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1

Toxicities of selected substances to freshwater biota  

Energy Technology Data Exchange (ETDEWEB)

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.

Hohreiter, D.W.

1980-05-01

2

Bioaccumulation factors for radionuclides in freshwater biota  

International Nuclear Information System (INIS)

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

3

Radionuclide data bases available for bioaccumulation factors for freshwater biota  

International Nuclear Information System (INIS)

Aquatic models currently in use for dose assessment simulate the transfer of radionuclides in aquatic environments and the transfer to man. In these models the assimilation of a radionuclide in aquatic biota is calculated by using a simple empirical relationship known as the bioaccumulation factor (BF) to represent the transfer of the radionuclide from water to organism. The purpose of this article is to review data bases that are available for BFs for freshwater biota and to identify the uncertainties associated with them. Data bases for raidoisotopes of Co, Cs, C, H, I, Pu, Ra, Ru, Sr, and U are reviewed. With the exception of ruthenium and carbon, the review is restricted to BFs determined for natural freshwater systems. Factors influencing the variability of BFs are identified, uncertainties associated with the validation of BFs are discussed, and some guidance is given for collecting data and measuring BFs

4

Application of the ERICA Assessment Tool to freshwater biota in Finland  

Energy Technology Data Exchange (ETDEWEB)

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

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

2010-01-15

5

Application of the ERICA Assessment Tool to freshwater biota in Finland  

International Nuclear Information System (INIS)

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

6

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

Science.gov (United States)

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 (2-4×10(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

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

7

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

Energy Technology Data Exchange (ETDEWEB)

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

Fesenko, S., E-mail: s.fesenko@iaea.or [International Atomic Energy Agency, NAAL, 1400 Vienna (Austria); Fesenko, J.; Sanzharova, N.; Karpenko, E.; Titov, I. [Russian Institute of Agricultural Radiology and Radioecology, 249020 Obninsk (Russian Federation)

2011-01-15

8

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1993-08-01

9

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

International Nuclear Information System (INIS)

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

10

Correlation between stable nitrogen isotope ratios and concentrations of organochlorines in biota from a freshwater food web.  

Science.gov (United States)

The relationship between total concentrations of hexachlorocyclohexane (sigma HCH), sigma DDT, and chlorinated bornanes (toxaphene, sigma CHB) and the trophic position of biota from a subarctic lake was investigated using stable isotope ratios of nitrogen (15N/14N). Zooplankton, benthic invertebrates, and forage and piscivorous fishes were analysed for 15N/14N and organochlorines using mass spectrometry and high resolution capillary gas chromatography (GC-ECD), respectively. The trophic relationships of the biota were clearly defined, with 15N/14N increasing an average of 3.3/1000 from prey species to predator. Mean concentrations of sigma HCH were lowest in chironomids (subfamily Chironominae, 0.2 ng/g wet wt.) and highest in burbot liver (Lota lota; 30.2 ng/g wet wt.). Mean concentrations of sigma DDT and sigma CHB ranges from 0.5 and 2.0 (ng/g wet wt.), respectively, in snails (Family Limnaeidae), to 3430 and 2820 (ng/g wet wt.) in burbot liver. Regression analyses indicated that both the wet and lipid weight concentrations of sigma HCH, sigma DDT, and sigma CHB in the biota from this food web were significantly related to trophic position, as defined by delta 15 N. Results from this study indicated that delta 15 N can be used to predict concentrations of organochlorines in freshwater biota. PMID:7892576

Kidd, K A; Schindler, D W; Hesslein, R H; Muir, D C

1995-01-15

11

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

1977-06-01

12

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

International Nuclear Information System (INIS)

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

13

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2010-06-15

14

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

Energy Technology Data Exchange (ETDEWEB)

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

Yankovich, T. L.; Vives i Batlle, J.; Vives-Lynch, S.; Beresford, N. A.; Barnett, C. L.; Beaugelin-Seiller, K.; Brown, J. E.; Cheng, J.-J.; Copplestone, D.; Heling, R.; Hosseini, A.; Howard, B. J.; Kamboj, S.; Kryshev, A. I.; Nedveckaite, T.; Smith, J. T.; Wood, M. D.; Environmental Science Division; AREVA Resources; Environmental Science, Westlakes Scientific Consulting Ltd.; Centre for Ecology and Hydrology; IRSN; Norwegian Radiation Protection Authority; The Environment Agency; Nuclear Research and Consultancy Group; Univ. of Liverpool; School of Earth and Environmental Sciences; Inst. of Physics, Lithuania; State Enterprise Scientific Production Association

2010-06-09

15

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

Energy Technology Data Exchange (ETDEWEB)

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)

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

2012-01-15

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)  

International Nuclear Information System (INIS)

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

17

Selecting for extinction: nonrandom disease-associated extinction homogenizes amphibian biotas.  

Science.gov (United States)

Studying the patterns in which local extinctions occur is critical to understanding how extinctions affect biodiversity at local, regional and global spatial scales. To understand the importance of patterns of extinction at a regional spatial scale, we use data from extirpations associated with a widespread pathogenic agent of amphibian decline, Batrachochytrium dendrobatidis (Bd) as a model system. We apply novel null model analyses to these data to determine whether recent extirpations associated with Bd have resulted in selective extinction and homogenization of diverse tropical American amphibian biotas. We find that Bd-associated extinctions in this region were nonrandom and disproportionately, but not exclusively, affected low-occupancy and endemic species, resulting in homogenization of the remnant amphibian fauna. The pattern of extirpations also resulted in phylogenetic homogenization at the family level and ecological homogenization of reproductive mode and habitat association. Additionally, many more species were extirpated from the region than would be expected if extirpations occurred randomly. Our results indicate that amphibian declines in this region are an extinction filter, reducing regional amphibian biodiversity to highly similar relict assemblages and ultimately causing amplified biodiversity loss at regional and global scales. PMID:19694784

Smith, Kevin G; Lips, Karen R; Chase, Jonathan M

2009-10-01

18

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

Science.gov (United States)

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 freshwater needs in these areas are expected to cause additional problems. On the basis of remote sensing and ground truthing complemented by colonial archival material from the Dutch East India Company (1602-1800), we report that changes to the historic system of inland freshwater management have increased dramatically in recent times. Hydrological changes, such as interbasin transfers, have resulted in a qualitative ecological and socioeconomic degradation in three coastal lagoons in southern Sri Lanka. Variations in river hydrology have caused changes in the areas suitable as mangrove habitat and, thus, have resulted in an altered distribution. However, increases in mangrove area can mask the degradation of the site in terms of floristic composition, significance of the species, and biodiversity (this effect is termed "cryptic ecological degradation"). It is important that such changes be carefully monitored to ensure biological and socioeconomic sustainability. PMID:15797030

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

2005-03-29

19

A review and model assessment of {sup 32}P and {sup 33}P uptake to biota in freshwater systems  

Energy Technology Data Exchange (ETDEWEB)

Bioaccumulation of key short-lived radionuclides such as {sup 131}I and {sup 32,33}P 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: {yields} A model is developed for radiophosphorus uptake to fish. {yields} Concentration ratios for {sup 32,33}P in fish may be over-estimated in freshwater systems. {yields} New recommended values for {sup 32,33}P concentration ratios are given. {yields} Farmed fish are likely to have much lower {sup 32,33}P uptake than wild fish.

Smith, J.T., E-mail: jim.smith@port.ac.u [School of Earth and Environmental Sciences, University of Portsmouth, Burnaby Bldg, Burnaby Road, Portsmouth PO1 3QL (United Kingdom); Bowes, M.J. [Centre for Ecology and Hydrology, Maclean Building, Benson Lane, Crowmarsh Gifford, Wallingford, Oxfordshire OX10 8BB (United Kingdom); Cailes, C.R. [Environment Agency, Richard Fairclough House, Knutsford Road, Warrington WA4 1HT (United Kingdom)

2011-04-15

20

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

International Nuclear Information System (INIS)

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

 
 
 
 
21

Selective and universal primers for trematode barcoding in freshwater snails.  

Science.gov (United States)

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

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

2014-07-01

22

Radioprotection of nonhuman biota  

International Nuclear Information System (INIS)

Radioprotection has historically focused on humans with the assumption that human protection confers protection of nonhuman biota. However, there is a need to scientifically and independently demonstrate protection of nonhuman biota. Approaches to address impacts of radiation on nonhuman biota include applying an ecological risk assessment paradigm, setting dose limits, defining reference organisms, and assessing a geographic region. Recommendations include harmonization of a radioprotection framework for both humans and nonhuman biota, a consistent methodology to evaluate radionuclide and nonradionuclide contaminants, a graded assessment approach, development of dosimetric models for reference organisms, compilation of a radiological effects database, and periodic expert review of methodology

23

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

Science.gov (United States)

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

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

2014-01-01

24

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

Science.gov (United States)

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

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

2014-01-01

25

Conserving Madagascar's Freshwater Biodiversity  

Science.gov (United States)

This peer-reviewed article from BioScience is about conserving freshwater diversity in Madagascar. The island nation of Madagascar, an international conservation priority, is now also recognized as a global hotspot for freshwater biodiversity. Three emerging characteristics of Madagascar's threatened freshwater biota deserve increased attention from the scientific and conservation communities. First, species richness is not low, as was once assumed for both the freshwater fishes and the invertebrates. Second, many species are restricted to a specific region or even to single river basins. Often these species are also limited to streams or rivers draining primary forest habitat. Finally, many of the island's freshwater fishes are basal taxa, having diverged earlier than any other extant members of their clade. As such, these taxa assume disproportional phylogenetic importance. In the face of ongoing environmental threats, links among microendemism, forest stream specialization, and basal phylogenetic position highlight the importance and vulnerability of these species and provide a powerful incentive for immediate conservation action.

JONATHAN P. BENSTEAD, PATRICK H. DE RHAM, JEAN-LUC GATTOLLIAT, FRANÃÂOIS-MARIE GIBON, PAUL V. LOISELLE, MICHEL SARTORI, JOHN S. SPARKS, and MELANIE L. J. STIASSNY (;)

2003-11-01

26

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

DEFF Research Database (Denmark)

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

Ferchaud, Anne-Laure; Pedersen, Susanne H.

2014-01-01

27

Selection of native freshwater microalgae and cyanobacteria for CO2 biofixation.  

Science.gov (United States)

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

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

2013-01-01

28

The partial monitoring system BIOTA  

International Nuclear Information System (INIS)

The partial monitoring system BIOTA included three sub-systems: - plants; - animals; - biotopes. Monitoring aimed on 19 species of plants and 8 species of animals. All monitored species are classified in Red Red Data List of plants of the Slovak Republic and in Decree No. 24/2003 Coll. Laws, by which is realised the law No. 543/2002 Coll. Laws about the nature and landscape protection. This project comes out from implementation of European agreements and directives into national legislative. The subject of monitoring are selected plant and animal species which are significant from European or national aspect. They are mainly endemic, critically endangered, diminishing and rare species. Also species which are bio-indicating responsible were included into monitoring. From 50 monitored plant and animal species, 45 belong among European significant, included in some of supplements of Directive about birds or Directive about biotopes

29

Eutrophication as a driver of r-selection traits in a freshwater fish.  

Science.gov (United States)

This study tested whether eutrophication could influence life-history traits of a cyprinid, Chanodichthys erythropterus, in 10 Chinese lakes. Using the von Bertalanffy growth model, the asymptotic length (L? ) and the growth performance index (IGRO ) were significantly affected by eutrophication. The gonado-somatic index (IG ) and relative fecundity (FR ) were significantly lower in mesotrophic lakes than in eutrophic and hypertrophic lakes. These results indicate that increasing eutrophication affects the life-history tactics of a freshwater fish. PMID:24925695

Lin, M; Chevalier, M; Lek, S; Zhang, L; Gozlan, R E; Liu, J; Zhang, T; Ye, S; Li, W; Li, Z

2014-08-01

30

Responses of selected aquatic biota in Watts Bar Reservoir to thermal discharges from Kingston Steam-Electric Plant in 1978 and 1979  

Energy Technology Data Exchange (ETDEWEB)

Results of the 1978 and 1979 investigations on the effects of the power plant on the biota of Watts Bar Reservoir are presented and compared to the results of the 1973 to 1975 studies. Water chemistry, phytoplankton, periphyton, zooplankton and benthic macroinvertebrate data were collected. Water quality parameter values in 1978 and 1979 were within expected ranges. Upstream/downstream differences in phytoplankton density in 1978 and 1979 were not attributed to thermal effects but to plant operation. Lower cell density and chlorophyll a concentrations in 1979 were attributed to increased turbidity accompanying higher flows. Low abundance of blue-green algae (Cyanophyta) at thermally affected stations suggested that differences in composition among stations were not due to thermal effect but to complex mixing patterns of several water masses. Thermal effluent was not shown to adversely affect the periphyton community downstream of the plant. Substantial differences in zooplankton density between upstream and downstream stations were indicative of some type of plant effect. No adverse effects were observed on the benthic macroinvertebrate community in either 1978 or 1979. 57 references, 17 figures, 23 tables. (MDF)

Craven, T.M.; Dycus, D.L.; Tomljanovich, D.A.

1983-07-01

31

Analysis of selected antibiotics in surface freshwater and seawater using direct injection in liquid chromatography electrospray ionization tandem mass spectrometry.  

Science.gov (United States)

Emerging contaminants such as antibiotics have received recent attention as they have been detected in natural waters and health concerns over potential antibiotic resistance. With the purpose to investigate fast and high-throughput analysis, and eventually the continuous on-line analysis of emerging contaminants, this study presents results on the analysis of seven selected antibiotics (sulfadiazine, sulfamethazine, sulfamerazine, sulfamethoxazole, chloramphenicol, lincomycin, tylosin) in surface freshwater and seawater using direct injection of a small sample volume (20?L) in liquid chromatography electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS). Notably, direct injection of seawater in the LC-ESI-MS/MS was made possible on account of the post-column switch on the system, which allows diversion of salt-containing solutions flushed out of the column to the waste. Mean recoveries based on the isotope dilution method average 95±14% and 96±28% amongst the compounds for spiked freshwater and seawater, respectively. Linearity across six spiking levels was assessed and the response was linear (r(2)>0.99) for all compounds. Direct injection concentrations were compared for real samples to those obtained with the conventional SPE-based analysis and both techniques concurs on the presence/absence and levels of the compounds in real samples. These results suggest direct injection is a reliable method to detect antibiotics in both freshwater and seawater. Method detection limits for the direct injection technique (37pg/L to 226ng/L in freshwater, and from 16pg/to 26ng/L in seawater) are sufficient for a number of environmental applications, for example the fast screening of water samples for ecological risk assessments. In the present study of real samples, this new method allowed for example the positive detection of some compounds (e.g. lincomycin) down to the sub ng/L range. The direct injection method appears to be relatively cheaper and faster, requires a smaller sample size, and is more robust to equipment cross-contamination as compared to the conventional SPE-based method. PMID:24642398

Bayen, Stéphane; Yi, Xinzhu; Segovia, Elvagris; Zhou, Zhi; Kelly, Barry C

2014-04-18

32

BIOACCUMULATION OF HEAVY AND ESSENTIAL METALS IN THE SELECTED FRESHWATER FISH SPECIES FROM PREUMAL LAKE CUDDALORE DISTRICT, TAMILNADU, INDIA.  

Directory of Open Access Journals (Sweden)

Full Text Available The present study was conducted to determine the heavy and essential metals, chromium, cadmium, copper, lead, iron, zinc and manganese concentrations in gill, liver, kidney, intestine and muscle of the available freshwater fish Mystus vittatus, Heteropneustes fossilis, Glossogobius giuris, Notopterous notopterous and Tilapia mossambica of the Perumal lake Cuddalore district, Tamilnadu, India collected during the January 2011- December 2011. Heavy and essential metals concentrations varied in significantly depending upon the type of fish tissues and locations. In the selected freshwater fish, liver tissues appeared to have significantly higher tendency to bioaccumulation of chromium followed by Cd, Cu, Pb, Fe, Zn and Mn. The maximum level of chromium was found in the liver tissue of Heteropneustes fossilis, while the minimum level of zinc was observed in the muscle tissue of Notopterous notopterous. Among the analyzed metals chromium, cadmium, iron, zinc and manganese levels were exceed the WHO recommended limits. Copper and lead levels within the permissible limits for human consumption might be representing a risk for human health.

G. AMBEDKAR

2013-01-01

33

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

Directory of Open Access Journals (Sweden)

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

Roxanne D. Cayasan

2013-07-01

34

Derivation and selection of freshwater sediment quality values in Washington state  

Energy Technology Data Exchange (ETDEWEB)

To derive chemical-based Freshwater Sediment Quality Values (FSQV), bioassay data (Hyalella azteca, Microtox, Chironomus tentans, Daphnia magna, Ceriodaphnia dubia, and Hexagenia limbata) and chemistry data (metals, PAH, pesticide/PCBs, and phenols) were merged from 33 studies and 245 sites in Washington and Oregon into a single database. Apparent Effects Thresholds (AET) and Probable AETs (PAET: 95th percentile of no effects sites) were calculated for Hyalella azteca (n = 228) and Microtox. The efficiency and sensitivity of these values in predicting biological response from chemical concentrations were compared with Ontario`s Severe Effects Level (SEL), Environment Canada`s Probable Effects Level (PEL) and Threshold Effects Level (TEL), EPA`s Equilibrium Partitioning (EQP), and Washington`s marine Sediment management Standards (SMS). For PAH, dry weight normalized values for AETs and PAETs were significantly more sensitive and efficient than organic carbon normalized values. TEL was always the most sensitive and least efficient.

Cubbage, J.; Breidenbach, S.; Batts, D. [Washington Dept. of Ecology, Olympia, WA (United States)

1995-12-31

35

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

2004-09-15

36

Toxicity, sublethal effects, and potential modes of action of select fungicides on freshwater fish and invertebrates  

Science.gov (United States)

Despite decades of agricultural and urban use of fungicides and widespread detection of these pesticides in surface waters, relatively few data are available on the effects of fungicides on fish and invertebrates in the aquatic environment. Nine fungicides are reviewed in this report: azoxystrobin, boscalid, chlorothalonil, fludioxonil, myclobutanil, fenarimol, pyraclostrobin, pyrimethanil, and zoxamide. These fungicides were identified as emerging chemicals of concern because of their high or increasing global use rates, detection frequency in surface waters, or likely persistence in the environment. A review of the literature revealed significant sublethal effects of fungicides on fish, aquatic invertebrates, and ecosystems, including zooplankton and fish reproduction, fish immune function, zooplankton community composition, metabolic enzymes, and ecosystem processes, such as leaf decomposition in streams, among other biological effects. Some of these effects can occur at fungicide concentrations well below single-species acute lethality values (48- or 96-hour concentration that effects a response in 50 percent of the organisms, that is, effective concentration killing 50 percent of the organisms in 48 or 96 hours) and chronic sublethal values (for example, 21-day no observed adverse effects concentration), indicating that single-species toxicity values may dramatically underestimate the toxic potency of some fungicides. Fungicide modes of toxic action in fungi can sometimes reflect the biochemical and (or) physiological effects of fungicides observed in vertebrates and invertebrates; however, far more studies are needed to explore the potential to predict effects in nontarget organisms based on specific fungicide modes of toxic action. Fungicides can also have additive and (or) synergistic effects when used with other fungicides and insecticides, highlighting the need to study pesticide mixtures that occur in surface waters. For fungicides that partition to organic matter in sediment and soils, it is particularly important to determine their effects on freshwater mussels and other freshwater benthic invertebrates in contact with sediments, as available toxicity studies with pelagic species, mainly Daphnia magna, may not be representative of these benthic organisms. Finally, there is a critical need for studies of the chronic effects of fungicides on reproduction, immunocompetence, and ecosystem function; sublethal endpoints with population and community-level relevance.

Elskus, Adria A.

2012-01-01

37

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

International Nuclear Information System (INIS)

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

38

Short-term bioconcentration studies of Np in freshwater biota  

International Nuclear Information System (INIS)

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

39

Alpha radiation weighting factors for biota  

International Nuclear Information System (INIS)

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)

40

Hydrometeorological variables predict fecal indicator bacteria densities in freshwater: data-driven methods for variable selection.  

