. The problems of radiation protection of biota can be solved in two ways -through the system of basic principles of the International Commission of Radiological Protection (ICRP) according to which if the radiation standards protect man, biota are also protected against ionizing radiation (Publication 60). The basis for justification of the thesis 'protected is man, protected are biota' is the fact that man is the most radiosensitive living organism. Besides, protection of human health is the highest priority. At the same time, in recent years increasing in popularity is the view point according to which the analysis of radiation protection of man, on the one hand, and biota, on the other hand, must be independent. It should be noted that there may be situations where man is not present or there are no food chains leading to man (eg, at sites of radwastes burial). For these situations independent standards on permissible exposure levels need to be developed. An essential aspect of radiation protection of biota is a nonequidosal irradiation of plants and animals, on the one hand, and man on the other hand in the same radiological situations, with biota receiving in most cases significantly higher absorbed doses. An anthropocentric approach to the environmental protection against ionizing radiation (protected is man, protected are biota), developed by ICRP, requires experimental evidence that biota are really protected (it is insufficient to state this only a priori). The main ICRP principles of radiation protection of man were analyzed. Special features of biota protection against ionizing radiation were described. According to the Declaration on Environment adopted at the conference in Rio de Janeiro in 1992, special attention should be paid to maintain biodiversity in nature and sustainable environmental conditions of growing anthropogenic burdens. At present, in a number of countries, standards on the permissible exposure of biota have been legislatively introduced. Arguments in favour of an independent analysis of radiation protection of the environment versus man were analyzed. A viewpoint was put forward that radiation protection of man and biota need to be based on a unified system of conceptual representations ensuring a simultaneous radiation safety of man and living organisms as connected components of ecosystems. This suggests a rational use of theoretically justificated and tested by the longtime practice basic ICRP approaches providing the radiation protection of humans. It is important that principles of the environmental protection from ionizing radiation should be compatible with principles of the environmental protection against other pollutants. (author)

  5. Fatty Acid composition and levels of selected polyunsaturated Fatty acids in four commercial important freshwater fish species from lake victoria, Tanzania.

    Robert, Agnes; Mfilinge, Prosper; Limbu, Samwel M; Mwita, Chacha J

    2014-01-01

    Fatty acids (FAs) particularly ?3 and ?6 polyunsaturated fatty acids (PUFAs) play important role in human health. This study aimed to investigate the composition and levels of selected ?3 PUFAs in four commercial fish species, Nile perch (Lates niloticus), Nile tilapia (Oreochromis niloticus), Tilapia zillii, and dagaa (Rastrineobola argentea) from Mwanza Gulf in Lake Victoria. The results indicated that 36 types of FAs with different saturation levels were detected. These FAs were dominated by docosahexaenoic (DHA), eicosapentaenoic (EPA), docosapentaenoic (DPA), and eicosatetraenoic acids. O. niloticus had the highest composition of FAs (34) compared to L. niloticus (27), T. zillii (26), and R. argentea (21). The levels of EPA differed significantly among the four commercial fish species (F = 6.19, ?P = 0.001). The highest EPA levels were found in R. argentea followed by L. niloticus and O. niloticus and the lowest in T. zillii. The DPA levels showed no significant difference among the four fish species studied (F = 0.652, ?P = 0.583). The study concluded that all four commercial species collected from Mwanza Gulf are good for human health, but R. argentea is the best for consumption because it contains higher levels of ?3 FAs, mainly EPA. PMID:25610654

  6. Freshwater pearl culture in India

    Janaki Ram, K.

    1997-01-01

    Freshwater pearl culture is growing as a source of employment and income in many Southeast Asian countries. Bangladesh, Thailand, the Philippines and Vietnam have initiated freshwater pearl culture projects in recent years. In India, the Central Institute of Freshwater Aquaculture is carrying out research on identification of suitable local pearl mussel species (Genera Lamellidens)defining appropriate surgical implantation procedures, developing post-operative care procedures and captive pond...

  7. The origin of island biota: Several things in one

    Grandcolas Philippe

    2015-01-01

    Full Text Available Islands can be continental or oceanic. The latter ones, well known as test tubes or natural laboratories, are only colonized by dispersal and their biota are new assemblages of species with subsequent and potentially interesting evolutionary events. Their study however requires considering sophisticated hypotheses of colonization, keeping geological knowledge independent and sampling widely the island regional context.

  8. Estimation of Biota Sediment Accumulation Factor (BSAF) from Paired Observations of Chemical Concentrations in Biota and Sediment (External Review Draft)

    This report was written in response to a March 2004 request from EPA's Ecological Risk Assessment Forum (ERAF) for information about estimating Biota-Sediment Accumulation Factors (BSAFs). BSAF is a parameter describing bioaccumulation of sediment-associated organic compounds or...

  9. Range size patterns in European freshwater trematodes

    Thieltges, David; Hof, Christian; Borregaard, Michael Krabbe; Dehling, Matthias; Brändle, Martin; Brandl, Roland; Poulin, Robert

    2011-01-01

    Aim We investigated the relationship between host and parasite diversity as well as latitudinal gradients in parasite diversity on a continental scale in European freshwater trematodes. Location European freshwaters. Methods We extracted distributional data for 564 freshwater trematodes across 25...

  10. Arctic freshwater synthesis: Introduction

    Prowse, T.; Bring, A.; Mârd, J.; Carmack, E.

    2015-11-01

    In response to a joint request from the World Climate Research Program's Climate and Cryosphere Project, the International Arctic Science Committee, and the Arctic Council's Arctic Monitoring and Assessment Program, an updated scientific assessment has been conducted of the Arctic Freshwater System (AFS), entitled the Arctic Freshwater Synthesis (AFSΣ). The major reason for joint request was an increasing concern that changes to the AFS have produced, and could produce even greater, changes to biogeophysical and socioeconomic systems of special importance to northern residents and also produce extra-Arctic climatic effects that will have global consequences. Hence, the key objective of the AFSΣ was to produce an updated, comprehensive, and integrated review of the structure and function of the entire AFS. The AFSΣ was organized around six key thematic areas: atmosphere, oceans, terrestrial hydrology, terrestrial ecology, resources and modeling, and the review of each coauthored by an international group of scientists and published as separate manuscripts in this special issue of Journal of Geophysical Research-Biogeosciences. This AFSΣ—Introduction reviews the motivations for, and foci of, previous studies of the AFS, discusses criteria used to define the domain of the AFS, and details key characteristics of the definition adopted for the AFSΣ.

  11. Determination of methylmercury in marine biota samples: method validation.

    Carrasco, Luis; Vassileva, Emilia

    2014-05-01

    Regulatory authorities are expected to measure concentration of contaminants in foodstuffs, but the simple determination of total amount cannot be sufficient for fully judging its impact on the human health. In particular, the methylation of metals generally increases their toxicity; therefore validated analytical methods producing reliable results for the assessment of methylated species are highly needed. Nowadays, there is no legal limit for methylmercury (MeHg) in food matrices. Hence, no standardized method for the determination of MeHg exists within the international jurisdiction. Contemplating the possibility of a future legislative limit, a method for low level determination of MeHg in marine biota matrixes, based on aqueous-phase ethylation followed by purge and trap and gas chromatography (GC) coupled to pyrolysis-atomic fluorescence spectrometry (Py-AFS) detection, has been developed and validated. Five different extraction procedures, namely acid and alkaline leaching assisted by microwave and conventional oven heating, as well as enzymatic digestion, were evaluated in terms of their efficiency to extract MeHg from Scallop soft tissue IAEA-452 Certified Reference Material. Alkaline extraction with 25% (w/w) KOH in methanol, microwave-assisted extraction (MAE) with 5M HCl and enzymatic digestion with protease XIV yielded the highest extraction recoveries. Standard addition or the introduction of a dilution step were successfully applied to overcome the matrix effects observed when microwave-assisted extraction using 25% (w/w) KOH in methanol or 25% (w/v) aqueous TMAH were used. ISO 17025 and Eurachem guidelines were followed to perform the validation of the methodology. Accordingly, blanks, selectivity, calibration curve, linearity (0.9995), working range (1-800pg), recovery (97%), precision, traceability, limit of detection (0.45pg), limit of quantification (0.85pg) and expanded uncertainty (15.86%, k=2) were assessed with Fish protein Dorm-3 Certified Reference Material. The major contributions to the expanded uncertainty, i.e. 86.1%, arose from the uncertainty associated with recovery, followed by the contribution from fluorescence signal. Additional validation of the methodology developed was effectuated by the comparison with the values reported for MeHg in the IAEA-452 inter-laboratory comparison exercise. PMID:24720970

  12. Soil Biota and Litter Decay in High Arctic Ecosystems

    Gonzlez, G.; Rivera, F.; Makarova, O.; Gould, W. A.

    2006-12-01

    Frost heave action contributes to the formation of non-sorted circles in the High Arctic. Non-sorted circles tend to heave more than the surrounding tundra due to deeper thaw and the formation of ice lenses. Thus, the geomorphology, soils and vegetation on the centers of the patterned-ground feature (non-sorted circles) as compared to the surrounding soils (inter-circles) can be different. We established a decomposition experiment to look at in situ decay rates of the most dominant graminoid species on non-sorted circles and adjacent inter-circle soils along a climatic gradient in the Canadian High Arctic as a component of a larger study looking at the biocomplexity of small-featured patterned ground ecosystems. Additionally, we investigated variation in soil chemical properties and biota, including soil microarthropods and microbial composition and biomass, as they relate to climate, topographic position, and litter decay rates. Our three sites locations, from coldest to warmest, are Isachsen, Ellef Ringnes Island (ER), NU (bioclimatic subzone A); Mould Bay (MB), Prince Patrick Island, NT (bioclimatic subzone B), and Green Cabin (GC), Aulavik National Park, Thomsen River, Banks Island, NT (bioclimatic subzone C). Our sample design included the selection of 15 non-sorted circles and adjacent inter-circle areas within the zonal vegetation at each site (a total of 90 sites), and a second set of 3 non-sorted circles and adjacent inter-circle areas in dry, mesic and wet tundra at each of the sites. Soil invertebrates were sampled at each site using both pitfall traps, soil microbial biomass was determined using substrate induced respiration and bacterial populations were determined using the most probable number method. Decomposition rates were measured using litterbags and as the percent of mass remaining of Carex misandra, Luzula nivalis and Alopecuris alpinus in GC, MB and ER, respectively. Our findings indicate these graminoid species decayed significantly over time at a rate of 10-15 % mass loss / yr during the first year of decay. Decay rates are different in non-sorted circles vs. inter-circle soils along the climatic gradient. In MB, L. nivalis seems to decay faster in the inter-circle soils than in non-sorted circles (0.05 microarthropod did not differ between positions at MB.

  13. Marine and freshwater toxins.

    Hungerford, James M

    2006-01-01

    In a very busy and exciting year, 2005 included First Action approval of a much needed official method for paralytic shellfish toxins and multiple international toxin symposia highlighted by groundbreaking research. These are the first-year milestones and activities of the Marine and Freshwater Toxins Task Force and Analytical Community. Inaugurated in 2004 and described in detail in last year's General Referee Report (1) this international toxins group has grown to 150 members from many regions and countries. Perhaps most important they are now making important and global contributions to food safety and to providing alternatives to animal-based assays. Official Method 2005.06 was first approved in late 2004 by the Task Force and subsequently Official First Action in 2005 (2) by the Methods Committee on Natural Toxins and Food Allergens and the Official Methods Board. This nonproprietary method (3) is a precolumn oxidation, liquid chromatographic method that makes good use of fluorescence detection to provide high sensitivity detection of the saxitoxins. It has also proven to be rugged enough for regulatory use and the highest level of validation. As pointed out in the report of method principle investigator and Study Director James Lawrence, approval of 2005.06 now provides the first official alternative to the mouse bioassay after many decades of shellfish monitoring. This past year in April 2005 the group also held their first international conference, "Marine and Freshwater Toxins Analysis: Ist Joint Symposium and AOAC Task Force Meeting," in Baiona, Spain. The 4-day conference consisted of research and stakeholder presentations and symposium-integrated subgroup sessions on ciguatoxins, saxitoxin assays and liquid chromatography (LC) methods for saxitoxins and domoic acids, okadaiates and azaspiracids, and yessotoxins. Many of these subgroups were recently formed in 2005 and are working towards their goals of producing officially validated analytical methods. (Abstracts from the Baiona 2005 meeting cited in this report can be found in the online version of the conference abstract book in the Files and Folders section of the Marine and Freshwater Toxins online community at www.aoac.org.) An active topic for discussion in Baiona and subsequent Task Force activities was the expert consultation for Codex which met in Oslo, Norway in 2004 (previously described and cited in last year's GR report, ref 1). The consultation group's executive summary report (http://www.fao.org/es/ESN/food/risk_biotoxin en.stm) describes suggested changes in action levels as well as methods, method validation, and other issues. September 2005 saw the AOAC Task Force efforts further supported by another symposium, "Marine and Freshwater Toxins: Quality Methods for Food Safety and International Trade," at the AOAC INTERNATIONAL Annual Conference in Orlando, Florida. The multidisciplinary talks at this full day symposium ranged from ciguatoxins to cyanobacterial toxins, and spanned toxicology, biochemistry, molecular biology and analytical chemistry. Again, the symposium preceded Task Force meetings. Toxin subgroups, including a new group on cyanobacterial toxins, met for engaging and productive subgroup discussions. All of these activities were preceded by a Wiley Award symposium for Task Force member Mike Quilliam of NRC Canada. These talks, presented at a half-day symposium on the first day of the Annual Meeting, focused on Quilliam's work with LC tandem mass spectrometry (LC/MS/MS) and certified reference standards and materials, and included related presentations by some of his many research collaborators. To maintain flow and continuity between symposia and between Task Force meetings, the group now uses new electronic discussion forums. Individual subgroup areas, under the Marine and Freshwater Toxins Task Force, comprise this online community. First introduced by AOAC INTERNATIONAL in early 2005, these new resources are being used to distribute information and to supplement the in-person subgroup meetings and electronic mail in the group's validation efforts. PMID:16512256

  14. Benthic macro-biota in Gaula River - Kumaon Himalaya

    Mohan, M.

    2005-01-01

    The density of benthic macro-biota in number over weight of biomass at three sampling stations was 29 units m²/0.614 g m² to 171 units m²/11.346 m² at Station I; 22 units m²/0.410 g m² to 155 units m²/8.717 m² at Station II; 15 units m² 10.321 g m² to 122 units m²/6.793 g m² at Station III. The Caddis fly larvae were the most dominant component and contributed 52.41% in the macro-biota. These animals were abundant in Gaula River when benthic algae were abundant; water is well oxygenated, alka...

  15. Enhanced activities of organically bound tritium in biota samples

    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

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

    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

  17. Burgess shale-type biotas were not entirely burrowed away

    Gaines, Robert R.; Droser, Mary L.; Orr, Patrick J.; Garson, Daniel; Hammarlund, Emma; Qi, Changshi; Canfield, Donald Eugene

    2012-01-01

    Burgess Shale-type biotas occur globally in the Cambrian record and offer unparalleled insight into the Cambrian explosion, the initial Phanerozoic radiation of the Metazoa. Deposits bearing exceptionally preserved soft-bodied fossils are unusually common in Cambrian strata; more than 40 are now......, however, suggest a more complex scenario. Ichnologic and microstratigraphic data from Burgess Shale-type deposits indicate that (1) bioturbation exerts a limiting effect on soft-bodied preservation; (2) the observed increase in the depth and extent or bioturbation following the Middle Cambrian would have...... restricted preservation of Burgess Shale type biotas in a number of settings; but (3) increasing depth and extent of bioturbation would not have affected preservation in many other settings, including the most richly fossiliferous portions of the Chengjiang (China) deposit and the Greater Phyllopod Bed of...

  18. Relationship between water solubility of chlorobenzenes and their effects on a freshwater green alga

    Wong, P.T.S.; Chau, Y.K.; Rhamey, J.S.; Docker, M.

    1984-01-01

    The effective concentrations of benzene and 12 chlorobenzenes that reduced 50% of the primary productivity (EC/sub 50/) of a freshwater green alga, Ankistrodesmus falcatus, were determined. Benzene was the least toxic chemical and the toxicity increased as the degree of chlorine substitution in the aromatic ring increased. No EC/sub 50/ value could be obtained for HCB. A quantitative relationship was found to exist between water solubility, lipophilicity and the EC/sub 50/. A good correlation was also observed between the EC/sub 50/ for this alga and other toxicity data for various aquatic biota.

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

    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)

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

    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)

  1. The Human Vaginal Bacterial Biota and Bacterial Vaginosis

    Sujatha Srinivasan; David N. Fredricks

    2008-01-01

    The bacterial biota of the human vagina can have a profound impact on the health of women and their neonates. Changes in the vaginal microbiota have been associated with several adverse health outcomes including premature birth, pelvic inflammatory disease, and acquisition of HIV infection. Cultivation-independent molecular methods have provided new insights regarding bacterial diversity in this important niche, particularly in women with the common condition bacterial vaginosis (BV). PCR met...

  2. Determination of volatile organic compounds in marine biota

    Roose, P.; Brinkman, U.A.Th.

    1998-01-01

    A method was developed that allows the simultaneous determination of the volatile organochlorines (VOCs) chloroform, tetrachloromethane, 1,1-dichloroethane, 1,2-dichloroethane, 1,1,1-trichloroethane, trichloroethene and tetrachloroethene and the volatile aromatics benzene, toluene, ethylbenzene and the xylenes (BTEX) in marine biota. The biological tissue is first homogenised (at 0°C) using an ultra-turrax blender and transferred to a 25-ml EPA vial. After addition of 15 ml of water and inter...

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

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

    nature and of general interest for inferring pollution tolerance or otherwise by the biota. Although it is difficult to include all possible chemicals and variables for moni toring assimilation efficiencies, the controlled experimentation of this study... concentrations during the pre-monsoon was faster than the other two seasons. This might be taken to indicate their potential to 245 I NRamaiah, Azra Ansari, Anita Sadhasivan, Sushant Naik, and KSawkar efficiently utilize the added nutrient supplies once...

  4. Declines of biomes and biotas and the future of evolution

    Woodruff, David S

    2001-01-01

    Although panel discussants disagreed whether the biodiversity crisis constitutes a mass extinction event, all agreed that current extinction rates are 50500 times background and are increasing and that the consequences for the future evolution of life are serious. In response to the on-going rapid decline of biomes and homogenization of biotas, the panelists predicted changes in species geographic ranges, genetic risks of extinction, genetic assimilation, natural sele...

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

    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)

  6. THE EDIACARA BIOTA: Neoproterozoic Origin of Animals and Their Ecosystems

    Narbonne, Guy M.

    2005-01-01

    The Ediacara biota (575-542 Ma) marks the first appearance of large, architecturally complex organisms in Earth history. Present evidence suggests that the Ediacara biota included a mixture of stem- and crown-group radial animals, stem-group bilaterian animals, "failed experiments" in animal evolution, and perhaps representatives of other eukaryotic kingdoms. These soft-bodied organisms were preserved under (or rarely within) event beds of sand or volcanic ash, and four distinct preservational styles (Flinders-, Fermeuse-, Conception-, and Nama-style) profoundly affected the types of organisms and features that could be preserved. Even the earliest Ediacaran communities (575-565 Ma) show vertical and lateral niche subdivision of the sessile, benthic, filter-feeding organisms, which is strikingly like that of Phanerozoic and modern communities. Later biological and ecological innovations include mobility (>555 Ma), calcification (550 Ma), and predation (biota abruptly disappeared 542 million years ago, probably as a consequence of mass extinction andor biological interactions with the rapidly evolving animals of the Cambrian explosio

  7. Soil biota reduce allelopathic effects of the invasive Eupatorium adenophorum.

    Zhu, Xunzhi; Zhang, Jintun; Ma, Keping

    2011-01-01

    Allelopathy has been hypothesized to play a role in exotic plant invasions, and study of this process can improve our understanding of how direct and indirect plant interactions influence plant community organization and ecosystem functioning. However, allelopathic effects can be highly conditional. For example allelopathic effects demonstrated in vivo can be difficult to demonstrate in field soils. Here we tested phytotoxicity of Eupatorium adenophorum (croftonweed), one of the most destructive exotic species in China, to a native plant species Brassica rapa both in sand and in native soil. Our results suggested that natural soils from different invaded habitats alleviated or eliminated the efficacy of potential allelochemicals relative to sand cultures. When that soil is sterilized, the allelopathic effects returned; suggesting that soil biota were responsible for the reduced phytotoxicity in natural soils. Neither of the two allelopathic compounds (9-Oxo-10,11-dehydroageraphorone and 9b-Hydroxyageraphorone) of E. adenophorum could be found in natural soils infested by the invader, and when those compounds were added to the soils as leachates, they showed substantial degradation after 24 hours in natural soils but not in sand. Our findings emphasize that soil biota can reduce the allelopathic effects of invaders on other plants, and therefore can reduce community invasibility. These results also suggest that soil biota may have stronger or weaker effects on allelopathic interactions depending on how allelochemicals are delivered. PMID:21980442

  8. Pesticide toxicity index for freshwater aquatic organisms, 2nd edition

    Munn, Mark D.; Gilliom, Robert J.; Moran, Patrick W.; Nowell, Lisa H.

    2006-01-01

    The U.S. Geological Survey's National Water-Quality Assessment (NAWQA) Program is designed to assess current water-quality conditions, changes in water quality over time, and the effects of natural and human factors on water quality for the Nation's streams and ground-water resources. For streams, one of the most difficult parts of the assessment is to link chemical conditions to effects on aquatic biota, particularly for pesticides, which tend to occur in streams as complex mixtures with strong seasonal patterns. A Pesticide Toxicity Index (PTI) was developed that combines pesticide exposure of aquatic biota (measured concentrations of pesticides in stream water) with acute toxicity estimates (standard endpoints from laboratory bioassays) to produce a single index value for a sample or site. The development of the PTI was limited to pesticide compounds routinely measured in NAWQA studies and to toxicity data readily available from existing databases. Qualifying toxicity data were found for one or more types of test organisms for 124 of the 185 pesticide compounds measured in NAWQA samples, but with a wide range of available bioassays per compound (1 to 232). In the databases examined, there were a total of 3,669 bioassays for the 124 compounds, including 398 48-hour EC50 values (concentration at which 50 percent of test organisms exhibit a sublethal response) for freshwater cladocerans, 699 96-hour LC50 values (concentration lethal to 50 percent of test organisms) for freshwater benthic invertebrates, and 2,572 96-hour LC50 values for freshwater fish. The PTI for a particular sample is the sum of toxicity quotients (measured concentration divided by the median toxicity concentration from bioassays) for each detected pesticide, and thus, is based on the concentration addition model of pesticide toxicity. The PTI can be calculated for specific groups of pesticides and for specific taxonomic groups. Although the PTI does not determine whether water in a sample is toxic to aquatic organisms, its values can be used to rank or compare the toxicity of samples or sites on a relative basis for use in further analysis or additional assessments. The PTI approach may be useful as a basis for comparing the potential significance of pesticides in different streams on a common basis, for evaluating relations between pesticide exposure and observed biological conditions, and for prioritizing where further studies are most needed.

  9. Toxicity of uranium and copper individually, and in combination, to a tropical freshwater macrophyte (Lemna aequinoctialis).

    Charles, Amanda L; Markich, Scott J; Ralph, Peter

    2006-03-01

    Copper (Cu) and uranium (U) are of potential ecotoxicological concern to tropical freshwater biota in northern Australia, as a result of mining activities. Few data are available on the toxicity of U, and no data are available on the toxic interaction of Cu and U, to freshwater biota. This study determined the toxicity of Cu and U individually, and in combination, to a tropical freshwater macrophyte, Lemna aequinoctialis (duckweed), in a synthetic soft water (27 degrees C; pH, 6.5; hardness, 40 mg CaCO3 l-1, alkalinity, 16 mg CaCO3 l-1), typical of many fresh surface waters in coastal northern Australia. The growth rate of L. aequinoctialis decreased with increasing Cu or U concentrations, with the concentration of Cu inhibiting growth by 50% (EC50) being 16+/-1.0 microg l-1, with a minimum detectable effect concentration (MDEC) of 3.2 microg l-1. The concentration of U inhibiting growth by 50% (EC50) was 758+/-35 microg l-1 with a MDEC of 112 microg l-1. The EC50 value for the exposure of L. aequinoctialis to equitoxic mixtures of Cu and U was significantly (P0.05) higher than one toxic unit (1.35; 95% confidence interval, 1.18-1.52), indicating that the combined effects of Cu and U are less than additive (antagonistic). Therefore, inhibition of the growth rate of L. aequinoctialis was reduced when Cu and U were present in equitoxic mixtures, relative to individual metal exposures. Since non-additive (e.g. antagonistic) interactions of metal mixtures cannot be predicted using current mixture models, these results have important potential implications for the protection of freshwater ecosystems through the derivation of national water quality guidelines. PMID:15982709

  10. Consideration of biota dose assessment methodology in preparation of environmental impact statements

    The U.S. Nuclear Regulatory Commission (NRC) has been working with the U.S. Department of Energy (DOE) and U.S. Environmental Protection Agency on developing methods, models, and guidance within a graded approach for evaluating radiation doses to biota. This effort has been headed by DOE and is predominately a screening tool to demonstrate compliance with dose to biota standards at existing DOE facilities. The graded approach does, however, have the capability of incorporating site specific pathway and biota data to estimate doses to biota. Two questions under consideration by the NRC are: is a biota dose assessment methodology needed in the existing National Environmental Policy Act (NEPA) framework and how should a biota dose assessment methodology be incorporated into the preparation of an Environmental Impact Statement (EIS). The paper discusses the protection of biota in context of the existing framework of NEPA and the Endangered Species Act, and how protection of biota is typically addressed in EISs prepared by the NRC. The paper also discusses whether the proposed biota dose methodology needs to be considered in preparation of NEPA documents, given the protection afforded under these Acts. The paper also identifies circumstances where an NRC NEPA document would use the dose methodology for impact assessment to biota. (author)

  11. Fast Evolution from Precast Bricks: Genomics of Young Freshwater Populations of Threespine Stickleback Gasterosteus aculeatus

    Terekhanova, Nadezhda V.; Logacheva, Maria D.; Penin, Aleksey A.; Neretina, Tatiana V.; Barmintseva, Anna E.; Bazykin, Georgii A.; Kondrashov, Alexey S.; Mugue, Nikolai S.