Science.gov (United States)

Statistical models of microbial water quality inform risk management for water recreation. Current research focuses on resource-intensive, location-specific data collection and water quality modeling, but this approach may be cost-prohibitive for risk managers responsible for numerous recreation sites. As an alternative, we tested the ability of two data-driven models, tree regression and random forests with conditional inference trees, to select readily available hydrometeorological variables for use in linear mixed effects (LME) models predicting bacterial density. The study included the Chicago Area Waterway System (CAWS) and Lake Michigan beaches and harbors in Chicago, Illinois, at which Escherichia coli and enterococci were measured seasonally in 2007-2009. Tree regression node variables reduced data dimensionality by >50 %. Variable importance ranks from random forests were used in a forward-step selection based on R (2) and root mean squared prediction error (RMSPE). We found two to three variables explained bacteria densities well relative to random forests with all variables. LME models with tree- or forest-selected variables performed reasonably well (0.335?models for Lake Michigan had good prediction accuracy with respect to the single sample maximum standard (72-77 %), but limited sensitivity (23-62 %). Results suggest that our alternative approach is feasible and performs similarly to more resource-intensive approaches. PMID:22736208

Jones, Rachael M; Liu, Li; Dorevitch, Samuel

2013-03-01

 
 
 
 
41

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

Directory of Open Access Journals (Sweden)

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

A.N.H. Banu

2004-01-01

42

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

Scientific Electronic Library Online (English)

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

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

43

Antibacterial properties of extracts from selected planktonic freshwater cyanobacteria--a comparative study of bacterial bioassays.  

Science.gov (United States)

Aqueous and methanol extracts from five selected cyanobacteria were examined for antibacterial properties in six different bacterial bioassays. All five cyanobacteria revealed antibacterial properties. Methanol extracts made from Tychonema bourrellyi, Aphanizomenon flos-aquae and Cylindrospermopsis raciborskii showed the most pronounced inhibitory effects, Aqueous extracts made from Microcystis aeruginosa and T. bourrellyi possessed evident antibacterial properties. The bacterial bioassays were based on agar diffusion tests and included pour-plate methods commonly used to detect residues of antibacterial substances in food. In addition, a pourplate bioassay with Aeromonas hydrophila was developed and described. Antibacterial effects were observed in five of the six bacterial bioassays. No antibacterial effect was observed in the Micrococcus luteus bioassay. Bioassays based on Aer. hydrophila, Bacillus cereus and B. subtilis grown in Antibiotic Medium 8, pH5.85, seemed to be sensitive and suitable. The MIC value of diluted MeOH extracts made from C. raciborskii and T. bourrellyi against Aer. hydrophila corresponded to 38 mg freeze-dried cyanobacteria. Bacillus subtilis was more sensitive when grown in a culture medium with pH 5.85 than 7.9. The antibacterial properties of extracts from the cyanobacteria examined differed from defined cyanotoxins and antibacterial substances. The pattern of inhibition in the bacterial bioassays indicated that various antibacterial substances are involved. PMID:9717298

Ostensvik, O; Skulberg, O M; Underdal, B; Hormazabal, V

1998-06-01

44

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

Science.gov (United States)

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

Alamri, Saad A.; Mohamed, Zakaria A.

2013-01-01

45

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

Science.gov (United States)

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

Alamri, Saad A; Mohamed, Zakaria A

2013-10-01

46

Bioeconomic Analysis of Selected Conservation Practices on Soil Erosion and Freshwater Fisheries  

Science.gov (United States)

Farmers can generate environmental benefits (improved water quality and fisheries and wildlife habitat), but they may not be able to quantify them. Furthermore, farmers may reduce their incomes from managing lands to produce these positive externalities but receive little monetary compensation in return. This study simulated the relationship between agricultural practices, water quality, fish responses to suspended sediment and farm income within two small watersheds, one of a cool water stream and one of a warm water stream. Using the Agricultural Drainage and Pesticide Transport (ADAPT) model, this study related best management practices (BMPs) to calculated instream suspended sediment concentrations by estimating sediment delivery, runoff, base flow, and streambank erosion to quantify the effects of suspended sediment exposure on fish communities. By implementing selected BMPs in each watershed, annual net farm income declined 18,000 to 28,000 (1 to 3 percent) from previous levels. "Lethal" fish events from suspended sediments in the cool water watershed decreased by 60 percent as conservation tillage and riparian buffers increased. Despite reducing suspended sediments by 25 percent, BMPs in the warm water watershed did not reduce the negative response of the fisheries. Differences in responses (physical and biological) between watersheds highlight potential gains in economic efficiency by targeting BMPs or by offering performance based "green payments."

Westra, John V.; Zimmerman, Julie K. H.; Vondracek, Bruce

2005-04-01

47

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

Energy Technology Data Exchange (ETDEWEB)

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.

Vocke, R.W.

1979-01-01

48

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

International Nuclear Information System (INIS)

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

49

BIOACCUMULATION OF HEAVY AND ESSENTIAL METALS IN THE SELECTED FRESHWATER FISH SPECIES FROM PREUMAL LAKE CUDDALORE DISTRICT, TAMILNADU, INDIA.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The present study was conducted to determine the heavy and essential metals, chromium, cadmium, copper, lead, iron, zinc and manganese concentrations in gill, liver, kidney, intestine and muscle of the available freshwater fish Mystus vittatus, Heteropneustes fossilis, Glossogobius giuris, Notopterous notopterous and Tilapia mossambica of the Perumal lake Cuddalore district, Tamilnadu, India collected during the January 2011- December 2011. Heavy and essential metals concentrati...

Ambedkar, G.; Muniyan, M.

2013-01-01

50

Bioaccumulation of some heavy metals and the haematological indices in some selected freshwater fishes in river Manyara, Nigeria  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The present study examined the bioaccumulation of some heavy metals (Lead, chromium and cadmium) in some freshwater fishes (Tilapia zilli, Labeo coubie and Synodontis membranaceous) and their haematological indices in river Manyara in Niger State, Nigeria. The accumulation of the metals examined in these fishes was significantly different (P P...

Et Al, Moody F. O.

2013-01-01

51

Proposed Release Guides to Protect Aquatic Biota  

Energy Technology Data Exchange (ETDEWEB)

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.

Marter, W.L.

2001-03-28

52

Environmental influences on marine biota off Southern Africa  

Energy Technology Data Exchange (ETDEWEB)

The influence of the environment on selected elements of Southern Africa's marine biota is reviewed in order to provide a basis for examining possible impacts of anticipated climate change on the biota. There is regional coherence in some biotic and oceanographic indices, suggestive that environmental perturbations may affect large areas. The northern Benguela region is influenced by Benguela Ninos, which occur infrequently but result in southward displacements of both local populations and more tropical species. The Benguela Ninos seemingly benefit survival of the early stages of some organisms, but may decrease the production of others by up to 50%. In the southern Benguela region, a major shift in species dominance occurred in the early 1960s. It is likely that the environment exerted an influence, but the mechanism is not known and the ability to predict both the timing and nature of ecosystem change remains poor.

Crawford, R.J.M.; Shannon, L.V. (Sea Fisheries Research Inst. (South Africa)); Siegfried, W.R.; Villacastin-Herrero, C.A.; Underhill, L.G. (Univ. of Cape Town, Rondebosch (South Africa))

53

Freshwater Ecosystems  

Science.gov (United States)

In this activity, learners create a freshwater ecosystem in a large plastic bottle. Learners cut and prepare bottles, then fill with water, aquatic plants, snails and fish. Learners observe their mini-ecosystem over time to see what changes--such as the color of the water, the water temperature, plant growth, and behavior and/or population of the snails or fish. The activity serves as a model for larger freshwater ecosystems such as ponds, lakes, rivers, streams, wetlands, reservoirs and groundwater.

Jersey, New; Center, Liberty S.; Coalition, New J.

2006-01-01

54

Part 7: Monitoring of biota  

International Nuclear Information System (INIS)

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

55

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

Science.gov (United States)

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. PMID:24495913

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

2014-01-01

56

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

Science.gov (United States)

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.

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

2014-02-01

57

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

International Nuclear Information System (INIS)

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

58

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

International Nuclear Information System (INIS)

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)

59

Precambrian biota: protistan origin of trace fossils?  

Science.gov (United States)

Some Precambrian trace fossils have been presented as evidence for the early origin of bilaterians; the recent finding that large amoeboid protists leave macroscopic traces at the bottom of the deep ocean questions the metazoan nature of early trace fossils, stressing the importance of single-cell organisms in Precambrian biota. PMID:19138588

Pawlowski, Jan; Gooday, Andrew J

2009-01-13

60

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

Directory of Open Access Journals (Sweden)

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.

Paillisson J.-M.

2011-05-01

 
 
 
 
61

Temporal trends of Hg in Arctic biota, an update  

DEFF Research Database (Denmark)

A statistically robust method was applied to 83 time-series of mercury 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, mostly under the auspices of the Arctic Monitoring and Assessment Program (AMAP). Sampling locations ranged from Alaska in the west to northern Scandinavia in the east. Information from recently published temporal trend studies was tabulated to supplement the results of the statistical analyses. No generally consistent trend was evident across tissues and species from the circumpolar Arctic during the last 30years or so. However, there was a clear west-to-east gradient in the occurrence of recent increasing Hg trends, with larger numbers and a higher proportion of biotic datasets in the Canadian and Greenland region of the Arctic showing significant increases than in the North Atlantic Arctic. Most of the increasing datasets were for marine species, especially marine mammals. A total of 16 (19%) out of the 83 time-series could be classified as "adequate", where adequate is defined as the number of actual monitoring years in a time-series being equal to or greater than the number of years of sampling required to detect a 5% annual change in Hg concentrations, with a significance level of P

Rigét, Frank; Braune, Birgit

2011-01-01

62

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

Science.gov (United States)

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.

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

2008-12-01

63

Freshwater Flow Charts - 1995  

Energy Technology Data Exchange (ETDEWEB)

This report covers the following: (1) Explanation of Charts Showing Freshwater Flow in 1995; (2) Estimated U.S. Freshwater Flow in 1995 (chart); (3) Estimated California Freshwater Flow in 1995 (chart); (4) Estimated New Mexico Freshwater Flow in 1995 (chart); and (5) Web locations and credits.

Kaiper, G V

2003-11-21

64

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

Veraart, J. A.; Groot, R. S.; Perello?, G.; Riddiford, N. J.; Roijackers, R. M. M.

2004-01-01

65

Freshwater Ulva (Chlorophyta) as a bioaccumulator of selected heavy metals (Cd, Ni and Pb) and alkaline earth metals (Ca and Mg)  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We analyzed the ability of freshwater taxa of the genus Ulva (Ulvaceae, Chlorophyta) to serve as bioindicators of metal in lakes and rivers. Changes in heavy metal (Ni, Cd and Pb) and alkaline earth metal (Ca and Mg) concentrations in freshwater Ulva thalli were investigated during the period from June to August 2010. The study was conducted in two ecosystems in Western Poland, the Malta lake (10 sites) and the Nielba river (six sites). Three components were collected for each sample, includi...

Rybak, Andrzej; Messyasz, Beata; ?e?ska, Bogus?awa

2012-01-01

66

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

Science.gov (United States)

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

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

2009-01-30

67

Radiological dose conversion factors for non-human biota for Canada's nuclear fuel waste disposal concept assessment  

Energy Technology Data Exchange (ETDEWEB)

For the Canadian Nuclear Fuel Waste Management Program, transport models are used to predict radionuclide movement from an underground vault to the surface environment. Potential radiological doses to humans are calculated and used as a criterion to assess the safety and acceptability of the concept. However, protection of the environment is also a key issue in the permanent disposal of used nuclear fuel. Hence, an estimate of radiological doses to non-human biota is needed to assess the environmental impact. In this report, we present dose conversion factors for calculation of radiological doses to non-human biota. Four generic organisms have been identified, representing animals and plants related to the human food chain: a freshwater fish, a terrestrial plant, a terrestrial mammal, and a terrestrial bird. We calculate the dose converson factors for both internal and external radiation sources, for the radionuclides 14-C, 99-Tc, 129-I, and 137-Cs, which are of key importance. (auth)

Amiro, B.D.

1992-01-15

68

A Silurian soft-bodied biota  

Science.gov (United States)

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.

Mikulic, D. G.; Briggs, D. E. G.; Kluessendorf, J.

1985-01-01

69

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

Energy Technology Data Exchange (ETDEWEB)

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)

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

2013-12-15

70

Interactions of radionuclides with marine biota  

International Nuclear Information System (INIS)

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

71

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1978-06-01

72

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

2013-02-15

73

ACCUMULATION OF HEAVY METALS IN BIOTA OF VYRLYTSA LAKE  

Directory of Open Access Journals (Sweden)

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

Tetiana Bilyk

2011-03-01

74

Decline of radionuclides in Columbia River biota  

International Nuclear Information System (INIS)

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

75

Decline of radionuclides in Columbia River biota  

Energy Technology Data Exchange (ETDEWEB)

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.

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

1980-03-01

76

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

Science.gov (United States)

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.

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

2013-04-01

77

Sensitivity of hypogean and epigean freshwater copepods to agricultural pollutants.  

Science.gov (United States)

Widespread pollution from agriculture is one of the major causes of the poor freshwater quality currently observed across Europe. Several studies have addressed the direct impact of agricultural pollutants on freshwater biota by means of laboratory bioassays; however, as far as copepod crustaceans are concerned, the ecotoxicological research is scarce for freshwater species and almost nonexistent for the hypogean ones. In this study, we conducted a comparative analysis of the available literature data on the sensitivity of freshwater copepods to agricultural pollutants. We also assessed the acute and chronic sensitivity of a hypogean and an epigean species, both belonging to the Crustacea Copepoda Cyclopoida Cyclopidae, to two N-fertilizers (urea and ammonium nitrate) and two herbicides (ARIANE(TM) II from Dow AgroSciences LLC, and Imazamox), widely used for cereal agriculture in Europe. According to the literature review, freshwater copepods are sensitive to a range of pesticides and N-fertilizers. Ecotoxicological studies on hypogean species of copepods account only one study. There are no standardized protocols available for acute and chronic toxicity tests for freshwater copepods, making comparisons about sensitivity difficult. From our experiments, ionized ammonia proved to be more toxic than the herbicide Imazamox, in both short and chronic bioassays. Urea was the less toxic chemical for both species. The hypogean species was more sensitive than the epigean one to all chemicals. For both species and for all tested chemicals, acute lethality and chronic lethality were induced at concentrations higher than the law limits of good water body quality in Europe, except for ionized ammonia, which provoked the chronic lethality of the hypogean species at a lower concentration. The hazardous concentration (HC) of un-ionized ammonia for 5 % of freshwater copepods, obtained by a species sensitivity distribution, was 92 ?g l(-1), significantly lower than the HC computed for traditional test species from freshwater environments. PMID:24352541

Di Lorenzo, T; Di Marzio, W D; Sáenz, M E; Baratti, M; Dedonno, A A; Iannucci, A; Cannicci, S; Messana, G; Galassi, D M P

2014-03-01

78

Choosing an alpha radiation weighting factor for doses to non-human biota  

International Nuclear Information System (INIS)

The risk to non-human biota from exposure to ionizing radiation is of current international interest. In calculating radiation doses to humans, it is common to multiply the absorbed dose by a factor to account for the relative biological effectiveness (RBE) of the radiation type. However, there is no international consensus on the appropriate value of such a factor for weighting doses to non-human biota. This paper summarizes our review of the literature on experimentally determined RBEs for internally deposited alpha-emitting radionuclides. The relevancy of each experimental result in selecting a radiation weighting factor for doses from alpha particles in biota was judged on the basis of criteria established a priori. We recommend a nominal alpha radiation weighting factor of 5 for population-relevant deterministic and stochastic endpoints, but to reflect the limitations in the experimental data, uncertainty ranges of 1-10 and 1-20 were selected for population-relevant deterministic and stochastic endpoints, respectively

79

Lixiviados de biosólidos sobre la biota dulceacuícola  

Directory of Open Access Journals (Sweden)

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.

Eduardo Andrés Flores Salinas

2010-04-01

80

Effects of thermal discharges on aquatic biota  

International Nuclear Information System (INIS)

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

 
 
 
 
81

Central Northwest Pacific biota and their radioactivity  

International Nuclear Information System (INIS)

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

82

Overview of the EMRAS biota dosimetry working group  

International Nuclear Information System (INIS)

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

83

Exceptionally preserved Late Ordovician biotas from Manitoba, Canada  

Science.gov (United States)

There are few body fossil biotas known from early Paleozoic accretionary shorelines, and very few examples of Ordovician soft-bodied assemblages. This study documents two recently discovered biotas from separate sedimentary basins in Manitoba, Canada, that provide unique information about tropical shoreline communities shortly before the Late Ordovician extinction event. Each site represents a distinct depositional environment, but they share biotic elements, including eurypterids, xiphosurids, and large problematic tubes. The William Lake biota, representing more restricted conditions, includes jellyfish that are among the best hydromedusan body fossils known. Rocks at the Airport Cove site, deposited under more open circulation, contain scolecodonts and noncalcified algae. These biotas have some parallels with the recently described Middle Ordovician Winneshiek Lagerstätte, but are also similar to some Late Silurian assemblages. Considered together, early Paleozoic marginal marine deposits are a rich but as yet poorly known source of paleobiodiversity data.

Young, Graham A.; Rudkin, David M.; Dobrzanski, Edward P.; Robson, Sean P.; Nowlan, Godfrey S.

2007-10-01

84

Interactions between marine biota and ENSO: a conceptual model analysis  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 ...

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

2011-01-01

85

Effect of chronic selenium exposure on the freshwater bivalve Corbicula fluminea  

International Nuclear Information System (INIS)

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

86

Transient Changes in the Biosphere as a Result of Freshwater Hosing  

Science.gov (United States)

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

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

2013-12-01

87

Rationale for WFD Freshwater Classification  

Rationale for Water Framework Directive (WFD) Freshwater Classification RIVER AND LAKES CLASSIFICATIONS Introduction This text describes how WFD Freshwater Classification has been established. It describes the ...

88

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

Hermoso, Virgilio; Clavero, Miguel

2011-01-01

89

Approaches to estimating the transfer of radionuclides to arctic biota  

International Nuclear Information System (INIS)

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)

90

Establishing a database of radionuclide transfer parameters for freshwater wildlife.  

Science.gov (United States)

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. PMID:23103210

Yankovich, T; Beresford, N A; Fesenko, S; Fesenko, J; Phaneuf, M; Dagher, E; Outola, I; Andersson, P; Thiessen, K; Ryan, J; Wood, M D; Bollhöfer, A; Barnett, C L; Copplestone, D

2013-12-01

91

Ecodosimetry weighting factor (eR) for non-human biota  

International Nuclear Information System (INIS)

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 radiatiocts, to which RBE values in human radiation protection relate. For tritium ?-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 ?-emitters is not the larger, limiting value of RBE value observed at low doses, but rather a value around 5. (author)

92

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

International Nuclear Information System (INIS)

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)

93

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

International Nuclear Information System (INIS)

1 - Description of problem or function: LADTAP2 performs environmental dose analyses for releases of liquid effluents from light-water nuclear power plants into surface waters during routine operation. The analyses estimate radiation doses to individuals, population groups, and biota from ingestion (aquatic foods, water, and terrestrial irrigated foods) and external exposure (shoreline, swimming, and boating) pathways. The calculated doses provide information for National Environmental Policy Act (NEPA) evaluations and for determining compliance with Appendix I of 10 CFR 50 (the 'ALARA' philosophy). The program consists of a hydrologic model chosen to represent mixing in the effluent impoundment system and the receiving surface waters and the exposure pathway models which estimate exposure of selected groups at various water usage locations in the environment. Two types of population doses are calculated. An ALARA analysis is performed based on exposure of people within 50 miles of the site, and a NEPA analysis is performed based on exposure of the entire U.S. population to effluents from the site. A population-dose analysis prepared in the form of a cost-benefit table presents the total-body and thyroid doses from each radionuclide released and the population doses (total-body and thyroid) per curie of each radionuclide released. 2 - Method of solution: The impoundment system is represented by one of four hydrologic models: direct release to the receiving water, lineirect 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

94

Enhanced activities of organically bound tritium in biota samples.  

Science.gov (United States)

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. PMID:24582481

Svetlik, I; Fejgl, M; Malátová, I; Tomaskova, L

2014-11-01

95

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

International Nuclear Information System (INIS)

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 ?g L?1 U at 20 mg CaCO3 L?1 hardness, increasing to 547 ?g 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

96

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

International Nuclear Information System (INIS)

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

97

Radiation exposure to marine biota around the Fukushima Daiichi NPP.  

Science.gov (United States)

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

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

2014-05-01

98

Modelling potential impacts of effective dispersant use on aquatic biota  

International Nuclear Information System (INIS)

er. An exception to the support of dispersant use would be if sensitive water column biota are present in the area of the slick. The conclusions applied to unconfined water bodies that were at least 10 metres deep. 18 refs., 4 tabs., 5 figs

99

Multimedia fate modeling and comparative impact on freshwater ecosystems of pharmaceuticals from biosolids-amended soils.  

Science.gov (United States)

This study modeled the impact on freshwater ecosystems of pharmaceuticals detected in biosolids following application on agricultural soils. The detected sulfonamides and hydrochlorothiazide displayed comparatively moderate retention in solid matrices and, therefore, higher transfer fractions from biosolids to the freshwater compartment. However, the residence times of these pharmaceuticals in freshwater were estimated to be short due to abiotic degradation processes. The non-steroidal anti-inflammatory mefenamic acid had the highest environmental impact on aquatic ecosystems and warrants further investigation. The estimation of the solid-water partitioning coefficient was generally the most influential parameter of the probabilistic comparative impact assessment. These results and the modeling approach used in this study serve to prioritize pharmaceuticals in the research effort to assess the risks and the environmental impacts on aquatic biota of these emerging pollutants. PMID:23746366

Morais, Sérgio Alberto; Delerue-Matos, Cristina; Gabarrell, Xavier; Blánquez, Paqui

2013-09-01

100

Biota and biological parameters as environmental indicators  

Science.gov (United States)

This is the third of several compilations of briefing papers on water quality by the U.S. Geological Survey. Each briefing paper is prepared in a simple, nontechnical, easy-to-understand manner. This U.S. Geological Survey Circular contains papers on selected organic substances in water. Briefing papers are included on ' Why study organic substances in water. ', ' Taste and odor in water ', and ' Classification and fractionation of organic solutes in natural waters'. (USGS)

Greeson, Phillip E., (Edited By)

1981-01-01

 
 
 
 
101

Heavy metals in seawater, sediments, and biota from the coastal area of Yancheng City, China.  

Science.gov (United States)

A systematic investigation was carried out to analyze the concentration levels of heavy metals in sample seawater, sediments, and biota collected from the coastal area of Yancheng City in Jiangsu Province, China. The authors assessed the impact of these heavy metals in different environmental samples in terms of potential risks to ecology and also to the human population exposed to this area. In addition, a further investigation was carried out to test the toxicity to early-life-stage zebrafish (Danio rerio) of selected samples that were considered to pose higher levels of potential risks to ecology or human health. Chemical analysis showed relatively higher concentrations of heavy metals in the seawater and biota samples collected from Xiangshui County and Binhai County, China. The heavy metal concentrations in different samples collected from the close vicinity of Dafeng Port, China, were also considerable. In all seawater and sediment samples, heavy metals showed a relatively moderate level of risk to ecological species; for consumption of marine organisms, heavy metals had adverse impacts on human health. Toxicity assessment indicated that the selected environmental samples or their extracts had significant toxicity to zebrafish early-life stages, including lethality, teratogenicity, and hatching delay (or advance). Thus the present study provides highly useful and important information on heavy metal pollution in Jiangsu Province. PMID:24619970

Fu, Jie; Wang, Hui; Billah, Shah M Reduwan; Yu, Hongxia; Zhang, Xiaowei

2014-08-01

102

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

Energy Technology Data Exchange (ETDEWEB)

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

Garisto, N.; Kovacs, R.; Janes, A. [SENES Consultants Limited, Richmond Hill, Ontario (Canada)

2010-07-01

103

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

International Nuclear Information System (INIS)

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

104

PBDEs in freshwater mussels and fish from Flanders, Belgium  

Energy Technology Data Exchange (ETDEWEB)

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.

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

105

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

Energy Technology Data Exchange (ETDEWEB)

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

Beresford, N.A. [Centre for Ecology and Hydrology, CEH-Lancaster, Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster LA1 4AP (United Kingdom)], E-mail: nab@ceh.ac.uk; Barnett, C.L.; Howard, B.J.; Scott, W.A. [Centre for Ecology and Hydrology, CEH-Lancaster, Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster LA1 4AP (United Kingdom); Brown, J.E. [Norwegian Radiation Protection Authority, Department of Emergency Preparedness and Environmental Radioactivity, Grini naeringspark 13, Post Box 55, NO-1332 Osteras (Norway); Copplestone, D. [Environment Agency, Richard Fairclough House, Knutsford Road, Warrington, Cheshire WA4 1HG (United Kingdom)

2008-09-15

106

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

International Nuclear Information System (INIS)

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

107

What are the toxicological effects of mercury in Arctic biota?  

DEFF Research Database (Denmark)

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.

Dietz, Rune; Sonne, Christian

2012-01-01

108

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

Energy Technology Data Exchange (ETDEWEB)

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)

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

109

Water quality and aquatic biota in Magela Creek  

International Nuclear Information System (INIS)

Within the Alligator Rivers Region the aquatic environment is potentially the most likely part of the natural environment to be adversely affected as a result of the proposed uranium mining and milling operations. Current knowledge relating to the existing aquatic biota and water quality in the region is reviewed with particular emphasis on the Magela Creek Catchment. Attention is given to identifying the most important potential impacts and to management strategies that will minimise such impacts

110

Conversion ratios for the foodstuffs and biota environmental surveillance program  

Energy Technology Data Exchange (ETDEWEB)

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

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

1998-09-01

111

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

Directory of Open Access Journals (Sweden)

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.

Lokman P Mark

2010-09-01

112

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

Directory of Open Access Journals (Sweden)

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

Stewart Donald T

2008-05-01

113

Davis Pond Freshwater Prediversion Biomonitoring Study: Freshwater Fisheries and Eagles  

Science.gov (United States)

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

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

2008-01-01

114

Prevalence of chemical defenses among freshwater plants.  

Science.gov (United States)

Although macrophyte herbivore interactions in freshwater systems were generally disregarded for many years, recent data suggest that herbivory can be intense and important in structuring freshwater communities. This has led to the hypothesis that chemical defenses should be common among freshwater plants, but few studies have reported such chemical defenses, and no previous studies have assessed the frequency of chemical defenses among a substantial number of freshwater plant species. In a study of 21 macrophyte species co-occurring with the omnivorous crayfish Procambarus acutus in a southeastern USA wetland environment, we found that extracts of 11 species (52%) deterred feeding by P. acutus when tested in artificial foods at natural concentrations. Of these 11 chemically defended species, one species, Eupatorium capillifolium, consistently had a more unpalatable extract following mechanical damage to plant tissue, indicative of an activated chemical defense. Because herbivores are commonly nitrogen-limited and select food based on several plant traits, including plant nutritional value, it might be expected that chemical defenses would be especially important for protein-rich plants. However, we found no relationship between soluble protein concentration and deterrence of plant extracts. PMID:16124238

Prusak, Anne C; O'Neal, Jennifer; Kubanek, Julia

2005-05-01

115

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

International Nuclear Information System (INIS)

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

116

Global ocean freshwater transport pathways  

Science.gov (United States)

Variations in the atmospheric hydrological cycle are most easily observed through ocean salinity changes, and therefore it is useful to understand the basic ocean circulations responsible for maintaining the mean ocean salinity distribution. Ocean freshwater transports are calculated here from geostrophic and Ekman velocities and salinities. The net transports are assigned quantitatively to upper ocean gyre circulations, intermediate and deep overturning, and Bering Strait/Indonesian Throughflow. Excess freshwater input into the ocean in high latitudes must be transported via ocean circulation to the evaporative lower latitudes. High latitude northern hemisphere freshwater input of about 0.6 Sv is removed southwards through deep and intermediate water formation (NADW and NPIW). In complete contrast, high latitude southern hemisphere freshwater, also about 0.6 Sv, is removed northwards via the Atlantic, Pacific and Indian gyres, rather than through deep water formation. This northern-southern hemisphere asymmetry is consistent with the known "Drake Passage" effect. Excess evaporation in the Atlantic and Indian Oceans is balanced by inflow of freshwater from other regions; each transfer is quantified here. The Pacific Ocean is nearly neutral with respect to freshwater. It is seen that the NADW freshwater balance is nearly closed within the Atlantic/Arctic Ocean and the freshwater transport associated with export of NADW to the Southern Ocean is only a small component of the Atlantic freshwater budget. Bering Strait's small freshwater transport of NPIW salinity, because the Pacific has a much smaller overturning rate than the Atlantic.

Talley, L.

2008-12-01

117

Assessment of Marine Biota Doses Arising from the Radioactive Sea Discharges of the COGEMA La Hague Facility. A Comprehensive Case Study (Consensus Appraisal)  

International Nuclear Information System (INIS)

This paper reports an assessment of radiation doses to marine biota arising from the radioactive sea discharges (as liquid effluents) of the COGEMA La Hague facility. The La Hague facility is located in the northwest part of France, in the north-west tip of the Nord-Cotentin Peninsula, along the English Channel south shore. The case study was primarily based on the large amount of data from recent studies of the Nord-Cotentin Radioecology Group (GRNC) and from a recent environmental impact assessment of the 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. This conclusion and the dose rate predictions in this study are in close agreement with those for the marine biota of Cap La Hague reported in the MARINAII study recently undertaken for the European Commission. This case study has been presented and discussed at a recent specific workshop of international experts held at La Hague on April 15, 2003. This paper briefly presents the case study and put a particular focus on the study consensus appraisal (which includes the major conclusion stated above) that resulted from the workshop and on an industry perspective on the emerging topic of protection of non-human biota species. The points highlighted in the consensus appraisal have been incorporated in the study final report. The reader is invited to consult the consensus appraisal, contained in the study final report, for an independent and transparent opinion on the La Hague case study that was expressed by a group of international experts. (Author) 15 refs

118

Burgess shale-type biotas were not entirely burrowed away  

DEFF Research Database (Denmark)

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 known. The well-documented decline of soft-bodied preservation following the Middle Cambrian represents the closure of a taphonomic window that was only intermittently open in marine environments thereafter. The prevailing hypothesis for this secular shift in taphonomic conditions of outer shelf environments is that soft-bodied biotas were literally burrowed away from the fossil record by increasing infaunal activity in muddy substrate environments; this would have affected geochemical gradients and increased the efficiency of organic matter recycling in sediments. New and recently published data, however, suggest a more complex scenario. Ichnologic and microstratigraphic data from Burgess Shale-type deposits indicatethat (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 the Burgess Shale (Canada). Therefore, increasing bioturbation cannot account for the apparent loss of this pathway from the fossil record, and requires that other circumstances, including, but not limited to, widespread benthic anoxia, facilitated widespread exceptional preservation in the Cambrian.

Hammarlund, Emma; Canfield, Donald Eugene

2012-01-01

119

Technetium distribution and accumulation in marine sediments and biota  

International Nuclear Information System (INIS)

Technetium normally exists in marine environments as pertechnetate Tcsup(VII). However when sediments are reduced and organic rich, it becomes fixed rapidly to them. Bacterial activity does not seem to be responsible. Concentration factors for Tc in biota are generally 10-20 but two exceptions are macrophytic algae (1100) and polychaetes (300-800). Biological half lives are weeks or months. Retention was generally about 20% of that in the food source, and 25% of that was retained in the digestive gland or liver. (author)

120

Anthropogenic radionuclides in biota samples from the Caspian Sea  

International Nuclear Information System (INIS)

The Caspian Sea has been recently a subject of many scientific studies mainly related to sea level changes and pollution. For this purpose, two sampling expeditions were organised by IAEA in the Caspian Sea in 1995 and 1996. The aim was to investigate oceanographic conditions, water dynamics and the distribution of anthropogenic radionuclides 90Sr, 137Cs and 239,240Pu in the water column. Considering the unique biodiversity of the Caspian Sea, there has also been interest to obtain information on radionuclide concentrations in biota samples, first of all in sturgeons and in caviar as their production is strongly linked to economical regional needs. The radioactive contamination of Caspian Sea biota has been investigated by analyzing natural 210Po and anthropogenic 137Cs, 239,240Pu and 241Am in biota samples collected in April 1999 offshore of Astrakhan, in the north Caspian Sea. More biota samples from the South West Caspian Sea (Artom Island, June 1999; Devechi District and Neftechala, November 1999) were collected and analyzed for 210Po, 137Cs, 90Sr, 239,240Pu and 241Am. The sampled species were different types of sturgeons (Sevruga, Russkyi Osyotr and Beluga) as well as fresh spawn and caviar. Other fish species (e.g. Cyprinidae) and one algae sample (Cladofila) have also been analysed. Flesh parts have only been analysed in the case oarts 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

 
 
 
 
121

Population Dynamics of Biota on the Roots of Azolla microphylla Kaulfuss  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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, C...

NITA ETIKAWATI; JUTONO

2000-01-01

122

Activated chemical defenses suppress herbivory on freshwater red algae.  

Science.gov (United States)

The rapid life cycles of freshwater algae are hypothesized to suppress selection for chemical defenses against herbivores, but this notion remains untested. Investigations of chemical defenses are rare for freshwater macrophytes and absent for freshwater red algae. We used crayfish to assess the palatability of five freshwater red algae relative to a palatable green alga and a chemically defended aquatic moss. We then assessed the roles of structural, nutritional, and chemical traits in reducing palatability. Both native and non-native crayfish preferred the green alga Cladophora glomerata to four of the five red algae. Batrachospermum helminthosum, Kumanoa holtonii, and Tuomeya americana employed activated chemical defenses that suppressed feeding by 30-60 % following damage to algal tissues. Paralemanea annulata was defended by its cartilaginous structure, while Boldia erythrosiphon was palatable. Activated defenses are thought to reduce ecological costs by expressing potent defenses only when actually needed; thus, activation might be favored in freshwater red algae whose short-lived gametophytes must grow and reproduce rapidly over a brief growing season. The frequency of activated chemical defenses found here (three of five species) is 3-20× higher than for surveys of marine algae or aquatic vascular plants. If typical for freshwater red algae, this suggests that (1) their chemical defenses may go undetected if chemical activation is not considered and (2) herbivory has been an important selective force in the evolution of freshwater Rhodophyta. Investigations of defenses in freshwater rhodophytes contribute to among-system comparisons and provide insights into the generality of plant-herbivore interactions and their evolution. PMID:23011851

Goodman, Keri M; Hay, Mark E

2013-04-01

123

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

Scientific Electronic Library Online (English)

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

Jean Paul, Metzger; Lilian, Casatti.

124

Interactions between marine biota and ENSO: a conceptual model analysis  

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

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

M. Heinemann

2011-01-01

125

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

International Nuclear Information System (INIS)

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

126

Surface-water-quality assessment of the Yakima River basin, Washington; distribution of pesticides and other organic compounds in water, sediment, and aquatic biota, 1987-91; with a section on dissolved organic carbon in the Yakima River basin  

Science.gov (United States)

During 1987-91, chemical data were collected for pesticides and other organic compounds in surface water, streambed sediment, suspended sediment, agricultural soil, and aquatic biota to determine the occurrence, distribution, transport, and fate of organic compounds in the Yakima River basin in Washington. The report describes the chemical and physical properties of the compounds most frequently detected in the water column; organochlorine compounds including DDT, organophosphorus compounds, thiocarbamate and sulfite compounds, acetamide and triazine compounds, and chlorophenoxy-acetic acid and benzoic compounds. Concentrations are evaluated relative to chronic-toxicity water quality criteria and guidelines for the protection of human health and freshwater aquatic life.

Rinella, Joseph F.; McKenzie, Stuart W.; Crawford, J. Kent; Foreman, William T.; Fuhrer, Gregory J.; Morace, Jennifer L.; Aiken, George R.

1999-01-01

127

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

Science.gov (United States)

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

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

128

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

International Nuclear Information System (INIS)

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

129

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

International Nuclear Information System (INIS)

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

130

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

International Nuclear Information System (INIS)

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

131

Population Dynamics of Biota on the Roots of Azolla microphylla Kaulfuss  

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

NITA ETIKAWATI

2000-01-01

132

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

Science.gov (United States)

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 across an abiotic gradient. Our candidate tree species was European beech (Fagus sylvatica L.), whose regeneration is extremely responsive to soil biota activity. In a greenhouse experiment, we measured tree survival in sterilized and non-sterilized soils collected across an elevation gradient in the French Alps. Negative effects of soil biota on tree survival decreased with elevation, similar to shifts observed in plant-plant interactions. Hence, soil biota effects must be included in theoretical models of plant biotic interactions to accurately represent and predict the effects of abiotic gradient on plant communities. PMID:21525055

Defossez, Emmanuel; Courbaud, Benoît; Marcais, Benoît; Thuiller, Wilfried; Granda, Elena; Kunstler, Georges

2011-10-23

133

Agrochemical residue-biota interactions in soil and aquatic ecosystems  

International Nuclear Information System (INIS)

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

134

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

Science.gov (United States)

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

Kaspar, Matthew Jason

135

Effects of mineralized artesian water on the fresh-water biota of Taylor Slough, Everglades National Park, Florida  

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The feasibility of using water from the Floridian aquifer during periods of drought to maintain water levels in the aquatic communities at the Royal Palm Visitor Center in Everglades National Park was tested.

Kolipinski, Milton C.; Higer, Aaron L.

1969-01-01

136

Deriving freshwater quality criteria for 2,4-dichlorophenol for protection of aquatic life in China  

International Nuclear Information System (INIS)

Criteria were established for an organic pollutant in freshwaters of China. - Freshwater quality criteria for 2,4-dichlorophenol (2,4-DCP) were developed with particular reference to the aquatic biota in China, and based on USEPA's guidelines. Acute toxicity tests were performed on nine different domestic species indigenous to China to determine 48-h LC50 and 96-h LC50 values for 2,4-DCP. In addition, 21 day survival-reproduction tests with Daphnia magna, 30-day embryo-larval tests with Carassius auratus, 60 day fry-juvenile test with Ctenopharyngodon idellus, 30 d early life stage tests with Bufo bufo gargarizans and 96 h growth inhibition tests with Scenedesms obliqaus were conducted, to estimate lower chronic limit (LCL) and upper chronic limit (UCL) values. The final acute value (FAV) was 2.49 mg/l 2,4-DCP. Acute-to-chronic ratios (ACR) ranged from 3.74 to 22.5. The final chronic value (FCV) and the final plant value (FPV) of 2.4-DCP were 0.212 mg/l and 7.07 mg/l respectively. Based on FAV, FCV, and FPV, a criteria maximum concentration (CMC) of 1.25 mg/l and a criterion continuous concentration (CCC) of 0.212 mg/l were derived. The results of this study provide useful data for deriving national or local water quality criteria for 2,4-DCP based on aquatic biota in China

137

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

Scientific Electronic Library Online (English)

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

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

2013-06-01

138

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2008-10-09

139

Application of an environmental impact assessment methodology to a site discharging low levels of radioactivity to a freshwater environment in Norway.  

Science.gov (United States)

Significant shifts in opinion regarding environmental protection from ionising radiation have resulted in the development and availability of bespoke approaches for the assessment of impacts on wildlife from radioactive contaminants. The application of such assessment methodologies to actual situations, however, remains relatively limited. This paper describes the implementation of the ERICA Integrated Approach and associated tools within the context of routine discharges of radioactive materials to a freshwater environment. The article follows the implementation through its relevant stages and discusses strengths and weaknesses of the approach in relation to the case study. For current discharge levels, 137Cs and 60Co constitute the main dose contributors to the majority of reference organisms studied, although 241Am and 3H are the main contributors for the phyto- and zooplankton categories. Patterns are observed depending on whether the reference organism is sediment-associated or not. At current discharge levels, none of the reference organisms exceeded or approached the selected screening level, and impacts on biota could be regarded as negligible. PMID:20237837

Hosseini, Ali; Brown, Justin Emrys; Dowdall, Mark; Standring, William; Strand, Per

2011-02-01

140

Polychlorinated alkanes in fish from Norwegian freshwater.  

Science.gov (United States)

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. SigmasPCA concentration ranged from 108 to 3700 ng/g fat. The highest value was found in the south of Norway near an industrial area. PMID:12806048

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

2002-01-16

 
 
 
 
141

Comprehensive monitoring of synthetic musk compounds from freshwater to coastal environments in Korea: with consideration of ecological concerns and bioaccumulation.  