    2014-01-01

    Adaptation is driven by natural selection; however, many adaptations are caused by weak selection acting over large timescales, complicating its study. Therefore, it is rarely possible to study selection comprehensively in natural environments. The threespine stickleback (Gasterosteus aculeatus) is a well-studied model organism with a short generation time, small genome size, and many genetic and genomic tools available. Within this originally marine species, populations have recurrently adapted to freshwater all over its range. This evolution involved extensive parallelism: pre-existing alleles that adapt sticklebacks to freshwater habitats, but are also present at low frequencies in marine populations, have been recruited repeatedly. While a number of genomic regions responsible for this adaptation have been identified, the details of selection remain poorly understood. Using whole-genome resequencing, we compare pooled genomic samples from marine and freshwater populations of the White Sea basin, and identify 19 short genomic regions that are highly divergent between them, including three known inversions. 17 of these regions overlap protein-coding genes, including a number of genes with predicted functions that are relevant for adaptation to the freshwater environment. We then analyze four additional independently derived young freshwater populations of known ages, two natural and two artificially established, and use the observed shifts of allelic frequencies to estimate the strength of positive selection. Adaptation turns out to be quite rapid, indicating strong selection acting simultaneously at multiple regions of the genome, with selection coefficients of up to 0.27. High divergence between marine and freshwater genotypes, lack of reduction in polymorphism in regions responsible for adaptation, and high frequencies of freshwater alleles observed even in young freshwater populations are all consistent with rapid assembly of G. aculeatus freshwater genotypes from pre-existing genomic regions of adaptive variation, with strong selection that favors this assembly acting simultaneously at multiple loci. PMID:25299485

  12. Polychlorinated Alkanes in Fish from Norwegian Freshwater

    Borgen, Anders R.; Martin Schlabach; Roland Kallenborn; Eirik Fjeld

    2002-01-01

    Short-chain polychlorinated alkanes (sPCAs) have been measured in freshwater fish samples from different lakes all over Norway and from the Norwegian Arctic. The analyses were performed with high-resolution GC coupled to high-resolution MS in electron capture negative ion mode. The species investigated were trout, Arctic char, and burbot (Lota lota). Muscle tissue in the lake trout and Arctic char, and liver in burbot, were selected for analyses because of their high lipid content. ?sPCA conc...

  13. Comparative radiation impact on biota and man in the area affected by the accident at the Chernobyl nuclear power plant

    Fesenko, S.V. [Russian Institute of Agricultural Radiology and Agroecology, Kievskoe shosse, Kaluga region, Obninsk 249020 (Russian Federation) and International Atomic Energy Agency, Agency' s Laboratories, Seibersdorf A-2444 (Austria)]. E-mail: s.fesenko@iaea.org; Alexakhin, R.M. [Russian Institute of Agricultural Radiology and Agroecology, Kievskoe shosse, Kaluga region, Obninsk 249020 (Russian Federation); Geras' kin, S.A. [Russian Institute of Agricultural Radiology and Agroecology, Kievskoe shosse, Kaluga region, Obninsk 249020 (Russian Federation); Sanzharova, N.I. [Russian Institute of Agricultural Radiology and Agroecology, Kievskoe shosse, Kaluga region, Obninsk 249020 (Russian Federation); Spirin, Ye.V. [Russian Institute of Agricultural Radiology and Agroecology, Kievskoe shosse, Kaluga region, Obninsk 249020 (Russian Federation); Spiridonov, S.I. [Russian Institute of Agricultural Radiology and Agroecology, Kievskoe shosse, Kaluga region, Obninsk 249020 (Russian Federation); Gontarenko, I.A. [Russian Institute of Agricultural Radiology and Agroecology, Kievskoe shosse, Kaluga region, Obninsk 249020 (Russian Federation); Strand, P. [Norwegian Radiation Protection Authority, Oesteras (Norway)

    2005-07-01

    A methodological approach for a comparative assessment of ionising radiation effects on man and non-human species, based on the use of Radiation Impact Factor (RIF) - ratios of actual exposure doses to biota species and man to critical dose is described. As such doses, radiation safety standards limiting radiation exposure of man and doses at which radiobiological effects in non-human species were not observed after the Chernobyl accident, were employed. For the study area within the 30 km ChNPP zone dose burdens to 10 reference biota groups and the population (with and without evacuation) and the corresponding RIFs were calculated. It has been found that in 1986 (early period after the accident) the emergency radiation standards for man do not guarantee adequate protection of the environment, some species of which could be affected more than man. In 1991 RIFs for man were considerably (by factor of 20.0-1.1 x 10{sup 5}) higher compared with those for selected non-human species. Thus, for the long term after the accident radiation safety standards for man are shown to ensure radiation safety for biota as well.

  14. Comparative radiation impact on biota and man in the area affected by the accident at the Chernobyl nuclear power plant

    A methodological approach for a comparative assessment of ionising radiation effects on man and non-human species, based on the use of Radiation Impact Factor (RIF) - ratios of actual exposure doses to biota species and man to critical dose is described. As such doses, radiation safety standards limiting radiation exposure of man and doses at which radiobiological effects in non-human species were not observed after the Chernobyl accident, were employed. For the study area within the 30 km ChNPP zone dose burdens to 10 reference biota groups and the population (with and without evacuation) and the corresponding RIFs were calculated. It has been found that in 1986 (early period after the accident) the emergency radiation standards for man do not guarantee adequate protection of the environment, some species of which could be affected more than man. In 1991 RIFs for man were considerably (by factor of 20.0-1.1 x 105) higher compared with those for selected non-human species. Thus, for the long term after the accident radiation safety standards for man are shown to ensure radiation safety for biota as well

  15. Speciation of pyrithione in freshwaters

    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...

  16. Phylogenetic diversity of freshwater picocyanobacteria

    Callieri, Cristiana; Coci, Manuela

    2012-01-01

    Picocyanobacteria are photosynthetic prokaryotes, coccoid or rod-shaped, with a cell diameter < 2 ?m. They are common in lakes and oceans, and abundant across a wide spectrum of trophic conditions (Callieri et al 2012). The dominant genus of freshwater picocyanobacteria is Synechococcus. Analysis of 16S rRNA gene of freshwater Synechococcus showed its polyphyletic origin, requiring better insights in the present classification of the genus and possibly a revision. We isolated more than 40 pic...

  17. [Lactobacilli of freshwater fishes].

    Kvasnikov, E I; Kovalenko, N K; Materinskaia, L G

    1977-01-01

    Normal microflora in the intestinal tract of fishes inhabiting fresh-water reservoirs includes lactic bacteria. The number of the bacteria depends on the animal species, the composition of food, the age, and the season. The highest number of these microorganisms (hundreds of millions per gram of the intestinal content) is found in carps. Enterococci are most often encountered in fishes inhabiting ponds: Streptococcus faecalis Andrewes a. Horder, Str. faecium Orla-Jensen, Str. bovis Orla-Jensen. Lactobacilli are more typical of fishes in water reserviors: Lactobacillus plantarum (Orla-Jensen) Bergey et al., L. casei (Orla-Jensen) Hansen a. Lessel, L. casei var. casei, L. casei var. rhamnosus, L. Casei var. alactosus, L. leichmannii (Henneberg) Bergey et al., L. acidophillus (Moro) Hansen a. Mocquot, L. Fermenti Beijerinck, L. cellobiosus Rogosa et al., L. Buchneri (Henneberg) Bergey et al. The content of lactic bacteria varies in water reservoirs; their highest content is found in ooze (tens of thousands per gram). PMID:909475

  18. Anthropogenic radionuclides in biota samples from the Caspian Sea

    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

  19. Local Adaptation of Aboveground Herbivores towards Plant Phenotypes Induced by Soil Biota

    Bonte, Dries; De Roissart, Annelies; Vandegehuchte, Martijn; Ballhorn, Daniel J; Van Leeuwen, Thomas; de la Pena, Eduardo

    2010-01-01

    Background: Soil biota may trigger strong physiological responses in plants and consequently induce distinct phenotypes. Plant phenotype, in turn, has a strong impact on herbivore performance. Here, we tested the hypothesis that aboveground herbivores are able to adapt to plant phenotypes induced by soil biota. Methodology and Principal Findings: We bred spider mites for 15 generations on snap beans with three different belowground biotic interactions: (i) no biota (to serve as control), (...

  20. Exploitation of soil biota ecosystem services in agriculture: a bioeconomic approach

    Foudi, Sébastien

    2012-01-01

    This paper analyzes the interactions between soil biota and agricultural practices in the exploitation of soil ecosystem services. A theoretical bioeconomic model stylized this set of interactions and combined a production function approach with optimal control theory. In the model, a farmer decides his optimal use of external input and land use given that (i) land uses modify soil biota composition, (ii) the external input reduces soil biota population. The results show how the combination o...

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

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

    Johansen, M.P.; Barnett, C. L.; Beresford, N.A.; Brown, J E; Černe, M.; Howard, B. J.; Kamboj, S.; Keum, D-K.; Smodiš, B.; Twining, J.R.; Vandenhove, H.; Vives i Batlle, J.; Wood, M D; C. Yu

    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...

  3. Biotic replacement and mass extinction of the Ediacara biota.

    Darroch, Simon A F; Sperling, Erik A; Boag, Thomas H; Racicot, Rachel A; Mason, Sara J; Morgan, Alex S; Tweedt, Sarah; Myrow, Paul; Johnston, David T; Erwin, Douglas H; Laflamme, Marc

    2015-09-01

    The latest Neoproterozoic extinction of the Ediacara biota has been variously attributed to catastrophic removal by perturbations to global geochemical cycles, 'biotic replacement' by Cambrian-type ecosystem engineers, and a taphonomic artefact. We perform the first critical test of the 'biotic replacement' hypothesis using combined palaeoecological and geochemical data collected from the youngest Ediacaran strata in southern Namibia. We find that, even after accounting for a variety of potential sampling and taphonomic biases, the Ediacaran assemblage preserved at Farm Swartpunt has significantly lower genus richness than older assemblages. Geochemical and sedimentological analyses confirm an oxygenated and non-restricted palaeoenvironment for fossil-bearing sediments, thus suggesting that oxygen stress and/or hypersalinity are unlikely to be responsible for the low diversity of communities preserved at Swartpunt. These combined analyses suggest depauperate communities characterized the latest Ediacaran and provide the first quantitative support for the biotic replacement model for the end of the Ediacara biota. Although more sites (especially those recording different palaeoenvironments) are undoubtedly needed, this study provides the first quantitative palaeoecological evidence to suggest that evolutionary innovation, ecosystem engineering and biological interactions may have ultimately caused the first mass extinction of complex life. PMID:26336166

  4. CONSOLIDATION OF BASELINE INFORMATION, DEVELOPMENT OF METHODOLOGY, AND INVESTIGATION OF THERMAL IMPACTS ON FRESHWATER SHELLFISH, INSECTS, AND OTHER BIOTA

    A computerized information system was developed for storing, retrieving, and analyzing data collected during limnological surveys. To facilitate storage of information, a series of hierarchial codes was developed. These codes not only reduced storage requirements, but also helped...

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

    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...

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

    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...

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

    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.

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

    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. Contaminants in fine sediments and their consequences for biota of the Severn Estuary.

    Langston, W J; Pope, N D; Jonas, P J C; Nikitic, C; Field, M D R; Dowell, B; Shillabeer, N; Swarbrick, R H; Brown, A R

    2010-01-01

    When the first MPB special issue was published 25 years ago it was suggested that high body burdens of metals and selected organic pollutants in the Severn Estuary were the result of anthropogenic loadings from a variety of sources. The objective of this synopsis is to illustrate recent trends for contaminants (metals, PAHs, PCBs) in sediments and benthic biota and to consider the evidence for improved environmental quality over the last quarter of a century. Contaminants in sediments and sediment-dwelling fauna such as Hediste(=Nereis)diversicolor are, generally, evenly distributed over the estuary - which is the consequence of extensive re-suspension and redistribution of fine sediment by strong tidal currents. Such dispersal tends to mask the influences of individual discharges and physical characteristics are considered to be the major drivers affecting biodiversity in the Severn Estuary, often overshadowing contaminant concerns. Following the closure of major industries and the introduction of stricter pollution control, many inputs have ceased or been reduced and there are indications that environmental concentrations are now lower. Bioaccumulation of most contaminants has declined accordingly (with the possible exception of Cr). Intuitively, better environmental quality should be linked to ecological improvements. However, due to the dynamic nature of the system (and a lack of biological-effects data) it is difficult to establish direct relationships between inputs, body burdens and biological/ecological consequence. Uniquely, the long-term integrated monitoring program of AstraZeneca (Avonmouth) indicates that recovery of faunal diversity and abundance has occurred in mid-sections of the estuary in recent years implying that contaminants have indeed been a forcing feature for Severn biota. In this context, we highlight contaminant issues and biogeochemical changes which may need to be addressed in connection with the development of proposals for tidal energy schemes. PMID:20106492

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

    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)

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

    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

  12. Native Freshwater Fish and Mussel Species Richness

    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. Experimental study of subarctic magnetosphere conditions as possible exogenous factor for northern biota

    The possible role f some magnetosphere processes effects on northern biota was investigated under laboratory conditions. The some specific for Kola subarctic area magnetosphere pulsation time series were responses in cereal plants which appear as change of growth time course were found. The results of the study shown the one possible way of solar-terrestrial effects on northern biota. 7 refs

  14. THE IMPORTANCE OF THE BIODIVERSITY OF SOIL BIOTA IN ARID ECOSYSTEMS

    The importance of soil biota in maintaining ecosystem integrity is examined by a review of studies of soil processes and soil biota in arid ecosystems. In decomposition and mineralization processes, there is a temporal succession of microarthropod and nematode species. Tydeid mit...

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

    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

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

    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

  17. 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

    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.)

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

    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 Duncans 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.

  19. Nearctic freshwater tardigrades: a review

    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.

  20. Evaluating Alternative Strategies for Investments in Freshwater Conservation

    Cheruvelil, K. S.; Kramer, D. B.; Zhang, T.; Ligmann-Zielinska, A.; Soranno, P.; Bremigan, M. T.

    2012-12-01

    Efforts towards systematic conservation planning for freshwaters have progressed far less than similar efforts in the terrestrial and marine environments. Although there are differences in the coupled human and natural systems that distinguish freshwater, terrestrial, and marine environments, many of the tools that have been used in terrestrial and marine systems can also be used for conservation planning for freshwater resources. In this paper, we used one such tool, return on investment (ROI), to identify optimal conservation portfolios. Our overarching research question is: how do different strategies for evaluating ROI benefits influence the resulting portfolio and the outcome of interest - in our case, water quality? Specifically, we examined investments to convert farmed agricultural land to fallow land to improve water quality in 55 inland lakes in southwestern Michigan. We simulated investments and compared the ROIs for the following strategies: 1) economic; 2) ecological; 3) environmental policy and 4) agricultural policy. We also tested the well-established assumption that riparian lands, those abutting and within 30 m of freshwater shorelines, have the greatest potential to influence water quality. We found that 1) investments in freshwater resources through the conservation of riparian land are more effective than the conservation of randomly selected parcels of similar land area in the catchment; 2) the costs and benefits of riparian land conservation vary considerably among lakes; 3) the choice of investment strategies results in very different conservation portfolios; 4) the resulting conservation portfolios have very different distributional and policy implications. These analyses and results provide a foundation on which to improve systematic conservation planning for freshwaters.

  1. RGIMEN DE CAUDAL ECOLGICO, HERRAMIENTA DE GESTIN PARA CONSERVAR LA BIOTA ACUTICA / ECOLOGICAL FLOW REGIMEN, MANAGEMENT TOOLTO PRESERVE ACUATIC BIOTA

    Mnica Luca, Izquierdo Santacruz; Sandra Milena, Madroero Palacios.

    2013-06-01

    Full Text Available RESUMEN En el presente artculo de revisin se consolid informacin sobre el Rgimen de Caudal Ecolgico, al constituirse en una herramienta de gestin en la conservacin de la Biota Acutica. De esta manera, se considera relevante informar a la comunidad acadmica y actores de gestin, sobre la im [...] portancia de la gestin del recurso hdrico, el anlisis de conceptos sobre el caudal ambiental y ecolgico, la descripcin de las diferentes metodologas que permiten su determinacin y la normatividad ambiental que lo protege. Finalmente, se hace especial nfasis, en la metodologa ecohidrulica en la que se aplica el modelo IFIM-PHABSIM, considerada la modelacin del hbitat fluvial, que precisa de informacin sobre la relacin entre la densidad de organismos acuticos y variables hidrulicas de velocidad, profundidad y sustrato; obteniendo como resultado curvas de idoneidad de hbitat e ndices de idoneidad, que permitirn entender el funcionamiento de los ecosistemas acuticos, utilizando dicha informacin en el manejo y planificacin del recurso hdrico. 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.

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

    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 (δ13C) and nitrogen (δ15N). 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 δ13C and δ15N 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, δ13C, and δ15N.

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

    Abdul Aziz; Ashit Ranjan Paul

    2015-01-01

    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 Farakk...

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

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

    Bhattacharyya, S.; Klerks, P.L.; Nyman, J.A

    2003-04-01

    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.

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

    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

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

    Emery, R.; Klopfer, D.C.; Skalski, J.R.

    1981-07-01

    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.

  8. A New Fluorinated Surfactant Contaminant in Biota: Perfluorobutane Sulfonamide in Several Fish Species.

    Chu, Shaogang; Letcher, Robert J; McGoldrick, Daryl J; Backus, Sean M

    2016-01-19

    Environmental contamination and regulation of longer-chain perfluoroalkyl substances (PFASs) such as perfluorooctanesulfonate (PFOS) has given rise to the increased use of shorter-chain PFASs as alternatives in new products, although confirmation of their presence in the environment remains limited. In this study, the PFAS alternative, perfluoro-1-butane-sulfonamide (FBSA), was identified for the first time in biota in homogenate samples of fish by liquid chromatography-quadrupole time-of-flight mass spectrometry (LC-Q-ToF-MS) and quantified by ultra high performance liquid chromatography-triple quadrupole mass spectrometry (UHPLC-QQQ-MS/MS). In one flounder (Platichthys flesus) muscle sample from the Western Scheldt, The Netherlands, FBSA concentration was at 80.12 ng/g wet weight (w.w.) and was exceeded only by PFOS. FBSA was also detected in 32 out of 33 samples of freshwater fish collected (2009-2010) from water bodies across Canada. In lake trout (Salvelinus namaycush) from northern Canada (e.g., Lake Kusawa (Yukon Territory), Great Bear Lake (Northwest Territories and in the Arctic), and Lake Athabasca (northern Alberta)), the concentrations of FBSA ranged from below method detection limit (<0.01 ng/g w.w) to 0.44 ng/g w.w. and were much lower than those reported for lake trout from the more urbanized and industrialized Laurentian Great Lakes sites (3.17 1.53 ng/g w.w.). In three species of fish purchased from a supermarket in Ottawa (ON, Canada), FBSA concentrations were the lowest of all fish and ranged from < MLOD to 0.29 ng/g w.w. and 0.03 to 0.76 ng/g w.w. in muscle and liver, respectively. FBSA is a bioaccumulative contaminant in fish in Canada and possibly in The Netherlands. It is likely sourced from new alternative perfluorobutane-based products, as well as other shorter chain perfluoroalkyl-based products. PMID:26649981

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

    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

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

    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.

  11. Cable Bacteria in Freshwater Sediments

    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 freshwater stream Giber Å, Denmark, was incubated in the laboratory. After 2 weeks, pH signatures and...... 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...

  12. Cable Bacteria in Freshwater Sediments

    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 freshwater stream Giber , Denmark, was incubated in the laboratory. After 2 weeks, pH signatures and...... 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...

  13. Determination of 210Po in sediment and benthic biota across Thane creek, Mumbai, India

    The study of sediment and benthic biota in coastal areas has great importance for understanding the interaction between human activities and marine systems. The 210Po activity has been commonly used as environmental tracer in many environmental studies. 210Po was determined in sediment and benthic biota samples collected from different locations across Thane Creek area, Mumbai, India. The activity of 210Po in grab sediment samples collected from different locations was found to be in the range of 18.24 to 30.52 Bq/Kg whereas, 210Po activity concentration varied between 3.89 and 41.45 Bq/Kg of biota muscles. (author)

  14. Are there signs of acidification reversal in freshwaters of the low mountain ranges in Germany?

    Alewell, C.; M. Armbruster; J. Bittersohl; Evans, C. D.; Meesenburg, H.; Moritz, K; Prechtel, A.

    2001-01-01

    The reversal of freshwater acidification in the low mountain ranges of Germany is of public, political and scientific concern, because these regions are near natural ecosystems and function as an important drinking water supply. The aim of this study was to evaluate the status and trends of acidification reversal after two decades of reduced anthropogenic deposition in selected freshwaters of the low mountain ranges in the Harz, the Fichtelgebirge, the Bavarian Forest, the Spessart and the Bl...

  15. Are there signs of acidification reversal in freshwaters of the low mountain ranges in Germany?

    Alewell, C.; M. Armbruster; J. Bittersohl; Evans, C. D.; Meesenburg, H.; Moritz, K; Prechtel, A.

    2002-01-01

    The reversal of freshwater acidification in the low mountain ranges of Germany is of public, political and scientific concern, because these regions are near natural ecosystems and function as an important drinking water supply. The aim of this study was to evaluate the status and trends of acidification reversal after two decades of reduced anthropogenic deposition in selected freshwaters of the low mountain ranges in the Harz, the Fichtelgebirge, the Bavarian Forest, th...

  16. Footprints of climate change on Mediterranean Sea biota

    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.

  17. Organophosphorous flame retardants in biota from Svalbard, Norway.

    Hallanger, Ingeborg G; Sagerup, Kjetil; Evenset, Anita; Kovacs, Kit M; Leonards, Pim; Fuglei, Eva; Routti, Heli; Aars, Jon; Strøm, Hallvard; Lydersen, Christian; Gabrielsen, Geir Wing

    2015-12-15

    Eight arctic species, including fish, birds and mammals, from diverse habitats (marine and terrestrial) within the Svalbard Archipelago, Norway, were screened for 14 organophosphorus flame retardant (PFR) compounds. Ten PFRs were detected: tris(2-chloroethyl)phosphate (TCEP), tris(2-chloroisopropyl)phosphate (TCIPP), tris(1,3-dichloro-2-propyl)phosphate (TDCIPP), triphenyl phosphate (TPHP); 2-ethylhexyl diphenyl phosphate (EHDPP); tris(2-butoxyethyl)phosphate (TBOEP); tritolyl phosphate (TCrP); triisobutyl phosphate (TIBP); tris(2-ethylhexyl)phosphate (TEHP); and butyl diphenyl phosphate (DPhBP). The greatest number of different PFR compounds, and the highest detection frequency were measured in capelin (Mallotus villotus), and the lowest in Brünnich's guillemot (Uria lomvia). The highest concentrations of ΣPFR, as well as the highest concentration of a single PFR compound, TBOEP, were measured in arctic fox (Vulpes lagopus). The presence of PFR compounds in arctic biota indicates that these compounds can undergo long-range transport and are, to some degree, persistent and bioaccumulated. The potential for biomagnification from fish to higher trophic levels seems to be limited. PMID:26453403

  18. Towards an improved ability to estimate internal dose to non-human biota; Development of conceptual models for reference non-human biota

    Conceptual models have been developed for Reference Fish and Amphibian based on the chemical composition of biota tissues. It was found that these non-human biota can be divided into simplified compartments, where the number of compartments depends upon the element being considered. In most cases, one of two conceptual models can be applied to assess internal partitioning patterns between tissues: 1.) Elements can be relatively uniformly-distributed throughout the body (i.e. whole organism is represented by one homogeneous compartment); or 2.) Elements can be sub-divided between two to three homogeneous compartments. Although preliminary, this work is aimed at developing realistic frameworks to facilitate estimation of internal dose to non-human biota for use in Ecological Risk Assessment (ERA) and Environmental Effects Monitoring (EEM)

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

    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...

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

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

    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...

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

    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)

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

    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)

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

    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.

  5. The freshwater reservoir effect in radiocarbon dating

    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-...

  6. The freshwater reservoir effect in radiocarbon dating

    Philippsen, Bente

    2012-01-01

    The freshwater reservoir effect can result in too high radiocarbon ages of samples from lakes and rivers, including the bones of people whose subsistence was based on freshwater fish, and pottery in which fish was cooked. In my talk, I will explain the causes and consequences of this effect. Two case studies will show the 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 a...

  7. Freshwater for resilience: a shift in thinking.

    Folke, Carl

    2003-01-01

    Humanity shapes freshwater flows and biosphere dynamics from a local to a global scale. Successful management of target resources in the short term tends to alienate the social and economic development process from its ultimate dependence on the life-supporting environment. Freshwater becomes transformed into a resource for optimal management in development, neglecting the multiple functions of freshwater in dynamic landscapes and its fundamental role as the bloodstream of the biosphere. The ...

  8. Assessment of mercury and methylmercury in water, sediment, and biota in Sulphur Creek in the vicinity of the Clyde Gold Mine and the Elgin Mercury Mine, Colusa County, California

    Hothem, Roger L.; Rytuba, James J.; Brussee, Brianne E.; Goldstein, Daniel N.

    2013-01-01

    At the request of the U.S. Bureau of Land Management, we performed a study during April–July 2010 to characterize mercury (Hg), monomethyl mercury (MMeHg), and other geochemical constituents in sediment, water, and biota at the Clyde Gold Mine and the Elgin Mercury Mine, located in neighboring subwatersheds of Sulphur Creek, Colusa County, California. This study was in support of a Comprehensive Environmental Response, Compensation, and Liability Act - Removal Site Investigation. The investigation was in response to an abatement notification from the California Central Valley Regional Water Quality Control Board to evaluate the release of Hg from the Clyde and Elgin mines. Samples of water, sediment, and biota (aquatic macroinvertebrates) were collected from sites upstream and downstream from the two mine sites to evaluate the level of Hg contamination contributed by each mine to the aquatic ecosystem. Physical parameters, as well as dissolved organic carbon, total Hg (HgT), and MMeHg were analyzed in water and sediment. Other relevant geochemical constituents were analyzed in sediment, filtered water, and unfiltered water. Samples of aquatic macroinvertebrates from each mine were analyzed for HgT and MMeHg. The presence of low to moderate concentrations of HgT and MMeHg in water, sediment, and biota from the Freshwater Branch of Sulphur Creek, and the lack of significant increases in these concentrations downstream from the Clyde Mine indicated that this mine is not a significant source of Hg to the watershed during low flow conditions. Although concentrations of HgT and MMeHg were generally higher in samples of sediment and water from the Elgin Mine compared to the Clyde Mine, concentrations in comparable biota from the two mine areas were similar. It is likely that highly saline effluent from nearby hot springs contribute more Hg to the West Fork of Sulphur Creek than the mine waste material at the Elgin Mine.

  9. Assessing Long Term Freshwater Needs in the Arctic

    Strang, E. T.; White, D. M.

    2005-12-01

    The objective of this research is to understand how humans rely on freshwater at local and regional scales in selected parts of the Arctic, how these dependencies have changed in the recent past, and how they are likely to change in the future. The study seeks to incorporate likely effects of climate change on the hydrologic cycle and water availability. This poster describes results to date on historical and future water demand on the Seward Peninsula. Water use can be divided into domestic and industrial water use. Historic domestic water demand, that is, water used for drinking, cooking and cleaning, has increased over the past 40 years as piped water and sewer systems were installed in many villages. Domestic demand can increase by as much as 900 percent when a community installs piped water. Predictions of future water use indicate that the demand for freshwater could rise to considerably higher levels than current usage in the next century due to upgrades to water systems and increases to populations. Historically, industrial water use on the Seward Peninsula was primarily due to mining activities. Preliminary results suggest that water use in the Nome Mining District decreased proportionally with the decline of placer mining operations last century, but the planned construction of a new gold mine in the Nome area could significantly increase freshwater use for mining in the future. The long-term goal of this study is to use historic pressures on the freshwater resource to better understand its vulnerability. Predictions indicate that the domestic demand for freshwater will rise in the future due to population growth and changes to water treatment and delivery technology. The poster addresses current water use on the Seward Peninsula and possible future water demand.

  10. Literature Review and Database of Relations Between Salinity and Aquatic Biota: Applications to Bowdoin National Wildlife Refuge, Montana

    Gleason, Robert A.; Tangen, Brian A.; Laubhan, Murray K.; Finocchiaro, Raymond G.; Stamm, John F.

    2009-01-01

    Long-term accumulation of salts in wetlands at Bowdoin National Wildlife Refuge (NWR), Mont., has raised concern among wetland managers that increasing salinity may threaten plant and invertebrate communities that provide important habitat and food resources for migratory waterfowl. Currently, the U.S. Fish and Wildlife Service (USFWS) is evaluating various water management strategies to help maintain suitable ranges of salinity to sustain plant and invertebrate resources of importance to wildlife. To support this evaluation, the USFWS requested that the U.S. Geological Survey (USGS) provide information on salinity ranges of water and soil for common plants and invertebrates on Bowdoin NWR lands. To address this need, we conducted a search of the literature on occurrences of plants and invertebrates in relation to salinity and pH of the water and soil. The compiled literature was used to (1) provide a general overview of salinity concepts, (2) document published tolerances and adaptations of biota to salinity, (3) develop databases that the USFWS can use to summarize the range of reported salinity values associated with plant and invertebrate taxa, and (4) perform database summaries that describe reported salinity ranges associated with plants and invertebrates at Bowdoin NWR. The purpose of this report is to synthesize information to facilitate a better understanding of the ecological relations between salinity and flora and fauna when developing wetland management strategies. A primary focus of this report is to provide information to help evaluate and address salinity issues at Bowdoin NWR; however, the accompanying databases, as well as concepts and information discussed, are applicable to other areas or refuges. The accompanying databases include salinity values reported for 411 plant taxa and 330 invertebrate taxa. The databases are available in Microsoft Excel version 2007 (http://pubs.usgs.gov/sir/2009/5098/downloads/databases_21april2009.xls) and contain 27 data fields that include variables such as taxonomic identification, values for salinity and pH, wetland classification, location of study, and source of data. The databases are not exhaustive of the literature and are biased toward wetland habitats located in the glaciated North-Central United States; however, the databases do encompass a diversity of biota commonly found in brackish and freshwater inland wetland habitats.

  11. Soil biota as a natural resource for the restoration of degraded chernozems

    Senicovscaia, Irina

    2014-01-01

    The role of biota as a natural resource for the restoration of degraded chernozems of the Republic of Moldova is under discussion till nowadays. The status of biota of old-arable chernozems in conditions of the green manure applications has been evaluated statistically. Two experimental sites located in the central and southern zone of the Republic of Moldova have been tested by soil biological indicators during 2010-2012. The application of vetch as a green manure had created conditions for ...

  12. SUPPRESSION ABILITY OF CRUDE EXTRACT DERIVED FROM MARINE BIOTA AGAINST FUSARIUM OXYSPORUM F.SP. VANILLAE

    I Ketut Suada; Ni Wayan Suniti

    2010-01-01

    The objective of this research was to investigate suppression ability of marine biota extracts against Fusarium oxysporum f.sp. vanillae of vanilla stem rot. Samples were collected at intertidal zones and in the depth of 1-7 m from seven beaches in Bali. Screening of active compounds of biota extracts were conducted using inhibition zone of well diffusion method on Potato Dextrose Agar (PDA). The extract was tested in-vitro in PDA medium using completely randomized design with three replicate...

  13. Do interactions between plant and soil biota change with elevation? A study on Fagus sylvatica

    Defossez, E.; Courbaud, B.; Marcais, B.; Thuiller, W.; Granda, E.; Kunstler, G.

    2011-01-01

    Theoretical models predict weakening of negative biotic interactions and strengthening of positive interactions with increasing abiotic stress. However, most empirical tests have been restricted to plant–plant interactions. No empirical study has examined theoretical predictions of interactions between plants and below-ground micro-organisms, although soil biota strongly regulates plant community composition and dynamics. We examined variability in soil biota effects on tree regeneration acro...

  14. Soil biota community structure and abundance under agricultural intensification and extensification

    Postma-Blaauw, M.B.; Goede, R.G.M. de; BLOEM, J; Faber, J.H.; Brussaard, L.

    2010-01-01

    Understanding the impacts of agricultural intensification and extensification on soil biota communities is useful in order to preserve and restore biological diversity in agricultural soils and enhance the role of soil biota in agroecosystem functioning. Over four consecutive years, we investigated the effects of agricultural intensification and extensification (including conversion of grassland to arable land and vice versa, increased and decreased levels of mineral fertilization, and monocu...

  15. Effaced preservation in the Ediacara biota and its implications for the early macrofossil record

    Liu, AG; Mcilroy, D; Antcliffe, JB; Brasier, MD

    2011-01-01

    Abstract: Ediacaran structures known as 'pizza discs' or Ivesheadia have long been considered enigmatic. They are amongst the oldest known members of the Ediacara biota, apparently restricted to the Avalonian successions of Newfoundland and the UK, c. 579-560Ma. Here, we suggest that these impressions are taphomorphs, resulting from the post-mortem decay of the frondose Ediacaran biota. Ediacaran fossils range from well-preserved, high-fidelity variants to almost completely effaced specimens....

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

    Wladimir C. Paradas

    2007-03-01

    Full Text Available 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, Brazil. 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.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 janeiro, 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.

  17. Natural radioactivity in some specimens of the marine biota

    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)

  18. Linking stormflow hydrology and biota in suburban streams

    Shuster, W. D.; Roy, A.; Zhang, Y.; Morrison, M.

    2005-12-01

    Suburban land development has been found to alter the hydrology of landscapes, changing streamflow transient behavior (i.e., storm "flashiness"), which may contribute to some of the commonly observed and typically negative impacts of development on aquatic ecosystems. The linkages between residential development, hydrologic response, and the structure of biotic assemblages in receiving waters, however, remain poorly characterized. The Shepherd Creek catchment in Cincinnati, Ohio (USA) is approximately 20 km2, half of which lies within an undeveloped city park. The other half of the catchment represents a mix of 1960-1980s era residential parcels in the headwaters, and horse and cattle pastures downstream. We use baseline monitoring data from five subcatchments (drainages with varying coverage in residential land use) where hydrologic, habitat, and biological monitoring is conducted. Flow transient behavior was characterized by deriving rise and fall rates from continuous (5-min.) gage records and macroinvertebrate and periphyton assemblages were assessed using metrics and ordination. Subcatchments exhibited scoured streambeds, high algal cell counts that were dominated by blue-green algae, and generally tolerant macroinvertebrate assemblages. These impairments appear to be related in part to a combination of rapid rise and fall rates for storm events, poor water quality, and a pronounced lack of benthic habitat for some of the sites. Flow transients may offer a mechanistic explanation for the structure of biological assemblages, linking land use to biological condition. We discuss how stormwater infiltration via parcel-level best management practices may restore some aspects of hydrology and biota within these degraded stream ecosystems.

  19. Marine biota sightings during 3D marine seismic surveys

    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)

  20. Influence of global change-related impacts on the mercury toxicity of freshwater algal communities.

    Val, Jonatan; Muñiz, Selene; Gomà, Joan; Navarro, Enrique

    2016-01-01

    The climatic-change related increase of temperatures, are expected to alter the distribution and survival of freshwater species, ecosystem functions, and also the effects of toxicants to aquatic biota. This study has thus assessed, as a first time, the modulating effect of climate-change drivers on the mercury (Hg) toxicity of freshwater algal photosynthesis. Natural benthic algal communities (periphyton) have been exposed to Hg under present and future temperature scenarios (rise of 5 °C). The modulating effect of other factors (also altered by global change), as the quality and amount of suspended and dissolved materials in the rivers, has been also assessed, exposing algae to Hg in natural river water or a synthetic medium. The EC50 values ranged from the 0.15-0.74 ppm for the most sensitive communities, to the 24-40 ppm for the most tolerant. The higher tolerance shown by communities exposed to higher Hg concentrations, as Jabarrella was in agreement with the Pollution Induced Community Tolerance concept. In other cases, the dominance of the invasive diatom Didymosphenia geminata explained the tolerance or sensitivity of the community to the Hg toxicity. Results shown that while increases in the suspended solids reduced Hg bioavailability, changes in the dissolved materials - such as organic carbon - may increase it and thus its toxic effects on biota. The impacts of the increase of temperatures on the toxicological behaviour of periphyton (combining both changes at species composition and physiological acclimation) would be certainly modulated by other effects at the land level (i.e., alterations in the amount and quality of dissolved and particulate substances arriving to the rivers). PMID:26024757

  1. The RESRAD-BIOTA code for application in biota dose evaluation: Providing screening and organism-specific assessment capabilities for use within an environmental protection framework

    The RESRAD-BIOTA code was developed through a partnership between offices of the U.S. Department of Energy, the U.S. Environmental Protection Agency, and the U.S. Nuclear Regulatory Commission. RESRAD-BIOTA is being designed to provide a full spectrum of analysis capabilities, from practical conservative screening methods using Biota Concentration Guides - to more realistic organism-specific dose assessment. A beta version of the RESRAD-BIOTA code is currently available for unofficial use and testing. Continued coordination and partnerships with U.S. agencies and international organizations is providing opportunities for the inclusion of additional evaluation approaches and capabilities, such as: (1) development of BCGs for additional radionuclides; (2) additional flexibility for specifying and expanding organism options; (3) improvements to environmental transfer factor parameter datasets; (4) inclusion of additional 'reference organism geometries' (e.g., dose conversion factors for ellipsoids of appropriate size and shielding properties for different sized organisms, appropriate for specific ecosystem types); and (5) sensitivity and uncertainty analysis capability for calculated dose estimates. (author)

  2. Adiciones a la Biota de Uredinales (fungi de Colombia Addictions to the Uredinales Biota (fungi in Colombia

    Katherin Maritza Vanegas Berrouet

    2011-12-01

    Full Text Available Colecciones de plantas con síntomas de hongos royas (Uredinales, Basidiomycota realizadas en los últimos años en los departamentos de Amazonas, Antioquia, Caldas, Cundinamarca, Tolima y Valle del Cauca han sido estudiadas y depositadas en el Museo Micológico de la Universidad Nacional de Colombia, Sede Medellín (MMUNM. Entre las novedades encontradas, se registran por primera vez para Colombia las royas: Puccinia investita, Sphenospora pallida, Crossopsora piperis, Uredo psychotriicola y Pucciniosira solani. Se adiciona la familia botánica Dioscoreaceae para la Biota de Uredinales colombianos. Se hace la corrección del nombre anamórfico Uredo parthenii publicado para Colombia en 2003, por el nombre teliomorfico válido Puccinia schileana. Son registrados seis nuevos hospedantes parasitados por royas en Colombia, entre estos reviste importancia la colección sobre Origanum vulgare L. una planta aromática y medicinal cultivada mundialmente.Plant collections with symptoms of rusts fungi (Uredinales, Basidiomycota made during recent years in provinces of Amazonas, Antioquia, Caldas, Cundinamarca, Tolima and Valle del Cauca have been studied and deposited in Museo Micológico of Universidad Nacional de Colombia, Sede Medellín (MMUNM. The rusts species Puccinia investita, Sphenospora pallida, Crossopsora piperis, Uredo psychotriicola and Pucciniosira solani are new records for Colombia. A first record for this country of rust fungi in plants of family Dioscoreaceae has been also made. The anamorphic name Uredo parthenii published in 2003 in Colombia, has been corrected by the valid teleomorph Puccinia schileana. Finally, six new hosts parasitized by rusts are recorded, including Origanum vulgare L. a world-wide important aromatic and medicinal plant.

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

    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

  4. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Raster surface generated for the "freshwater" thickness of the Floridan aquifer system

    U.S. Geological Survey, Department of the Interior Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  5. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Contours for the "freshwater" thickness of the Floridan aquifer system

    U.S. Geological Survey, Department of the Interior Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  6. DS926 Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina -- Points for the "freshwater" thickness of the Floridan aquifer system

    U.S. Geological Survey, Department of the Interior Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system were developed to define an updated hydrogeologic framework as part...

  7. Freshwater autotrophic picoplankton: a review

    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.

  8. Freshwater Ecology. LC Science Tracer Bullet.

    Niskern, Diana, Comp.

    Freshwater ecosystems include lakes, ponds, streams, rivers, and certain types of wetlands. This literature and resources guide is not intended to be a comprehensive bibliography on freshwater ecology; the guide is designed--as the name of the series implies--to put the reader or student "on target." Other literature guides related to freshwater…

  9. Farming of Freshwater Rainbow Trout in Denmark

    Jokumsen, Alfred; Svendsen, Lars Moeslund

    Textbook on Farming of Freshwater Rainbow Trout in Denmark. Danish edition with the title: Opdræt af regnbueørred i Danmark......Textbook on Farming of Freshwater Rainbow Trout in Denmark. Danish edition with the title: Opdræt af regnbueørred i Danmark...

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

    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.

  11. The freshwater reservoir effect in radiocarbon dating

    Philippsen, Bente

    The freshwater reservoir effect can result in too high radiocarbon ages of samples from lakes and rivers, including the bones of people whose subsistence was based on freshwater fish, and pottery in which fish was cooked. In my talk, I will explain the causes and consequences of this effect. Two...... case studies will show the 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 years can occur within one river. In the Limfjord, freshwater influence...... caused reservoir ages to vary between 250 and 700 years during the period 5400 BC - AD 700. Finally, I will discuss the implications of the freshwater reservoir effect for radiocarbon dating of Mesolithic pottery from inland sites of the Ertebølle culture in Northern Germany....

  12. Diversity and distribution of fauna of the Nasese Shore, Suva, Fiji Islands with reference to existing threats to the biota

    Dissanayake Mudiyanselage Suratissa

    2016-03-01

    Full Text Available Faunal diversity and distribution in the Nasese Shore, Suva, Fiji Islands were studied April–August 2014. The belt transect method was employed to study the species richness and abundance of the fauna. Opportunistic observations were performed to supplement the species richness of the selected habitat types: sandy, rocky and muddy (SRM; Habitat 1; mangrove and sandy (MNS; Habitat 2; muddy and sandy (MS; Habitat 3; and rocky and coral (RC; Habitat 4. Sampling was performed during high and low tide. Faunal density was highest in the RC substrate. The density of mud skippers was significantly higher in the MNS habitat than in the other habitats. This findings could well indicate the environmental pollution levels of this habitat. The Shanon–Weiner Index indicated that the RC habitat possesses the highest diversity, whereas the MS habitat possesses the lowest diversity. In addition, major threats to the biota existed.

  13. The effect of water hardness on the toxicity of uranium to a tropical freshwater alga Chlorella sp.

    Charles, Amanda L; Markich, Scott J; Stauber, Jennifer L; De Filippis, Lou F

    2002-10-01

    Uranium (U) derived from mining activities is of potential ecotoxicological concern to freshwater biota in tropical northern Australia. Few data are available on the effects of water hardness (Ca and/or Mg), which is elevated in U mine wastewaters, on the toxicity and bioavailability of U to freshwater biota, particularly algae. This study determined the effect of water hardness (8, 40, 100 and 400 mg CaCO(3) x l(-1), added as calcium (Ca) and magnesium (Mg) sulphate) on the toxicity (72 h growth rate inhibition) of U to the unicellular green alga, Chlorella sp., in synthetic freshwater, at constant pH (7.0) and alkalinity (8 mg CaCO(3) x l(-1)), similar in chemical composition to sandy coastal streams in tropical northern Australia. A 50-fold increase in water hardness resulted in a 5-fold decrease (P0.05) differences in the predicted speciation (% distribution) of U amongst the four water hardness levels. The reduction in U toxicity with increasing water hardness was most likely due to competition between U and Ca and/or Mg for binding sites on the algal cell surface. The minimum detectable effect concentrations of U were approximately 3 and 24 times higher (at 8 and 400 mg CaCO(3)x l(-1) hardness, respectively) than the national interim U guideline value (0.5 micro g x l(-1)) for protecting aquatic ecosystems. Overall, the results reinforce the need for a more flexible U guideline based on a hardness-dependent algorithm, which may allow environmental managers to relax the national guideline for U on a site-specific basis. PMID:12204587

  14. Toxicity of soil iodine to terrestrial biota, with implications for 129I

    The environmental impact of 129I has traditionally been assessed by its radiological effects on human health; however, protection of human health does not ensure protection of other biota. Because of the very long half-life of 129I, there is a relatively high molar concentration of I associated with any specified level of radioactivity. The potential exists for chemical toxicity to non-human biota to exceed radiological toxicity in importance. The authors reviewed the literature and conducted laboratory bioassays to obtain information on the chemical toxicity of inorganic I to terrestrial biota. Levels as low as 5 mg I kg-1 soil may have detrimental effects. If this were as 129I, the corresponding radiological effects to non-human biota may not be as important as the chemical toxicity. However, because of the very low risk factor applied to protect humans, levels of 129I in the environment acceptable for human health appear to be acceptable for other biota at the higher risk levels commonly used for them. (author)

  15. Hanford's West Lake and the Biota Dose Assessment Committee's screening methodology

    Full text: Radionuclide data collected at the Hanford Nuclear Reservation's West Lake (a small seepage pond) was used to test the utility of the U.S. Department of Energy's Biota Dose Assessment Screening Methodology for protection of plants and animals from ionizing radiation. The Hanford Site environmental surveillance database was queried for all 1999 data on radionuclides in surface water, soil and sediment. Maximum and mean radionuclide concentrations were determined for each combination of radionuclide + media. These data were entered into the Biota Dose Assessment Committee's 'Biota Concentration Guide Calculator', a semi-automated tool used to determine compliance with proposed biota dose limits for shorebirds (riparian animals with a proposed dose limit of 0.1 rad/day). Concentrations in the aquatic environment did not pass the screen. Further review of the data indicated that a water sample taken from the lake exceeded the limiting water concentration for uranium. As a consequence of the assessment, a limited biota monitoring effort was established to determine the potential exposure of wildlife at West Lake. The effort involved determining residence time of breeding shorebirds and actual tissue burdens of radionuclides in the birds. In the final analysis, West Lake was determined to be in compliance with proposed radiological dose limits. The application of this methodology has helped to identify a potential exposure problem and provide direction for the sampling program. (author)

  16. Significance of the air pathway in contributing radiation dose to biota

    A screening methodology was developed as part of the U.S. Department of Energy's (DOE) graded approach for evaluating radiation doses to aquatic and terrestrial biota from contaminants released into the environment. Included in the graded approach methodology were limiting media concentrations for water, soil, and sediment for twenty-three radionuclides. These concentrations were designed to restrict potential doses to biota below biota dose limits (i.e., dose rate guidelines) specified within existing and proposed DOE regulations. While implicitly included in the derivation of limiting media concentrations, separate biota concentration guides (BCGs) for air were not provided. This paper presents BCGs for air developed within the context and framework of the DOE methodology. The same twenty-three radionuclides are examined. Three air exposure pathways are considered: external exposure (cloudshine), inhalation, and absorption. Allometric equations are used to assess exposure via inhalation, and simplifying assumptions (similar to those used in human dose calculations) are used to assess external and absorption pathways. For purposes of comparison, the air BCGs are compared to current DOE air concentration limits for humans. This analysis validated the initial assumption that the air pathway is unlikely to be a major exposure pathway for biota. In addition, limits for humans are sufficiently restrictive that at sites with active air releases no populations of terrestrial animals or plants are likely to receive significant doses from this exposure pathway. (author)

  17. Contamination of estuarine water, biota, and sediment by halogenated organic compounds: A field study

    Pereira, W.E.; Rostad, C.E.; Chiou, C.T.; Brinton, T.I.; Barber, L.B., II; Demcheck, D.K.; Demas, C.R.

    1988-01-01

    Studies conducted in the vicinity of an industrial outfall in the Calcasieu River estuary, Louisiana, have shown that water, bottom and suspended sediment, and four different species of biota are contaminated with halogenated organic compounds (HOC) including haloarenes. A "salting-out" effect in the estuary moderately enhanced the partitioning tendency of the contaminants into biota and sediments. Contaminant concentrations in water, suspended sediments, and biota were found to be far below the values predicted on the basis of the assumption of phase equilibria with respect to concentrations in bottom sediment. Relative concentration factors of HOC between biota (catfish) and bottom sediment increased with increasing octanol/estuarine water partition coefficients (Kow*), maximizing at log Kow* of about 5, although these ratios were considerably less than equilibrium values. In contrast, contaminant concentrations in water, biota, and suspended sediments were much closer to equilibrium values. Bioconcentration factors of HOC determined on the basis of lipid content for four different biotic species correlated reasonably well with equilibrium triolein/water partition coefficients (Ktw).

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

    Suseno, Heny

    2014-03-01

    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.

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

    Suseno, Heny, E-mail: henis@batan.go.id [Radioactive Waste Technology Center - The Indonesia Nuclear Energy Agency (BATAN) (Indonesia)

    2014-03-24

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

    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

  1. Studies on the estimation of radiation dose to typical non human biota around Kaiga nuclear power plant

    It is necessary to prove exclusively that biota is sufficiently protected from ionizing radiation since pathway leading to biota exposure is quite different compared to that for human being and non human biota has access to contaminated areas while human access is limited. The radiation from purely natural sources may be a useful benchmark since radiation at these levels is tolerated by biota. This paper presents the estimation of radiation dose to typical members of biota around Kaiga site, which includes a herbivorous mammalian species (cow), one avio fauna (pigeon), one burrowing animal (earthworm) and an aquatic animal (fish). The internal and external doses to species from naturally occurring radio nuclides were evaluated from concentrations of radio nuclides in soil, air, water and dietary items and the relevant concentration factors. An attempt is made for the evaluation of dose to above biota from reactor originated radio nuclides. The study identifies the most significant radionuclide, most significant pathway leading to radiological risk to member of biota from natural sources and reactor-produced radionuclides. From the computed dose to biota per unit release from reactor, study identifies the significant radionuclide and pathways for reactor produced radionuclides. The study conclusively proves that biota dose from reactor produced radionuclides from KGS is negligible. (author)

  2. Metal toxicity to freshwater organisms as a function of pH: A meta-analysis.

    Wang, Zhen; Meador, James P; Leung, Kenneth M Y

    2016-02-01

    Acidification caused by climate change and seasonal fluctuation can have profound implications for chemical toxicity to freshwater organisms. The present study aims to address this challenging issue through a comprehensive meta-analysis by comparing acute median lethal or effect concentration data (LC50 or EC50) for 10 metals and metalloids for various freshwater species obtained at different pH values. Our results revealed that element toxicity generally follows three different models, including Model-I: decreasing toxicity with increasing pH, Model-II: increasing toxicity with increasing pH, and Model-III: minimal toxicity at intermediate (optimal) pH (pHopt) with increasing toxicity as pH increases or decreases from pHopt. We further examined these observations by constructing pH-dependent species sensitivity distributions (SSDs). The results indicated that the 10(th) percentile hazardous concentrations (HC10s) for copper, lead, selenium and silver generally exhibited a positive linear relationship with pH, following the Model-I. The ability to accurately predict toxicity of elements to biota in natural waters as a function of pH may be limited, however, the pH-dependent SSD approach presented in this study facilitates and helps characterize the role of pH in water quality guidelines and ecological risk assessment. PMID:26498103

  3. Field screening of water, soil, bottom sediment, and biota associated with irrigation drainage in the Dolores Project and the Macos River basin, southwestern Colorado, 1994

    Butler, D.L.; Osmundson, B.C.; Krueger, R.P.

    1997-01-01

    A reconnaissance investigation for the National Irrigation Water Quality Program in 1990 indicated elevated selenium concentrations in some water and biota samples collected in the Dolores Project in southwestern Colorado. High selenium concentrations also were indicated in bird samples collected in the Mancos Project in 1989. In 1994, field screenings were done in parts of the Dolores Project and Mancos River Basin to collect additional selenium data associated with irrigation inthose areas. Selenium is mobilized from soils in newly irrigated areas of the Dolores Project called the Dove Creek area, which includes newly (since 1987) irrigated land north of Cortez and south of Dove Creek.Selenium was detected in 18 of 20stream samples, and the maximum concentration was 12micrograms per liter. The Dove Creek area is unique compared to other study areas of the National Irrigation Water Quality Program becauseselenium concentrations probably are indicative of initial leaching conditions in a newly irrigated area.Selenium concentrations in nine shallow soil samples from the Dove Creek area ranged from 0.13 to 0.20 micrograms per gram. Selenium concentrations in bottom sediment from six ponds were less than the level of concern for fish and wildlife of 4 micrograms per gram. Many biota samples collected in the Dove Creek area had elevated selenium concentrations when compared to various guidelines and effect levels,although selenium concentrations in water, soil, and bottom sediment were relatively low. Selenium concentrations in 12 of 14 aquatic-invertebratesamples from ponds exceeded 3 micrograms per gram dry weight, a dietary guideline for protection of fish and wildlife. The mean seleniumconcentration of 10.3 micrograms per gram dry weight in aquatic bird eggs exceeded the guideline for reduced hatchability of 8 micrograms per gramdry weight. Two ponds in the Dove Creek area had a high selenium hazard rating based on a new protocol for assessing selenium hazard in theenvironment; however, waterfowl were reproducing at the two ponds. Three tributary streams of Mc Elmo Creek that drain irrigated areas of the Montezuma Valley south of the creek were sampled in 1994. Mud Creek probably is the largest source of selenium to Mc Elmo Creek. Most biota samples from Mud Creek had elevated selenium concentrations when compared to guidelines for dietary items and freshwater fish. Selenium concentrations in water samples collected in the Mancos River Basin upstream from Navajo Wash, which includes the Mancos Project, ranged from less than 1 to 10 micrograms per liter. Mud Creek contributed about 74 percent of the selenium load to the upper Mancos River in March 1994.Selenium concentrations were much higher in Navajo Wash; a sample collected in March had 97 micrograms per liter of selenium. Bottom-sediment samples from two ponds in the Mancos Projectexceeded the concentration of concern of 4 micrograms per gram. The highest selenium concentrations in biota samples from streams in the Mancos River Basin were for samples from Navajo Wash. Mostconcentrations in biota in the upper Mancos River Basin were less than guidelines. Mean selenium concentrations in eggs from aquatic birds collected at three ponds in the Mancos Project slightly exceed the guideline associated with reduced hatchability.Five bird livers had a mean selenium concentration of 32.6 micrograms per gram dry weight, whichslightly exceeded the mean concentration of 30 micrograms per gram dry weight that is associated with reproductive impairment. Two of the pondshad a high selenium hazard rating; however, mallard reproduction was observed in 1994 at one of the ponds that had a high selenium-hazard rating.

  4. Potential ecological risk of heavy metal contamination in sediments and macrobenthos in coastal wetlands induced by freshwater releases: A case study in the Yellow River Delta, China.