Science.gov (United States)

This study investigated the concentration levels of synthetic musk compounds (SMCs), including HHCB (1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta-(g)-2-benzopyran), AHTN (7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4-tetrahydronaphthalene), MK (Musk ketone), and MX (Musk xylene), in freshwater, freshwater and coastal sediments, and coastal bivalves from freshwater to coastal environments. The levels in freshwater close to sewage treatment plants (STPs) showed higher contamination and suggested a medium to high ecological risk, especially posed by MK making more than 65% contribution to the combined risk by the total SMCs. STP effluent discharge points showed higher SMC concentrations in freshwater and coastal sediments. Predominant HHCB contributions regardless of sample types such as abiota and biota were consistent with the greater usage of HHCB than AHTN and MK in Korea. However, the higher contributions of AHTN than those predicted from AHTN consumption in Korea indicate the need for further research on the characteristic properties of individual SMCs, including partitioning, biomagnification, degradation, and metabolism for a realistic risk characterization. With respect to the highest HHCB levels in coastal bivalves reported, we determined the biota-sediment accumulation factor (BSAF) to understand the bioaccumulation of SMCs between coastal sediment and bivalves. The calculated BSAF values suggested that SMCs in bivalves were not biomagnified via the food chain but mostly partitioned from sediment. To our knowledge, this is the first study to measure BSAF values of SMCs, especially HHCB, AHTN, and MK, in coastal bivalve samples. PMID:23978700

Lee, In-Seok; Kim, Un-Jung; Oh, Jeong-Eun; Choi, Minkyu; Hwang, Dong-Woon

2014-02-01

142

The BIOTA Biodiversity Observatories in Africa--a standardized framework for large-scale environmental monitoring.  

Science.gov (United States)

The international, interdisciplinary biodiversity research project BIOTA AFRICA initiated a standardized biodiversity monitoring network along climatic gradients across the African continent. Due to an identified lack of adequate monitoring designs, BIOTA AFRICA developed and implemented the standardized BIOTA Biodiversity Observatories, that meet the following criteria (a) enable long-term monitoring of biodiversity, potential driving factors, and relevant indicators with adequate spatial and temporal resolution, (b) facilitate comparability of data generated within different ecosystems, (c) allow integration of many disciplines, (d) allow spatial up-scaling, and (e) be applicable within a network approach. A BIOTA Observatory encompasses an area of 1 km(2) and is subdivided into 100 1-ha plots. For meeting the needs of sampling of different organism groups, the hectare plot is again subdivided into standardized subplots, whose sizes follow a geometric series. To allow for different sampling intensities but at the same time to characterize the whole square kilometer, the number of hectare plots to be sampled depends on the requirements of the respective discipline. A hierarchical ranking of the hectare plots ensures that all disciplines monitor as many hectare plots jointly as possible. The BIOTA Observatory design assures repeated, multidisciplinary standardized inventories of biodiversity and its environmental drivers, including options for spatial up- and downscaling and different sampling intensities. BIOTA Observatories have been installed along climatic and landscape gradients in Morocco, West Africa, and southern Africa. In regions with varying land use, several BIOTA Observatories are situated close to each other to analyze management effects. PMID:21448628

Jürgens, Norbert; Schmiedel, Ute; Haarmeyer, Daniela H; Dengler, Jürgen; Finckh, Manfred; Goetze, Dethardt; Gröngröft, Alexander; Hahn, Karen; Koulibaly, Annick; Luther-Mosebach, Jona; Muche, Gerhard; Oldeland, Jens; Petersen, Andreas; Porembski, Stefan; Rutherford, Michael C; Schmidt, Marco; Sinsin, Brice; Strohbach, Ben J; Thiombiano, Adjima; Wittig, Rüdiger; Zizka, Georg

2012-01-01

143

Speciation of pyrithione in freshwaters  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

Lofts, S.

2009-01-01

144

Are metals of antifouling paints transferred to marine biota?  

Scientific Electronic Library Online (English)

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

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

2007-03-01

145

Are metals of antifouling paints transferred to marine biota?  

Directory of Open Access Journals (Sweden)

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.

Wladimir C. Paradas

2007-03-01

146

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

Science.gov (United States)

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 random mutations 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. PMID:22922185

Smetacek, Victor

2012-09-01

147

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

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Full Text Available 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 potential new taxa, e.g. a new species of Vetulicola. This new occurrence not only expands the palaeogeographic distribution of the Guanshan Biota, but also strengthens the ties between the younger Chengjiang Biota and the older Kaili Biota (and also the coeval Burgess Shale community

Liu J N

2012-02-01

148

Macroecological patterns of species distribution, composition and richness of the Azorean terrestrial biota  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We investigate the macroecological patterns of the terrestrial biota of the Azorean archipelago, namely the species-range size distributions, the distance decay of similarity, and the island species–area relationship (ISAR). We use the most recent up-to-date checklists to describe the diversity at the island level for nine groups (Lichens, Fungi, Diatoms, Bryophytes, Vascular Plants, Nematodes, Molluscs, Arthropods, Vertebrates). The particularities of the Azorean biota result in some diffe...

Borges, Paulo A. V.; Cardoso, Pedro; Cunha, Regina Trista?o Da; Gabriel, Rosalina; Gonc?alves, Vitor; Hortal, Joaqui?n; Martins, Anto?nio M. Frias; Melo, Ireneia; Rodrigues, Pedro; Santos, Ana M.; Silva, Lui?s; Triantis, Kostas A.; Vieira, Paulo; Vieira, Virgi?lio

2011-01-01

149

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  

Science.gov (United States)

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.

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

2013-01-01

150

The estimation of absorbed dose rates for non-human biota : an extended inter-comparison.  

Energy Technology Data Exchange (ETDEWEB)

An exercise to compare 10 approaches for the calculation of unweighted whole-body absorbed dose rates was conducted for 74 radionuclides and five of the ICRP's Reference Animals and Plants, or RAPs (duck, frog, flatfish egg, rat and elongated earthworm), selected for this exercise to cover a range of body sizes, dimensions and exposure scenarios. Results were analysed using a non-parametric method requiring no specific hypotheses about the statistical distribution of data. The obtained unweighted absorbed dose rates for internal exposure compare well between the different approaches, with 70% of the results falling within a range of variation of {+-}20%. The variation is greater for external exposure, although 90% of the estimates are within an order of magnitude of one another. There are some discernible patterns where specific models over- or under-predicted. These are explained based on the methodological differences including number of daughter products included in the calculation of dose rate for a parent nuclide; source-target geometry; databases for discrete energy and yield of radionuclides; rounding errors in integration algorithms; and intrinsic differences in calculation methods. For certain radionuclides, these factors combine to generate systematic variations between approaches. Overall, the technique chosen to interpret the data enabled methodological differences in dosimetry calculations to be quantified and compared, allowing the identification of common issues between different approaches and providing greater assurance on the fundamental dose conversion coefficient approaches used in available models for assessing radiological effects to biota.

Batlle, J. V. I.; Beaugelin-Seiller, K.; Beresford, N. A.; Copplestone, D.; Horyna, J.; Hosseini, A.; Johansen, M.; Kamboj, S.; Keum, D.-K.; Kurosawa, N.; Newsome, L.; Olyslaegers, G.; Vandenhove, H.; Ryufuku, S.; Lynch, S. V.; Wood, M. D.; Yu, C. (Environmental Science Division); (Westlakes Scientific Consulting Ltd.); (Inst. de Radioprotection et de Surete Nucleaire); (Centre for Ecology & Hydrology); (Norwegian Radiation Protection Authority); (State Office for Nuclear Safety); (Korea Atomic Energy Research Institute); (Visible Information Centre Inc.); (Belgian Nuclear Research Centre); (University of Liverpool)

2011-05-01

151

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

Science.gov (United States)

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

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

2012-11-01

152

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

Science.gov (United States)

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.

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

2009-01-01

153

Marine biota sightings during 3D marine seismic surveys  

Energy Technology Data Exchange (ETDEWEB)

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)

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

154

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

International Nuclear Information System (INIS)

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)

155

Mercury Contamination in Forest and Freshwater Ecosystems in the Northeastern United States  

Science.gov (United States)

This peer reviewed article form Bioscience journal is about mercury contamination in forest and freshwater ecosystems in the northeastern United States. Eastern North America receives elevated atmospheric mercury deposition from a combination of local, regional, and global sources. Anthropogenic emissions originate largely from electric utilities, incinerators, and industrial processes. The mercury species in these emissions have variable atmospheric residence times, which influence their atmospheric transport and deposition patterns. Forested regions with a prevalence of wetlands and of unproductive surface waters promote high concentrations of mercury in freshwater biota and thus are particularly sensitive to mercury deposition. Through fish consumption, humans and wildlife are exposed to methylmercury, which markedly bioaccumulates up the freshwater food chain. Average mercury concentrations in yellow perch fillets exceed the Environmental Protection Agency's human health criterion across the region, and mercury concentrations are high enough in piscivorous wildlife to cause adverse behavioral, physiological, and reproductive effects. Initiatives are under way to decrease mercury emissions from electric utilities in the United States by roughly 70%.

CHARLES T. DRISCOLL, YOUNG-JI HAN, CELIA Y. CHEN, DAVID C. EVERS, KATHLEEN FALLON LAMBERT, THOMAS M. HOLSEN, NEIL C. KAMMAN, RONALD K. MUNSON (;)

2007-01-01

156

Nearctic freshwater tardigrades: a review  

Directory of Open Access Journals (Sweden)

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.

Juliana G. HINTON

2007-09-01

157

International Year of Freshwater 2003  

Science.gov (United States)

Near the conclusion of the year 2000, the United Nations General Assembly created a resolution to proclaim 2002 as the International Year of Freshwater. Given the importance of freshwater to all human, plant, and animal life, this designation seems altogether fitting and timely. As the resolution notes, it is hoped that many governments and political actors will use the year to increase awareness of the importance of sustainable freshwater use, management, and protection. To this end, this helpful Web site provides a host of online resources designed to educate the web-browsing public about various events related to this overriding theme, along with presenting an online library of publications about freshwater. Visitors can read the online newsletter, Splash, along with browsing a water library, organized by themes (such as water and society and ecosystems), and geographic regions. Another compelling feature are the water proverbs taken from a number of areas, including the Middle East and Latin America. Given the global mission of the site it is refreshing to note that many of the materials are also available in French and Spanish. [KMG

2003-01-01

158

Dissolved Organic Matter in Freshwaters  

Science.gov (United States)

Organic matter in freshwaters exists as dissolved molecules, colloids, and particles. It is appropriate to regard these distinctions as dynamic, however, because organic matter can be interconverted readily between these forms by dissolution and precipitation, sorption and desorption, aggregation and disaggregation, etc. Dissolved organic matter (DOM), the subject of this chapter, is defined operationally as the fraction of organic matter in a water sample that passes through a 0.45 ?m filter. In the authors' opinion, the scientific literature on organic matter in freshwaters will be better reflected in this review, if data are considered without regard to the manner in which water samples may have been filtered. This more general approach is warranted because: * many submicron colloids and some microorganisms can pass through 0.45 ?m filters; * the effective pore size of a 0.45 ?m filter is usually unknown, because it is decreased by partial clogging during the filtration of a water sample; * some important studies have been conducted on unfiltered samples or on samples that were filtered through other types of filters; and * some important studies have been conducted on samples that were concentrated with ultrafiltration (UF), nanofiltration (NF), or reverse osmosis (RO) membranes.As methods for fractionation and isolation of organic matter in freshwaters have evolved, and as the intensity of research has waxed and waned in various academic disciplines, a rich and potentially confusing nomenclature has evolved for organic matter in freshwaters. Some of the more commonly encountered descriptors and their associated acronyms, if any, are yellow organic acids (YOAs), aquatic humus, DOM, and natural organic matter (NOM). Regardless of the terminology used in the original literature, the organic matter in freshwaters is referred to as DOM in this review, except when it is necessary to be more specific.

Perdue, E. M.; Ritchie, J. D.

2003-12-01

159

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

2014-03-24

160

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

Science.gov (United States)

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).

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

 
 
 
 
161

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

International Nuclear Information System (INIS)

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

162

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

Science.gov (United States)

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.

Suseno, Heny

2014-03-01

163

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

International Nuclear Information System (INIS)

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)

164

Deriving freshwater quality criteria for iron, lead, nickel, and zinc for protection of aquatic life in Malaysia.  

Science.gov (United States)

Freshwater quality criteria for iron (Fe), lead (Pb), nickel (Ni), and zinc (Zn) were developed with particular reference to aquatic biota in Malaysia, and based on USEPA's guidelines. Acute toxicity tests were performed on eight different freshwater domestic species in Malaysia which were Macrobrachium lanchesteri (prawn), two fish: Poecilia reticulata and Rasbora sumatrana, Melanoides tuberculata (snail), Stenocypris major (ostracod), Chironomus javanus (midge larvae), Nais elinguis (annelid), and Duttaphrynus melanostictus (tadpole) to determine 96 h LC(50) values for Fe, Pb, Ni, and Zn. The final acute value (FAV) for Fe, Pb, Ni, and Zn were 74.5, 17.0, 165, and 304.9 ?g L(-1), respectively. Using an estimated acute-to-chronic ratio (ACR) of 8.3, the value for final chronic value (FCV) was derived. Based on FAV and FCV, a criterion maximum concentration (CMC) and a criterion continuous concentration (CCC) for Fe, Pb, Ni, and Zn that are 37.2, 8.5, 82.5, and 152.4 ?g?L(-1) and 9.0, 2.0, 19.9, and 36.7 ?g?L(-1), respectively, were derived. The results of this study provide useful data for deriving national or local water quality criteria for Fe, Pb, Ni, and Zn based on aquatic biota in Malaysia. Based on LC(50) values, this study indicated that N. elinguis, M. lanchesteri, N. elinguis, and R. sumatrana were the most sensitive to Fe, Pb, Ni, and Zn, respectively. PMID:22919358

Shuhaimi-Othman, M; Nadzifah, Y; Nur-Amalina, R; Umirah, N S

2012-01-01

165

Deriving freshwater quality criteria for copper, cadmium, aluminum and manganese for protection of aquatic life in Malaysia.  

Science.gov (United States)

Freshwater quality criteria for copper (Cu), cadmium (Cd), aluminum (Al), and manganese (Mn) were developed with particular reference to aquatic biota in Malaysia, and based on USEPA's guidelines. Acute toxicity tests were performed on eight different freshwater domestic species in Malaysia, which were Macrobrachiumlanchesteri (prawn), two fish -Poeciliareticulata and Rasborasumatrana, Melanoidestuberculata (snail), Stenocyprismajor (ostracod), Chironomusjavanus (midge larvae), Naiselinguis (annelid), and Duttaphrynusmelanostictus (tadpole), to determine 96-h LC50 values for Cu, Cd, Al, and Mn. The final acute values (FAVs) for Cu, Cd, Al, and Mn were 2.5, 3.0, 977.8, and 78.3 ?gL(-1), respectively. Using an estimated acute-to-chronic ratio (ACR) of 8.3, the value for final chronic value (FCV) was derived. Based on FAV and FCV, a Criterion Maximum Concentration (CMC) and a criterion Continuous Concentration (CCC) for Cu, Cd, Al, and Mn of 1.3, 1.5, 488.9, and 39.1 ?gL(-1) and 0.3, 0.36, 117.8, and 9.4 ?gL(-1), respectively, were derived. The results of this study provide useful data for deriving national or local water quality criteria for Cu, Cd, Al, and Mn based on aquatic biota in Malaysia. Based on LC50 values, this study indicated that R.sumatrana, M.lanchesteri, C.javanus, and N.elinguis were the most sensitive to Cu, Cd, Al, and Mn, respectively. PMID:23246727

Shuhaimi-Othman, M; Nadzifah, Y; Nur-Amalina, R; Umirah, N S

2013-03-01

166

Cued in: advances and opportunities in freshwater chemical ecology.  

Science.gov (United States)

We focus this mini-review on how naturally occurring chemical cues mediate ecological interactions, especially interspecific competition and predation in freshwater communities. Although freshwater chemical ecology lags behind terrestrial and marine chemical ecology, we identify recent progress toward: (1) identifying the chemical composition of cues important in food web interactions, e.g., specific glucosinolates, benzyl succinoates, and lignoids as deterrents to herbivory on freshwater macrophytes; (2) employing a nonreductionist approach that tests for emergent responses to suites of multiple chemical cues, e.g., trade-offs in snail refuge-seeking behavior in the presence of chemical cues from both fish and crayfish; (3) investigating how abiotic forces, such as hydrodynamics, impact chemical communication across a broad spatial and temporal scale, e.g., drift responses of mayfly nymphs to whole-stream additions of trout cue; and (4) quantifying the importance of genetic variability, e.g., how chemical cues change selective pressures of local environments. The questions of interest in freshwater chemical ecology cross taxonomic boundaries; traverse broad spatial and temporal scales; demonstrate nonlinear, unpredictable results; and necessitate a multidisciplinary approach for adequate understanding. PMID:12474890

Burks, Romi L; Lodge, David M

2002-10-01

167

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

International Nuclear Information System (INIS)

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

168

Contrasting size evolution in marine and freshwater diatoms.  

Science.gov (United States)

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

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

2009-02-24

169

Phylogeography of an Island endemic, the Puerto Rican Freshwater Crab (Epilobocera sinuatifrons).  

Science.gov (United States)

The endemic Puerto Rican crab, Epilobocera sinuatifrons (Pseudothelphusidae), has a freshwater-dependant life-history strategy, although the species has some capabilities for terrestrial movement as adults. In contrast to all other freshwater decapods on the island (e.g., caridean shrimp), E. sinuatifrons does not undertake amphidromous migration, and is restricted to purely freshwater habitats and adjacent riparian zones. As Puerto Rico has a dynamic geologic history, we predicted that both the life history of E. sinuatifrons and the geological history of the island would be important determinants of phylogeographic structuring in the species. Using a fragment of the cytochrome c oxidase subunit 1 mtDNA (mitochondrial DNA) gene, we tested for deviations from panmixia among and within rivers draining Puerto Rico and used statistical phylogeography to explore processes that may explain extant patterns of genetic variation in the species. While populations of E. sinuatifrons were significantly differentiated among rivers, they were likely to be recently derived because nested clade analysis (NCA) indicated evolutionarily recent restricted gene flow with isolation by distance (IBD) and contiguous range expansion at various spatial scales. Ongoing drainage rearrangements associated with faulting and land slippage were invoked as processes involved in sporadic gene flow among rivers throughout the Pleistocene. Patterns of genetic differentiation conformed to IBD and population demographic statistics were nonsignificant, indicating that although recently derived, populations from different rivers were in drift-mutation equilibrium. A shallow (0.6 million years ago), paraphyletic split was observed in the haplotype network, which NCA indicated arose via allopatric fragmentation. This split coincides with an area of high relief in central Puerto Rico that may have experienced relatively little drainage rearrangements. Shallow but significant genetic isolation of populations of E. sinuatifrons among Puerto Rican rivers suggests phylogeographic patterns that are intermediate to terrestrial habitat specialists (highly divergent populations) and other freshwater biota, such as amphidromous species and insects with aerial adult dispersal (highly connected populations). PMID:18252729

Cook, Benjamin D; Pringle, Catherine M; Hughes, Jane M

2008-01-01

170

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

International Nuclear Information System (INIS)

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

171

Deriving freshwater quality criteria for 2,4-dichlorophenol for protection of aquatic life in China  

Energy Technology Data Exchange (ETDEWEB)

Criteria were established for an organic pollutant in freshwaters of China. - Freshwater quality criteria for 2,4-dichlorophenol (2,4-DCP) were developed with particular reference to the aquatic biota in China, and based on USEPA's guidelines. Acute toxicity tests were performed on nine different domestic species indigenous to China to determine 48-h LC{sub 50} and 96-h LC{sub 50} values for 2,4-DCP. In addition, 21 day survival-reproduction tests with Daphnia magna, 30-day embryo-larval tests with Carassius auratus, 60 day fry-juvenile test with Ctenopharyngodon idellus, 30 d early life stage tests with Bufo bufo gargarizans and 96 h growth inhibition tests with Scenedesms obliqaus were conducted, to estimate lower chronic limit (LCL) and upper chronic limit (UCL) values. The final acute value (FAV) was 2.49 mg/l 2,4-DCP. Acute-to-chronic ratios (ACR) ranged from 3.74 to 22.5. The final chronic value (FCV) and the final plant value (FPV) of 2.4-DCP were 0.212 mg/l and 7.07 mg/l respectively. Based on FAV, FCV, and FPV, a criteria maximum concentration (CMC) of 1.25 mg/l and a criterion continuous concentration (CCC) of 0.212 mg/l were derived. The results of this study provide useful data for deriving national or local water quality criteria for 2,4-DCP based on aquatic biota in China.