    Li, Ming; Yang, Wei; Sun, Tao; Jin, Yuwan

    2016-02-15

    We investigated the nine heavy metal contents in the sediments and macrobenthos of the Yellow River Delta Wetlands using three experimental areas that received freshwater releases and one reference area that did not. Heavy metal contents, the single-factor contamination index (SFCI), the metal contamination index (MCI), and the biota-sediment accumulation factor (BSAF) were used to evaluate the potential ecological risk and bioaccumulation. We found that As exceeded the national standard value by more than 50%, and that the ranges of SFCI for each metal were generally larger in autumn than in spring. MCI showed no clear pattern, but the BSAF results suggest that Cd bioaccumulates from sediments to macrobenthos. Pollution-resistant species such as Corophium sinense, Chironomus sp., and Einfeldia sp. became dominant in the areas receiving freshwater releases, and provide direct evidence of ecological risk in the wetlands. Our results provide preliminary information to guide managers for ecological risk assessments. PMID:26719069

  5. 40 CFR 35.1605-3 - Publicly owned freshwater lake.

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Publicly owned freshwater lake. 35.1605... Owned Freshwater Lakes § 35.1605-3 Publicly owned freshwater lake. A freshwater lake that offers public... maintaining the public access and recreational facilities of this lake or other publicly owned...

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

    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)

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

    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

  8. The trace element analysis in freshwater fish species, water and sediment in Iyidere stream (Rize-Turkey).

    Verep, Bulent; Mutlu, Cengiz; Apaydin, Gokhan; Cevik, Ugur

    2012-07-15

    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 lyidere 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. PMID:24171246

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

    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.

  10. Assessment of radiation-ecological impact on aquatic biota in the area of NPP location

    The methodology of Assessment of radiation-ecological impact (REI) on the natural environments according to the Roshydromet radiometric data developed by RPA Typhoon is described. In the document the following procedure of assessment of radiation impact on biota is suggested: identification of REI sources; analysis of radiation monitoring data and model estimations of radionuclide transfer in environment; feasibility and choice of representative environment objects for REI assessment; estimation of the REI value on representative environment objects; presentation of results of REI assessment. The results of REI on aquatic biota of Kalinin NPP cooling pond (1999-2012) are presented

  11. Net effects of multiple stressors in freshwater ecosystems: a meta-analysis.

    Jackson, Michelle C; Loewen, Charlie J G; Vinebrooke, Rolf D; Chimimba, Christian T

    2016-01-01

    The accelerating rate of global change has focused attention on the cumulative impacts of novel and extreme environmental changes (i.e. stressors), especially in marine ecosystems. As integrators of local catchment and regional processes, freshwater ecosystems are also ranked highly sensitive to the net effects of multiple stressors, yet there has not been a large-scale quantitative synthesis. We analysed data from 88 papers including 286 responses of freshwater ecosystems to paired stressors and discovered that overall, their cumulative mean effect size was less than the sum of their single effects (i.e. an antagonistic interaction). Net effects of dual stressors on diversity and functional performance response metrics were additive and antagonistic, respectively. Across individual studies, a simple vote-counting method revealed that the net effects of stressor pairs were frequently more antagonistic (41%) than synergistic (28%), additive (16%) or reversed (15%). Here, we define a reversal as occurring when the net impact of two stressors is in the opposite direction (negative or positive) from that of the sum of their single effects. While warming paired with nutrification resulted in additive net effects, the overall mean net effect of warming combined with a second stressor was antagonistic. Most importantly, the mean net effects across all stressor pairs and response metrics were consistently antagonistic or additive, contrasting the greater prevalence of reported synergies in marine systems. Here, a possible explanation for more antagonistic responses by freshwater biota to stressors is that the inherent greater environmental variability of smaller aquatic ecosystems fosters greater potential for acclimation and co-adaptation to multiple stressors. PMID:26149723

  12. Management of freshwater invasive alien species

    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

  13. The freshwater reservoir effect in radiocarbon dating

    Philippsen, Bente

    2013-01-01

    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......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...

  14. Human dispersal of freshwater invasive fauna

    Banha, Filipe Miguel Santos

    2016-01-01

    The main goal of this thesis was to improve the knowledge on the mechanisms involved on Human dispersal of freshwater invasive fauna, contributing for the management of these problematic species. Several vectors were investigated, both accidental and intentional, from a freshwater invaders list that included some of the worse species. It was found that the red swamp crayfish and the signal crayfish presented desiccation survival capacities compatible with long-distance human-mediated dispersa...

  15. Scientific assessment of freshwater harmful algal blooms

    Lopez, C. B.; Jewett, E.B.; Dortch, Q.; Walton, B.T.; Hudnell, H.K.

    2008-01-01

    In 2004, Congress reauthorized the Harmful Algal Bloom and Hypoxia Research and Control Act of 1998 with the Harmful Algal Bloom and Hypoxia Amendments Act (HABHRCA 2004). The 2004 legislation required the generation of five reports, including this "Scientific Assessment of Freshwater Harmful Algal Blooms." HABHRCA 2004 stipulates that this report 1) examine the causes, consequences, and economic costs of freshwater HABs, 2) establish priorities and guidelines for a research program on freshw...

  16. Recent advances in tropical freshwater aquaculture

    Varghese, T.J.

    1988-01-01

    Several technological advances have been made in tropical freshwater aquaculture during the last three decades. Hatchery production of carp seed was achieved in India and China towards the late 1950's. Channel catfish farming in the U.S. has grown phenomenally. Development of the technology of high density culture using artificial aeration and nutritionally balanced diets has revolutionized freshwater aquaculture, particularly in Israel. Culture of fishes in cages, pens and running water have...

  17. Freshwater Commercial Bycatch: an Understated Conservation Problem

    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.

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

    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...

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

    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...

  20. COMMUNITY DEVELOPMENT IN FRESHWATER MICROCOSMS

    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.

  1. Evolution of the Freshwater Eels

    Aoyama, Jun; Tsukamoto, Katsumi

    The freshwater anguillid eels have an unusual life history and world-wide distribution. Questions about the phylogenetic relationships of this group and how their long spawning migrations and larval phase may contribute to their global distribution have not been addressed. This paper is first presentation of molecular phylogeny of Anguilla species, and based on this phylogenetic tree we suggest new aspect of the evolution of this group. Namely, ancestral eels originated during the Eocene or earlier, in the western Pacific Ocean near present-day Indonesia. A group derived from this ancestor dispersed westward, probably by larval transport in the global circum-equatorial current through the northern edge of the Tethys Sea. This group split into the ancestor of the European and American eels, which entered into the Atlantic Ocean, and a second group, which dispersed southward and split into the east African species and Australian species. Thus the world-wide distribution of the eel family can be understood from knowledge of continental drift, ocean currents, a specialized larva and evolutionary forces favoring dispersal and speciation of segregated gene pool.

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

    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)

  3. Assessment of doses and risk due to natural radionuclides in edible biota of Domiasiat, Meghalaya

    A radiation dose assessment exercise was carried out for the edible biota Solanum nigrum, Carica papaya, Raphnus sativum and Phaseolus domesticus due to naturally available radionuclides 40K, 238U and 232Th in the Domiasiat area in Meghalaya (India)). The concentration of radionuclides in biota and corresponding soil was measured by the NaI(Tl) detector having a minimum detection limit (efficiency, 32.4 %) and machine counting time of 3000 s. The obtained transfer factor for 40K was 0.3061, 0.7163, 0.1988 and 0.1279, for 232Th 0.0003, 2.22 E-05, 2.71 E-05 and 3.45 E-05 and for 238U 1.46 E-05, 9.73 E-05, 1.46 E-05 and 3.11 E-05 (ratio) in each biota, respectively. The detailed physiological and morphological study of the biota was carried out. The point source dose distribution (sourcetarget) hypothesis was applied for the radiation absorbed fraction. The generated data were modelled using FASSET and obtained un-weighted total dose was 1.78 E-04, 6.84 E-03, 8.46 E-03 and 1.73 E-04μGy h-1, respectively, finally compared with the IAEA and UNSCEAR data set for screening level dose risk assessment. (authors)

  4. Assessment of doses and risk due to natural radionuclides in edible biota of Domiasiat, Meghalaya.

    Kumar, N; Chaturvedi, S S; Jha, S K

    2012-07-01

    A radiation dose assessment exercise was carried out for the edible biota Solanum nigrum, Carica papaya, Raphnus sativum and Phaseolus domesticus due to naturally available radionuclides (40)K, (238)U and (232)Th in the Domiasiat area in Meghalaya, India. The concentration of radionuclides in biota and corresponding soil was measured by the NaI(Tl) detector having a minimum detection limit (efficiency, 32.4%) and machine counting time of 3000 s. The obtained transfer factor for (40)K was 0.3061, 0.7163, 0.1988 and 0.1279, for (232)Th 0.0003, 2.22E-05, 2.71E-05 and 3.45E-05 and for (238)U 1.46E-05, 9.73E-05, 1.46E-05 and 3.11E-05 (ratio) in each biota, respectively. The detailed physiological and morphological study of the biota was carried out. The point source dose distribution (source?target) hypothesis was applied for the radiation absorbed fraction. The generated data were modelled using FASSET and obtained un-weighted total dose was 1.78E-04, 6.84E-03, 8.46E-03 and 1.73E-04 ?Gy h(-1), respectively, finally compared with the IAEA and UNSCEAR data set for screening level dose risk assessment. PMID:22155750

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

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

    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 techniq...

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

    Heděnec, Petr; Novotný, D.; Usťak, S.; Honzík, R.; Váňa, V.; Petříková, V.; Frouz, Jan

    2015-01-01

    Roč. 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) Subject RIV: DF - Soil Science Impact factor: 3.394, year: 2014

  7. Antioxidative and oxidative changes in the digestive gland cells of freshwater mussels Unio tumidus caused by selected phenolic compounds in the presence of H(2)O(2) or Cu(2+) ions.

    Labieniec, Magdalena; Gabryelak, Teresa

    2007-02-01

    Research on biomarkers as early bioindicators of perturbation in populations and individuals has received increasing interest during recent decades. These ecotoxicity studies allow us to measure the impact of environmental stressors and to monitor and evaluate the degradation or restoration of systems. In the present study we used bivalve molluscs (mussels), which are sensitive biomarkers of aquatic ecosystem pollution, to assess the effects of three polyphenols: tannic acid, ellagic acid and gallic acid. These compounds were used in the 1-60 microM concentration range, alone and in the presence of H(2)O(2) (40 and 100 microM) or Cu(2+) ions (50 microM). The fluorescence probe dichlorofluorescein-diacetate (DCFH-DA) was used to measure reactive oxygen species (ROS). The oxidation of DCFH-DA to the fluorescent DCF (dichlorofluorescein) by the phenolic compounds was investigated spectrofluorimetrically. The results showed that the polyphenols tested can act as antioxidants against the ROS present in the digestive gland cells, but their activity is decreased after incubation with hydrogen peroxide or copper ions. SH-groups were determined spectrophotometrically using Ellman's reagent. The results showed that oxidative modification of proteins increased in a concentration-dependent manner in cells incubated with polyphenols (above 15 microM) alone. Incubation of the cells with phenolic acids and H(2)O(2) or Cu(2+) ions revealed that the phenolic acids had prooxidant properties in all concentrations used except for 1 microM tannic and ellagic acid and 40 microM H(2)O(2). DNA fragmentation was estimated by a fluorescence method using Hoechst 33258/propidium iodine binding. The data showed that the phenolic acids alone and in the presence of hydrogen peroxide or copper ions can induce apoptosis and necrosis. The methods used and results obtained indicate that the polyphenols selected can act not only as antioxidants but also as prooxidants in digestive gland cells of Unio tumidus. PMID:17084585

  8. Temporal changes in radionuclide transfer to biota in Canadian shields lakes receiving chronic inputs

    Changes in environmental contaminant levels are often assessed using non-human biota as bio-monitors, due to their ability to accumulate trace elements found at low levels in natural systems over time. This is often accomplished through direct comparisons of contaminant concentrations in indicator species with those present in surface waters, in the form of transfer factors; however, transfer factors can vary by orders of magnitude between species, between systems, and possibly within systems. In addition, transfer factors are applied under a steady state assumption, whereby the relationship between contaminant concentrations in biota tissues and concentrations in abiotic media in the surrounding environment are assumed constant through space and time. As a result, quantification of changes in transfer factors of contaminants, such as radionuclides, in aquatic systems receiving chronic inputs will provide useful insight as to whether variability in transfer factors is related to changes in contaminant fluxes through a lake. Perch Lake (Chalk River, Ontario) represents an ideal system to address such issues, since it has received chronic inputs of 60Co, 137Cs, 90Sr, and 3H that have been changing over a 40 to 50 year period. Changes in transfer of these radionuclides to biota have, therefore, been compared with changes in radionuclide source terms over time. In general, with few exceptions, radionuclide transfer factors were fairly consistent over this period, as indicated by strong correlations between measured and estimated values. This conclusion was further strengthened by comparing radionuclide transfer factors measured in Perch Lake biota relative to those reported for other Canadian Shield lakes, which showed similar values. Based on findings for these radionuclides, it is appropriate to apply generic transfer factors to estimate levels in aquatic biota based on concentrations in surface waters of Canadian Shield lakes. (author)

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

    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. 134Cs, 137Cs, and 60Co 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 134Cs, 137Cs, and 60Co to the selected organisms based on the biological models developed. The total dose rates of 134Cs, 137Cs, and 60Co to the six organisms were all <0.001 μGy h−1. - Highlights: • Pre-assessment for biota dose rates from Haiyang Nuclear Power Plant was made. • The site-specific transfer parameters were obtained by neutron activation analysis. • The dose rates of 134Cs, 137Cs, and 60Co to the organisms were <0.001 μGy h−1

  10. From regionally predictable to locally complex population structure in a freshwater top predator: River systems are not always the unit of connectivity in Northern Pike Esox lucius

    Bekkevold, Dorte; Jacobsen, Lene; Hansen, Jakob Hemmer; Berg, Søren; Skov, Christian

    2015-01-01

    Contemporary genetic diversity is the product of both historical and contemporary forces, such as climatic and geological processes affecting range distribution and continuously moulded by evolutionary forces selection, gene flow and genetic drift. Predatory freshwater fishes, such as Northern Pi...

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

    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...

  12. Greenland Freshwater Input to the North Atlantic

    Beaird, N.; Straneo, F.

    2014-12-01

    The Greenland Ice Sheet (GrIS) is losing mass at an unprecedented rate. The associated increased freshwater flux directly contributes to sea level rise, but also has dynamical implications for the Atlantic Meridional Overturning Circulation and global climate. The freshwater buoyancy forcing from marine terminating outlet glaciers is distributed throughout the depth of coastal fjords. When coupled with strong fjord stratification, this buoyancy forcing can drive significant water mass transformation (WMT) of subsurface waters in the fjord. The WMT differs substantially from a simple freshwater input to the surface ocean. This often overlooked small-scale overturning has potentially important consequences for the influence of GrIS freshwater on large scale ocean circulation and needs to be accounted for in studies of GrIS impact on the ocean. From ship-based and moored hydrographic measurements in East Greenland (2008 to 2013) we describe the character and temporal variability of meltwater driven WMT. While melting always adds freshwater to the ocean, the corresponding WMT causes a seasonally variable vertical redistribution of heat and salt. Observations show that the seasonal cycle of the WMT lags surface air temperatures by several months. We discuss how the WMT and its timing might impact the boundary current system in East Greenland, and implications for its representation in numerical models and impact on North Atlantic deep convection.

  13. Fate of 60Co and 134Cs added to the hypolimnion of a Canadian Shield lake: accumulation in biota

    The addition of 60Co and 134Cs to the anaerobic hypolimnion of a thermally stratified Canadian Shield lake in summer initially isolated the exposure of biota to only zooplankton that undergo vertical migration into this region of the lake. Once the radionuclides became mixed throughout the water column with autumn turnover, other biota were exposed to the radionuclides. In general, 60Co concentrations in biota were low because of the rapid loss to the sediments. Exceptions were for initial 60Co concentrations in filter-feeders (cladocerans and clams) during autumn turnover. Concentrations of 134CS were higher in biota the following spring and summer, reflecting the tendency of 134Cs to remain in the water column. Concentrations of 134Cs still continued to increase in forage fish 1 year following the radionuclide addition. The addition of radionuclides to the hypolimnion resulted in higher concentrations in forage fish than when added to the epilimnion. Radionuclide concentrations in biota varied with taxon and were greatest in periphyton. This study demonstrates that radionuclides that may enter the bottom waters of a lake as a result of nuclear fuel waste disposal will be available to biota and result in a radiation dose to aquatic biota and to humans via the water-fish-human pathway. (author)

  14. Soil and freshwater nematodes of the Iberian fauna: A synthesis

    Peña-Santiago, R.

    2006-12-01

    Full Text Available The first available compilation of Iberian soil and freshwater nematodes is presented in this paper. The inventory is currently made up of 981 species belonging to 236 genera, 77 families and 12 orders. Data of the Iberian nematode fauna are compared with other components of the Iberian biota, as well as the nematode fauna of other geographical regions. Quantitative and qualitative aspects of the nematode inventory are analyzed and discussed, paying special attention to the kind of information available for each species, and concluding that practically one-third of Iberian species are deficiently characterized and need further study. Endemicity of Iberian species is also considered: 143 species, 14.6% of the total, are restricted (in their distribution to the Iberian geography, most of them being members of the orders Dorylaimida (87 and Tylenchida (29, which are also the most diversified nematode taxa. Practical or applied interest of knowledge of the Iberian nematode fauna is commented and supported with examples and recent contributions. Finally, an alphabetical list of the species, ordered by specific name, is provided.

    En esta contribución se presenta una recopilación de las especies ibéricas de nematodos de suelo y de agua dulce, la primera de este tipo realizada hasta el momento. El inventario actual lo componen 981 especies de 236 géneros, 77 familias y 12 órdenes. Los datos correspondiente a la fauna ibérica de nematodos se compara con la de otros táxones de la biota ibérica. Se analizan y se discuten distintos aspectos cuantitativos y cualitativos de la fauna nematológica, con especial énfasis en el tipo de información disponible sobre cada especie, y se concluye que casi una tercera parte de las especies ibéricas permanecen insuficientemente caracterizadas, razón por la cual requieren de estudios adicionales. La endemicidad de las especies es así mismo objeto de atención: 143 especies, un 14.6% del total están restringidas en su distribución al ámbito ibérico, en su mayor parte pertenecientes a los órdenes Dorylaimida (87 y Tylenchida (29, por otra parte los más diversificados de entre los pertenecientes al filo. El interés básico y aplicado del conocimiento de la fauna de nematodos es comentado e ilustrado con aportaciones recientes y ejemplos. Por último, se presenta una lista de todas las especies de la fauna ibérica, ordenadas alfabéticamente por su epíteto específico.

  15. Sulfate reduction in freshwater peatlands

    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 μM. 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 μM h-1 while in B and C they were 1 and 0.05 μM h-1, respectively. Methane production rates, however, were more uniform across the three nutrient regimes. Maximum rates in A (ca. 1.5 μg d-1 g-1) were found 10 cm below the water table, in B (ca. 1.0 μg d-1 g-1) in the vicinity of the water table, and in C (0.75 μg 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

  16. Sulfate reduction in freshwater peatlands

    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

  17. CROATIAN FRESHWATER FISHERIES IN 1996.

    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.

  18. CROATIAN FRESHWATER FISHERIES IN 1997

    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.

  19. Ecosystem Services : In Nordic Freshwater Management

    Magnussen, Kristin; Hasler, Berit; Zandersen, Marianne

    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......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...... 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....

  20. Sulfate reduction and methanogenesis at a freshwater

    Iversen, Vibeke Margrethe Nyvang; Andersen, Martin Søgaard; Jakobsen, Rasmus

    The freshwater-seawater interface was studied in a ~9-m thick anaerobic aquifer located in marine sand and gravel with thin peat lenses. Very limited amounts of iron-oxides are present. Consequently, the dominating redox processes are sulfate reduction and methanogenesis, and the groundwater is...... enriched in dissolved sulfide, methane and bicarbonate. Under normal conditions the seawater-freshwater interface is found at a depth of 4 m at the coastline and reaches the bottom of the aquifer 40 m inland. However, occasional flooding of the area occurs, introducing sulfate to the aquifer. Groundwater...... chemistry was studied in a 120 m transect perpendicular to the coast. Cores were taken for radiotracer rate measurements of sulfate reduction and methanogenesis. In the saline part of the aquifer 35 m inland, sulfate reduction was the dominant process with rates of 0.1-10 mM/year. In the freshwater part 100...

  1. Open minded and open access : introducing NeoBiota, a new peer-reviewed journal of biological invasions

    Ingolf Kühn; Ingo Kowarik; Johannes Kollmann; Uwe Starfinger; Sven Bacher; Tim Blackburn; Ramiro Bustamante; Laura Celesti-Grapow; Milan Chytrý; Robert Colautti; Franz Essl; Llewellyn Foxcroft; Stephan Gollasch; Emili García-Berthou; José Hierro

    2011-01-01

    The Editorial presents the focus, scope, policies, and the inaugural issue of NeoBiota, a new open access peer-reviewed journal of biological invasions. The new journal NeoBiota is a continuation of the former NEOBIOTA publication series. The journal will deal with all aspects of invasion biology and impose no restrictions on manuscript size neither on use of color. NeoBiota implies an XML-based editorial workflow and several cutting-edge innovations in publishing and dissemination, such as s...

  2. Changes to the ocular biota with time in extended- and daily-wear disposable contact lens use.

    Stapleton, F; Willcox, M D; Fleming, C. M.; Hickson, S; Sweeney, D F; Holden, B. A.

    1995-01-01

    Gram-negative bacteria may play a role in the etiology of certain soft contact lens (SCL)-related diseases. Contact lens (CL) wear may modify the normal ocular biota, providing a more favorable environment for potential pathogens. This study reports temporal changes in ocular biota in daily-wear (DW) and extended-wear (EW) disposable SCL use in experienced and neophyte wearers. Lid margin and bulbar conjunctival biota were sampled prior to CL fitting in 26 previous DW SCL users, 18 previous E...

  3. Open minded and open access: introducing NeoBiota, a new peer-reviewed journal of biological invasions

    Ingolf Khn

    2011-08-01

    Full Text Available The Editorial presents the focus, scope, policies, and the inaugural issue of NeoBiota, a new open access peer-reviewed journal of biological invasions. The new journal NeoBiota is a continuation of the former NEOBIOTA publication series. The journal will deal with all aspects of invasion biology and impose no restrictions on manuscript size neither on use of color. NeoBiota implies an XML-based editorial workflow and several cutting-edge innovations in publishing and dissemination, such as semantic markup of and enhancements to published texts, data publication, and extensive cross-linking within the journal and to external sources.

  4. FRESHWATER FISHERY OF THE REPUBLIC OF CROATIA

    Zlatko Homen; Irena Jahutka; Ante Miura; Vesna Fu?ek; Josip Sui?

    1999-01-01

    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 ...

  5. Effects of Pollution on Freshwater Organisms.

    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

  6. Freshwater exposure pathways in the Nordic countries

    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)

  7. Freshwater reservoir effect variability in Northern Germany

    Philippsen, B.; Heinemeier, J.

    The freshwater reservoir effect is a potential problem when radiocarbon dating fish bones, shells, human bones, or food crusts on pottery from sites near rivers or lakes. The reservoir age in hardwater rivers can be up to several thousand years and may be highly variable. Accurate 14C dating of...... freshwater-based samples requires knowing the order of magnitude of the reservoir effect and its degree of variability. Measurements on modern riverine materials may not give a single reservoir age correction that can be applied to archaeological samples, but they show the order of magnitude and variability...

  8. Dispersion Of Crude Oil And Petroleum Products In Freshwater

    The objective of this research was to investigate the relationship between dispersion effectiveness in freshwater and the surfactant composition for fresh and weathered crude oil. Although limited research on the chemical dispersion of crude oil and petroleum products in freshwat...

  9. Threatened and Endangered Freshwater Fish and Mussel Species Richness

    U.S. Environmental Protection Agency — These data represent predicted current distributions of all US listed Threatened and Endangered freshwater fish and freshwater mussels in the Middle-Atlantic...

  10. Freshwater rotifers from Hordaland, western Norway, with a survey of freshwater rotifers previously found in Norway

    Brit Godske Bjørklund

    2010-01-01

      Bjørklund BG. 2009. Freshwater rotifers from Hordaland western Norway with a u survey of freshwater rotifers previously found in Norway. Fauna Norvegica29: 11-54. A total of 156 species (or subspecies) o rotifers, mostly non-planktonic, have been identified from freshwater or slightly brackish-water localities in the county of Hordaland; 83 are new to Norway and 24 others are new to the county. One hundred of the species were collected from the two valleys of Eksingedalen and Teigdalen in...

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

    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)

  12. First Record of Freshwater Fish on the Cape Verdean Archipelago

    Lucek, Kay Jurka Olaf; Lemoine, Mélissa

    2012-01-01

    The Cape Verdean islands form a distinct aquatic freshwater ecoregion characterized mainly by temporal water bodies with an adapted invertebrate community. Freshwater fish were not previously recorded from the archipelago. During a non-exhaustive survey of freshwater bodies on five islands of the archipelago, the first presence of a freshwater fish was recorded. Using barcoding sequences, the species was identified as the guppy (Poecilia reticulata), a highly invasive species alien to the Cap...

  13. Prospects for monitoring freshwater ecosystems towards the 2010 targets

    Revenga, C.; Campbell, I; Abell, R; de Villiers, P; Bryer, M

    2005-01-01

    Human activities have severely affected the condition of freshwater ecosystems worldwide. Physical alteration, habitat loss, water withdrawal, pollution, overexploitation and the introduction of non-native species all contribute to the decline in freshwater species. Today, freshwater species are, in general, at higher risk of extinction than those in forests, grasslands and coastal ecosystems. For North America alone, the projected extinction rate for freshwater fauna is five times greater th...

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

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

    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...... 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...... 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...

  15. Estimating the mortality to aquatic biota from oil releases under water

    A three-dimensional model has been developed to estimate the mortality of aquatic biota from accidental oil releases near the water surface or in deep water. The model is an extension of model previously developed by Yapa and Zheng. This new model incorporates the concentration distribution of polynuclear aromatic hydrocarbon (PAH) to predict the mortality of aquatic biota. It is believed that PAHs comprise the toxic fraction of crude or refined oil. The composition of petroleum hydrocarbons is important in determining the oil toxicity. Computer models can fill gaps when this complete field data is not available. The computer models can take into account the decomposition of oil properties due to weathering and biological factors. This particular computer model was developed to simulate the duration and exposure of known concentrations to toxic substances. The model estimates the resulting acute mortality of marine species. 63 refs., 20 figs

  16. SUPPRESSION ABILITY OF CRUDE EXTRACT DERIVED FROM MARINE BIOTA AGAINST FUSARIUM OXYSPORUM F.SP. VANILLAE

    I Ketut Suada

    2010-06-01

    Full Text Available The objective of this research was to investigate suppression ability of marine biota extracts against Fusarium oxysporum f.sp. vanillae of vanilla stem rot. Samples were collected at intertidal zones and in the depth of 1-7 m from seven beaches in Bali. Screening of active compounds of biota extracts were conducted using inhibition zone of well diffusion method on Potato Dextrose Agar (PDA. The extract was tested in-vitro in PDA medium using completely randomized design with three replicates. The methanolic extract of Aglaophenia sp. was able to suppress the growth of F. oxysporum f.sp. vanillae effectively, with minimum inhibition concentration (MIC of 0.05 %. The extract inhibited colony growth diameter and total mycelial dry weight.

  17. 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

    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

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

    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.

  19. Defoliation reduces soil biota - and modifies stimulating effects of elevated CO2.

    Dam, Marie; Christensen, Søren

    2015-11-01

    To understand the responses to external disturbance such as defoliation and possible feedback mechanisms at global change in terrestrial ecosystems, it is necessary to examine the extent and nature of effects on aboveground-belowground interactions. We studied a temperate heathland system subjected to experimental climate and atmospheric factors based on prognoses for year 2075 and further exposed to defoliation. By defoliating plants, we were able to study how global change modifies the interactions of the plant-soil system. Shoot production, root biomass, microbial biomass, and nematode abundance were assessed in the rhizosphere of manually defoliated patches of Deschampsia flexuosa in June in a full-factorial FACE experiment with the treatments: increased atmospheric CO 2, increased nighttime temperatures, summer droughts, and all of their combinations. We found a negative effect of defoliation on microbial biomass that was not apparently affected by global change. The negative effect of defoliation cascades through to soil nematodes as dependent on CO 2 and drought. At ambient CO 2, drought and defoliation each reduced nematodes. In contrast, at elevated CO 2, a combination of drought and defoliation was needed to reduce nematodes. We found positive effects of CO 2 on root density and microbial biomass. Defoliation affected soil biota negatively, whereas elevated CO 2 stimulated the plant-soil system. This effect seen in June is contrasted by the effects seen in September at the same site. Late season defoliation increased activity and biomass of soil biota and more so at elevated CO 2. Based on soil biota responses, plants defoliated in active growth therefore conserve resources, whereas defoliation after termination of growth results in release of resources. This result challenges the idea that plants via exudation of organic carbon stimulate their rhizosphere biota when in apparent need of nutrients for growth. PMID:26640664

  20. New occurence of the Cambrian (Stage 4, Series 2) Guanshan Biota in Huize, Yunnan, South China

    Liu J N; Ou Q; Han J; Zhang Z.F.; He T J; Yao X Y; Fu D J; Shu D G

    2012-01-01

    Typical elements of the Guanshan Biota are reported from the Cambrian Stage 4 Wulongqing Formation of Huize, Qujing, South China, approximately 100 km north of the Guanshan fossil sites previously reported. Lithostratigraphy and biostratigraphy of the current Zhujiaqing section are also discussed herein. Representatives of various phyla recovered therein include not only previously described sponges, palaeoscolecids, arthropods, brachiopods, echinoderms, and vetulicolians, but also some poten...

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

    Dong Ren; ChungKun Shih; Conrad Labandeira

    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 ...

  2. Guidance for dispersant decision-making : potential for impacts on aquatic biota

    French McCay, D.; Graham, E. [Applied Science Associates Inc., South Kingstown, RI (United States)

    2009-07-01

    This presentation discussed issues regarding the uncertainty about the efficacy of dispersant use and the tradeoffs of impact caused by floating versus dispersed oil. Laboratory and tank experimentations have been used to better understand the impacts to water column organisms and the fate and toxicity of oil. The Spill Impact Model Application Package (SIMAP) developed by Applied Science Associates Inc. was run to simulate hypothetical oil spills with and without dispersant use under a range of environmental conditions. SIMAP quantifies fates and concentrations of subsurface oil components, including dissolved and particulate components, along with areas swept by floating oil of various thicknesses. The 3-D physical fates model in SIMAP estimates distribution of whole oil and oil components on the water surface, on shorelines, in the water column, and in sediments. It simulates processes such as spreading; evaporation of volatiles from surface oil; transport on the surface and in the water column; randomized dispersion from small-scale mixing; emulsification; entrainment of oil and droplets into the water; dissolution of soluble components; volatilization of dissolved hydrocarbons from the surface water; adherence of oil droplets to suspended sediments; adsorption of soluble and semi-soluble aromatics to suspended sediments; sedimentation; stranding on shorelines; and degradation. The results revealed the water volume where acute toxic effects would occur and impact birds and other wildlife. In order to put these impact volumes and areas in perspective, typical densities of biota in various geographical regions were used to compare injuries with which to evaluate tradeoffs. As a general conclusion, the tradeoff with respect to wildlife versus water column biota is in favour of dispersant use for oil volumes greater than 2 m{sup 3}, while remaining protective of all species. Dispersing more than this volume in a single location during a short period of time could impact biota in the surface mixed layer, depending on winds, degree of current shear, weathering state, temperature and sensitivity of the aquatic biota. 35 refs., 1 tab., 15 figs.

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

    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)

  4. Biota of a Pennsylvanian muddy coast: habitat within the Mazonian delta complex, northeast Illinois

    Baird, G.C.

    1985-03-01

    The Mazon Creek biota (Westphalian D) is composed of plants and animals from terrestrial fresh water and marginal marine habitats. Fossil animals, including jellyfish, worms, crustaceans, holothurians, insects, chordates, and problematica occur in sideritic concretions on spoilpiles of more than 100 abandoned coal mines in a five county region (Mazon Creek area) of northeast Illinois. These fossils record rapid burial and early diagenesis in a muddy, delta-influenced coastal setting submerged during marine transgression.

  5. International Recommendations on Calculation of Absorbed Dose in Biota: A Comprehensive Revue

    Wagner de S. Pereira; Alphonse Kelecom

    2014-01-01

    Since the early times, radioprotection has been focused on the human being. Currently this approach has changed, being now also necessary to take care of the protection of the environment from unwanted effects of ionizing radiation. To this end, several institutions (UNSCEAR, ICRP, IAEA, DOE, ACRP) and consortia of institutions (FASSET, ERICA) have established procedures in order to protect the biota of such effects. Developed procedures are based on the calculation of ...

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

    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

  7. Critical appraisal of tubular putative eumetazoans from the Ediacaran Weng'an Doushantuo biota

    Cunningham, John A.; Vargas, Kelly; Pengju, Liu; Belivanova, Veneta; Marone, Federica; Martínez-Pérez, Carlos; Guizar-Sicairos, Manuel; Holler, Mirko; Bengtson, Stefan; Donoghue, Philip C. J.

    2015-01-01

    Molecular clock analyses estimate that crown-group animals began diversifying hundreds of millions of years before the start of the Cambrian period. However, the fossil record has not yielded unequivocal evidence for animals during this interval. Some of the most promising candidates for Precambrian animals occur in the Weng'an biota of South China, including a suite of tubular fossils assigned to Sinocyclocyclicus, Ramitubus, Crassitubus and Quadratitubus, that have been interpreted as soft-...

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

    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 ČR GA526/01/1055; GA ČR(CZ) GA526/06/0728; GA AV ČR 1QS600660505 Institutional research plan: CEZ:AV0Z60660521 Keywords : soil * soil biota * post mining sites Subject RIV: EH - Ecology, Behaviour

  9. 40 CFR 35.1605-2 - Freshwater lake.

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Freshwater lake. 35.1605-2 Section 35... STATE AND LOCAL ASSISTANCE Cooperative Agreements for Protecting and Restoring Publicly Owned Freshwater Lakes § 35.1605-2 Freshwater lake. Any inland pond, reservoir, impoundment, or other similar body...

  10. CROATIAN FRESHWATER FISHERIES IN 1994

    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.

  11. CROATIAN FRESHWATER FISHERIES IN 1995

    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 Draganići: 15.60 tons of fish per employee.

  12. A case study in the Chernobyl exclusion zone - Part 2: predicting radiation induced effects in biota

    In recent years national and international programmes have proposed a number of frameworks and methodologies to assess the protection of wildlife from ionising radiations. Whilst some of these are now being used by national authorities there has been little attempt to rigorously test their predictions against available data. In part this is because there are few sites where radiation induced effects have been observed. The Chernobyl exclusion zone represents a site where assessment framework predictions from exposure through to effects can be thoroughly tested. In a separate paper, we have tested predictions of terrestrial radionuclide transfer models developed within the EC FP5 project FASSET against available radionuclide activity concentration database for terrestrial biota in the exclusion zone. In this paper we use the dose conversion factors developed within the FASSET project to estimate internal and external doses to biota within the exclusion zone. The estimated doses are then used to predict effects at different biological levels of organisation using the FASSET Radiation Effects Database (FRED); predicted effects are compared to observed effects within the Chernobyl exclusion zone. The observed effects data for the exclusion zone covers organisms from soil biota through to fish and mammals. Results of the comparison are used to make recommendations for future improvements to assessment frameworks. (author)

  13. Cretaceous biota of the Tringulo Mineiro region (Brazil: A review of recent finds

    Candeiro, C. R. A.

    2007-06-01

    Full Text Available The Bauru Group (Adamantina, Uberaba, and Marlia Formations crop out in the Tringulo 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 Marlia en la regin del Tringulo Mineiro, Provincia de Minas Gerais, Brasil, posee un rico contenido de biota continental. Los taxa de invertebrados y vertebrados de estos estratos, as como las correlaciones biostratigrficas con otros yacimientos fsiles de Argentina, sugieren una edad del Cretcico Tardo. La diversidad de la asociacin fsil registrada en las formaciones del Tringulo Mineiro se resume en el presente trabajo e incluye: sapos, lagartos, tortugas, cocodrilianos, titanosaurideos, dinosaurios abelisaurideos y carcharodontosaurideos. Esta asociacin es importante para la comprensin de las faunas del sur de Amrica y tambin de las del Cretcico de frica.

  14. Fuzzy logic modeling of bioaccumulation pattern of metals in coastal biota of Ondo State, Nigeria.

    Agunbiade, Foluso O; Olu-Owolabi, Bamidele I; Adebowale, Kayode O

    2012-01-01

    The accumulation patterns of ten metals in tissues of plant, Eichornia crassipes, and fishes, Hydrocynus forskahlii and Oreochromis mossambicus, were modeled with simple fuzzy classification (SFC) to assess toxic effects of anthropogenic activities on the coastal biota. The plant sample was separated into root, stem, and leaves and the fishes into bones, internal tissues, and muscles. They were analyzed for As, Cd, Cr, Cu, Ni, Pb, V, Fe, Mn, and Zn after wet oxidation of their dried samples. The results were converted into membership functions of five accumulation classes and aggregated with SFC. The classification results showed that there was no metal accumulation in the plant parts while the fishes were classified into low accumulation category. The internal tissues of the fishes had higher metal accumulation than the other parts. Generally, Fe and Mn had highest concentrations in the biota but are natural to the area and may not constitute significant risk. Cr had the highest transfer and accumulation from the coastal water into the aquatic lives and may be indicative of risk prone system being a toxic metal. Metal contaminations in the zone had not significantly accumulated in the biota making them less prone to risk associated with metal accumulation. PMID:21374045

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

    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.)

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

    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

  17. Acute toxicity of heavy metals towards freshwater ciliated protists

    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. Acute toxicity of heavy metals towards freshwater ciliated protists

    Madoni, Paolo [Dipartimento di Scienze Ambientali, Universita degli Studi di Parma, Parco Area delle Scienze 11/A, 43100 Parma (Italy)]. E-mail: paolo.madoni@unipr.it; Romeo, Maria Giuseppa [Dipartimento di Scienze Ambientali, Universita degli Studi di Parma, Parco Area delle Scienze 11/A, 43100 Parma (Italy)

    2006-05-15

    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 LC{sub 5} 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{sup -1}, LC{sub 5}) and lead (0.12 mg l{sup -1}, LC{sub 5}), whilst E. aediculatus showed the highest sensitivity for nickel (0.03 mg l{sup -1}, LC{sub 5}). 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.

  19. Mathematical Explorations: Freshwater Scarcity: A Proportional Representation

    King, Alessandra

    2014-01-01

    Middle school students' mathematical understanding benefits from connecting mathematics to other content areas in the curriculum. This month's activity explores the issue of the scarcity of freshwater, a natural resource (activity sheets are included). This activity concentrates on the critical areas mentioned in the Common Core State…

  20. Neutron activation analysis of freshwater samples

    The authors report on some questions concerning the NAA of freshwater samples such as sample handling, reproducibility, blank values and determination limits for Na, Mg, Al, Cl, K, Ca, V, Mn, Sr, Ba, Fe, Co, Cu, Zn, As and Mo. (author)

  1. Tetanus after envenomations caused by freshwater stingrays.

    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

  2. FRESHWATER SNAILS (MOLLUSCA: GASTROPODA) OF NORTH AMERICA

    Freshwater gastropod mollusks are represented in North America (north of Mexico) by 15 families, 78 genera and, as treated in this manual, 499 species. They are grouped into two large subclasses, the gill-breathing, operculated Prosobranchia and the lung-breathing, non-operculate...

  3. Are freshwater pelagic ciliates important bacterivores?

    Šimek, Karel; Jezbera, Jan; Macek, Miroslav; Nedoma, Jiří; Dolan, J. R.

    Innsbruck : Institute for Limnology of the Austrian Academy of Sciences, 2003. s. 36. [Assessing the Variability in Aquatic Microbial Populations: Facts and Fiction. 16.02.2003-20.02.2003, Mondsee] Institutional research plan: CEZ:AV0Z6017912 Keywords : flagellate and ciliate bacterivory * freshwater plankton Subject RIV: EH - Ecology, Behaviour

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

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

    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...

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

    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

  6. The assembly of montane biotas: linking Andean tectonics and climatic oscillations to independent regimes of diversification in Pionus parrots

    Ribas, Camila C; Moyle, Robert G.; Miyaki, Cristina Y.; Cracraft, Joel

    2007-01-01

    The mechanisms underlying the taxonomic assembly of montane biotas are still poorly understood. Most hypotheses have assumed that the diversification of montane biotas is loosely coupled to Earth history and have emphasized instead the importance of multiple long-distance dispersal events and biotic interactions, particularly competition, for structuring the taxonomic composition and distribution of montane biotic elements. Here we use phylogenetic and biogeographic analyses of species in the...

  7. Identification and characterization of GABA(A) receptor modulatory diterpenes from Biota orientalis that decrease locomotor activity in mice.

    Zaugg, Janine; Khom, Sophia; Eigenmann, Daniela; Baburin, Igor; Hamburger, Matthias; Hering, Steffen

    2011-08-26

    An ethyl acetate extract of Biota orientalis leaves potentiated GABA-induced control current by 92.6% 22.5% when tested at 100 ?g/mL in Xenopus laevis oocytes expressing GABA(A) receptors (?????(2S) subtype) in two-microelectrode voltage clamp measurements. HPLC-based activity profiling was used to identify isopimaric acid (4) and sandaracopimaric acid (5) as the compounds largely responsible for the activity. Sandaracopimaradienolal (3) was characterized as a new natural product. Compounds 4 and 5 were investigated for GABA(A) receptor subtype selectivity at the subtypes ?????(2S), ?????(2S), ?????(2S), ?????(2S), ?????(2S), and ?????(2S). Sandaracopimaric acid (5) was significantly more potent than isopimaric acid (4) at the GABA(A) receptor subtypes ?????(2S), ?????(2S), and ?????(2S) (EC??4: 289.5 82.0, 364.8 85.0, and 317.0 83.7 ?M vs EC??5: 48.1 13.4, 31.2 4.8, and 40.7 14.7 ?M). The highest efficiency was reached by 4 and 5 on ??- and ??-containing receptor subtypes. In the open field test, ip administration of 5 induced a dose-dependent decrease of locomotor activity in a range of 3 to 30 mg/kg body weight in mice. No significant anxiolytic-like activity was observed in doses between 1 and 30 mg/kg body weight in mice. PMID:21793559

  8. Feedbacks between geomorphology and biota controlling Earth surface processes and landforms: A review of foundation concepts and current understandings

    Corenblit, Dov; Baas, Andreas C. W.; Bornette, Gudrun; Darrozes, José; Delmotte, Sébastien; Francis, Robert A.; Gurnell, Angela M.; Julien, Frédéric; Naiman, Robert J.; Steiger, Johannes

    2011-06-01

    This review article presents recent advances in the field of biogeomorphology related to the reciprocal coupling between Earth surface processes and landforms, and ecological and evolutionary processes. The aim is to present to the Earth Science community ecological and evolutionary concepts and associated recent conceptual developments for linking geomorphology and biota. The novelty of the proposed perspective is that (1) in the presence of geomorphologic-engineer species, which modify sediment and landform dynamics, natural selection operating at the scale of organisms may have consequences for the physical components of ecosystems, and particularly Earth surface processes and landforms; and (2) in return, these modifications of geomorphologic processes and landforms often feed back to the ecological characteristics of the ecosystem (structure and function) and thus to biological characteristics of engineer species and/or other species (adaptation and speciation). The main foundation concepts from ecology and evolutionary biology which have led only recently to an improved conception of landform dynamics in geomorphology are reviewed and discussed. The biogeomorphologic macroevolutionary insights proposed explicitly integrate geomorphologic niche-dimensions and processes within an ecosystem framework and reflect current theories of eco-evolutionary and ecological processes. Collectively, these lead to the definition of an integrated model describing the overall functioning of biogeomorphologic systems over ecological and evolutionary timescales.

  9. Freshwater flux to Sermilik Fjord, SE Greenland

    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.

  10. Investigation of manganese in salt- and freshwater pearls

    The trace element distribution in natural and cultured pearls is analysed by micro-PIXE, cathodoluminescence (CL) microscopy and spectroscopy and electron spin resonance (ESR) spectroscopy to develop a new method to distinguish cultured from natural pearls. These different kinds of pearls can be identified by their manganese content and its distribution in aragonite and calcite structure, respectively. Manganese content of natural freshwater pearls from Persian Gulf was compared to that of natural freshwater pearls from the Mississippi river (USA). Moreover manganese content of tissue-graft freshwater pearls from Chansu (China) was compared to that of natural freshwater pearls from the Mississippi river (USA). It was proved that the Chinese freshwater tissue-graft cultured pearls generally contain domains of calcite, emitting orange Mn2+-activated CL which are almost absent in the natural freshwater pearls from the Mississippi river. Freshwater pearls showing much higher Mn concentrations build in calcitic and aragonitic parts compared to saltwater pearls

  11. CROATIAN FRESHWATER FISHERY IN 2001 and 2002

    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 warmwater species and 280.44 t/ha for coldwater species. In the year 2002 production per unit area for warmwater species was 462.95 kg/ha, and for coldwater 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 20012002 in comparison with the period 19982000. 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.

  12. Physical processes in freshwater ecosystems

    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)

  13. Lead-induced biochemical changes in freshwater fish Oreochromis mossambicus

    Ruparelia, S.G.; Verma, Y.; Mehta, N.S.; Salyed, S.R. (National Institute of Occupational Health, Ahmedabad (India))

    1989-08-01

    Lead, a non-essential and non-beneficial element has considerably added the problem of health hazard to human and experimental mammals. It has also received much attention over the past few years as potentially important aquatic pollutant. Fishes are of great nutritional significance and their intoxication by lead causes retardation of growth and deterioration in the nutritional value. Very little attention has been paid to biochemical changes which develop more quickly in response to toxicants than any apparent morphological changes. Therefore, the present investigation was undertaken to evaluate the effect of lead on plasma chemistry of freshwater fish Oreochromis mossambicus. This fish was selected because of its wide availability, edibility in India and its suitability as a model fish for toxicity testing. The variables such as glucose, cholesterol and protein representing carbohydrate, lipid and protein metabolism were studied.

  14. Calorific and carbon values of marine and freshwater Protozoa

    Finlay, B. J.; Uhlig, G.

    1981-12-01

    Calorific and carbon values were determined for a variety of marine and freshwater Protozoa ( Noctiluca miliaris, Euplotes sp., Eufolliculina sp. respectively Tetrahymena pyriformis, Paramecium caudatum), their food sources (Bacteria, Dunaliella primolecta, Ceratium hirundinella), and for Protozoa-dominated plankton samples. Most calorific values lie close to the centre of the range covering organisms in general. Low values in some marine samples probably resulted from the retention of bound water in the dried material. When all results were combined with data selected from the literature, the dependence of calorific value on carbon content was highly significant. This relationship is probably also adequately described by an energy-carbon regression through the variety of organic compounds commonly found in organisms. Calorific value expressed per unit carbon is shown to vary little in Protozoa (mean conversion factor 46 J [mg C]-1) or throughout the range of biological materials considered in this study (45 J [mg C]-1).

  15. Bioaccumulation of polybrominated diphenyl ethers by the freshwater benthic amphipod Gammarus pulex.

    Tlili, Khawla; Labadie, Pierre; Bourges, Catherine; Desportes, Annie; Chevreuil, Marc

    2012-07-01

    This study reports on the relationship between polybrominated diphenyl ether (PBDE) levels in water, sediment, and the benthic macroinvertebrate Gammarus pulex, which plays a major ecological role in freshwater ecosystems. Samples were taken in a periurban watershed (near Paris, France), and PBDEs were systematically detected in sediment (≤727 ng g(-1) OC) and G. pulex (≤264 ng g(-1) lipids). PBDEs were also occasionally detected in the water column at low levels (∑ PBDEs < 1.5 ng L(-1)). The log values of bioaccumulation factors were in the range 7.8 ± 0.1-8.3 ± 0.4 L kg(-1) for tetra- and penta-BDEs, which were the only ones quantified in the dissolved phase of river water. Meanwhile, levels of individual tri- to hepta-PBDE congeners in G. pulex generally positively correlated with sediment levels, suggesting an equilibrium situation. Biota-to-sediment accumulation factors (BSAFs) of tri-hepta BDEs were congener specific and were in the range 0.5 ± 0.3-2.6 ± 1.2. For several PBDEs, BSAF values deviated from the expected range, likely because of in vivo metabolism. PMID:22367498

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

    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.

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

    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.

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

    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

  19. Population-specific renal proteomes of marine and freshwater three-spined sticklebacks.

    Kültz, Dietmar; Li, Johnathon; Paguio, Darlene; Pham, Tuan; Eidsaa, Marius; Almaas, Eivind

    2016-03-01

    Quantitative proteomics was used to reveal biochemical differences in kidneys of marine and freshwater three-spined sticklebacks. More than 1500 unambiguous proteins were identified, 106 of which are robustly co-translationally modified. Amino-terminal acetylation sites for 94 and proline hydroxylation sites for 12 proteins, including 4 protein disulfide isomerases having the consensus motif APWCGHCK, were determined. More than 1500 proteins were quantified by LC-MS/MS yielding 120 proteins with consistent population-specific abundance differences. Twenty-five of these were selected for validation by data-independent acquisition (DIA) and spectral library based MS2 quantitation. A dense biochemical network was revealed, which promotes the synthesis of the organic osmolytes betaine, sorbitol, trimethylamine oxid (TMAO), and urea. It contains 33 of 49 proteins that are elevated in marine compared to freshwater sticklebacks, including the most highly elevated proteins (dimethylaniline monooxygenase, alanine-glyoxylate aminotransferase, glycine N-methyltransferase). Freshwater stickleback kidneys contain elevated levels of proteolytic, cytoskeletal, extracellular matrix, and calcium signaling proteins. Proteins that are most elevated in freshwater sticklebacks are ES1 protein homolog, apoptosis-associated speck-like protein containing a CARD and caspase 1. Protein-abundance network analysis demonstrates significantly higher levels of synchronized abundance control in marine sticklebacks. The significance of these findings for biochemical diversification of renal function in marine and FW sticklebacks is discussed. PMID:26463136

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

    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.

  1. Assessing the freshwater distribution of yellow eel

    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.

  2. Freshwater fishes of Bontebok National Park

    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.

  3. Freshwater fishes of Tsitsikamma National Park

    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.

  4. Freshwater aquatic plant biomass production in Florida

    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.

  5. Freshwater biodiversity and aquatic insect diversification.

    Dijkstra, Klaas-Douwe B; Monaghan, Michael T; Pauls, Steffen U

    2014-01-01

    Inland waters cover less than 1% of Earth's surface but harbor more than 6% of all insect species: Nearly 100,000 species from 12 orders spend one or more life stages in freshwater. Little is known about how this remarkable diversity arose, although allopatric speciation and ecological adaptation are thought to be primary mechanisms. Freshwater habitats are highly susceptible to environmental change and exhibit marked ecological gradients. Standing waters appear to harbor more dispersive species than running waters, but there is little understanding of how this fundamental ecological difference has affected diversification. In contrast to the lack of evolutionary studies, the ecology and habitat preferences of aquatic insects have been intensively studied, in part because of their widespread use as bioindicators. The combination of phylogenetics with the extensive ecological data provides a promising avenue for future research, making aquatic insects highly suitable models for the study of ecological diversification. PMID:24160433

  6. Critical loads of sulphur and nitrogen for freshwaters in Great Britain and assessment of deposition reduction requirements with the First-order Acidity Balance (FAB) model

    Curtis, C.; Allott, T.; Hall, J.; Harriman, R.; Helliwell, R.; Hughes, M.; Kernan, M.; Reynolds, B; J. Ullyett

    2002-01-01

    The critical loads approach is widely used within Europe to assess the impacts of acid deposition on terrestrial and freshwater ecosystems. Recent work in Great Britain has focused on the national application of the First-order Acidity Balance (FAB) model to a freshwaters dataset of 1470 lake and stream water chemistry samples from sites across Britain which were selected to represent the most sensitive water bodies in their corresponding 10 km grid square. A ``Critical Load...

  7. Critical loads of sulphur and nitrogen for freshwaters in Great Britain and assessment of deposition reduction requirements with the First-order Acidity Balance (FAB) model

    Curtis, C.; Allott, T.; Hall, Janet; Harriman, R.; Helliwell, R.; Hughes, M.; Kernan, M.; Reynolds, B; J. Ullyett

    2000-01-01

    The critical loads approach is widely used within Europe to assess the impacts of acid deposition on terrestrial and freshwater ecosystems. Recent work in Great Britain has focused on the national application of the First-order Acidity Balance (FAB) model to a freshwaters dataset of 1470 lake and stream water chemistry samples from sites across Britain which were selected to represent the most sensitive water bodies in their corresponding 10 km grid square. A ``Critical Load Function" generat...

  8. Freshwater peat on the continental shelf

    Emery, K.O.; Wigley, R.L.; Bartlett, A.S.; Rubin, M.; Barghoorn, E.S.

    1967-01-01

    Freshwater peats from the continental shelf off northeastern United States contain the same general pollen sequence as peats from ponds that are above sea level and that are of comparable radiocarbon ages. These peats indicate that during glacial times of low sea level terrestrial vegetation covered the region that is now the continental shelf in an unbroken extension from the adjacent land areas to the north and west.

  9. Freshwater savings from marine protein consumption

    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. (paper)

  10. New records of freshwater fish for Uruguay

    Zarucki, M; I. González-Bergonzoni; Teixeira-de-Mello, F.; Duarte, A.; S. Serra; Quintans, F.; Loureiro, M.

    2010-01-01

    Based on National Collections records, this article presents the first report of eight freshwater fish speciesfor Uruguay in the middle and lower Uruguay River basin, extending their current distribution: Cyanocharax alegretensisMalabarba and Weitzman, 2003; Leporinus lacustris Amaral Campos, 1945; Microglanis aff. eurystoma Malabarba andMahler, 1998; Tatia boemia Koch and Reis, 1996; Lepthoplosternum pectorale (Boulenger, 1895); Crenicichla missioneiraLucena and Kullander, 1992; C. minuano L...