Yin Daqiang; Jin Hongjun; Yu Lingwei; Hu Shuangqing

2003-04-01

172

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

International Nuclear Information System (INIS)

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

173

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

Energy Technology Data Exchange (ETDEWEB)

The bioaccumulation of /sup 233/ /sup 234/U, /sup 238/U, /sup 238/Pu, /sup 239/ /sup 240/Pu, /sup 241/Am, and /sup 244/Cm 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 /sup 239/ /sup 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. 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, /sup 241/Am//sup 239/Pu, /sup 244/Cm//sup 239/Pu, and /sup 238/U//sup 239/Pu ratios were greater than the respective ratio in sediment while /sup 233/ /sup 234/U//sup 238/U, and /sup 239/ /sup 240/Pu//sup 238/Pu 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.

Garten, C.T. Jr.; Trabalka, J.R.; Bogle, M.A.

1981-01-01

174

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

International Nuclear Information System (INIS)

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

175

Biogeography of Iberian freshwater fishes revisited: The roles of historical versus contemporary constraints  

Science.gov (United States)

Aim The question of how much of the shared geographical distribution of biota is due to environmental vs. historical constraints remains unanswered. The aim of this paper is to disentangle the contribution of historical vs. contemporary factors to the distribution of freshwater fish species. In addition, it illustrates how quantifying the contribution of each type of factor improves the classification of biogeographical provinces. Location Iberian Peninsula, south-western Europe (c. 581,000 km2). Methods We used the most comprehensive data on native fish distributions for the Iberian Peninsula, compiled from Portuguese and Spanish sources on a 20-km grid-cell resolution. Overall, 58 species were analysed after being categorized into three groups according to their ability to disperse through saltwater: (1) species strictly intolerant of saltwater (primary species); (2) species partially tolerant of saltwater, making limited incursions into saltwaters (secondary species); and (3) saltwater-tolerant species that migrate back and forth from sea to freshwaters or have invaded freshwaters recently (peripheral species). Distance-based multivariate analyses were used to test the role of historical (basin formation) vs. contemporary environmental (climate) conditions in explaining current patterns of native fish assemblage composition. Cluster analyses were performed to explore species co-occurrence patterns and redefine biogeographical provinces based on the distributions of fishes. Results River basin boundaries were better at segregating species composition for all species groups than contemporary climate variables. This historical signal was especially evident for primary and secondary freshwater fishes. Eleven biogeographical provinces were delineated. Basins flowing to the Atlantic Ocean north of the Tagus Basin and those flowing to the Mediterranean Sea north of the Mijares Basin were the most dissimilar group. Primary and secondary freshwater species had higher province fidelity than peripheral species. Main conclusions The results support the hypothesis that historical factors exert greater constraints on native freshwater fish assemblages in the Iberian Peninsula than do current environmental factors. After examining patterns of assemblage variation across space, as evidenced by the biogeographical provinces, we discuss the likely dispersal and speciation events that underlie these patterns. ?? 2009 Blackwell Publishing Ltd.

Filipe, A.F.; Araujo, M.B.; Doadrio, I.; Angermeier, P.L.; Collares-Pereira, M. J.

2009-01-01

176

BSAFs and Food Web Modeling for Establishing Contaminant Relationships between Biota and Sediment  

Science.gov (United States)

The presentation will cover how to measure and evaluate BSAFs (biota-sediment accumulation factors), and how to construct, calibrate, validate, and evaluate food web models. The presentation will also discuss the advantages of the two approaches for establishing contaminant rel...

177

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

International Nuclear Information System (INIS)

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-04?Gy h-1, respectively, finally compared with the IAEA and UNSCEAR data set for screening level dose risk assessment. (authors)

178

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

Science.gov (United States)

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

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

2012-07-01

179

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

Science.gov (United States)

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 (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.

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

1995-01-01

180

A meta-analysis of responses of soil biota to global change.  

Science.gov (United States)

Global environmental changes are expected to impact the abundance of plants and animals aboveground, but comparably little is known about the responses of belowground organisms. Using meta-analysis, we synthesized results from over 75 manipulative experiments in order to test for patterns in the effects of elevated CO(2), warming, and altered precipitation on the abundance of soil biota related to taxonomy, body size, feeding habits, ecosystem type, local climate, treatment magnitude and duration, and greenhouse CO(2) enrichment. We found that the positive effect size of elevated CO(2) on the abundance of soil biota diminished with time, whereas the negative effect size of warming and positive effect size of precipitation intensified with time. Trophic group, body size, and experimental approaches best explained the responses of soil biota to elevated CO(2), whereas local climate and ecosystem type best explained responses to warming and altered precipitation. The abundance of microflora and microfauna, and particularly detritivores, increased with elevated CO(2), indicative of microbial C limitation under ambient CO(2). However, the effects of CO(2) were smaller in field studies than in greenhouse studies and were not significant for higher trophic levels. Effects of warming did not depend on taxon or body size, but reduced abundances were more likely to occur at the colder and drier sites. Precipitation limited all taxa and trophic groups, particularly in forest ecosystems. Our meta-analysis suggests that the responses of soil biota to global change are predictable and unique for each global change factor. PMID:21274573

Blankinship, Joseph C; Niklaus, Pascal A; Hungate, Bruce A

2011-03-01

 
 
 
 
181

Investigation on applicability of Biota dose assessment model to Japanese environment  

International Nuclear Information System (INIS)

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

182

Mercury accumulation in biota of Thunder Creek, Saskatchewan  

Energy Technology Data Exchange (ETDEWEB)

Collection of biological organisms was undertaken to investigate the bioaccumulation of mercury in the food chain, the results of which are reported. Two sites were selected on Thunder Creek; the control or background site, site number 2, is located approximately 2.5 km upstream, from site number 1. The selection of organisms for analysis was based on the presence and abundance of each at both locations. Only crayfish (Orconcetes virilis) pearl dace (Semotilus margarita) and brook stickleback (Culaea inconstans) were found to be sufficiently abundant. The importance of the data obtained is the significant difference in concentration between the upstream and downstream sites on Thunder Creek. This difference shows that more mercury is available to the biological community at site number 1 than at site number 2 confirming that mercury in the contaminated sediments is being methylated and taken up into the food chain.

Munro, D.J.; Gummer, W.D.

1980-12-01

183

Freshwater Ecoregions of the World: A New Map of Biogeographic Units for Freshwater Biodiversity Conservation  

Science.gov (United States)

We present a new map depicting the first global biogeographic regionalization of Earth's freshwater systems. This map of freshwater ecoregions is based on the distributions and compositions of freshwater fish species and incorporates major ecological and evolutionary patterns. Covering virtually all freshwater habitats on Earth, this ecoregion map, together with associated species data, is a useful tool for underpinning global and regional conservation planning efforts (particularly to identify outstanding and imperiled freshwater systems); for serving as a logical framework for large-scale conservation strategies; and for providing a global-scale knowledge base for increasing freshwater biogeographic literacy. Preliminary data for fish species compiled by ecoregion reveal some previously unrecognized areas of high biodiversity, highlighting the benefit of looking at the world's freshwaters through a new framework.

Robin Abell et al (WWF;)

2008-05-01

184

A mitogenic view on the evolutionary history of the Holarctic freshwater gadoid, burbot (Lota lota).  

Science.gov (United States)

Climatic oscillations during the Pleistocene epoch had a dramatic impact on the distribution of biota in the northern hemisphere. In order to trace glacial refugia and postglacial colonization routes on a global scale, we studied mitochondrial DNA sequence variation in a freshwater fish (burbot, Lota lota; Teleostei, Gadidae) with a circumpolar distribution. The subdivision of burbot in the subspecies Lota lota lota (Eurasia and Alaska) and Lota lota maculosa (North America, south of the Great Slave Lake) was reflected in two distinct mitochondrial lineages (average genetic distance is 2.08%). The lota form was characterized by 30 closely related haplotypes and a large part of its range (from Central Europe to Beringia) was characterized by two widespread ancestral haplotypes, implying that transcontinental exchange/migration was possible for cold-adapted freshwater taxa in recent evolutionary time. However, the derived mitochondrial variants observed in peripheral populations point to a recent separation from the core group and postglacial recolonization from distinct refugia. Beringia served as refuge from where L. l. lota dispersed southward into North America after the last glacial maximum. Genetic variation in the maculosa form consisted of three mitochondrial clades, which were linked to at least three southern refugia in North America. Two mitochondrial clades east of the Continental Divide (Mississippian and Missourian clades) had a distinct geographical distribution in the southern refuge zones but intergraded in the previously glaciated area. The third clade (Pacific) was exclusively found west of the Continental Divide. PMID:15969726

Van Houdt, J K J; De Cleyn, L; Perretti, A; Volckaert, F A M

2005-07-01

185

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

International Nuclear Information System (INIS)

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)

186

The freshwater reservoir effect in radiocarbon dating  

DEFF Research Database (Denmark)

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.

Philippsen, Bente

187

Freshwater autotrophic picoplankton: a review  

Directory of Open Access Journals (Sweden)

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.

John G. STOCKNER

2002-02-01

188

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

Science.gov (United States)

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

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

189

Tissue concentrations, bioaccumulation, and biomagnification of synthetic musks in freshwater fish from Taihu Lake, China.  

Science.gov (United States)

Synthetic musks are ubiquitous pollutants in aquatic environments. As hydrophobic chemicals, they can accumulate in terrestrial and aquatic organisms. Investigations into the bioaccumulation of these chemicals in aquatic ecosystem have, however, been limited, and previous results were inconsistent among species and ecosystem. Studies on this topic have been carried out in European countries, the USA, and Japan, but very few are known of the situation in China. The aim of this study was to investigate contaminant levels of musks in fish from Taihu Lake, the second largest freshwater lake in China, as well as bioaccumulation and biomagnification of the pollutants in the freshwater food chain. Five polycyclic musks and two nitro musks were determined in 24 fish species and nine surface sediment samples from Taihu Lake. HHCB (1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta[?]-2-benzopyran) and AHTN (7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4-tetrahydronaphthalene) were the predominant contaminants in the fish samples, with concentrations ranging from below the limit of detection (LOD) to 52.9 and from bioaccumulation characteristics were suggested, but no significant region-specific differences were observed. Normalized biota-sediment accumulation factors for HHCB and AHTN were noted to increase with trophic levels in fish. Trophic magnification factors were estimated at 1.12 for HHCB and 0.74 for AHTN. A biomagnification for HHCB, and probably biodilution for AHTN, in the freshwater food chain are indicated, when trophic magnification factors were concerned. However, the correlations between logarithmic concentrations of the chemicals and trophic levels were not statistically significant. Further study using long food chains in this lake is still needed. PMID:22855355

Zhang, Xiaolan; Xu, Qing; Man, Shoukuan; Zeng, Xiangying; Yu, Yingxin; Pang, Yuping; Sheng, Guoying; Fu, Jiamo

2013-01-01

190

Comparative uptake of uranium, thorium, and plutonium by biota inhabiting a contaminated Tennessee floodplain  

International Nuclear Information System (INIS)

The uptake of 238U, 232Th, and 239Pu from soil by fescue, grasshoppers, and small mammals was compared at the contaminated White Oak Creek floodplain in East Tennessee. Comparisons of actinide uptake were based on analyses of radionuclide ratios (U/Pu and Th/Pu) in soil and biota. U:Pu ratios in small mammal carcasses (shrews, mice, and rats) and bone samples from larger mammals (rabbit, woodchuck, opossum, and raccoon) were significantly greater (P less than or equal to 0.05) than U/Pu ratios in soil (based on 8M HNO3 extractable). There was no significant difference between Th/Pu ratios in animals and soil. The order of actinide accumulation by biota from the site relative to contaminated soil was U > Th approx. = Pu

191

Methods for calculating dose conversion coefficients for terrestrial and aquatic biota  

Energy Technology Data Exchange (ETDEWEB)

Plants and animals may be exposed to ionizing radiation from radionuclides in the environment. This paper describes the underlying data and assumptions to assess doses to biota due to internal and external exposure for a wide range of masses and shapes living in various habitats. A dosimetric module is implemented which is a user-friendly and flexible possibility to assess dose conversion coefficients for aquatic and terrestrial biota. The dose conversion coefficients have been derived for internal and various external exposure scenarios. The dosimetric model is linked to radionuclide decay and emission database, compatible with the ICRP Publication 38, thus providing a capability to compute dose conversion coefficients for any nuclide from the database and its daughter nuclides. The dosimetric module has been integrated into the ERICA Tool, but it can also be used as a stand-alone version.

Ulanovsky, A. [Helmholtz Zentrum Muenchen, German Research Center for Environmental Health, Institute of Radiation Protection, Ingolstaedter Landstrasse 1, D-85764 Neuherberg (Germany)], E-mail: ulanovsky@helmholtz-muenchen.de; Proehl, G. [Helmholtz Zentrum Muenchen, German Research Center for Environmental Health, Institute of Radiation Protection, Ingolstaedter Landstrasse 1, D-85764 Neuherberg (Germany); Gomez-Ros, J.M. [CIEMAT, Av. Complutense 22, 28040 Madrid (Spain)

2008-09-15

192

Methods for calculating dose conversion coefficients for terrestrial and aquatic biota  

International Nuclear Information System (INIS)

Plants and animals may be exposed to ionizing radiation from radionuclides in the environment. This paper describes the underlying data and assumptions to assess doses to biota due to internal and external exposure for a wide range of masses and shapes living in various habitats. A dosimetric module is implemented which is a user-friendly and flexible possibility to assess dose conversion coefficients for aquatic and terrestrial biota. The dose conversion coefficients have been derived for internal and various external exposure scenarios. The dosimetric model is linked to radionuclide decay and emission database, compatible with the ICRP Publication 38, thus providing a capability to compute dose conversion coefficients for any nuclide from the database and its daughter nuclides. The dosimetric module has been integrated into the ERICA Tool, but it can also be used as a stand-alone version

193

Dechlorane Plus and related compounds in aquatic and terrestrial biota: a review.  

Science.gov (United States)

Dechlorane Plus, dechlorane 602, dechlorane 603 and dechlorane 604 are flame retardants that have been used for a long time as a substitute for mirex, but they have not been noticed as environmental contaminants until recently (2006). Regardless of their large molecular size and very high lipophilicity (log K(OW)?> 9), Dechlorane Plus and related compounds have been detected in different aquatic and terrestrial species, supporting their bioaccumulation and biomagnification. Moreover, some studies showed different behaviour of the syn-Dechlorane Plus and anti-Dechlorane Plus isomers in the environment and different biomagnification factors in biota. This review describes the different analytical approaches applied to the determination of Dechlorane Plus and related compounds. Moreover, a summary of their levels in aquatic and terrestrial biota, as well as in humans, is presented, showing also current research results on their bioaccumulation and biomagnification potential. Finally, isomer-specific bioaccumulation of Dechlorane Plus is also discussed. PMID:22695503

Feo, M L; Barón, E; Eljarrat, E; Barceló, D

2012-11-01

194

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

International Nuclear Information System (INIS)

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

195

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

Energy Technology Data Exchange (ETDEWEB)

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 {sup 90}Sr, {sup 226}Ra 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)

Avila, R.; Beresford, N.A.; Broed, R.L. [Facilia AB Valsgardevagen, Bromma (Sweden)

2004-07-01

196

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

1994-06-01

197

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

Hayes P; Wilde V; Manchester S R; Collinson M

2010-01-01

198

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

Energy Technology Data Exchange (ETDEWEB)

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.

Baird, G.C.

1985-03-01

199

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

2009-07-01

200

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

International Nuclear Information System (INIS)

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

 
 
 
 
201

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

Directory of Open Access Journals (Sweden)

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

Candeiro, C. R. A.

2007-06-01

202

Occurrence of 17?-ethynylestradiol (EE2) in the environment and effect on exposed biota: a review.  

Science.gov (United States)

17?-ethynylestradiol (EE2) is a synthetic hormone, which is a derivative of the natural hormone, estradiol (E2). EE2 is an orally bio-active estrogen, and is one of the most commonly used medications for humans as well as livestock and aquaculture activity. EE2 has become a widespread problem in the environment due to its high resistance to the process of degradation and its tendency to (i) absorb organic matter, (ii) accumulate in sediment and (iii) concentrate in biota. Numerous studies have reported the ability of EE2 to alter sex determination, delay sexual maturity, and decrease the secondary sexual characteristics of exposed organisms even at a low concentration (ng/L) by mimicking its natural analogue, 17?-estradiol (E2). Thus, the aim of this review is to provide an overview of the science regarding EE2, the concentration levels in the environment (water, sediment and biota) and summarize the effects of this compound on exposed biota at various concentrations, stage life, sex, and species. The challenges in respect of EE2 include the extension of the limited database on the EE2 pollution profile in the environment, its fate and transport mechanism, as well as the exposure level of EE2 for better prediction and definition revision of EE2 toxicity end points, notably for the purpose of environmental risk assessment. PMID:24825791

Aris, Ahmad Zaharin; Shamsuddin, Aida Soraya; Praveena, Sarva Mangala

2014-08-01

203

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

International Nuclear Information System (INIS)

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

204

Accelerated extraction for determination of polycyclic aromatic hydrocarbons in marine biota  

Energy Technology Data Exchange (ETDEWEB)

A rapid and simple method is proposed for determination of polycyclic aromatic hydrocarbons (PAH) in complex matrices such as marine biota. The method uses sonication, by means of an ultrasonic probe, as a new tool for assisted extraction, coupled with reversed-phase liquid chromatography (RP-LC) with fluorescence detection (FL) for determination of 16 US EPA priority PAH. Separation and detection of the 16 PAH were complete in 45 min by RP-LC with a C{sub 18} column and acetonitrile-water gradient elution. Multivariate optimisation of the variables affecting extraction (ultrasound radiation amplitude, sonication time, and temperature of the water-bath in which the extraction cell was placed) was conducted. The accuracy of the method was determined by analysis of a certified reference material and comparison of the results obtained with those from another method (microwave-assisted extraction and GC-MS). The new technique avoids the main problems encountered in the determination of PAH in complex matrices such as marine biota, and no clean-up step is necessary. The method was applied to determination of PAH in estuarine biota samples from the Urdaibai estuary (Biscay, Spain). (orig.)

Sanz-Landaluze, J.; Gonzalez, L.; Dietz, C.; Camara, C. [University Complutense de Madrid, Ciudad Universitaria, Department of Analytical Chemistry, Faculty of Chemistry, Madrid (Spain); Bartolome, L.; Zuloaga, O. [Euskal Herriko Unibertsitatea, Department of Analytical Chemistry, Faculty of Technology, Bilbao (Spain)

2005-03-15

205

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

International Nuclear Information System (INIS)

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

206

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

Science.gov (United States)

Karst ecosystems are fragile and are in many regions degraded by anthropogenic activities. Current management of degraded karst areas focuses on aboveground vegetation succession or recovery and aims at establishing a forest ecosystem. Whether progressive succession of vegetation in karst areas is accompanied by establishment of soil biota is poorly understood. In the present study, soil microbial and nematode communities, as well as soil physico-chemical properties were studied along a progressive succession of secondary vegetation (from grassland to shrubland to forest) in a karst area in southwest China. Microbial biomass, nematode density, ratio of fungal to bacterial biomass, nematode structure index, and nematode enrichment index decreased with the secondary succession in the plant community. Overall, the results indicated a pattern of declines in soil biota abundance and food web complexity that was associated with a decrease in soil pH and a decrease in soil organic carbon content with the progressive secondary succession of the plant community. Our findings suggest that soil biota amendment is necessary during karst ecosystem restoration and establishment and management of grasslands may be feasible in karst areas. PMID:25379741

He, Xunyang; Liu, Lu; Wang, Kelin

2014-01-01

207

Pathogenic agents in freshwater resources  

Science.gov (United States)

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

Geldreich, Edwin E.