  11. Trends in freshwater and marine aquaculture

    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...

  12. Ecosystem Services : In Nordic Freshwater Management

    Magnussen, Kristin; Hasler, Berit; Zandersen, Marianne

    2014-01-01

    Human wellbeing is dependent upon and benefit from ecosystemservices which are delivered by well-functioning ecosystems.Ecosystem services can be mapped and assessed consistentlywithin an ecosystem service framework. This project aimsto explore the use and usefulness of the ecosystem serviceframework in freshwater management, particularly watermanagement according to the Water Framework Directive (WFD).There are several examples of how ecosystem services have beenused in WFD related studies i...

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

    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)

  14. Assessment of the impact of radionuclide releases from Canadian nuclear facilities on non-human biota

    The radiological impact of radionuclides released from nuclear facilities is being assessed for regulatory purposes using an ecological assessment framework. Hazard quotients are determined by dividing an estimated exposure value (EEV) by an estimated no effect value (ENEV). Values less than one indicate that environmental harm is not likely, whereas in Tier 2 or Tier 3 assessments values greater than one indicate the potential for environmental harm. Radiation exposure values are calculated using annual mean radionuclide concentrations in water, sediment and biota, and either published screening DCFs or dosimetry equations taking into account the geometry and size of the organism. A relative biological effectiveness (RBE) weighting factor of 40 for alpha emitters and 3 for tritium is used in the dose calculations. When radionuclide concentrations are not measured in biota, they are estimated from published geometric mean concentration ratios. Radionuclide concentrations in benthic invertebrates are assumed to be equivalent to those in the sediment. The radiation dose is the sum of the internal and external doses, except for benthic invertebrates where the total radiation dose is assumed to be from internal radiation exposure. The ENEVs for the various taxonomic groups are determined from literature data using an ecotoxicological approach. The ENEVs derived for radiation effects on biota are: 0.2 Gy·a-1 for fish, 2 G a-1 for both benthic invertebrates and terrestrial invertebrates, and 1 Gy·a-1 for algae, macrophytes, mammals and terrestrial plants. The assessment conducted for uranium mines and mills is presented as a case study outlining the recommended approach. The results suggest that a probabilistic Tier 3 assessment may not be necessary when environmental data are readily available. (author)

  15. Nutrients in a freshwater lagoon, lagos, nigeria

    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)

  16. THE DEVELOPMENT OF FRESHWATER FISHING IN ELAZIĞ

    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 Elazığ that increased its importance depending on the fishery activities in inland water in recent years. Our reasearch area, Elazığ, is situated in the Upper Fırat 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 Fırat 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 Kralkızı, 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 Elazığ.

  17. Extraction of Freshwater and Energy from Atmosphere

    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...

  18. Monitoring Global Freshwater Resources with GRACE

    Rodell, Matt; Famiglietti, Jay; Velicogna, Isabella; Swenson, Sean; Chambers, Don

    2011-01-01

    Freshwater resources include surface waters, groundwater, and seasonal snowpack. Given adequate ground based measurements, all of these can be monitored effectively, however, outside of the developed world such measurements often are not systematic and the data not centralized, and as a result reports of freshwater availability may be largely anecdotal. Even in the developed world it can be difficult to quantify changes in groundwater storage over large scales. Owing to its global coverage, satellite remote sensing has become a valuable tool for freshwater resources assessment. In particular, the Gravity Recovery and Climate Experiment (GRACE) has demonstrated an unequaled ability to monitor total terrestrial water storage including groundwater at regional to continental scales. In this presentation we will identify apparent trends in terrestrial water storage observed by GRACE over the past nine years and attempt to explain their origins and predict whether they are likely to continue. Trends in certain regions where groundwater extraction has significantly depleted aquifers, including northern India and California, will be discussed in detail.

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

    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 μGy h-1. (author)

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

    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)

  1. Amino acid racemization on Mars: implications for the preservation of biomolecules from an extinct martian biota

    Bada, J. L.; McDonald, G. D.; Miller, S. L. (Principal Investigator)

    1995-01-01

    Using kinetic data, we have estimated the racemization half-lives and times for total racemization of amino acids under conditions relevant to the surface of Mars. Amino acids from an extinct martian biota maintained in a dry, cold (<250 K) environment would not have racemized significantly over the lifetime of the planet. Racemization would have taken place in environments where liquid water was present even for time periods of only a few million years following biotic extinction. The best preservation of both amino acid homochirality and nucleic acid genetic information associated with extinct martian life would be in the polar regions.

  2. Natural radioactivity status in mining settling ponds: Bioaccumulation of Radium in biota and the derived dose

    A radiological survey has been carried out in two mining settling ponds in Upper Silesia in Poland based on natural radionuclide inventory in abiotic environment and the consequent dose rate assessment for representative species of biota. The distribution of natural radionuclides in the two mining settling ponds was studied in relation to the abiotic environment and the biotic environment interaction. More specific, the study was focused at the abandoned settling ponds of Rontok and Bojszowy, characterized by the presence of high salinity levels and enhanced Radium concentrations, in comparison with the wide Polish territory

  3. BIOTA DO SOLO E SUAS RELAÇÕES ECOLÓGICAS COM O SISTEMA RADICULAR

    Carmen Maria Coimbra Manhães

    2013-11-01

    Full Text Available Soil is a natural resource essential to human survival. Its we pulled our food, for the food prodution to be more balanced, it is necessary manage and conserve well this natural resource. Especially in regard to soil biota, for being active life is very sensitive to anthropogenic soil management, becoming an easy target in the process of degradation and soil impoverishment. The soil fauna is characterized as individuals who spend most of their life cycle in the soil. This article aimed at reporting the various specific ecological relationships that occur between soil biota and the root system and its main consequences for the soil-rhizosphere, using for this purpose a literature review. The study of the ecology of the rhizosphere can be considered as a multidisciplinary study, very important to unravel mysteries that occur within the soil and elucidate important issues that have not yet been completely elucidated. O solo é um recurso natural essencial para a sobrevivência humana. dele retiramos o nosso alimento, para que a produção de alimentos seja mais equilibrada, é necessário manejar e conservar bem este recurso natural. Principalmente no que se refere à biota do solo, pois por se tratar de vida ativa é muito sensível ás ações antrópicas de manejo do solo, se tornando um alvo fácil no processo de degradação e empobrecimento do solo. A fauna do solose caracteriza como indivíduos que passam a maior parte do seu ciclo de vida no solo. este artigo objetivo relatar as várias relações ecológicas específicas que ocorrem entre a biota do solo e o sistema radicular e suas principais consequências para o sistema solo-rizosfera, utilizando para isto de uma revisão de literatura. O estudo da ecologia da rizosfera pode ser considerado como um estudo multidisciplinar, muito importante para se desvendar mistérios que ocorrem dentro do solo e elucidar questões importantes que até agora não foram completamente elucidadas.

  4. Ecosystem services driven by soil biota - Relevance and management in land use

    Potthoff, Martin; Peres, Guenola; Zaller, Johann; Pullemann, Mirjam; Taylor, Astrid

    2015-04-01

    To understand how land use systems affect soil biodiversity and how soil biodiversity (i.e. the performance of functional groups) feeds back to soil functions and ecosystem services is essential to establish sustainable practices in future soil management. This poster aims to summaries the current knowledge and perspectives on soil biota as the driver of key processes in soil and ecosystem functioning. We will list key processes and the driving organisms, as well as indicate and valuate management practices refering to current European projects. In conclusion we will suggest implementation strategies and identify research needs.

  5. A new neuroprotective pinusolide derivative from the leaves of Biota orientalis.

    Koo, Kyung Ah; Sung, Sang Hyun; Kim, Young Choong

    2002-06-01

    A new pinusolide derivative, 15-methoxypinusolidic acid (1), and another new isopimarane diterpene, ent-isopimara-15-en-3 alpha,8 alpha-diol (2) with three known diterpenes, lambertianic acid (3), isopimara-8(9),15-dien-18-oic acid (4) and isopimara-7(8),15-dien-3 beta,18-diol (5) were isolated from the 90% MeOH fraction of Biota orientalis (L.) ENDL. (Cupressaceae) leaves. Chemical structures of 1-5 were elucidated by analyses of their spectral data, including the two-dimensional (2D) NMR technique. Compound 1 showed significant protective activity against glutamate-induced neurotoxicity in primary cultures of rat cortical cells. PMID:12045342

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

    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.

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

    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-2.65 ng/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

  8. The Earliest Fossil Evidence for Life on Land and the Freshwater Origin of Algae?

    Battison, L.; Brasier, M. D.; Antcliffe, J. B.

    2009-04-01

    Some 150 years ago, in 1859, Charles Darwin was greatly puzzled by a seeming absence of fossils in rocks older than the Cambrian period. He drew attention to a veritable Lost World that it is now known to have spanned more than 80 per cent of Earth History. And he made a prediction that we here bring again into focus: 'The presence of phosphate nodules and bituminous matter in some of the lowest azoic rocks probably indicates the former existence of life at these periods (Darwin 1859, p.307). His prediction came to fruition in 1899, when Sir Archibald Geikie announced to the world the first discovery of genuine microfossils in Precambrian phosphatic rocks, made by Jephro Teall, Ben Peach and John Horne within the Torridonian rocks of Scotland. The Torridonian phosphate of NW Scotland has, however, been rather little studied until recently. It is remarkable for its fidelity of fossil preservation, and also for its non-marine depositional setting. Dating to the end of the Mesoproterozoic Era around 1Ga ago, thick packages of fluvial sandstones are found to serve the remains of very ancient intermontane lake ecosystems. Fossil assemblages from terrestrial settings are rarely seen before the Devonian ~ 350 Ma ago. Evidence for freshwater and terrestrial life in the Precambrian has therefore been circumstantial rather than detailed and none has yet come from freshwater phosphate. We here demonstrate that phosphate from ~ 1200-1000 Ma Mesoproterozoic lake sediments of the Torridon Group preserve a remarkable suite of organisms forming a freshwater, terrestrial, phototrophic ecosystem. Ephemeral lakes and streams developed in intermontane basins within the interior of the supercontinent of Rodinia and periodically experienced prolonged desiccation allowing phosphate precipitation. The microbiology of these lake sediments is being studied in detail, where they are yielding - with the aid of Automontage - fresh evidence for the earliest known terrestrial ecology and lagerstatte. Delicate cellular structures, and even sub-cellular structures, can be preserved with high fidelity in the phosphate. These cells show evidence for life cycles that ranged from resting cysts - sometimes sculptured - to colonial vegetative stages and thence to single celled dispersal stages. Cyanobacteria, eukaryotic protists and algae are all present. The ecological structure and responses of these Torridon lake communities can be compared with those of modern, mainly acidiphilic, lakes. Together with sedimentary structures and wrinkle mats of demonstrably microbial origin, we can point to the variable development of seasonal eutrophication and stagnation in the photic zone of these ancient lakes. Population statistics of the various morphotypes reveal differences between the assemblages collected from older and younger units of the Torridon Group, attributable to differing lacustrine ecologies. Such exceptional preservation in the Proterozoic is part of an emerging picture of evolving taphonomic styles through time, in which better preservation of cells is found as we go further back into the fossil record. We attribute this remarkable preservation in the Proterozoic to very early diagenesis in a world before the evolution of a sediment Mixed Layer during the Cambrian explosion of the Metazoa. This evidence suggests that Earth's terrestrial biota and its associated phosphorus cycle were well established on land by ~1000 Ma ago. It also suggests that many algal groups, which today are obligate freshwater denizens, may have originated in freshwater lakes over a billion years ago.

  9. Field and model investigations of freshwater lenses in coastal aquifers

    Pauw, P.S.

    2015-01-01

    A major problem of sustaining freshwater supply from freshwater lens is the invasion of saline groundwater into a fresh groundwater body. In many coastal areas saltwater intrusion has led to well closure and reduced freshwater supply. Furthermore, in the future saltwater intrusion is expected to increase due to sea level rise, climate change, land subsidence, and increasing population density in coastal areas. In the Netherlands, these stresses will also have a severe impact on the fresh coas...

  10. Occurrence of microcystin-producing cyanobacteria in Ugandan freshwater habitats

    Okello, William; Portmann, Cyril; Erhard, Marcel; Gademann, Karl; Kurmayer, Rainer

    2010-01-01

    Microcystins (MCs) are cyclic heptapeptides that are the most abundant toxins produced by cyanobacteria in freshwater. The phytoplankton of many freshwater lakes in Eastern Africa is dominated by cyanobacteria. Less is known, however, on the occurrence of MC producers and the production of MCs. Twelve Ugandan freshwater habitats ranging from mesotrophic to hypertrophic conditions were sampled in May and June of 2004 and April of 2008 and were analyzed for their physico-chemical parameters, ph...

  11. Incidence and level of Vibrio parahaemolyticus associated with freshwater plankton.

    Sarkar, B. L.; Nair, G B; Sircar, B K; Pal, S. C.

    1983-01-01

    We isolated Vibrio parahaemolyticus from plankton samples collected from different freshwater areas in the vicinity of Calcutta, India. Levels of this organism in association with freshwater plankton were low (less than 90 organisms per g). All of the 16 strains of V. parahaemolyticus isolated in this study were Kanagawa negative, and all except 1 were untypable. The occurrence of V. parahaemolyticus in association with freshwater plankton suggests that adsorption onto plankton may aid the su...

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

    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 μg/L and 0.54 μg/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 μg/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

  13. Study of the behaviour of transuranics and possible chemical homologues in Lake Michigan water and biota

    Concentration factors for Pu, Am and U in Lake Michigan biota are compared to those of a number of stable trace elements that have short residence times in Lake Michigan water. The relative order of uptake for these nuclides in Lake Michigan biota is Am>Pu much>U. Evidence is summarized which suggests that the predominant oxidation state of 239, 240Pu in Lake Michigan water is 4+. Concentrations of 239, 240Pu in net plankton, filterable particulate matter, sediment trap, and benthic floc samples indicate that sorption by biogenic detritus, and settling of this material, can account for the reduced concentration of 239, 240Pu observed in surface waters during summer stratification, but that deposition into the sediments is primarily non-biological. Concentrations of 7Be, 144Ce and 137Cs in sediment trap samples show the effect of spring convective mixing and demonstrate the resuspension of mineral-rich surficial sediments during the summer months. The effect on the concentration of dissolved plutonium in the water column, of varying degrees of resuspension of sedimentary floc, is described using a simple mass-action model. A radiochemical method for the determination of americium and uranium in Lake Michigan environmental samples is also presented. (author)

  14. Spatial relationships among soil biota in a contaminated grassland ecosystem at Aberdeen Proving Ground, Maryland

    Kuperman, R. [Army ERDEC, Aberdeen Proving Ground, MD (United States); Williams, G. [Argonne National Lab., IL (United States); Parmelee, R. [Ohio State Univ., Columbus, OH (United States)

    1995-12-31

    Spatial relationships among soil nematodes and soil microorganisms were investigated in a grassland ecosystem contaminated with heavy metals in the US Army`s Aberdeen Proving Ground. The study quantified fungal and bacterial biomass, the abundance of soil protozoa, and nematodes. Geostatistical techniques were used to determine spatial distributions of these parameters and to evaluate various cross-correlations. The cross-correlations among soil biota numbers were analyzed using two methods: a cross general relative semi-variogram and an interactive graphical data representation using geostatistically estimated data distributions. Both the visualization technique and the cross general relative semi-variogram and an interactive graphical data representation using geostatistically estimated data distributions. Both the visualization technique and the cross general relative semi-variogram showed a negative correlation between the abundance of fungivore nematodes and fungal biomass, the abundance of bacterivore nematodes and bacterial biomass, the abundance of omnivore/predator nematodes and numbers of protozoa, and between numbers of protozoa and both fungal and bacterial biomass. The negative cross-correlation between soil biota and metal concentrations showed that soil fungi were particularly sensitive to heavy metal concentrations and can be used for quantitative ecological risk assessment of metal-contaminated soils. This study found that geostatistics are a useful tool for describing and analyzing spatial relationships among components of food webs in the soil community.

  15. Evidence of Helicobacter spp. in freshwaters from Roraima Tepui, Guayana Shield, South America.

    Fernández-Delgado, Milagro; Giarrizzo, Juan G; García-Amado, María A; Contreras, Monica; Salazar, Víctor; Barton, Hazel; Suárez, Paula

    2016-04-01

    Helicobacter presence and viability in waters is not well characterized. The identification of natural reservoirs and infection sources may provide novel insights into its waterborne transmission. The goal of this study was to investigated the occurrence of Helicobacter spp. in natural freshwaters from Roraima Tepui, a little studied and unique ecosystem of the Guayana Shield. Freshwaters collected from two localities at Roraima Tepui were cultured in HP selective broth and agar for Helicobacter pylori and analysed by fluorescent in situ hybridization (FISH), specific PCR assays, 16S rRNA gene sequencing and phylogenetic analysis. The presence of other bacteria in freshwater enrichments was determined using clone library sequencing of the 16S rRNA gene and phylogenetic inferences. Helicobacter spp. were detected by semi-nested PCR and FISH in freshwater enrichments from both sites. Coccoid viable but nonculturable (VBNC) cells were evidenced using 16S rRNA gene Helicobacter species and H. pylori-specific probes. Partial 16S rRNA gene sequences of two HP enrichments showed high similarity to H. pylori and Helicobacter nemestrinae (99-100 %). Other bacteria such as Serratia, Aquitalea, Chromobacterium, Mycobacterium, Acinetobacter, Curvibacter and Dysgonomonas were also detected using complete 16S rRNA gene sequences, with Serratia, Aquitalea and Chromobacterium the most common genera (40.9, 18.2 and 15.2 %, respectively). This is the first time that Helicobacter spp. have been reported in freshwaters of a tepui ecosystem. Our results contribute to the current knowledge of these bacteria in the aquatic environment and expand their known/potential sites outside the human host. PMID:26825784

  16. Accessory cells in the gill epithelium of the freshwater rainbow trout Salmo gairdneri.

    Pisam, M; Prunet, P; Rambourg, A

    1989-04-01

    Two types of mitochondria-rich cells were identified in the gill epithelium of the freshwater-adapted rainbow trout, Salmo gairdneri, after selective impregnation of their tubular system with reduced osmium. A first type consisted of large cells with a poorly developed and loosely anastomosed tubular system; thus, that resembled the chloride cells commonly encountered in the gill epithelium of freshwater-adapted euryhaline fishes. A second type comprised smaller cells with an extensively developed and tightly anastomosed tubular system. These never reached the basal lamina of the gill epithelium and were adjacent to chloride cells, to which they were linked by shallow apical junctions (100-200 nm); thus, they resembled accessory cells, which are currently found in the gill epithelium of seawater-adapted fishes but are usually lacking in freshwater living fishes. Transfer of the freshwater-adapted trout into seawater induced the proliferation of the tubular system in the chloride cells and the formation of lateral plasma membrane interdigitations between accessory cells and the apical portion of the chloride cells. The length of the apical junction sealing off this extended intercellular space was reduced to 20-50 nm. The tubular system of the accessory cells was not modified. The extension of the tubular system in the chloride cells of the seawater-adapted fishes indicated that, as in most euryhaline fishes, these cells have a role in the adaptation of the rainbow trout to seawater. In contrast, the function of the presumptive accessory cells in freshwater trout remains to be established. PMID:2756905

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

    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)

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

    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)

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

    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 μg/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 μg/kg total DDT. (author). 4 refs, 2 tabs

  20. Astrobiology and habitability studies in preparation for future Mars missions: trends from investigating minerals, organics and biota

    Ehrenfreund, P.; Röling, W. F. M.; Thiel, C. S.; Quinn, R.; Sephton, M. A.; Stoker, C.; Kotler, J. M.; Direito, S. O. L.; Martins, Z.; Orzechowska, G. E.; Kidd, R. D.; van Sluis, C. A.; Foing, B. H.

    2011-07-01

    Several robotic exploration missions will travel to Mars during this decade to investigate habitability and the possible presence of life. Field research at Mars analogue sites such as desert environments can provide important constraints for instrument calibration, landing site strategies and expected life detection targets. We have characterized the mineralogy, organic chemistry and microbiology of ten selected sample sites from the Utah desert in close vicinity to the Mars Desert Research Station (MDRS) during the EuroGeoMars 2009 campaign (organized by International Lunar Exploration Working Group (ILEWG), NASA Ames and ESA ESTEC). Compared with extremely arid deserts (such as the Atacama), organic and biological materials can be identified in a larger number of samples and subsequently be used to perform correlation studies. Among the important findings of this field research campaign are the diversity in the mineralogical composition of soil samples even when collected in close proximity, the low abundances of detectable polycyclic aromatic hydrocarbons (PAHs) and amino acids and the presence of biota of all three domains of life with significant heterogeneity. An extraordinary variety of putative extremophiles, mainly Bacteria and also Archaea and Eukarya was observed. The dominant factor in measurable bacterial abundance seems to be soil porosity and lower small (clay-sized) particle content. However, correlations between many measured parameters are difficult to establish. Field research conducted during the EuroGeoMars 2009 campaign shows that the geological history and depositional environment of the region, as well as the mineralogy influence the ability to detect compounds such as amino acids and DNA. Clays are known to strongly absorb and bind organic molecules often preventing extraction by even sophisticated laboratory methods. Our results indicate the need for further development and optimization of extraction procedures that release biological compounds from host matrices to enable the effective detection of biomarkers during future sampling campaigns on Earth and Mars.

  1. Changes to the ocular biota with time in extended- and daily-wear disposable contact lens use.

    Stapleton, F; Willcox, M D; Fleming, C M; Hickson, S; Sweeney, D F; Holden, B A

    1995-11-01

    Gram-negative bacteria may play a role in the etiology of certain soft contact lens (SCL)-related diseases. Contact lens (CL) wear may modify the normal ocular biota, providing a more favorable environment for potential pathogens. This study reports temporal changes in ocular biota in daily-wear (DW) and extended-wear (EW) disposable SCL use in experienced and neophyte wearers. Lid margin and bulbar conjunctival biota were sampled prior to CL fitting in 26 previous DW SCL users, 18 previous EW SCL users, and 26 neophytes. Wearers were fitted with an etafilcon A CL in one eye and a polymacon CL in the fellow eye. Lenses were worn on a daily basis by the 26 previous DW SCL wearers and on an EW basis by the remaining 44 subjects. The ocular biota was further sampled after 1, 3, 6, 9, and 12 months of wear. The ocular biota consisted of coagulase-negative staphylococci, Corynebacterium spp., Micrococcus spp., and Propionibacterium spp. Potential pathogens were rarely isolated at baseline. No significant trend of increasing ocular colonization was shown for extended CL wear. Lid and conjunctival colonization increased with DW SCL use (P < 0.001), although this increase occurred for nonpathogenic species only. Fewer potential pathogens were isolated from DW SCL than from EW SCL users (P < 0.05). The lid margin consistently showed greater colonization than the conjunctiva and may be a source of potential pathogens during CL wear. Hydrogel CL wear appears to modify the ocular biota. An increased number of commensal organisms were present in DW SCL use. EW SCL use altered the spectrum of organisms isolated. These alterations may suppress the normal ocular defense mechanisms and may be relevant in the pathogenesis of CL-related disease. PMID:7591092

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

    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

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

    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

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

    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

  5. Mapping spatial variability in redox conditions at the landscape scale using the stable isotopic compositions of biota

    We are attempting to use the ?15N, ?13C and ?34S of biota in marshes and riverine systems as indicators of local environmental conditions that may impact water salinity. The theoretical basis of this study is that the isotopic compositions of plankton and non-fixing plants reflect to a large extent the isotopic compositions of the dissolved N, C and S in the environment that is being utilized by the biota, as modified by various possible fractionating mechanisms in the plants

  6. Freshwater flux to Sermilik Fjord, SE Greenland

    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. Glycosylation of bisphenol A by freshwater microalgae.

    Nakajima, Nobuyoshi; Teramoto, Tetsuya; Kasai, Fumie; Sano, Tomoharu; Tamaoki, Masanori; Aono, Mitsuko; Kubo, Akihiro; Kamada, Hiroshi; Azumi, Yoshitaka; Saji, Hikaru

    2007-10-01

    The endocrine disruptor bisphenol A (BPA, 4,4'-isopropylidenediphenol) is used to manufacture polycarbonate plastic and epoxy resin linings of food and beverage cans, and the residues from these products are then sometimes discharged into rivers and lakes in waste leachates. However, the fate of BPA in the environment has not yet been thoroughly elucidated. Considering the effect of BPA on aquatic organisms, it is important that we estimate the concentration of BPA and its metabolites in the aquatic environment, but there are few data on the metabolites of BPA. Here, we focused on freshwater microalgae as organisms that contribute to the biodegradation or biotransformation of BPA in aquatic environments. When we added BPA to cultures of eight species of freshwater microalgae, a reduction in the concentration of BPA in the culture medium was observed in all cultures. BPA was metabolized to BPA glycosides by Pseudokirchneriella subcapitata, Scenedesmus acutus, Scenedesmus quadricauda, and Coelastrum reticulatum, and these metabolites were then released into the culture medium. The metabolite from P. subcapitata, S. acutus, and C. reticulatum was identified by FAB-MS and (1)H-NMR as bisphenol A-mono-O-beta-d-glucopyranoside (BPAGlc), and another metabolite, from S. quadricauda, was identified as bisphenol A-mono-O-beta-d-galactopyranoside (BPAGal). These results demonstrate that freshwater microalgae that inhabit universal environments can metabolize BPA to its glycosides. Because BPA glycosides accumulate in plants and algae, and may be digested to BPA by beta-glycosidase in animal intestines, more attention should be given to levels of BPA glycosides in the environment to estimate the ecological impact of discharged BPA. PMID:17629547

  8. Actinorhodopsin genes discovered in diverse freshwater habitats and among cultivated freshwater .i.Actinobacteria./i

    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

    Roč. 3, č. 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

  9. Dissolved methane in Indian freshwater reservoirs

    Narvenkar, G.; Naqvi, S.W.A.; Kurian, S.; Shenoy, D.M.; Pratihary, A.K.; Naik, H.; Patil, S.; Sarkar, A.; Gauns, M.

    stream_size 37936 stream_content_type text/plain stream_name Environ_Monit_Assess_2013_GN.pdf.txt stream_source_info Environ_Monit_Assess_2013_GN.pdf.txt Content-Encoding UTF-8 Content-Type text/plain; charset=UTF-8 1... Author version: Environ. Monit. Assess.; 2013, doi: 10.1007/s10661-013-3079-5 Dissolved methane in Indian freshwater reservoirs G. Narvenkara*, S. W. A. Naqvia, S. Kuriana, D.M. Shenoya, A.K. Pratiharya, , H. Naika, S. Patila, A. Sarkara, M. Gaunsa...

  10. 76 FR 17962 - Strengthening the Scientific Understanding of Climate Change Impacts on Freshwater Resources of...

    2011-03-31

    ... Geological Survey Strengthening the Scientific Understanding of Climate Change Impacts on Freshwater... titled ``Strengthening the Scientific Understanding of Climate Change Impacts on Freshwater Resources of the United States''. The report reviews key issues related to freshwater resource data and...

  11. A model for selecting bioindicators to monitor radionuclide concentrations using Amchitka Island in the Aleutians as a case study

    World War II and the Cold War have left the Unites States, and other Nations, with massive cleanup and remediation tasks for radioactive and other legacy hazardous wastes. While some sites can be cleaned up to acceptable residential risk levels, others will continue to hold hazardous wastes, which must be contained and monitored to protect human health and the environment. While media (soil, sediment, groundwater) monitoring is the usual norm at many radiological waste sites, for some situations (both biological and societal), biomonitoring may provide the necessary information to assure greater peace of mind for local and regional residents, and to protect ecologically valuable buffer lands or waters. In most cases, indicators are selected using scientific expertise and a literature review, but not all selected indicators will seem relevant to stakeholders. In this paper, I provide a model for the inclusion of stakeholders in the development of bioindicators for assessing radionuclide levels of biota in the marine environment around Amchitka Island, in the Aleutian Chain of Alaska. Amchitka was the site of three underground nuclear tests from 1965 to 1971. The process was stakeholder-initiated, stakeholder-driven, and included stakeholders during each phase. Phases included conceptualization, initial selection of biota and radionuclides, refinement of biota and radionuclide target lists, collection of biota, selection of biota and radionuclides for analysis, and selection of biota, tissues, and radionuclides for bioindicators. The process produced site-specific information on biota availability and on radionuclide levels that led to selection of site-appropriate bioindicators. I suggest that the lengthy, iterative, stakeholder-driven process described in this paper results in selection of bioindicators that are accepted by biologists, public health personnel, public-policy makers, resource agencies, regulatory agencies, subsistence hunters/fishers, and a wide range of other stakeholders. The process is applicable to other sites with ecologically important buffer lands or waters, or where contamination issues are contentious

  12. Freshwater rotifers from Hordaland, western Norway, with a survey of freshwater rotifers previously found in Norway

    Brit Godske Bjørklund

    2010-01-01

    Full Text Available   Bjørklund BG. 2009. Freshwater rotifers from Hordaland western Norway with a u survey of freshwater rotifers previously found in Norway. Fauna Norvegica29: 11-54. A total of 156 species (or subspecies o rotifers, mostly non-planktonic, have been identified from freshwater or slightly brackish-water localities in the county of Hordaland; 83 are new to Norway and 24 others are new to the county. One hundred of the species were collected from the two valleys of Eksingedalen and Teigdalen in spring and summer 1967. Samples were taken on the shallow shores of lake-like parts of the rivers, and in pools, tarns and small lakes. Forty more or less euryhaline fresh­water rotifers were also collected during studies of slightly brackish-water localities around Bergen in 1963-1969. A number of freshwater rotifers were collected at several localities in and around Bergen in 1968-1970, and on the western part of Hardangervidda. Of those so far identified ,23 are new to Norway and 8 more are new to the county. They are therefore included in the species list. A few additional ones are referred to in the taxonomical notes. All the species are listed with localities and habitat categories, or, in the case of the last-mentioned ones, just the district where they were collected. The paper includes notes, measurements and ,in most cases, figures regarding 44 little known, variable or taxonomically problematical species, especially in the genera Cephalodella and Trichocerca. Comments are given on the distribution , abundance and diversity of the species. The paper presents asurvey of previous investigations on rotifers in Norway, listing 200 previously recorded freshwater (a few euryhaline rotifers, giving other names, the authors who recorded the finds and, in most cases, the counties where the species were collected. 

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

    Salieri, Beatrice; Righi, Serena; Pasteris, Andrea; Olsen, Stig Irving

    2015-01-01

    , 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...

  14. Isolation and characterization of the microbial community of a freshwater distribution system

    This investigation provides generic information on culturable and non-culturable microbial community of a freshwater distribution system. Culture based and culture independent (16S rRNA gene sequencing) techniques were used to identify the resident microbial community of the system. Selective isolation of the fouling bacteria such as biofilm formers and corrosion causing bacteria was also attempted. Denaturing gradient gel electrophoresis (DGGE) was carried out and the bands were sequenced to obtain the diversity of the total bacterial types. Pseudomonas aeruginosa was predominantly observed in most of the samples. A variety of bacteria, related to groups such as Cyanobacteria, Proteobacteria, Actinobacteria, Bacteroidetes and Firmicutes were identified. The study highlights the relevance of the observed microbial diversity with respect to material deterioration in a freshwater distribution system, which can aid in designing effective control methods. (author)

  15. A new tropical algal test to assess the toxicity of metals in freshwaters. Supervising Scientists Report 133

    Copper (Cu) and uranium (U) are of potential ecotoxicological concern to tropical Australian freshwater biota as a result of mining impacts. No local data on the toxicity of these metals to tropical freshwater algae are currently available. The aim of this study was to develop a toxicity test for an Australian tropical freshwater alga that can be added to the suite of tests currently available for tropical freshwater invertebrates and fish. This toxicity test was used to investigate the toxicity of Cu and U to the alga Chlorella sp (new species) in a synthetic softwater and to specifically determine the effect of pH on metal toxicity over the range typically found in soft fresh surface waters in tropical northern Australia. A growth inhibition toxicity test was successfully developed for this alga, which was isolated from Kakadu National Park, Northern Territory, prior to conducting the toxicity testing. Key environmental parameters including light, temperature and nutrients were optimised to obtain acceptable algal growth rates over 72 hours. HEPES buffer (2 mM at pH 6.5) was found to be a suitable and practical option for pH control that could be incorporated in the test protocol for Chlorella sp. The results obtained in this study confirmed a lack of toxic effects by HEPES on the algae, as well as negligible complexation with both Cu and U. Adequate pH control (ie -1) than U (13 μg L-1), and more sensitive than other Australian tropical freshwater species, with an order of sensitivity: Alga ≥Crustacea > Cnidaria > Mollusca > Chordata. The toxicity of Cu and U was highly pH-dependent. Copper concentrations needed to inhibit growth by 50% (72 h EC50) increased from 1.5 to 35 μg Cu L-1 as the pH decreased from 6.5 to 5.7. The 72 h EC50 for U increased from 44 to 78 μg U L-1 over the same pH range. Decreased toxicity at pH 5.7 was due to lower concentrations of cell-bound and intracellular Cu and U compared to that at pH 6.5. These results are explained in terms of the possible mechanism of competition between H+ and the metal ion at the cell surface. The comparative sensitivity of Chlorella sp to Cu and U was also assessed. Chlorella sp was two times more sensitive to Cu than to U at pH 5.7 and up to 30 times more sensitive to Cu at pH 6.5 on a weight basis. However, on a molar basis, Chlorella sp was two times more sensitive to U than to Cu at pH 5.7. At pH 6.5, Cu was >8 times more toxic to the alga than U. This species was sensitive enough to detect adverse effects of Cu at the ANZECC guideline values of 5 μg Cu L-1, making it a sensitive test organism for the assessment of Cu contamination of freshwaters. However, the unusual, often non-sigmoidal, concentration-response curve for Chlorella sp may reduce the reproducibility of the toxicity test. Despite this, Chlorella sp does possess a number of desirable characteristics for use in toxicity assessment and therefore is recommended to be used as part of a battery of toxicity tests with other local freshwater organisms. In particular, the alga's high sensitivity to Cu and U and environmental relevance make it a suitable choice for site-specific testing of mine wastewaters in tropical Australia. The findings obtained in this study have the potential to be incorporated into future revisions of the Australian water quality guidelines

  16. Reclaiming freshwater sustainability in the Cadillac Desert

    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.; Hopmans, Jan W.; 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 be rendered infertile by salt, and water scarcity will pit growing desert cities against agribusiness in the face of dwindling water resources. Here we evaluate these claims using the best available data and scientific tools. Our analysis provides strong scientific support for many of Reisner's claims, except the notion that reservoir storage is imminently threatened by sediment. More broadly, we estimate that the equivalent of nearly 76% of streamflow in the Cadillac Desert region is currently appropriated by humans, and this figure could rise to nearly 86% under a doubling of the region's population. Thus, Reisner's incisive journalism led him to the same conclusions as those rendered by copious data, modern scientific tools, and the application of a more genuine scientific method. We close with a prospectus for reclaiming freshwater sustainability in the Cadillac Desert, including a suite of recommendations for reducing region-wide human appropriation of streamflow to a target level of 60%.

  17. Heart Rate Sensor for Freshwater Mussels

    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.

  18. Radurization of commercial freshwater fish species

    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)

  19. Ammonium transformation in a nitrogen-rich tidal freshwater marsh

    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 mars...

  20. Freshwater clams as bioconcentrators of avian influenza virus in water.

    Huyvaert, Kathryn P; Carlson, Jenny S; Bentler, Kevin T; Cobble, Kacy R; Nolte, Dale L; Franklin, Alan B

    2012-10-01

    We report experimental evidence for bioconcentration of a low-pathogenicity avian influenza virus (H6N8) in the tissue of freshwater clams. Our results support the concept that freshwater clams may provide an effective tool for use in the early detection of influenza A viruses in aquatic environments. PMID:22925022

  1. Greater diversification of freshwater than marine parasites of fish.

    Poulin, Robert

    2016-04-01

    The species richness of freshwater environments is disproportionately high compared with that of the oceans, given their respective sizes. If diversification rates are higher in freshwaters because they are isolated and heterogeneous, this should apply to parasites as well. Using 14 large datasets comprising 677 species of freshwater and marine fish, the hypothesis that freshwater parasites experience higher rates of diversification than marine ones is tested by contrasting the relative numbers of species per parasite genus between the regional endohelminth faunas of fish in both environments. The relationship between the number of parasite genera and the number of parasite species per host was well described by a power function, in both environments; although the exponent of this function was slightly lower for freshwater parasite faunas than marine ones, the difference was not significant. However, the ratio between the number of parasite species and the number of parasite genera per host species was significantly higher in freshwater fish than in marine ones. These findings suggest fundamental differences between the way parasite faunas diversify in freshwater versus marine habitats, with the independent evolution of conspecific parasite populations in isolated host populations being a more common phenomenon in freshwater environments. PMID:26802461

  2. Defoliation reduces soil biota - and modifies stimulating effects of elevated CO2

    Dam, Marie; Christensen, Søren

    2015-01-01

    to experimental climate and atmospheric factors based on prognoses for year 2075 and further exposed to defoliation. By defoliating plants, we were able to study how global change modifies the interactions of the plant-soil system. Shoot production, root biomass, microbial biomass, and nematode...... defoliation on microbial biomass that was not apparently affected by global change. The negative effect of defoliation cascades through to soil nematodes as dependent on CO2 and drought. At ambient CO2, drought and defoliation each reduced nematodes. In contrast, at elevated CO2, a combination of drought and...... defoliation was needed to reduce nematodes. We found positive effects of CO2 on root density and microbial biomass. Defoliation affected soil biota negatively, whereas elevated CO2 stimulated the plant-soil system. This effect seen in June is contrasted by the effects seen in September at the same site. Late...

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

    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.

  4. Is marine debris ingestion still a problem for the coastal marine biota of southern Brazil?

    Tourinho, Paula S; Ivar do Sul, Juliana A; Fillmann, Gilberto

    2010-03-01

    The accumulation of synthetic debris in marine and coastal environments is a consequence of the intensive and continuous release of these highly persistent materials. This study investigates the current status of marine debris ingestion by sea turtles and seabirds found along the southern Brazilian coast. All green turtles (n=34) and 40% of the seabirds (14 of 35) were found to have ingested debris. No correlation was found between the number of ingested items and turtle's size or weight. Most items were found in the intestine. Plastic was the main ingested material. Twelve Procellariiformes (66%), two Sphenisciformes (22%), but none of the eight Charadriiformes were found to be contaminated. Procellariiformes ingested the majority of items. Plastic was also the main ingested material. The ingestion of debris by turtles is probably an increasing problem on southern Brazilian coast. Seabirds feeding by diverse methods are contaminated, highlighting plastic hazard to these biota. PMID:19931101

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

    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

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

    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

  7. Floodplain data: ecosystem characteristics and /sup 137/Cs concentrations in biota and soil. [ORNL

    Van Voris, P.; Dahlman, R.C.

    1976-11-01

    Radiocesium (/sup 137/Cs) 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 /sup 137/Cs 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 /sup 137/Cs 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 /sup 137/Cs concentrations in biota and soil.

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

    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.

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

    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.

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

    Hsu, M.J. [Department of Biological Sciences, National Sun Yat-sen University, Kaohsiung 804, Taiwan (China); Selvaraj, K. [Institute of Marine Geology and Chemistry, National Sun Yat-sen University, Kaohsiung 804, Taiwan (China); Agoramoorthy, G. [Department of Pharmacy, Tajen University, Yanpu, Pingtung 907, Taiwan (China)]. E-mail: agoram@mail.tajen.edu.tw

    2006-09-15

    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.

  11. Bioaccumulation of artificial radionuclides and dose assessment to biota in the Yenisei River (Russia)

    The subject of this paper is reconstruction of accumulation of artificial radionuclides (32P, 137Cs, 65Zn, 51Cr, 54Mn) by the Yenisei River biota during the 25-years period (1975-2000), and estimation of the internal dose rates to the river organisms. Yenisei River is located in Central Siberia (Russia); since 1958 artificial radionuclides intake to the Yenisei River with the routine releases from the Krasnoyarsk Mining and Chemical Industrial Complex (KMCIC). Among the radionuclides presented in the releases, 32P is of particular importance. Reconstruction of the radionuclide assimilation by the Yenisei biota was performed using the ECOMOD model approach. The model considers a radionuclide as a tracer, identical in its properties to a stable (analogous) element participated in the metabolism of aquatic organism. Radionuclide assimilated by an organism goes to the production of new biomass, and to compensation of metabolic losses of the analogous bioelement. Basic equations of the general ECOMOD approach are described in the paper. The model was adapted to the conditions of the Yenisei River and applied to calculate the dynamics of 32P, 137Cs, 65Zn, 51Cr, 54Mn in the most typical Yenisei fish species: roach (non-predatory) and pike (predatory). Shown are the reconstructed activity concentrations in roach and pike at the distances 16-80 km downstream the KMCIC. Activity concentrations of 32P in the Yenisei fish were considerably higher comparing with other radionuclides. Activity concentrations of 32P, 65Zn, 51Cr, 54Mn in roach are higher than in pike, whereas activity concentrations of 137Cs are higher in predatory species. Results of the model reconstruction were compared with the available data of measurements, and such comparison confirms adequacy of the model predictions. Long-term dynamics of the internal exposure was estimated for the river organisms at the distances 16-80 km downstream the KMCIC. Average dose rates from incorporated ?-emitters were calculated taking into account geometric characteristics of organisms; ?- particles were assumed to be totally absorbed within the organisms. Average length of roach in the Yenisei River is 0.2 m, weight 0.17 kg; average length of pike in the Yenisei River is 0.52 m, weight 1.2 kg. Dose conversion factors for 32P, 137Cs, 65Zn, 51Cr and 54Mn are shown in Table 3. Annual average dose rates from incorporated radionuclides to the Yenisei biota are presented. Maximum dose rates occurred in 1975-1980 and varied from 11 mGy/year (predatory fish) to 63 mGy/year (molluscs). These levels were several times higher than the background exposure to the Yenisei organisms, which was estimated as 0.7-4 mGy/year. Major contributor to the internal exposure to the Yenisei biota is 32P (up to 95%)

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

    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)

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

    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)

  14. Impacts on non-human biota from a generic geological disposal facility for radioactive waste: some key assessment issues

    This paper provides an overview of key issues associated with the application of currently available biota dose assessment methods to consideration of potential environmental impacts from geological disposal facilities. It explores philosophical, methodological and practical assessment issues and reviews the implications of test assessment results in the context of recent and on-going challenges and debates.

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

    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

  16. Study of the uncertainty in estimation of the exposure of non-human biota to ionising radiation

    Uncertainty in estimations of the exposure of non-human biota to ionising radiation may arise from a number of sources including values of the model parameters, empirical data, measurement errors and biases in the sampling. The significance of the overall uncertainty of an exposure assessment will depend on how the estimated dose compares with reference doses used for risk characterisation. In this paper, we present the results of a study of the uncertainty in estimation of the exposure of non-human biota using some of the models and parameters recommended in the FASSET methodology. The study was carried out for semi-natural terrestrial, agricultural and marine ecosystems, and for four radionuclides (137Cs, 239Pu, 129I and 237Np). The parameters of the radionuclide transfer models showed the highest sensitivity and contributed the most to the uncertainty in the predictions of doses to biota. The most important ones were related to the bioavailability and mobility of radionuclides in the environment, for example soil-to-plant transfer factors, the bioaccumulation factors for marine biota and the gut uptake fraction for terrestrial mammals. In contrast, the dose conversion coefficients showed low sensitivity and contributed little to the overall uncertainty. Radiobiological effectiveness contributed to the overall uncertainty of the dose estimations for alpha emitters although to a lesser degree than a number of transfer model parameters

  17. Soil biota in Bt-corn: effect on community structure and function in laboratory and field experiments

    Frouz, Jan; Kocourek, F.

    České Budějovice : Institute of Soil Biology ASCR, 2005. s. 24. [Central European Workshop on Soil Zoology /8./. 20.04.2005-22.04.2005, České Budějovice] Institutional research plan: CEZ:AV0Z60660521 Keywords : soil biota * Bt- corn * laboratory and field experiments Subject RIV: EH - Ecology, Behaviour

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

    Zacharda, Miloslav; Boucníková, Eva

    Sup.1/2005, č. 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

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

    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

  20. Prehistoric Inuit whalers affected Arctic freshwater ecosystems.

    Douglas, Marianne S V; Smol, John P; Savelle, James M; Blais, Jules M

    2004-02-10

    It is commonly assumed that High Arctic lakes and ponds were not affected by direct local human activities before the arrival of Europeans, because most native peoples were primarily nomadic, maintained relatively low population densities, and practiced unintrusive hunting and gathering technologies. Our archeological and paleolimnological data show that this was not always the case. Thule Inuit whalers, whose winter settlements consisted of houses constructed from the bones of bowhead whales on Somerset Island between about anno Domini 1200 and 1600, markedly changed pond water quality and ecology. The arrival of whalers 8 centuries ago caused marked changes in water chemistry and the expansion of moss substrates. Although whalers abandoned the area >4 centuries ago, the legacy of these human disturbances is still evident in the pond's present-day limnology and is characterized by elevated nutrient concentrations and atypical biota. This is the earliest reported paleolimnological record of changes in aquatic ecology associated with local human activities in Canada or the United States, or for any circumpolar ecosystem. PMID:14745043

  1. Review of research on impacts to biota of discharges of naturally occurring radionuclides in produced water to the marine environment

    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. -- Highlights: ► Produced water from offshore oil industry contains naturally occurring radionuclides. ► Published research on the impacts to biota from these radionuclides is reviewed. ► Review includes impact of added chemicals on the fate of discharged radionuclides. ► Studies indicate negligible risk to biota but substantial uncertainties remain.

  2. Comparative study on the susceptibility of freshwater species to copper-based pesticides.

    de Oliveira-Filho, Eduardo Cyrino; Lopes, Renato Matos; Paumgartten, Francisco José Roma

    2004-07-01

    Copper compounds have been intentionally introduced into water bodies as aquatic plant herbicides, algicides and molluscicides. Copper-based fertilizers and fungicides have been widely used in agriculture as well. Despite the fact that copper is an essential element for all biota, elevated concentrations of this metal have been shown to affect a variety of aquatic organisms. Nonetheless, comparative studies on the susceptibility of different freshwater species to copper compounds have seldom been performed. This study was conducted to compare toxicity of copper-based pesticides (copper oxychloride, cuprous oxide and copper sulfate) to different freshwater target (Raphidocelis subcapitata, a planktonic alga and Biomphalaria glabrata, a snail) and non-target (Daphnia similis, a planktonic crustacean and Danio rerio, a fish) organisms. Test water parameters were as follows: pH = 7.4 +/- 0.1; hardness 44 +/- 1 mg/l as CaCO3; DO 8-9 mg/l at the beginning and > 4 mg/l at the end; temperature, fish and snails 25 +/- 1 degrees C, Daphnia 20 +/- 2 degrees C, algae 24 +/- 1 degrees C. D. similis (immobilization), 48-h EC50s (95% CLs) ranging from 0.013 (0.011-0.016) to 0.043 (0.033-0.057) mg Cu/l, and R. subcapitata (growth inhibition), 96-h IC50s from 0.071 (0.045-0.099) to 0.137 (0.090-0.174) mg Cu/l, were the most susceptible species. B. glabrata (lethality), 48-h LC50s from 0.179 (0.102-0.270) to 0.854 (0.553-1.457) mg Cu/l, and D. rerio (lethality), 48-h LC50s 0.063 (0.045-0.089), 0.192 (0.133-0.272) and 0.714 (0.494-1.016) mg Cu/l, were less susceptible than Daphnia to copper-based pesticides. Findings from the present study therefore suggest that increased levels of copper in water bodies is likely to adversely affect a variety of aquatic species. PMID:15183999

  3. Investigation of strength properties of freshwater ice

    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.

  4. Freshwater algae of the Nevada Test Site

    Taylor, W.D.; Giles, K.R.

    1979-06-01

    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.

  5. Freshwater algae of the Nevada Test Site

    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. Freshwater reservoir effect variability in Northern Germany

    Philippsen, Bente; Heinemeier, Jan

    2012-01-01

    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...... 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...

  7. Freshwater bryozoa of Tonle Sap, Cambodia.

    Hirose, Masato; Mawatari, Shunsuke F

    2007-06-01

    We identified a collection of freshwater bryozoans from Tonle Sap (meaning Tonle Lake), Cambodia, a body of water fed by the Mekong River and characterized by extreme fluctuations in water level between the wet and dry seasons. The collection also included specimens from the moat of Angkor Wat, located at the north end of the lake. We found four phylactolaemate species (Plumatella bombayensis, Plumatella casmiana, Plumatella vorstmani, Hyalinella lendenfeldi) and one ctenostome species (Hislopia cambodgiensis) from the lake, and only a single, additional phylactolaemate species (Plumatella javanica) from the moat. We provide brief descriptions of these species, photographs of colonies for some, and photomicrographs by light and scanning electron microscopy (SEM) of statoblasts. None of the species encountered in this study is endemic to Cambodia, and the wide distributions of the species are possibly related to the dispersability of floatoblasts by birds. We briefly discuss some of the taxonomic problems surrounding Hislopia cambodgiensis. PMID:17867866

  8. Gastric cryptosporidiosis in freshwater angelfish (Pterophyllum scalare)

    Murphy, B.G.; Bradway, D.; Walsh, T.; Sanders, G.E.; Snekvik, K.

    2009-01-01

    A freshwater angelfish (Pterophyllum scalare) hatchery experienced variable levels of emaciation, poor growth rates, swollen coelomic cavities, anorexia, listlessness, and increased mortality within their fish. Multiple chemotherapeutic trials had been attempted without success. In affected fish, large numbers of protozoa were identified both histologically and ultrastructurally associated with the gastric mucosa. The youngest cohort of parasitized fish was the most severely affected and demonstrated the greatest morbidity and mortality. The protozoa were morphologically most consistent with Cryptosporidium. All of the protozoan life stages were identified ultrastructurally and protozoal genomic DNA was isolated from parasitized tissue viscera and sequenced. Histological, ultrastructural, genetic, and phylogenetic analyses confirmed this protozoal organism to be a novel species of Cryptosporidium.

  9. Fouling and corrosion of freshwater heat exchangers

    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

  10. Monitoring endangered freshwater biodiversity using environmental DNA

    Thomsen, P.F.; Kielgast, J.; Iversen, L.L.; Wiuf, Carsten Henrik; Rasmussen, M.; Gilbert, M.T.P.; Orlando, Ludovic Antoine Alexandre; Willerslev, Eske

    2012-01-01

    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...... 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...

  11. Chemical analysis of endolymph and the growing otolith: fractionation of metals in freshwater fish species.

    Melancon, Sonia; Fryer, Brian J; Markham, James L

    2009-06-01

    The fractionation of metals from water to otolith is an area of research that has received relatively limited attention, especially in freshwater systems. The objectives of the present research were to study the metal partitioning between otolith and endolymph of two freshwater species: Lake trout (Salvelinus namaycush), and burbot (Lota lota). We also included the chemical analyses of water and blood from fish of the same species collected in the same area but during different years. These results provide insight regarding the partition of metals between water and fish. This is one of the first studies to provide a range of trace metal concentrations for endolymph and the growing otolith (both aragonite and vaterite) and to directly measure otolith-endolymph partition coefficients for freshwater fish. The trace elements (Mg, Sr, and Ba) most often used as otolith elemental tracers were the ones with the lowest uptake from water to blood. We found that endolymph and whole blood had similar metal concentrations, with Mg and Fe being the only elements enriched in whole blood. Results showed few significant differences in trace metal content between wild lake trout and burbot endolymph (except for K, Mg, and Ba), but significant differences existed between their aragonitic otoliths. These results suggest two different crystallization processes in these species or the presence of different proteins (and/or organic matrices) that would selectively influence elemental incorporation in the otoliths. PMID:19154085

  12. Compositions and constituents of freshwater dissolved organic matter isolated by reverse osmosis

    Highlights: • Concentration factor controls sorption of DOM and thus yields of reverse osmosis. • Solid-state 13C NMR was used to characterize RO-isolated DOM from freshwater. • C distribution of freshwater RO-DOM differs from that of reported marine DOM. • The compositions of DOM were transformed during transport from rivers to oceans. - Abstract: Dissolved organic matter (DOM) from riverine and lacustrine water was isolated using a reverse osmosis (RO) system. Solid-state 13C nuclear magnetic resonance (13C NMR) was used to quantitatively evaluate the compositions and constituents of DOM, which are compared with previous investigations on marine DOM. Results indicated that concentration factor (CF) was a key metric controlling yield and sorption of DOM on the RO system. The sorption was likely non-selective, based on the 13C NMR and δ13C analyses. Carbohydrates and lipids accounted for 25.0–41.5% and 30.2–46.3% of the identifiable DOM, followed by proteins (18.2–19.8%) and lignin (7.17–12.8%). The freshwater DOM contained much higher alkyl and aromatic C but lower alkoxyl and carboxyl C than marine DOM. The structural difference was not completely accounted for by using structure of high molecular weight (HMW) DOM, suggesting a size change involved in transformations of DOM during the transport from rivers to oceans

  13. Freshwater fishes in Greek lakes: Species richness and body size patterns

    Anthi Oikonomou

    2015-11-01

    Full Text Available Freshwater ecosystems are widely recognised as hotspots of biodiversity and endemism; thus they are of great value for conservation biogeography. Amongst the taxa found in freshwater ecosystems, fish are the ideal biological model for testing biogeographical patterns and have often been used in large-scale ecological and biogeographical analyses. Lakes of Greece provide a unique opportunity to test biogeographical theories, however, biogeographical studies in Greece at broader, regional, scales, based on the distribution of freshwater species, species richness and endemism, are scarce. The aim of the current study is to test the effect of key environmental factors and spatial variables on species richness of lacustrine fishes and to test their effect on species’ size distributions. We assembled datasets of species richness and body size and environmental (predictor factors for 13 Greek lakes. Model selection procedures revealed that fish species richness increased with ecosystem area and decreased with altitude. In addition, our results showed that latitude per se is a good predictor of body size. Indeed, the mean size of lacustrine communities in the northern and southern lake ecosystems differed significantly. These patterns reflect the biogeographical history of these areas and highlight the crucial role connectivity plays in communities’ species composition.