1996-02-01

208

Magnesium transport in freshwater teleosts  

Science.gov (United States)

The magnesium handling of freshwater teleost fish is discussed, with an emphasis on the role of branchial, intestinal and renal transport. In response to the eminent threat of constant diffusive losses of minerals such as magnesium, freshwater fish have developed efficient mechanisms for magnesium homeostasis. Magnesium losses are overcome by the uptake of magnesium from the food, making the intestine an important route for magnesium uptake. Some evidence suggests that intestinal magnesium uptake in fish is a regulated, cellular process. The ambient water is an additional magnesium source for fish, implicating the gills as a secondary route for magnesium uptake. Certainly, in some species, direct uptake from the water, probably via branchial routes, ameliorates the effects of a low-magnesium diet. The hard tissues, representing over 50 % of the total body magnesium pool, form a reservoir from which magnesium can be recruited to perform its functions in the cellular metabolism of soft tissues such as muscle. In fish, as in terrestrial vertebrates, the balance of a variety of elements becomes disturbed when the magnesium homeostasis of the soft tissues is disrupted. However, fish appear to be less sensitive than terrestrial vertebrates to these perturbations. Magnesium is reabsorbed in the kidneys to minimise losses. For renal cells, part of a cellular pathway has been elucidated that would allow absorptive magnesium transport (a magnesium conductive pathway in renal brush-border membranes). In some euryhaline teleosts, the kidneys appear to switch instantaneously to rapid magnesium secretion upon magnesium loading, a response common to marine fish that are threatened by diffusive magnesium entry. This enigmatic mechanism underlies the capacity of some euryhaline species to acclimate rapidly to sea water. Despite the progress made over the last decade, much of the cellular and molecular basis of magnesium transport in the gills, intestine and kidneys remains obscure. The application of fluorescent, radioactive and molecular probes, some of which have only recently become available, may yield rapid progress in the field of magnesium research. PMID:9622570

Bijvelds; Velden; Kolar; Flik

1998-07-01

209

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

International Nuclear Information System (INIS)

It is increasingly clear that the public, native tribes, and governmental agencies are interested in assessing the well-being of natural resources and ecosystems. This may take the form of understanding species presence, monitoring population status and trends, measuring behavior, or quantifying physiology, biological stresses, or chemical/radiological exposure through biomarkers. Often there is a separation between understanding the biological aspects of species well-being and assessing exposure to contaminants. In this paper we examine the applicability of using scuba sampling aimed primarily at specimen collection for radionuclide analysis to assess species presence/absence and to compare among sampling sites and depths. We were especially interested in whether dive transects could provide information on species presence and potential exposure to environmental contaminants. In June/July 2004 we sampled at 49 depth stations along 19 transects at Amchitka and Kiska Islands in the western Aleutian Islands in the Northern Pacific/Bering Sea region. Amchitka Island, a former World War II U.S. Navy base, was the site of three underground nuclear test shots from 1965 to 1971. Four to six transects were established at three Amchitka sites and two Kiska Sites, and 2 to 4 stations were sampled on each transect. Bottom conditions, weather and currents prevented a complete sampling of all stations. There were interspecific differences in the percent of stations where biota werin 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

210

Practical Implementation of Freshwater Pearl Mussel Measures  

...FAQsAccess KeysPractical Implementation of Freshwater Pearl Mussel MeasuresLast updated...to undertake a programme of works involving the practical implementation of measures to support the restoration of...

211

Effects of freshwater inflow on sediment transport  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This study investigates the effect that freshwater inflow has on the transport of dredged material in Liverpool Bay. The sediment dispersal is first simulated using constant density throughout the domain, and then density gradients and stratification will be allowed to develop from riverine inputs. The first case shows the sediments slowly being transported east-westwards away from the estuary; while the simulation with freshwater shows the sediment being rapidly transported south-eastward to...

Souza, A. J.; Lane, A.

2013-01-01

212

Future freshwater demands in the Arctic  

Science.gov (United States)

The overall objective of our research is to understand how humans rely on freshwater at local and regional scales in the Arctic, how these dependencies have changed in the recent past, and how they are likely to change in the future. This study will take place on the Seward Peninsula where climate induced changes in the hydrologic cycle are already being observed. This presentation will describe the human dependencies on freshwater in the Arctic. In particular, we will discuss the effects of inadequate quantity or quality of freshwater on Arctic inhabitants. The freshwater used by humans in the Arctic for drinking, cooking, and washing is derived in many cases from surface water, such as lakes and streams. Since the surface water frozen 6-9 months of the year in the Arctic, communities that rely on rivers and lakes must treat and store large volumes of water for use during winter. The stored water must be heated throughout the winter and distributed on an as-needed basis. Unfortunately, when not enough water can be gathered in the summer or stored in the winter, the entire community may be without freshwater. During these months, water must be collected by individuals from ice, snow, and rain. Collecting water during breakup can be dangerous. River ice is rotten, there is too little snow for snow mobiles, and the tundra is too soft all terrain vehicles. While the state of Alaska and Federal programs are making progress towards developing sustainable water sources for Alaska's Arctic communities, freshwater remains a precious commodity. Communities throughout the Arctic, including Canada and Russia, have similar problems with obtaining and purifying freshwater. As climate induced changes are being observed in the Arctic, the threat to the freshwater resource is now a greater concern than ever. This study is being funded under the NSF Arctic System Science Program, Human Dimensions of the Arctic (OPP-0328686).

White, D.; Strang, E. T.; Hinzman, L.; Alessa, L.; Kliskey, A.

2004-12-01

213

Ecology of freshwater mussels in disturbed environments  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

O?sterling, Martin

2006-01-01

214

Deriving freshwater quality criteria for 2,4,6-trichlorophenol for protection of aquatic life in China.  

Science.gov (United States)

Freshwater quality criteria of 2,4,6-trichlorophenol (2,4,6-TCP) were developed with particular reference to the aquatic biota in China, and based on USEPA's guidelines. Acute toxicity tests were performed on nine different domestic species indigenous to China to determine 48 h LC(50) and 96 h LC(50) values for 2,4,6-TCP. In addition, 21 d survival-reproduction test with Daphnia magna, 30 d embryo-larval test with Carassius auratus, 60 d fry-juvenile test with Ctenopharyngodon idellus, 30 d early life stage test with Bufo bufo gargarizans and 96 h growth inhibition test with Scenedesmus obliqaus were also conducted to estimate lower chronic limit and upper chronic limit values. The final acute value (FAV) was 2.01 mg/l 2,4,6-TCP. Acute-to-chronic ratios ranged from 5.01 to 12.2. The final chronic value (FCV) and the final plant value (FPV) of 2,4,6-TCP were 0.226 and 2.24 mg/l respectively. Based on FAV, FCV and FPV for 2,4,6-TCP, a criteria maximum concentration of 1.01 mg/l and a criterion continuous concentration of 0.226 mg/l were derived. The results of this study provide useful data for deriving national or local water quality criteria for 2,4,6-TCP based on aquatic biota in China. PMID:12729688

Yin, Daqiang; Hu, Shuangqing; Jin, Hongjun; Yu, Lingwei

2003-07-01

215

Freshwater Commercial Bycatch: an Understated Conservation Problem  

Energy Technology Data Exchange (ETDEWEB)

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.

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

2011-04-01

216

Perfluoroalkyl acid contamination and polyunsaturated fatty acid composition of French freshwater and marine fishes.  

Science.gov (United States)

In this study, French marine and freshwater fish perfluoroalkyl acid (PFAA) contamination are presented along with their fatty acid (FA) composition to provide further elements for a risk/benefit balance of fish consumption to be assessed. The 29 most consumed marine fish species were collected in four metropolitan French coastal areas in 2004 to constitute composite samples. Geographical differences in terms of consumed species and contamination level were taken into account. Three hundred and eighty-seven composite samples corresponding to 16 freshwater fish species collected between 2008 and 2010 in the six major French rivers or their tributaries were selected among the French national agency for water and aquatic environments freshwater fish sample library. The raw edible parts were analyzed for FA composition and PFAA contamination. Results show that freshwater fishes are more contaminated by PFAAs than marine fishes and do not share the same contamination profile. Freshwater fish contamination is mostly driven by perfluorooctane sulfonate (PFOS) (75%), whereas marine fish contamination is split between perfluorooctanoic acid (PFOA) (24%), PFOS (20%), perfluorohexanoic acid (PFHxA) (15%), perfluoropentanoic acid (PFHpA) (11%), and perfluorobutanoic acid (PFBA) (11%). Common carp, pike-perch, European perch, thicklip grey mullet, and common roach presented the most unfavorable balance profile due to their high level of PFAAs and low level of n-3 long-chain polyunsaturated fatty acids (LC-PUFAs). These data could be used, if needed, in an updated opinion on fish consumption that takes into account PFAA contamination. PMID:25004121

Yamada, Ami; Bemrah, Nawel; Veyrand, Bruno; Pollono, Charles; Merlo, Mathilde; Desvignes, Virginie; Sirot, Véronique; Oseredczuk, Marine; Marchand, Philippe; Cariou, Ronan; Antignac, Jean-Phillippe; Le Bizec, Bruno; Leblanc, Jean-Charles

2014-07-30

217

Methane release by freshwater pockmarks  

Science.gov (United States)

In the eastern part of Lake Constance (Germany) near the Rhine River hundreds of pockmarks, morphological depressions at the lake floor, were observed. The diameter of these pockmarks was up to 16 m and at a high number of them permanent release of methane bubbles was detected. The isotopic analysis of the escaping gas indicated methane of biogenic origin.. At the shallow pockmarks (10 m), migration of gas bubbles through the sediment caused increased methane concentrations in the pore waters close to the sediments as compared to sites unaffected by bubble migration outside the pockmarks. Thus, the diffusive methane flux and oxidation rates were much higher inside the pockmark than outside. Nevertheless, methane ebullition into the water column is by far the dominating pathway of methane release (estimated 10 L h-1). At the deep pockmark (80 m) - even though bubble release was observed -, the sediment inside the pockmark had the same methane concentrations and geochemistry compared with a reference site outside the pockmark. In profundal freshwater sediments a strong recent methanogenesis leads to high methane concentrations, often above saturation. So, additional emerging methane (bubbles) from deeper layers escapes from the sediment essentially unaffected by diffsuion into the sediment or by methane oxidation. Thus, the background concentration of methane in the sediment, determines if methane passes through the sedimentary filter or is directly released into the water column and possibly the atmosphere.

Bussmann, Ingeborg; Schlömer, Stefan; Schlüter, Michael; Wessels, Martin

2010-05-01

218

COMMUNITY DEVELOPMENT IN FRESHWATER MICROCOSMS  

Energy Technology Data Exchange (ETDEWEB)

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.

Rees, John T.

1978-01-01

219

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

Scientific Electronic Library Online (English)

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

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

2009-12-01

220

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

Directory of Open Access Journals (Sweden)

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

Ajai K. Srivastav

2009-12-01

 
 
 
 
221

Deep-sea biota of the Northeast Atlantic and their radioactivity  

International Nuclear Information System (INIS)

The nuclides 60Co, 90Sr, 137Cs, 238Pu, 239Pu and 241Am in present dumpsite biota did not increase relative to earlier years. To support the conclusions that artificial nuclides levels did not increase by dumping during the past few years, 137Cs was chosen as the nuclide that was most often positively detected in nearly all families of biota. Median values of 137Cs for various important families of biota for the years 1980 to 1986 are summarized. The median was chosen as an index because the geometric mean may occasionally be biased. It was calculated from significant values only. Each median is characterized by the number of significant values and the number of values below the detection limit. Also included is the median 137Cs value obtained by combining all values from all other sites investigated in the years 1980 to 1984. An increase of 137Cs at the present dumpsite from 1980 to 1986 cannot be concluded from these data, considering especially the low number of available single values. Comparing the weighted mean of the annual medians at the present dumpsite with the median value summarizing all available values from other sites up to 1984 reveals excellent agreement. There is only one exception, which was noted in earlier years: the median for Actiniaria at other sites is significantly higher due to Actiniaria levels from the original dumpsite. Actiniaria from the original dumpsite show higher 137Cs values than Actiniaria from other sites in the NE Atlantic. This finding in relation to findings for other artificial and naturally-occurring nuclides as well as radionuclides in Holo-thuroidea leads to the conclusion that contamination by leaching from radioactive waste drums dumped in 1967 cannot be established for the original dumpsite

222

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

International Nuclear Information System (INIS)

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 inverteG 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)

223

The Baltic Sea ice biota (March 1994): A study of the protistan community  

DEFF Research Database (Denmark)

The diversity of the protist communities of the water column and ice along the Finnish coast of the Baltic Sea was studied during March 1994. The preliminary identification of the organisms was made light microscopically on live material, while further identification of e.g. scale-bearing flagellates was based on whole mounts using light and electron microscopy. The ice biota and the winter plankton was dominated by diatoms. Other abundant groups were choanoflagellates, chrysophytes, chlorophytes, dinoflagellates and protists of uncertain affinity. The highest brine salinities (up to 30 permill ) and the most diverse ice biota were found at two stations in the Bothnian Bay, where the number of recorded taxa was 71 and 74. In the water column the numbers were much lower (34 and 42). In the Bothnian Sea and along the southern coast of Finland the ice biota was less diverse, and the number of protist taxa ranged from 21 to 47. A few taxa showed a special preference for the ice habitat. New distribution records to the Baltic Sea are Navicula pelagica (Bacillariophyceae), Cryothecomonas armigera (Protista incertae sedis), and the genus Polytomella (Chlorophyceae). The abundance and vertical distribution of C. armigera, other flagellates, Monoraphidium contortum (Chlorophyceae), and diatoms in the ice at station I was studied using inverted light microscopy and sedimentation chambers. M. contortum was found to be the cause of a distinct green colouration of the ice. With the exception of C. armigera, all other protist taxa formed well-defined maxima within the ice interior. The number of cells in such abundance peaks varied from approximately 2.5 times 10-5 M. contortum cells l-1 to 2 times l0-6 diatoms l-1 of melted sea ice.

Ikavalko, Johanna; Thomsen, Helge Abildhauge

1997-01-01

224

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

International Nuclear Information System (INIS)

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

225

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

International Nuclear Information System (INIS)

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

226

Nutrients in freshwater (CSI 020) - Assessment published Dec 2010 — European Environment Agency (EEA)  

...soer2010, biodiversity, csi, nitrates, nutrients, freshwater quality, lakes, rivers, water, orthophosphate, thematic assessments, freshwater, phosphorus ...soer2010, biodiversity, csi, nitrates, nutrients, freshwater quality, lakes, rivers, water, orthophosphate, thematic assessments, freshwater, phosphorus ...

227

AVES.NET: The Freshwater Dinoflagellates  

Science.gov (United States)

Hosted by AVES.NET, this website about Freshwater Dinoflagellates was created by Victor W. Fazio III and Dr. Susan Carty of Heidelberg College (Tiffin, Ohio). Two main attractions of this site are the Freshwater Dinoflagellate Image Archive, and the Recent Additions-Freshwater Dinoflagellate Images 2003 (from the 2003-04 winter field season). Individual Dinoflagellate image pages generally include a ventral view, dorsal view, or both, and the pages featuring species from Ohio include county distribution maps. Site visitors can email Dr. Carty for permission to use any of the images. The website also contains a List of Freshwater Dinoflagellates in Ohio, some of which link to the individual image pages. Additionally, the site offers a Review of Online Images of Freshwater Dinoflagellates including links to many other host sites, and a link to an online article by Dr. Susan Carty and Daniel E. Wujek entitled _A New Species of Peridinium and New Records of Dinoflagellates and Silica-Scaled Chrysophytes from Belize._ [NL

Carty, Susan; Fazio, Victor W. (1962-)

228

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

Energy Technology Data Exchange (ETDEWEB)

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 {mu}g/L and 0.54 {mu}g/g dry weight, respectively). Biomagnification of selenium resulted in approximately 1.5 to 6 fold increase in the selenium concentration between plankton, invertebrates and fish. However, no biomagnification was observed between forage and predatory fish. Although some aquatic biota (e.g., forage fish) exceeded the lower limit of the proposed 3 to 11 {mu}g/g (dry weight) dietary toxicity threshold for fish, no adverse effects of selenium could be identified in this aquatic system. Continued environmental monitoring is recommended to avoid potential selenium impacts.

Muscatello, J.R. [Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK S7N 5B3 (Canada); Janz, D.M. [Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK S7N 5B3 (Canada); Department of Veterinary Biomedical Sciences, University of Saskatchewan, 52 Campus Drive, Saskatoon, SK S7N 5B4 (Canada)], E-mail: david.janz@usask.ca

2009-02-01

229

Decrease of radionuclides in Columbia River biota following closure of Hanford reactors  

International Nuclear Information System (INIS)

In January 1971, the last of nine plutonium production reactors using direct discharge of once-through cooling waters into the Columbia River was closed. Sampling was conducted at three stations on the Columbia River to document the decline of radionuclides in the biota of the Columbia River ecosystem. Concentrations of 60Co in seston, periphyton and invertebrates did not decrease to the degree that the other radionuclides did. Levels of 60Co in fish showed some decreases. Zinc-65 was present in the biota in highest concentrations. The amounts in seston and periphyton decreased rapidly and were measurable only until the spring of 1973. Zinc-65 in caddisfly larvae was not measurable by February 1973, but concentrations in McNary chironomids fluctuated between unmeasurable levels to 24 pCi/g dry weight (DW). In suckers and squawfish, 65Zn decreased to fairly low, constant levels of 1 and 3 pCi/g DW, respectively. The data showed that in a river-reservoir complex, the measurable concentrations of fission-produced radionuclides decreased to extremely low or unmeasurable levels within 18-24 months after cessation of discharge of reactor once-through cooling water into the river. On the basis of data from the free-flowing sampling station, the decrease would probably be even more rapid in an unimpounded river. (author)

230

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

231

Improved cleanup technique for gas chromatographic-mass spectrometric determination of alkylphenols from biota extract.  

Science.gov (United States)

A simple and economical cleanup technique was developed to determine alkylphenols by GC-MS from biological extracts containing relatively high lipids. The lipids were successfully removed from bivalve extracts through a two-step cleanup. The new method is a combination of Florisil adsorption chromatography and silyl derivatization technique. Low and high (non-polar and highly polar) molecular weight lipids were removed from the biota extract with deactivated Florisil column in the first step. And in the second step, middle molecular weight (middle polar) lipids were removed in an activated Florisil column after the alkylphenols were converted to corresponding silyl derivatives with bis(trimethylsilyl)trifluoroacetamide (BSTFA). On the basis of the above results, a simple cleanup kit was developed for convenience. The technique was optimized with reference to the activity of packing materials and polarity of eluting solvents. Only 3g of Florisil, 25 mL of hexane and 10 mL of dichloromethane were required for one sample. The recoveries of alkylphenols from spiked samples varied from 88 to 103% with a low relative standard deviation (mean value: 5.3%) and the recovery was similar or even higher than other methods currently in use. The technique was successfully applied to mussel samples from Masan Bay, South Korea. Simultaneous measurement of these compounds in water, sediment and biota; the resulting bio-concentration factor and their relationships confirm previously published works, validating the method applied. PMID:17920609

Wang, Juan; Dong, Meihua; Shim, Won Joon; Kannan, Narayanan; Li, Donghao

2007-11-01

232

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

International Nuclear Information System (INIS)

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

233

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

International Nuclear Information System (INIS)

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

234

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

DEFF Research Database (Denmark)

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

El Albani, Abderrazak; Bengtson, Stefan

2014-01-01

235

The 2.1 Ga old Francevillian biota: biogenicity, taphonomy and biodiversity.  

Science.gov (United States)

The Paleoproterozoic Era witnessed crucial steps in the evolution of Earth's surface environments following the first appreciable rise of free atmospheric oxygen concentrations ?2.3 to 2.1 Ga ago, and concomitant shallow ocean oxygenation. While most sedimentary successions deposited during this time interval have experienced thermal overprinting from burial diagenesis and metamorphism, the ca. 2.1 Ga black shales of the Francevillian B Formation (FB2) cropping out in southeastern Gabon have not. The Francevillian Formation contains centimeter-sized structures interpreted as organized and spatially discrete populations of colonial organisms living in an oxygenated marine ecosystem. Here, new material from the FB2 black shales is presented and analyzed to further explore its biogenicity and taphonomy. Our extended record comprises variably sized, shaped, and structured pyritized macrofossils of lobate, elongated, and rod-shaped morphologies as well as abundant non-pyritized disk-shaped macrofossils and organic-walled acritarchs. Combined microtomography, geochemistry, and sedimentary analysis suggest a biota fossilized during early diagenesis. The emergence of this biota follows a rise in atmospheric oxygen, which is consistent with the idea that surface oxygenation allowed the evolution and ecological expansion of complex megascopic life. PMID:24963687

El Albani, Abderrazak; Bengtson, Stefan; Canfield, Donald E; Riboulleau, Armelle; Rollion Bard, Claire; Macchiarelli, Roberto; Ngombi Pemba, Lauriss; Hammarlund, Emma; Meunier, Alain; Moubiya Mouele, Idalina; Benzerara, Karim; Bernard, Sylvain; Boulvais, Philippe; Chaussidon, Marc; Cesari, Christian; Fontaine, Claude; Chi-Fru, Ernest; Garcia Ruiz, Juan Manuel; Gauthier-Lafaye, François; Mazurier, Arnaud; Pierson-Wickmann, Anne Catherine; Rouxel, Olivier; Trentesaux, Alain; Vecoli, Marco; Versteegh, Gerard J M; White, Lee; Whitehouse, Martin; Bekker, Andrey

2014-01-01

236

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

International Nuclear Information System (INIS)

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

237

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

Directory of Open Access Journals (Sweden)

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

Ichsan Ridwan

2010-02-01

238

137Cs in freshwater fish in Finland  

International Nuclear Information System (INIS)

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

239

Uptake of ?-emitting radionuclides by aquatic biota exposed to contaminated water before and after passage through the ground  

International Nuclear Information System (INIS)

Three experimental systems were designed to investigate the differential accumulation of radionuclides by biota from low-level aqueous effluents after passage through the ground. One system received river water (control), one received dilute low-level radioactive effluents (trench), and the third received the low-level effluents after it had percolated through about 260 m or porous gravel (springs). Biota studied included filamentous green algae, clams (Corbicula), goldfish (Carassius auratus), carp (Cyprinus carpio), and Veronica. Trophic level differences in accumulation of the various radionuclides from the diluted trench water were not consistent but generally followed the pattern algae > goldfish > molluscs > carp. Cobalt-60 was accumulated to the highest level of any radionuclide, and accumulation levels at the three sites were directly related to the concentration of 60Co in the water. Manganese-54, 59Fe, and 106Ru were also accumulated to measurable levels in biota at the springs site indicating their bioavailability after passage through the ground

240

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

International Nuclear Information System (INIS)

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

 
 
 
 
241

Marine incursion: the freshwater herring of Lake Tanganyika are the product of a marine invasion into west Africa.  

Science.gov (United States)

The spectacular marine-like diversity of the endemic fauna of Lake Tanganyika, the oldest of the African Great Lakes, led early researchers to suggest that the lake must have once been connected to the ocean. Recent geophysical reconstructions clearly indicate that Lake Tanganyika formed by rifting in the African subcontinent and was never directly linked to the sea. Although the Lake has a high proportion of specialized endemics, the absence of close relatives outside Tanganyika has complicated phylogeographic reconstructions of the timing of lake colonization and intralacustrine diversification. The freshwater herring of Lake Tanganyika are members of a large group of pellonuline herring found in western and southern Africa, offering one of the best opportunities to trace the evolutionary history of members of Tanganyika's biota. Molecular phylogenetic reconstructions indicate that herring colonized West Africa 25-50MYA, at the end of a major marine incursion in the region. Pellonuline herring subsequently experienced an evolutionary radiation in West Africa, spreading across the continent and reaching East Africa's Lake Tanganyika during its early formation. While Lake Tanganyika has never been directly connected with the sea, the endemic freshwater herring of the lake are the descendents of an ancient marine incursion, a scenario which may also explain the origin of other Tanganyikan endemics. PMID:18431469

Wilson, Anthony B; Teugels, Guy G; Meyer, Axel

2008-01-01

242

Acute and chronic effects of sodium and potassium on the tropical freshwater cladoceran Pseudosida ramosa.  

Science.gov (United States)

In this study, the toxicities of sodium and potassium to the tropical freshwater cladoceran Pseudosida ramosa were assessed. Acute toxicity tests on this species showed that the 48-h LC(50) of Na(+) was 556 mg l(-1), while that of K(+) was 17.7 mg l(-1). Long-term exposure of female P. ramosa to sodium reduced the total number of survivors from 10 to 6 at a concentration of 249 mg l(-1), 21-day fecundity from 20.4 to 14.3 eggs female(-1) at concentrations ranging from 72 to 249 mg l(-1), 21-day fertility from 20.1 to 6.5 neonates female(-1) at concentrations ranging from 25 to 249 mg l(-1). Furthermore, fecundity of each brood from the second to the fifth was significantly lower at 249 mg l(-1) and fertility of each brood from the first to the fifth at concentrations ranging from 25 to 249 mg l(-1). A significant decrease in fertility was associated with an increase in the number of aborted eggs. Long-term exposure to potassium decreased the 21-day fecundity of P. ramosa from 14.2 to 10.8 eggs female(-1) at a concentration of 11 mg l(-1) and fertility (fourth brood only) at 6.2 and 11 mg l(-1). Tropical reservoirs located near areas where the soil is overloaded with fertilizers and ferti-irrigation with vinasse already show concentrations of Na(+) and K(+) very close to those producing sub-lethal long-term effects on P. ramosa. A possible consequence is that organisms of the aquatic biota cannot adapt and freshwater taxa may become locally extinct, transferring dominance to salt-tolerant taxa. PMID:20978846

Freitas, Emanuela Cristina; Rocha, Odete

2011-01-01

243

Host-specificity and dynamics in bacterial communities associated with Bloom-forming freshwater phytoplankton.  

Science.gov (United States)

Many freshwater phytoplankton species have the potential to form transient nuisance blooms that affect water quality and other aquatic biota. Heterotrophic bacteria can influence such blooms via nutrient regeneration but also via antagonism and other biotic interactions. We studied the composition of bacterial communities associated with three bloom-forming freshwater phytoplankton species, the diatom Aulacoseira granulata and the cyanobacteria Microcystis aeruginosa and Cylindrospermopsis raciborskii. Experimental cultures incubated with and without lake bacteria were sampled in three different growth phases and bacterial community composition was assessed by 454-Pyrosequencing of 16S rRNA gene amplicons. Betaproteobacteria were dominant in all cultures inoculated with lake bacteria, but decreased during the experiment. In contrast, Alphaproteobacteria, which made up the second most abundant class of bacteria, increased overall during the course of the experiment. Other bacterial classes responded in contrasting ways to the experimental incubations causing significantly different bacterial communities to develop in response to host phytoplankton species, growth phase and between attached and free-living fractions. Differences in bacterial community composition between cyanobacteria and diatom cultures were greater than between the two cyanobacteria. Despite the significance, major differences between phytoplankton cultures were in the proportion of the OTUs rather than in the absence or presence of specific taxa. Different phytoplankton species favoring different bacterial communities may have important consequences for the fate of organic matter in systems where these bloom forming species occur. The dynamics and development of transient blooms may also be affected as bacterial communities seem to influence phytoplankton species growth in contrasting ways. PMID:24465807

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

2014-01-01

244

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

Science.gov (United States)

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.

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

245

SD @ the International Conference on Freshwater  

...Freshwater International Conference on Freshwater Bonn, Germany; 3 - 7 December, 2001 Tuesday, 4 December HTML TEXT PDF Wednesday, 5 December HTML TEXT PDF Daily Reports: ...Thursday 6, December HTML TEXT PDF Friday 7, December HTML TEXT PDF Summary HTML TEXT PDF Daily coverage (pictures ... The Conference Record (not yet available) documents all the proceedings, proposals and initiatives that were presented by the participants but ...land tenure, and Northern consumption patterns Listen to the RealAudio In a recorded presentation, Kader Asmal, South Africa�s Minister for Education,...

246

Freshwater exposure pathways in the Nordic countries  

International Nuclear Information System (INIS)

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

247

CROATIAN FRESHWATER FISHERIES IN 1997  

Directory of Open Access Journals (Sweden)

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.

Mirko Turk

1998-10-01

248

CROATIAN FRESHWATER FISHERIES IN 1996.  

Directory of Open Access Journals (Sweden)

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.

Mirko Turk

1997-07-01

249

Anthropogenic PAHs in Sediment-Dwelling Biota from Mangrove Areas of the Calabar River, SE Niger Delta, Nigeria  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Polycyclic aromatic hydrocarbons (PAHs) in mangrove sediment-dwelling biota (crabs and molluscs) from the Calabar River, SE Niger Delta of Nigeria were analyzed using GC-MS in order to assess the degree of contamination of the river by anthropogenic activity. The associated sediment samples (where these biota were collected) showed much higher total PAH (TPAH) concentration (16,028.3 ng/g dry weight (dw)) at the upper mangrove area (UMA) than that found toward the river mouth (MR; 1,667.5 ...

Adie, Peter A.; Offem, John O.; Oyo Ita, Orok E.; Ekpo, Bassey O.

2012-01-01

250

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

2008-11-15

251

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2008-01-01

252

Three new species of Thaumatomastix (Thaumatomastigidae, Protista incertae sedis) a ubiquitous genus from the Antarctic ice biota  

DEFF Research Database (Denmark)

Recent opportunities to sample live material from in particular the Antarctic ice biota have resulted in the discovery of numerous autotrophic and heterotrophic flagellate components of this community. In certain samples, some of these hitherto neglected types of organisms are obviously key components of the ice biota. One such example is found in species of the heterotrophic flagellate genus Thaumatomastix (Thaumatomastigidae, Protista incertae sedis). Three new species are described (T. splendida sp. nov., T. fragilis sp. nov., and T. fusiformis sp, nov.) one of which (T. splendida) has been found to be ubiquitous in Antarctic sea ice and also most likely a significant member of the Arctic sea ice community.

Thomsen, Helge Abildhauge; Kosman, Carol

1995-01-01

253

Toxicity assessment of oil-contaminated freshwater sediments.  

Science.gov (United States)

The performance of four microscale toxicity bioassays conducted on whole sediments was evaluated during a bioremediation project undertaken in 1999-2000 on a crude oil-contaminated freshwater shoreline of the St. Lawrence River, Quebec, Canada. The toxicity tests assessed included: (1) the Microtox solid-phase assay (MSPT), (2) the Biotox Flash solid-phase test (Flash), (3) the algal solid-phase assay (ASPA), and 4) the Ostracodtoxkit solid-phase assay. Data generated with these assays were compared with those obtained using the standard endobenthic amphipod (Hyalella azteca) bioassay. Bioanalytical comparisons indicated that all five solid-phase tests were useful in detecting the toxicity of oiled sediments; however, statistical analyses distinguished a difference in response between the invertebrate (amphipod and Ostracodtoxkit) and bacterial luminescence tests (MSPT and Flash). Based on these results, it is recommended that careful selection of biotests be made in the design of the test battery for assessment of residual oil sediment toxicity. Time-series toxicity data generated with ASPA indicated that oiled sediments in the freshwater wetlands of the St. Lawrence River remained toxic to phytoplankton for at least 65 weeks and that remediation treatment was able to accelerate detoxification by 16 weeks. PMID:15269895

Blaise, Christian; Gagné, François; Chèvre, Nathalie; Harwood, Manon; Lee, Ken; Lappalainen, Juha; Chial, Belgis; Persoone, Guido; Doe, Ken

2004-08-01

254

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

International Nuclear Information System (INIS)

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 selea 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

255

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

Science.gov (United States)

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. PMID:17698056

Burger, Joanna

2007-11-01

256

Environmental Risk assessment by multi-bio marker responses in aquatic biota of three trophic levels in a lake of the Mexican Central Plateau  

International Nuclear Information System (INIS)

Aquatic ecosystems continually are impacted by wastewater and lixiviation of the adjacent areas. The inputs of xenobiotics generate complex mixtures that provoke adverse effects in the aquatic biota. The use of a battery of bio markers for the toxic effect assessment of xenobiotics in the aquatic biota is usefully for the environmental risk assessment (ERA). (Author)

257

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

258

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

Science.gov (United States)

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

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

2011-10-01

259

Review of Salmon and Freshwater Fisheries  

Oct 11, 2000 ... The Objectives and Scope of Fisheries Legislation (Chapter 3) ... in numerical \\order and indicates where they appear in the Review. ... Government \\involvement in the conservation of salmon and freshwater fish and the .... already \\best practice to make known the results of relevant research to the Veterinary.

260

Mathematical Explorations: Freshwater Scarcity: A Proportional Representation  

Science.gov (United States)

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…

King, Alessandra

2014-01-01

 
 
 
 
261

Freshwater savings from marine protein consumption  

Science.gov (United States)

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.

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

2014-01-01

262

CROATIAN FRESHWATER FISHERIES IN 1995  

Directory of Open Access Journals (Sweden)

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

Mirko Turk

1996-06-01

263

CROATIAN FRESHWATER FISHERIES IN 1994  

Directory of Open Access Journals (Sweden)

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.

Mirko Turk

1995-09-01

264

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

Directory of Open Access Journals (Sweden)

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.

Hayes P

2010-03-01

265

Dynamic model for the assessment of radiological exposure to marine biota  

Energy Technology Data Exchange (ETDEWEB)

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.

Vives i Batlle, J. [Westlakes Scientific Consulting Ltd, The Princess Royal Building, Westlakes Science and Technology Park, Moor Row, Cumbria CA24 3LN (United Kingdom)], E-mail: jordi.vives@westlakes.ac.uk; Wilson, R.C.; Watts, S.J.; Jones, S.R.; McDonald, P.; Vives-Lynch, S. [Westlakes Scientific Consulting Ltd, The Princess Royal Building, Westlakes Science and Technology Park, Moor Row, Cumbria CA24 3LN (United Kingdom)

2008-11-15

266

Doses to Terrestrial Biota in the Vicinity of BNFL Sellafield, Cumbria, UK (invited paper)  

International Nuclear Information System (INIS)

Source terms and corresponding radionuclide activity concentrations in biota for 134Cs, 137Cs, 238Pu, 239+240Pu and 241Am have been assessed for three semi-natural ecosystems in the vicinity of BNFL Sellafield, Cumbria, UK. Estimates of absorbed doses (mGy.d-1) have been calculated. Doses to key indicator species, Oniscus asellus (detritivorous invertebrate), Carabus violaceous (predatory invertebrate) and Apodemus sylvaticus (granivorous wood mouse) are discussed with reference to the 1 mGy.d-1 level, below which it is postulated that no observable effects on populations in a terrestrial ecosystem occur. Implications for the 'critical group' and 'reference model' approaches for a framework of radiological environmental protection are discussed. The need to assess the most highly exposed species is advanced. New research focused on the application of biomarker techniques as a mechanism for determining the interactions and effects of environmental contaminants on ecosystem structure and functioning is presented. (author)

267

Some bioaccumulation factors and biota-sediment accumulation factors for polycyclic aromatic hydrocarbons in Lake Trout  

Energy Technology Data Exchange (ETDEWEB)

Bioaccumulation factors (BAFs) and biota-sediment accumulation factors (BSAFs) for phenanthrene, fluoranthene, pyrene, benz[a]anthracene, and chrysene/triphenylene were calculated using the tissue data of Zabik et al. for Salvelinus namaycush siscowet with a 20.5% lipid content, the water data of Baker and Eisenreich, and the sediment data of Baker and Eisenreich for the Lake Superior ecosystem. Log BAFs, both lipid normalized and based on the freely dissolved concentration of the chemical in the water, of 1.95, 3.22, 4.72, 4.73, and 3.61 were calculated for phenanthrene, fluoranthene, pyrene, benz[a]anthracene, and chrysene/triphenylene, respectively. The BSAFs for phenanthrene, fluoranthene, pyrene, benz[a]anthracene, and chrysene/tripenylene were 0.00011, 0.00016, 0.0071, 0.0054, and 0.00033, respectively.

Burkhard, L.P.; Lukasewycz, M.T.

2000-05-01

268

Taiwan's industrial heavy metal pollution threatens terrestrial biota  

Energy Technology Data Exchange (ETDEWEB)

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.

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

269

Studies on monitoring of river water quality by neutron activation analysis of aquatic biota  

International Nuclear Information System (INIS)

In order to clarify the possibility of a new method to monitor the river water quality by neutron activation analysis of aquatic biota, the followings were investigated: (1) the species of fish, water plants and aquatic insects which we can collect easily in Tamagawa River basin, (2) problems in pre-treatment of biological samples, and (3) relationship between elemental concentrations in biological samples and in river water. We found that the biological species suitable for the analytical investigation are Carassius auratus langsdorfii (GINBUNA), Pseudorasbora parva (MOTSUGO), Potamageton orientalis Hagst. (AINOKOITOMO), Elodea nuttalli (Planch.) St. John (KOKANADAMO), Cheuma-topsyche brevilineata (Iwata) (KOGATASHIMATOBIKERA) and Hydropsyche orientalis Martynov (URUMASHIMATOBIKERA). Fish samples showed apparently different concentrations of elements in each part of their bodies. Simple washing of water plants and aquatic insects was found not to be enough to eliminate rock-oriented particles. Such elements as Ag, Mn and Zn showed relationships of their concentrations between in biological samples and in river water. (author)

270

Nuclear explosives, ionizin.o. radiation and the effects on the biota of the natural environment  

International Nuclear Information System (INIS)

After giving a general discussion of nuclear explosives, weapons testing and peaceful use of nuclear explosives under Plowshare project, ecological studies carried out at weapon test sites and Plowshare project sites in United States are reviewed. It is noted that though considerable data are available on the behaviour of radionuclides in natural environments on these sites, only a few observations of effects of ionizing radiations on the biota of the natural environments of these sites have been made. The major effects on the natural environments of these sites have been attributed to physical effects of nuclear detonations and site preparation. These effects are physical destruction of plants and animals and habitat modification such as soil disturbances. Recolonization of ground zeros and adjacent areas is observed to follow the successional pattern unique to the site. Observed effects of ionizing radiation on shrubs in the vicinity of cratering tests appear to be inconsequential when one considers the ecosystem as a whole. (M.G.B.)

271

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

Science.gov (United States)

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.

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

2014-03-01

272

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

Directory of Open Access Journals (Sweden)

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

Ki-Hyun Kim

2014-04-01

273

Transfer of hexabromocyclododecane from industrial effluents to sediments and biota: Case study in Cinca river (Spain)  

Science.gov (United States)

SummaryThis work is part of the research included in the European project AQUATERRA, focused on the study of different persistent organic pollutants (POPs) in different risk zones along the Ebro River basin. Within monitoring programmes, a high contaminated area was detected, located along the Cinca River, a tributary of Ebro River, downstream a heavily industrialized town (Monzón). Data showed a high hexabromocyclododecane (HBCD) contamination in this area. Our work included the analysis of sediments and biota, with special attention on aspects such as temporal trends, bioavailability and bioaccumulation of these contaminants. Moreover, an attempt of identification of source contamination was carried out, with the analysis of industrial effluents. The industry responsible of the contamination was identified.

Guerra, Paula; Cal, Agustina De La; Marsh, Göran; Eljarrat, Ethel; Barceló, Damià

2009-05-01

274

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

International Nuclear Information System (INIS)

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

275

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

Directory of Open Access Journals (Sweden)

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

Conrad Labandeira

2011-09-01

276

Bioaccumulation of alkaline soil metals (Ca, Mg) and heavy metals (Cd, Ni, Pb) patterns expressed by freshwater species of Ulva (Wielkopolska, Poland)  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The paper includes results of the first study on the accumulation of selected metals in freshwater populations of Ulva taxa at 16 sites in Poland. The thalli examined contained very high concentrations of Ca and Mg, owing to well-developed surface incrustations of carbonate. Among the heavy metals investigated, the most significant concentration in the thalli was Ni, whereas the lowest was Pb. The median concentrations of Ni and Cd in the freshwater Ulva thalli were significantly ...

Rybak, Andrzej; Messyasz, Beata; ?e?ska, Bogus?awa

2012-01-01

277

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

International Nuclear Information System (INIS)

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%)

278

PERMODELAN UJI LOGAM BERAT PADA BADAN AIR, BIOTA DAN SEDIMEN DI PERAIRAN MUARA DAS BARITO  

Directory of Open Access Journals (Sweden)

Full Text Available This research aimed to determine heavy metal content at water body, sediment and biota, determining plankton what overflows and parameter of water quality which not fulfill standard criterion quality of water in Estuary of Barito River. Method of data Analyse used to determine status of water quality with STORET model and EQI (Environmental Quality Index Model, and calculation of indices for the analysis of plankton and Geographic Information System. Result of research show heavy metal rate at body of water especially Hg (0.2753 mg/l, dan Pb (0.17667 mg/l and residing at biota (Giant Prawn have accumulate by heavy metal of Hg. Pb, Cu, As, Cr6+ and Cd. Sediment residing at Estuary of Barito River have accumulate by heavy metal but still under maximum boundary which have been specified. Result of research show calculation by using method of ordinary kriging with semivariogram/covariance modeling for heavy metal model at body obtained value of Average of standard error equal to 0.00609 (RMS = 0.00512 at Estuary River of Kelayan, 0.02441 (RMS = 0.02638 at Estuary of Alalak and 0.01641 (RMS = 0.01430 at station of Estuary River of Kuin. Result of calculation Semivariogram of heavy metal model at sediment, obtained of Average of Standard Error equal to 0.98181 (RMS = 1.14015 at station I, station II equal to 1.14015 (RMS = 1.79179 and station III equal to 1.19635 (RMS = 1.25590. Status of water quality at station perception according to Model of STORET categorized is weight, while pursuant to Model of Environmental Quality Index (EQI categorized as impure territorial water.