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

    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.

  15. Resolving and modelling trace metal partitioning in a freshwater sediment

    Elevated concentrations of trace metals in sediments pose toxicological risks to biota and may impair water quality. the sediment-water interface is the site where gradients in physical, chemical and biological properties are the greatest. Both chemical and microbiological transformation processes are responsible for cycling elements between water and sediments. (Author)

  16. HISTOPATHOLOGICAL CHANGES IN THE OVARIES AND MUSCLE TISSUES OF FRESHWATER FAIRY SHRIMP STREPTOCEPHALUS DICHOTOMUS (BAIRD, 1860, EXPOSED TO MALATHION AND GLYPHOSATE

    Arun Kumar MS* and A Jawahar Ali

    2014-08-01

    Full Text Available Possible impact of organophosphorus pesticides namely malathion and glyphosate on the ovaries and muscle tissues of the freshwater fairy shrimp Streptocephalus dichotomus were reported here for the first time. Preadult fairy shrimps were exposed to sub lethal concentration (1/5th of 96hrs LC50 of malathion (2.0 ppm and glyphosate (0.0011 ppm for a period of 30 days. Histological observations revealed a few marked pathological lesions such as mild destruction of epithelial layer, follicle cells, nurse cells, necrosis and degeneration of oocytes in the ovaries. Similarly degeneration of muscles, necrosis of muscle fibers, haemorrhages and appearance of pigmented cells in the muscle tissues were evident compared to control. The structural alterations observed in the ovaries and muscle tissues of the freshwater fairy shrimp are suggestive that malathion and glyphosate caused tissue damage at the tested concentrations. Therefore, the findings of this investigation can be taken as biomarkers for monitoring pesticides contamination in aquatic biota.

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

    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 μL-1 and 0.02-2.26 pg μL-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.

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

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

    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.

  20. Culture of Freshwater Prawns (Macrobrachium Rosenbergii) Using Geothermal Waste Water

    Johnson, William C.

    1978-01-01

    The farming of freshwater prawns (Macrobrachium rosenbergii) in geothermal-heated water has been demonstrated to be feasible in a non-tropical climate. The husbandry of prawns is being done in two outdoor raceway ponds, 9.1 m by 2.5 m and 29 m by 3.5 m that are 1.2 m deep. The ponds are not shielded from the ambient climate which during the winter months has recorded air temperatures as low as -20oC. A selected brood stock is held in a small spawning building where larvae are hatched in artificial saltwater and reared to the post-larvae stage which makes the facility self-supporting. This project is providing a model for potential investors to utilize the low-temperature geothermal resources in the western United States for warm water aquaculture. Zooplankton, macroscopic crusteans, from a local euthrophic lake are being fed to the post-larvae and adult prawns in addition to prepared commercial dry pelleted foods to keep operational costs at a minimum. Initial measurements of growth and weight gains indicate the production of two crops of prawns per year at seven to the pond is possible. No work on intensive culture has been done. Plans to enlarge the facility and do work on developing intensive culture are being considered.

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

    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.

  2. Four New Records for the Freshwater Algae of Turkey

    Memet VAROL

    2015-08-01

    Full Text Available Despite the fact that planktonic algae are a critical component of freshwater ecosystems, our understanding of their diversity and species distributions is still rather poor. This study contributes new information to the knowledge of Turkish freshwater microflora. A total of 84 phytoplankton samples were collected from 7 sites in the Tigris River from February 2008 to January 2009. Four taxa representing new records for the freshwater algal flora of Turkey were identified from the river. They belong to the following phyla: 1 (Oscillatoria nitida  to Cyanobacteria, 2 (Micractinium bornhemiense and Lagerheimia wratislaviensis to Chlorophyta and 1 (Audouinella chalybaea to Rhodophyta.

  3. Glaciers in Svalbard: mass balance, runoff and freshwater flux

    Hagen, Jon Ove; Kohler, Jack; Melvold, Kjetil; Winther, Jan-Gunnar

    2003-01-01

    Gain or loss of the freshwater stored in Svalbard glaciers has both global implications for sea level and, on a more local scale, impacts upon the hydrology of rivers and the freshwater flux to fjords. This paper gives an overview of the potential runoff from the Svalbard glaciers. The freshwater flux from basins of different scales is quantified. In small basins (A < 10 km2), the extra runoff due to the negative mass balance of the glaciers is related to the proportion of glacier cover and c...

  4. Freshwater methane emissions offset the continental carbon sink.

    Bastviken, David; Tranvik, Lars J; Downing, John A; Crill, Patrick M; Enrich-Prast, Alex

    2011-01-01

    Inland waters (lakes, reservoirs, streams, and rivers) are often substantial methane (CH(4)) sources in the terrestrial landscape. They are, however, not yet well integrated in global greenhouse gas (GHG) budgets. Data from 474 freshwater ecosystems and the most recent global water area estimates indicate that freshwaters emit at least 103 teragrams of CH(4) year(-1), corresponding to 0.65 petagrams of C as carbon dioxide (CO(2)) equivalents year(-1), offsetting 25% of the estimated land carbon sink. Thus, the continental GHG sink may be considerably overestimated, and freshwaters need to be recognized as important in the global carbon cycle. PMID:21212349

  5. Survival strategies of freshwater insects in cold environments

    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.

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

    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...

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

    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

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

    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)

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

    Burger, Joanna [Division of Life Sciences, Rutgers University, 604 Allison Road, Piscataway, New Jersey 08854-8082 (United States) and Consortium for Risk Evaluation with Stakeholder Participation (CRESP) and Environmental and Occupational Health Sciences Institute (EOHSI), Piscataway, New Jersey (United States)]. E-mail: burger@biology.rutgers.edu; Jewett, Stephen [Institute of Marine Science, University of Alaska, Fairbanks, Fairbanks, Alaska 99775-7220 (United States); Gochfeld, Michael [Consortium for Risk Evaluation with Stakeholder Participation (CRESP), and Environmental and Occupational Health Sciences Institute (EOHSI), Piscataway, New Jersey (United States); Environmental and Community Medicine, UMDNJ-Robert Wood Johnson Medical School, Piscataway, New Jersey 08854 (United States); Hoberg, Max [Institute of Marine Science, University of Alaska, Fairbanks, Fairbanks, Alaska 99775-7220 (United States); Harper, Shawn [Institute of Marine Science, University of Alaska, Fairbanks, Fairbanks, Alaska 99775-7220 (United States); Chenelot, Heloise [Institute of Marine Science, University of Alaska, Fairbanks, Fairbanks, Alaska 99775-7220 (United States); Jeitner, Christian [Division of Life Sciences, Rutgers University, 604 Allison Road, Piscataway, New Jersey 08854-8082 (United States); Consortium for Risk Evaluation with Stakeholder Participation (CRESP), and Environmental and Occupational Health Sciences Institute (EOHSI), Piscataway, New Jersey (United States); Burke, Sean [Division of Life Sciences, Rutgers University, 604 Allison Road, Piscataway, New Jersey 08854-8082 (United States); Consortium for Risk Evaluation with Stakeholder Participation (CRESP), and Environmental and Occupational Health Sciences Institute (EOHSI), Piscataway, New Jersey (United States)

    2006-10-01

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

    Burger, Joanna; Jewett, Stephen; Gochfeld, Michael; Hoberg, Max; Harper, Shawn; Chenelot, Heloise; Jeitner, Christian; Burke, Sean

    2006-10-01

    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. PMID:16828148

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

    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

  12. FRESHWATER FISHERY OF THE REPUBLIC OF CROATIA

    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.

  13. THE BALTIC CARRIER OIL SPILL AT THE SOUTH-EASTERN COASTS OF DENMARK: TEN YEARS ON, AN ECOLOGICAL ASSESSMENT OF BIOTA AND SEDIMENT COMPARTMENT TO EVALUATE CLEANUP OPERATIONS

    Enongene, Agnes Debime

    2013-01-01

    ABSTRACT The concentration of PAH in sediment and biota compartments of 3 sites along the South Eastern Coastlines of Denmark were studied following the old March 2001 Baltic Carrier oil spill accident in the Grøndsund Region of Denmark. The objectives of the studies were to examine for the presence of PAHs in sediments and two biota types with an aim to evaluate effectiveness of cleaning up operations at the time of the spill. Biota samples analyzed included Neries diversicolor and Mytil...

  14. The derivation of effects threshold concentrations of lead for European freshwater ecosystems.

    Van Sprang, Patrick A; Nys, Charlotte; Blust, Ronny J P; Chowdhury, Jasim; Gustafsson, Jon P; Janssen, Colin J; De Schamphelaere, Karel A C

    2016-05-01

    The main objective of the present study was to derive ecologically relevant effect threshold concentrations of (dissolved) Pb for selected European Union (EU) freshwater rivers, using the 2008 EU Voluntary Risk Assessment Report as a starting point and more advanced methodologies than those used in the Voluntary Risk Assessment Report. This included 1) implementing more robust quality criteria for selecting chronic toxicity data; 2) the conversion of total to dissolved Pb concentrations using a combination of an empirical equation relating inorganic Pb solubility and geochemical speciation modeling to account for effects of dissolved organic matter; 3) the use of bioavailability models for chronic toxicity for species belonging to 3 different trophic levels; and 4) the use of robust methods for large data set handling (such as species sensitivity distribution [SSD] analysis). The authors used published bioavailability models for an algal species (Pseudokirchneriella subcapitata) and a daphnid (Ceriodaphnia dubia) and developed a new model for the fathead minnow (Pimephales promelas). The research has shown that these models are also useful for, and reasonably accurate in, predicting chronic toxicity to other species, including a snail, a rotifer, midge larvae, and an aquatic plant (read-across). A comprehensive chronic toxicity data set for Pb was compiled, comprising 159 individual high-quality toxicity data for 25 different species. By applying the total dissolved conversion and the bioavailability models, normalized toxicity values were obtained, which were then entered into a SSD analysis. Based on the parametric best-fitting SSDs, the authors calculated that ecological threshold concentrations of Pb protecting 95% of freshwater species for 7 selected European freshwater scenarios were between 6.3 μg dissolved Pb/L and 31.1 μg dissolved Pb/L. Environ Toxicol Chem 2016;35:1310-1320. © 2015 SETAC. PMID:26590360

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

    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 indm-2, the mean biomass ranged from 28 to 428 gm-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 indm-2 in 1992 to 228 indm-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.

  16. Evaluating the use of side-scan sonar for detecting freshwater mussel beds in turbid river environments

    Powers, Jarrod; Brewer, Shannon K.; Long, James M.; Campbell, Thomas

    2015-01-01

    Side-scan sonar is a valuable tool for mapping habitat features in many aquatic systems suggesting it may also be useful for locating sedentary biota. The objective of this study was to determine if side-scan sonar could be used to identify freshwater mussel (unionid) beds and the required environmental conditions. We used side-scan sonar to develop a series of mussel-bed reference images by placing mussel shells within homogenous areas of fine and coarse substrates. We then used side-scan sonar to map a 32-km river reach during spring and summer. Using our mussel-bed reference images, several river locations were identified where mussel beds appeared to exist in the scanned images and we chose a subset of sites (n = 17) for field validation. The validation confirmed that ~60% of the sites had mussel beds and ~80% had some mussels or shells present. Water depth was significantly related to our ability to predict mussel-bed locations: predictive ability was greatest at depths of 1–2 m, but decreased in water >2-m deep. We determined side-scan sonar is an effective tool for preliminary assessments of mussel presence during times when they are located at or above the substrate surface and in relatively fine substrates excluding fine silt.

  17. The legacy of a vanished sea: a high level of diversification within a European freshwater amphipod species complex driven by 15 My of Paratethys regression.

    Mamos, Tomasz; Wattier, Remi; Burzy?ski, Artur; Grabowski, Micha?

    2016-02-01

    The formation of continental Europe in the Neogene was due to the regression of the Tethys Ocean and of the Paratethys Sea. The dynamic geology of the area and repetitious transitions between marine and freshwater conditions presented opportunities for the colonization of newly emerging hydrological networks and diversification of aquatic biota. Implementing mitochondrial and nuclear markers in conjunction with a large-scale sampling strategy, we investigated the impact of this spatiotemporal framework on the evolutionary history of a freshwater crustacean morphospecies. The Gammarus balcanicus species complex is widely distributed in the area previously occupied by the Paratethys Sea. Our results revealed its high diversification and polyphyly in relation to a number of other morphospecies. The distribution of the studied amphipod is generally characterized by very high local endemism and divergence. The Bayesian time-calibrated reconstruction of phylogeny and geographical distribution of ancestral nodes indicates that this species complex started to diversify in the Early Miocene in the central Balkans, partially in the shallow epicontinental sea. It is possible that there were several episodes of inland water colonization by local brackish water lineages. Subsequent diversification within clades and spread to new areas could have been induced by Alpine orogeny in the Miocene/Pliocene and, finally, by Pleistocene glaciations. The present distribution of clades, in many cases, still reflects Miocene palaeogeography of the area. Our results point out that investigations of the historical aspect of cryptic diversity in other taxa may help in a general understanding of the origins of freshwater invertebrate fauna of Europe. PMID:26615060

  18. Accounting for the dissociating properties of organic chemicals in LCIA: An uncertainty analysis applied to micropollutants in the assessment of freshwater ecotoxicity

    Highlights: ► Fate parameters of dissociating chemicals were estimated and applied to an LCIA model. ► Results were compared to the default model using non-polar partitioning regressions. ► Negligible differences were estimated for direct emissions to freshwater. ► Results were overestimated in the default model for indirect emissions. ► Sorption of the cationic fraction of organic bases was the most influential parameter. -- Abstract: In life cycle impact assessment (LCIA) models, the sorption of the ionic fraction of dissociating organic chemicals is not adequately modeled because conventional non-polar partitioning models are applied. Therefore, high uncertainties are expected when modeling the mobility, as well as the bioavailability for uptake by exposed biota and degradation, of dissociating organic chemicals. Alternative regressions that account for the ionized fraction of a molecule to estimate fate parameters were applied to the USEtox model. The most sensitive model parameters in the estimation of ecotoxicological characterization factors (CFs) of micropollutants were evaluated by Monte Carlo analysis in both the default USEtox model and the alternative approach. Negligible differences of CFs values and 95% confidence limits between the two approaches were estimated for direct emissions to the freshwater compartment; however the default USEtox model overestimates CFs and the 95% confidence limits of basic compounds up to three orders and four orders of magnitude, respectively, relatively to the alternative approach for emissions to the agricultural soil compartment. For three emission scenarios, LCIA results show that the default USEtox model overestimates freshwater ecotoxicity impacts for the emission scenarios to agricultural soil by one order of magnitude, and larger confidence limits were estimated, relatively to the alternative approach

  19. Bibliography on cycling of trace metals in freshwater ecosystems

    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

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

    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...

  1. Imperiled Freshwater and Diadromous Fishes of North America

    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...

  2. Information to help reduce environmental impacts from freshwater oil spills

    The American Petroleum Institute (API) has been working since 1990 to provide information to help the response community minimize the impact of spills to pared jointly with the US inland freshwater. Projects have included a manual, pre National Oceanic and Atmospheric Administration (NOAA), to give guidance on the cleanup techniques that will minimize environmental impacts on spills in freshwater habitats. Nearing completion are a literature review and annotated bibliography of the environmental and human health effects of oil spilled in freshwater habitats. The use of chemical treating agents for freshwater spill applications is being studied with input from other industry and government groups. A project has begun, with funding from API, the Louisiana Applied Oil Spill Research and Development Program, NOAA, the Marine Spill Response Corporation (MSRC), and the US Department of Energy, to evaluate in situ burning of oil spilled in marshes

  3. Freshwater mussels of the Noxubee National Wildlife Refuge

    US Fish and Wildlife Service, Department of the Interior — This is a summary of the freshwater mussels on Noxubee National Wildlife Refuge. The species listed and assoicated informaiton is based on existing literature. The...

  4. Freshwater mussels of Cahaba River National Wildlife Refuge

    US Fish and Wildlife Service, Department of the Interior — This is a summary of 2004 freshwater mussel inventory on Cahaba River National Wildlife Refuge. The Cahaba River National Wildlife Refuge was established for the...

  5. The freshwater ecology of Amchitka Island: Progress reports

    US Fish and Wildlife Service, Department of the Interior — This report covers the freshwater ecology of Amchitka Island. The objective of the study was to conduct a preliminary survey of lake types including chemical,...

  6. Freshwater mussels of North Mississippi National Wildlife Refuge Complex

    US Fish and Wildlife Service, Department of the Interior — A literature search of the distribution of freshwater mussels anticipated to be found on refuges assoicated with the North Mississippi Refuges Cjomplex and museum...

  7. Methods for freshwater riverine input into regional ocean models

    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.

  8. Potential Risks of Freshwater Aquifer Contamination with Geosequestration

    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.

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

    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...

  10. Chemical Footprint Method for Improved Communication of Freshwater Ecotoxicity Impacts in the Context of Ecological Limits

    Bjørn, Anders; Diamond, Miriam; Birkved, Morten; Hauschild, Michael Zwicky

    2014-01-01

    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...... differentiated fate factors would be useful and pointed out other major sources of uncertainty and some opportunities to reduce these....

  11. Maintenance of previously uncultured freshwater archaea from anoxic waters under laboratory conditions.

    Plasencia, Anna; Baeras, Llus; Llirs, Marc; Casamayor, Emilio O; Borrego, Carles

    2011-02-01

    Culture conditions for the maintenance of previously uncultured members of the Archaea thriving in anoxic water layers of stratified freshwater lakes are described. The proposed enrichment conditions, based on the use of defined medium composition and the maintenance of anoxia, have been proven effective for the maintenance of the archaeal community with virtually no changes over time for periods up to 6 months as revealed by a PCR-DGGE analysis. Phylotypes belonging to groups poorly represented in culture collections such as the Deep-Sea Hydrothermal Vent Euryarchaeota (DHVE) and the Miscellaneous Crenarchaeotic Group (MCG) were maintained and selectively enriched when compared to the correspondent indigenous planktonic archaeal community. PMID:20077005

  12. Evolutionary lag times and recent origin of the biota of an ancient desert (Atacama–Sechura)

    Guerrero, Pablo C.; Rosas, Marcelo; Arroyo, Mary T. K.; Wiens, John J.

    2013-01-01

    The assembly of regional biotas and organismal responses to anthropogenic climate change both depend on the capacity of organisms to adapt to novel ecological conditions. Here we demonstrate the concept of evolutionary lag time, the time between when a climatic regime or habitat develops in a region and when it is colonized by a given clade. We analyzed the time of colonization of four clades (three plant genera and one lizard genus) into the Atacama–Sechura Desert of South America, one of Earth’s driest and oldest deserts. We reconstructed time-calibrated phylogenies for each clade and analyzed the timing of shifts in climatic distributions and biogeography and compared these estimates to independent geological estimates of the time of origin of these deserts. Chaetanthera and Malesherbia (plants) and Liolaemus (animal) invaded arid regions of the Atacama–Sechura Desert in the last 10 million years, some 20 million years after the initial onset of aridity in the region. There are also major lag times between when these clades colonized the region and when they invaded arid habitats within the region (typically 4–14 million years). Similarly, hyperarid climates developed ∼8 million years ago, but the most diverse plant clade in these habitats (Nolana) only colonized them ∼2 million years ago. Similar evolutionary lag times may occur in other organisms and habitats, but these results are important in suggesting that many lineages may require very long time scales to adapt to modern desertification and climatic change. PMID:23798420

  13. Evolutionary lag times and recent origin of the biota of an ancient desert (Atacama-Sechura).

    Guerrero, Pablo C; Rosas, Marcelo; Arroyo, Mary T K; Wiens, John J

    2013-07-01

    The assembly of regional biotas and organismal responses to anthropogenic climate change both depend on the capacity of organisms to adapt to novel ecological conditions. Here we demonstrate the concept of evolutionary lag time, the time between when a climatic regime or habitat develops in a region and when it is colonized by a given clade. We analyzed the time of colonization of four clades (three plant genera and one lizard genus) into the Atacama-Sechura Desert of South America, one of Earth's driest and oldest deserts. We reconstructed time-calibrated phylogenies for each clade and analyzed the timing of shifts in climatic distributions and biogeography and compared these estimates to independent geological estimates of the time of origin of these deserts. Chaetanthera and Malesherbia (plants) and Liolaemus (animal) invaded arid regions of the Atacama-Sechura Desert in the last 10 million years, some 20 million years after the initial onset of aridity in the region. There are also major lag times between when these clades colonized the region and when they invaded arid habitats within the region (typically 4-14 million years). Similarly, hyperarid climates developed ∼8 million years ago, but the most diverse plant clade in these habitats (Nolana) only colonized them ∼2 million years ago. Similar evolutionary lag times may occur in other organisms and habitats, but these results are important in suggesting that many lineages may require very long time scales to adapt to modern desertification and climatic change. PMID:23798420

  14. The Triassic Marine Biota of Eastern Indonesia and its Interregional and Global Correlation: A Review

    Fauzie Hasibuan

    2014-06-01

    Full Text Available DOI: 10.17014/ijog.v5i1.91The interregional and global correlation of the Triassic biota of Indonesia was based on the review of previous workers and the author himself. Scythian Epoch (Early Triassic in Timor is subdivided into Early Scythian with Ophiceras demisso, Meekoceras sp., Pseudomonotis subaurita, Gervillia subpannonica, and Myophoria sp., whilst Late Scythian is indicated by the presence of Owenites egrediens and Sibirites sp. The presence of Anisian Stage (Middle Triassic in Misool is indicated by ammonite Beyrichites and bivalve Daonella lilintana. In Timor, this stage is pointed out by the presence of Joannites cymbiformis, Monophyllites wengensis, Protrachyceras archaelus, Daonella indica, Tracyceras cf. aon, Brochidium timorense, and Lima subpunctatoides. Terebellina mackayi found above Beyrichites-bearing bed in Misool has an age range from Anisian to Ladinian. It is concluded that the boundary between Anisian and Ladinian lies between beds with Beyrichites and Terebellina mackayi. Early Carnian Stage (Late Triassic in Timor is indicated by the presence of Joanites cymbiformis, Waldhausenites sp., Miltites sp., and Halogyra cipitiensis; whereas Late Carnian is indicated by the presence of Cladicites crassestriatus and Tropites subbulatus. The presence of Halobia verbeeki, Pinacoceras parma, Neobetites sp., Parabetites sp., Malayites sp., Amarassites sp., and Halorites sp., indicates the Early Norian Stage, whilst the presence of Cladiscites tornatus, Cyrtopleurits malayicus, and Trachypleuraspidites sp. implies the Late Norian. The Rhaetian Stage in Timor contains Choristoceras indoaustralicum, whereas in Misool it contains Choristoceras sp. and Cochloceras sp.

  15. Lixiviados de biosólidos sobre la biota dulceacuícola

    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.

  16. Doses to members of the general public and observed effects on biota: Chernobyl Forum update

    Anspaugh, Lynn R. [Division of Radiobiology, Department of Radiology, University of Utah, 729 Arapeen Way, Salt Lake City, UT 84112 (United States)]. E-mail: lanspaugh@aol.com

    2007-07-15

    The Chernobyl Forum was organized by the United Nations to examine the health and environmental effects of the accident at the Chernobyl Nuclear Power Station. This paper is concerned with the environmental effects, as determined by Expert Group Environment. The accident resulted in release of a large amount of radioactive materials over a period of 10 days. These materials were deposited throughout Europe with the three more affected countries being Belarus, Russia, and Ukraine. More than 5 million persons lived on territories in these countries judged to be contaminated at >37 kBq m{sup -2}. Many countermeasures were employed to mitigate the effects of the accident. The collective effective dose to the residents of the contaminated territories is estimated to be about 55 000 person-Sv. Effects on non-human biota were observed that ranged from minor to lethal; the current increase in the number and diversity of species in the most contaminated area is due to absence of human pressure.

  17. Delayed Behavioral Effects of Early Life Toxicant Exposures in Aquatic Biota

    Judith S. Weis

    2014-05-01

    Full Text Available Behavioral development occurs together with the development of the nervous system. Studies on mammals indicate that exposures to some chemicals during embryonic development at concentrations that do not produce anatomical malformations may nevertheless produce behavioral deficits later in life, an example of delayed effects. There have been reports of delayed effects in aquatic organisms. Delayed behavioral effects of mercury, chlorinated and other pesticides, polycyclic aromatic hydrocarbons (PAHs, and some synthetic hormones in the environment have been reported in fishes and invertebrates; in some cases behavioral effects are manifested years after the exposure. Another type of delayed behavioral effect results from exposure of mature females before fertilization (maternal exposure. Even when embryos and larvae are reared in clean water, offspring may manifest abnormal behaviors following maternal exposure. The reported behavioral changes are generally deleterious and compromise the fitness of the animal in its natural environment. Delayed effects and their impacts on fitness are not considered in standard short-term embryo bioassays, which will therefore underestimate neurotoxicity. The literature in the field is scattered and has not been reviewed. The objective of this paper is to review and synthesize what is known about delayed behavioral effects in aquatic biota.

  18. Doses to members of the general public and observed effects on biota: Chernobyl Forum update

    The Chernobyl Forum was organized by the United Nations to examine the health and environmental effects of the accident at the Chernobyl Nuclear Power Station. This paper is concerned with the environmental effects, as determined by Expert Group Environment. The accident resulted in release of a large amount of radioactive materials over a period of 10 days. These materials were deposited throughout Europe with the three more affected countries being Belarus, Russia, and Ukraine. More than 5 million persons lived on territories in these countries judged to be contaminated at >37 kBq m-2. Many countermeasures were employed to mitigate the effects of the accident. The collective effective dose to the residents of the contaminated territories is estimated to be about 55 000 person-Sv. Effects on non-human biota were observed that ranged from minor to lethal; the current increase in the number and diversity of species in the most contaminated area is due to absence of human pressure

  19. Novel brominated flame retardants and dechlorane plus in Greenland air and biota.

    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

  20. Geological sampling data and benthic biota classification: Buzzards Bay and Vineyard Sound, Massachusetts

    Ackerman, Seth D.; Pappal, Adrienne L.; Huntley, Emily C.; Blackwood, Dann S.; Schwab, William C.

    2015-01-01

    Sea-floor sample collection is an important component of a statewide cooperative mapping effort between the U.S. Geological Survey (USGS) and the Massachusetts Office of Coastal Zone Management (CZM). Sediment grab samples, bottom photographs, and video transects were collected within Vineyard Sound and Buzzards Bay in 2010 aboard the research vesselConnecticut. This report contains sample data and related information, including analyses of surficial-sediment grab samples, locations and images of sea-floor photography, survey lines along which sea-floor video was collected, and a classification of benthic biota observed in sea-floor photographs and based on the Coastal and Marine Ecological Classification Standard (CMECS). These sample data and analyses information are used to verify interpretations of geophysical data and are an essential part of geologic maps of the sea floor. These data also provide a valuable inventory of benthic habitat and resources. Geographic information system (GIS) data, maps, and interpretations, produced through the USGS and CZM mapping cooperative, are intended to aid efforts to manage coastal and marine resources and to provide baseline information for research focused on coastal evolution and environmental change.