Ichsan Ridwan

2012-02-01

279

Accumulation of exp (134) Cs, exp (137) Cs and exp (90) Sr radionuclides by the fishing ponds biota  

International Nuclear Information System (INIS)

The conditions and levels of biological productivity in ponds of different destination and grade of pollution were studied in biennial experiment. The radionuclides distribution was assessed in various components of biota and other elements of ponds ecosystems. It was determined that the small radiation doses influence negatively fish reproduction ability and immunological status

280

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

Energy Technology Data Exchange (ETDEWEB)

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.

Robinson, C A; Smith, K L [Enviros Consulting Limited, 61 The Shore, Leith, Edinburgh EH6 6RA (United Kingdom); Norris, S, E-mail: carol.robinson@enviros.co [Nuclear Decommissioning Authority, Radioactive Waste Management Directorate, Harwell Science and Innovation Campus, Curie Avenue, Harwell, Didcot OX11 0RH (United Kingdom)

2010-06-15

 
 
 
 
281

Modeling the importance of biota and black carbon as vectors of polybrominated diphenyl ethers (PBDEs) in the Baltic Sea ecosystem.  

Science.gov (United States)

The POPCYCLING-Baltic model, a nonsteady state spatially resolved mass balance model of chemical transport in the Baltic Sea environment was modified to include black carbon (BC), dissolved organic carbon (DOC) and food-web bioaccumulation. The importance of these modifications to the transport of PBDE congeners BDE-47, -99, -153, and -209 was assessed by comparing time-series simulated with and without black carbon and biota between 1970 and 2005. Inclusion of black carbon improved the model fit to measurements from air, soil, and biota, and had a major effect on the mass balance. Modeled bulk concentrations of PBDEs in sediments and soils increased by a factor of 3 while concentrations in biota decreased by a factor of 2-5. Black carbon also doubled the recovery time of the system due to the limited availability of PBDEs for degradation. In comparison, the inclusion of biota had only a minor effect on the overall mass balance and recovery times. The modified model is constructed as a flexible matrix and can also be applied to persistent organic pollutants in other ecosystems besides the Baltic Sea. PMID:18678013

Mattila, Tuomas J; Verta, Matti

2008-07-01

282

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

International Nuclear Information System (INIS)

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

283

Interactions with soil biota shift from negative to positive when a tree species is moved outside its native range.  

Science.gov (United States)

Studies evaluating plant-soil biota interactions in both native and introduced plant ranges are rare, and thus far have lacked robust experimental designs to account for several potential confounding factors. Here, we investigated the effects of soil biota on growth of Pinus contorta, which has been introduced from Canada to Sweden. Using Swedish and Canadian soils, we conducted two glasshouse experiments. The first experiment utilized unsterilized soil from each country, with a full-factorial cross of soil origin, tree provenance, and fertilizer addition. The second experiment utilized gamma-irradiated sterile soil from each country, with a full-factorial cross of soil origin, soil biota inoculation treatments, tree provenance, and fertilizer addition. The first experiment showed higher seedling growth on Swedish soil relative to Canadian soil. The second experiment showed this effect was due to differences in soil biotic communities between the two countries, and occurred independently of all other experimental factors. Our results provide strong evidence that plant interactions with soil biota can shift from negative to positive following introduction to a new region, and are relevant for understanding the success of some exotic forest plantations, and invasive and range-expanding native species. PMID:24444123

Gundale, Michael J; Kardol, Paul; Nilsson, Marie-Charlotte; Nilsson, Urban; Lucas, Richard W; Wardle, David A

2014-04-01

284

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

Science.gov (United States)

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. PMID:15700701

Avila, R; Beresford, N A; Agüero, A; Broed, R; Brown, J; Iospje, M; Robles, B; Suañez, A

2004-12-01

285

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

International Nuclear Information System (INIS)

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

286

CROATIAN FRESHWATER FISHERY IN 2001 and 2002  

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

Irena Jahutka

2003-09-01

287

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

International Nuclear Information System (INIS)

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.

288

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

Energy Technology Data Exchange (ETDEWEB)

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

Hosseini, Ali, E-mail: Ali.Hosseini@nrpa.n [Norwegian Radiation Protection Authority, Po Box 55, N-1332 Osteras (Norway); Brown, Justin E. [Norwegian Radiation Protection Authority, Po Box 55, N-1332 Osteras (Norway); Gwynn, Justin P. [Norwegian Radiation Protection Authority, The Fram Centre, N-9296 Tromso (Norway); Dowdall, Mark [Norwegian Radiation Protection Authority, Po Box 55, N-1332 Osteras (Norway)

2012-11-01

289

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

Science.gov (United States)

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

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

2013-09-01

290

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

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

2009-01-01

291

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

Directory of Open Access Journals (Sweden)

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

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

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

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

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

G. Kostoski

2010-07-01

292

Freshwater plankton response to acidification  

Energy Technology Data Exchange (ETDEWEB)

An in situ bag experiment was performed at circum-neutral Lake O'Woods, West Virgnia, where lakewater inside large enclosures was gradually acidified to pH 6.5 or 4.5, in order to examine plankton community succession during acidification. At acidic Cheat Lake (pH ca. 4.5), West Virginia, in situ feeding experiments and bag experiments were performed to evaluate the importance of selective herbivory in controlling algal community structure in acid lakes. The Lake O'Woods plankton community changed dramatically with increasing acidity. Species richness declined, as sensitive forms were eliminated. The phytoplankton became dominated by Peridinium inconspicuum and the filamentous green alga Mougoetia viridis, while euglenophytes, chrysophytes and diatoms were eliminated. Bosmina longirostris and Chydorus sphaericus were the dominant crustaceans at low pH. Only a single rotifer, Lecane luna, tolerated the acidic conditions. All others were eliminated at pH below 6.0. Despite the rapid acidification regime, the nature of the plankton community changes, as well as community structure at pH 4.5, were as predicted in the literature from earlier comparative studies. During the Cheat Lake feeding experiments, P. inconspicuum was always the extreme dominant alga. However, it was never significantly grazed by the herbivorous zooplankton. The herbivores selectively consumed the other, more rare algae, particularly the unicellular greens. Despite the existence of selective herbivory, algal community structure did not change inside enclosures where herbivores were excluded in a 26 and an 18 day experiment. Cheat Lake herbivores seem to have little effect on algal community structure. This is probably also true in most precipitation-acidified lakes. However, herbivore biomass, and also energy flow to higher trophic levels, may be suppressed because most of the primary producer biomass is inedible.

Havens, K.E. III

1984-01-01

293

Assessing the freshwater distribution of yellow eel  

Directory of Open Access Journals (Sweden)

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.

Lasne É.

2009-04-01

294

Assessing the freshwater distribution of yellow eel  

Directory of Open Access Journals (Sweden)

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.

É. Lasne

2008-01-01

295

SOME FRESHWATER SNAILS FROM NORTHERN IRAN  

Directory of Open Access Journals (Sweden)

Full Text Available There are many freshwater snails involved in the life cycle of parasitic flukes. Some of these animals, such as Bulinus spp and Lymnaea spp are very important in public health and veterinary medicine. For example, Bulinus trucatus and Lymnaeid snails transmit Human Bilharziosis and zoonotic Fascioliosis, respectively. For this reason most freshwater bodies of northern Iran, were searched for potential intermediate host snails of medical parasites. Thirteen mollusc taxa, i.e. 5 operculated shell-bearing versus 8 pulmonated snails were found during a snail survey, in the summer of 1992. Two taxa, viz. Anisus leucostoma and Bulinus truncatus were found to be new species for Iran and northern Iran, respectively.

A. Mansoorian

2000-08-01

296

Freshwater aquatic plant biomass production in Florida  

Energy Technology Data Exchange (ETDEWEB)

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.

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

1983-01-01

297

Freshwater invertebrates of subantarctic Marion Island  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract The freshwater habitats (mires; streams; crater lakes; inland, intermediate and coastal lakes and pools; and wallows on subantarctic Marion Island were examined for invertebrates. Sixty-eight species were found, 45 of which are new records for the Island. Of these 56 were bona fide aquatic invertebrates, the rest being terrestrial or brackish interlopers that had fallen or been blown into the water. The aquatic species include five platyhelminthes, a gastrotrich, three tardigrades, 28 rotifers, six nematodes, two annelids and twelve arthropods.  Most are familiar species that have been recorded on other subantarctic islands. The invertebrate faunas of the various freshwater habitats were basically similar in species composition but the abundances of particular species depended upon the water body size, distance from the sea and degree of eutrophication resulting from seabird and seal manuring.

Herbert John Dartnall

2013-03-01

298

Mesophilic Cellulolytic Clostridia from Freshwater Environments  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Eight strains of obligately anaerobic, mesophilic, cellulolytic bacteria were isolated from mud of freshwater environments. The isolates (C strains) were rod-shaped, gram negative, and formed terminal spherical to oval spores that swelled the sporangium. The guanine plus cytosine content of the DNA of the C strains ranged from 30.7 to 33.2 mol% (midpoint of thermal denaturation). The C strains fermented cellulose with formation primarily of acetate, ethanol, CO2, and H2. Reducing sugars accum...

Leschine, S. B.; Canale-parola, E.

1983-01-01

299

Extraction of Freshwater and Energy from Atmosphere  

CERN Document Server

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...

Bolonkin, Alexander

2007-01-01

300

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

International Nuclear Information System (INIS)

The aim of the study was assess the concentration of some selected heavy metals in water, sediments and biota (fish and crab) sampled from the Densu Delta. In situ and laboratory based analysis were carried out to measure the following physicochemical properties of surface water from the delta; temperature, pH, electrical conductivity (EC), salinity, total dissolved solids (TDS), alkalinity, sodium ion concentration (Na+), potassium ion concentration (K+), chloride ion concentration (Cl), bicarbonate concentration, phosphate concentration, nitrate concentration, sulphate concentration and biochemical oxygen demand (BOD). Heavy metal (Fe, Zn, Cu, Ni, Cd, Cr, Pb and Hg) concentrations in water, sediments, fish and crab sampled at six sites from the Densu Delta wetland in the month of December, 2009 were analysed using VARIAN Fast Sequential Atomic Absorption Spectrophotometer (AAS) model AA240 FS. Two fish species; Blackchin tilapia (Sarotherodon melanotheron), White mullet (Mugil curema) and one species of crab; Blue swimming crab (Callinectes amnicola) were collected from the Densu Delta wetland and analysed. Heavy metal contents in the fish were higher in gill tissue than muscle tissue while in crabs concentrations were higher in the soft tissue than the shell. Levels of Fe, Zn and Cu in the muscle tissue of S. melanotheron were greater than the levels detected in the muscle tissue of M. curema. Cd, Ni and Hg were detected in gill tissue but not in the muscle tissue 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)

 
 
 
 
301

Clonal diversity driven by parasitism in a freshwater snail.  

Science.gov (United States)

One explanation for the widespread abundance of sexual reproduction is the advantage that genetically diverse sexual lineages have under strong pressure from virulent coevolving parasites. Such parasites are believed to track common asexual host genotypes, resulting in negative frequency-dependent selection that counterbalances the population growth-rate advantage of asexuals in comparison with sexuals. In the face of genetically diverse asexual lineages, this advantage of sexual reproduction might be eroded, and instead sexual populations would be replaced by diverse assemblages of clonal lineages. We investigated whether parasite-mediated selection promotes clonal diversity in 22 natural populations of the freshwater snail Melanoides tuberculata. We found that infection prevalence explains the observed variation in the clonal diversity of M. tuberculata populations, whereas no such relationship was found between infection prevalence and male frequency. Clonal diversity and male frequency were independent of snail population density. Incorporating ecological factors such as presence/absence of fish, habitat geography and habitat type did not improve the predictive power of regression models. Approximately 11% of the clonal snail genotypes were shared among 2-4 populations, creating a web of 17 interconnected populations. Taken together, our study suggests that parasite-mediated selection coupled with host dispersal ecology promotes clonal diversity. This, in return, may erode the advantage of sexual reproduction in M. tuberculata populations. PMID:24118641

Dagan, Y; Liljeroos, K; Jokela, J; Ben-Ami, F

2013-11-01

302

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

Energy Technology Data Exchange (ETDEWEB)

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

Bjoern, Helena

1999-09-01

303

Retrospective monitoring of alkylphenols and alkylphenol monoethoxylates in aquatic biota from 1985 to 2001: results from the German Environmental Specimen Bank.  

Science.gov (United States)

Breams (Abramis brama) and zebra mussels (Dreissena polymorpha) from freshwater, and common mussels (Mytilus edulis) from marine ecosystems, archived in the German Environmental Specimen Bankwere analyzed for the presence of 4-nonylphenol (NP), 4-tert-octylphenol (OP), nonylphenol monoethoxylate (NP1EO), and octylphenol monoethoxylate (OP1EO). The samples were collected in the German rivers Elbe, Rhine, and Saar, and in Lake Belau between 1992 and 2001, as well as in the North Sea and Baltic Sea between 1985 and 2001. The main purpose of the study was to investigate the effectiveness of imposed reduction measures regarding the use of alkylphenol ethoxylates. NP1EO and OP were detected in all breams. NP was predominantly above the limit of quantification (LOQ, 2 ng/g; all data on a wet weight basis), and OP1EO was mostly below the LOQ (0.2 ng/g). Maximal concentrations of 112 ng/g NP, 259 ng/g NP1EO, 5.5 ng/g OP, and 2.6 ng/g OP1EO were found in Saar breams from 1994. NP was detected in all zebra mussels from the river Elbe (up to 41 ng/g), whereas in rather few samples OP and NP1EO were found at low levels. OP1EO was not detected in any sample. Concentrations in mussels and breams from the reference site Lake Belau were below the LOQ for all compounds. In marine biota NP was found until 1997 with maximum concentrations up to 9.7 ng/g, whereas NP1EO was detected at levels between 1.7 and 12.9 ng/g in very few samples collected at the end of the 1980s. A tendency of the concentrations to decrease was obvious for all sampling sites; it was most pronounced for NP1EO and NP after 1996/1997. The effectiveness of the reduction measures is most evident at the Saar sampling site Güdingen and the North Sea sampling site Eckwarderhörne. PMID:15074671

Wenzel, Andrea; Böhmer, Walter; Müller, Josef; Rüdel, Heinz; Schröter-Kermani, Christa

2004-03-15

304

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

International Nuclear Information System (INIS)

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

305

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2008-09-15

306

Po-210 and other radionuclides in terrestrial and freshwater environments  

International Nuclear Information System (INIS)

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

307

Historical human demands for freshwater in the Arctic  

Science.gov (United States)

The overall 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. This study is taking place on the Seward Peninsula where climate induced changes in the hydrologic cycle are currently being observed. This presentation will document results to date on historical industrial and domestic water demand on the Seward Peninsula. Preliminary results suggest that water use in the Nome Mining District decreased proportionally with the decline of placer mining operations. Water was used in placer gold mining operations on the Seward Peninsula to run hydraulic giants and sluice boxes. Because water was one of the limiting factors in mining operations, a series of ditches diverted nearly all available surface water in the Nome mining district between 1905 and 1914 for industrial use. The domestic water demand, that is, water used for drinking, cooking and cleaning, increased over the past 40 years as piped water and sewer systems were installed in many villages. Domestic demand can increase by 900% when a community installs piped water. The increase in demand corresponding to this change of delivery system can be seen in the difference between water consumption in a village with a central watering point, such as Wales, and a village such as Brevig Mission, where every house is connected to a piped water and sewer system. Historical pressures on the freshwater resource are being used to better understand the vulnerability of the resource now and in the future. This study is being funded under the NSF Arctic System Science Program, Human Dimensions of the Arctic (OPP-0328686).

Strang, E. T.; White, D.; Hinzman, L.

2004-12-01

308

Po-210 and other radionuclides in terrestrial and freshwater environments  

Energy Technology Data Exchange (ETDEWEB)

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)

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

309

Phytochemical and Antibacterial Study of Five Freshwater Algal Species  

Directory of Open Access Journals (Sweden)

Full Text Available A phytochemical study of five freshwater algal species isolated from an Egyptian water station and comparing their inhibition activities against three selected bacterial pathogens in order to correlate the biological activity and the chemical constituents of the algae. Five freshwater algal species, Anabaena sphaerica, Chroococcus turgidus, Oscillatoria limnetica and Spirulina platensis (blue-green algae, Cyanobacteria and Cosmarium leave (green algae were isolated from an Egyptian water station and purified using BG11 media and cultivated. The alcoholic and the aqueous extracts of the five species were evaluated for their inhibitory effect against three bacterial pathogens: Escherichia coli, Salmonella Typhimurium and Streptococcus faecalis using poured plate method. A comparative phytochemical study was performed to detect the main active components of the tested extracts. The obtained results revealed that both the MeOH and the aqueous extracts of Spirulina showed noticeable inhibitory activity against the three bacterial strains: 91.6% (0.7 mg mL-1, 86.2% (0.5 mg mL-1 and 100% (0.3 mg mL-1 for MeOH. and 74.4% (0.9 mg mL-1, 99.3% (0.9 mg mL-1 and 72.6% (0.1 mg mL-1 for H2O against E. coli, Salmonella and Streptococcus, respectively in comparison with other algal extracts. The latter exerted different inhibition activities depending on the types of the bacteria and the extract. It could be concluded that the antibacterial activity was strongly correlated with the quercitin and pigment contents for the MeOH extract and the carbohydrates and pigments contents for the aqueous extract.

G.H. Ali

2012-01-01

310

Steady-state model of biota sediment accumulation factor for metals in two marine bivalves  

Energy Technology Data Exchange (ETDEWEB)

A model of the biota sediment accumulation factor (BSAF) is developed to relate the ratio of metal concentrations in two marine bivalves (Crassostrea virginica and Mytilus edulis) to sediment metal concentration. A generalized metal BSAF can be approximated by a simple relationship that is a function of sediment to water column partitioning, the bioconcentration factor (BCF), the depuration rate, the metal assimilation efficiency from food, the bivalve feeding rate, and the growth rate. Analyses of Mussel Watch data indicate that the medium BSAF across stations varies by about three orders of magnitude from Zn, Cd, and Cu at the highest levels of BSAF = 1 to 10, while Cr has the lowest BSAF at 0.01. Total Hg is about 1.0 and Ni and Pb are approximately 0.1. Calibration of the model indicates that the food route of metal accumulation is significant for all metals but specially for Zn, Cd, Cu, and Hg where virtually all of the observed BSAF is calculated to be due to ingestion of metal from food in the overlying water. These results indicate a potential significance of the metal-binding protein metallothionein, which results in relatively high binding of metal and resulting low depuration rates.

Thomann, R.V.; Mahony, J.D. [Manhattan Coll., Riverdale, NY (United States). Dept. of Environmental Engineering; Mueller, R. [Havens and Emerson, Saddle Brook, NJ (United States)

1995-11-01

311

Sediment distribution coefficients and concentration factors for biota in the marine environment  

International Nuclear Information System (INIS)

In 1985 the IAEA published Technical Reports Series No. 247 (TRS 247), Sediment Kds and Concentration Factors for Radionuclides in the Marine Environment, which provided sediment distribution coefficients (Kds) and concentration factor (CF) data for marine biological material that could be used in models simulating the dispersion of radioactive waste that had been disposed of in the sea. TRS 247 described an approach for calculating sediment or water Kds using stable element geochemical data developed by J.M. Bewers, even though the use of field derived data was emphasized whenever possible. Over the years, TRS 247 has proved to be a valuable reference for radioecologists, marine modellers and other scientists involved in assessing the impact of radionuclides in the marine environment. In 2000 the IAEA initiated a revision of TRS 247 to take account of the new sets of data obtained since 1985.The outcome of this work is this report, which contains revised sediment Kds for the open ocean and ocean margins and CFs for marine biota. CFs for deep ocean ferromanganese nodules. In addition, this report contains CFs for a limited number of elements for marine mammals not included in TRS 247. This revision was carried out at three IAEA Consultants Meetings held in Monaco and Vienna between April 2000 and December 2002

312

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

International Nuclear Information System (INIS)

lver disc are counted with an alpha-ray counter (RC 605A, Nucleonix; efficiency of 35% for a 241Am standard; minimum detectable limit is 0.02 Bq), and the results were combined. After plating, the solution was stored for 6 months in glass bottles to allow the growth of 210Po from 210Pb. Subsequent determination of the ingrown 210Po was carried out as described above for the determination of 210Pb. The average 208Po recovery of 93 ± 2% was obtained by this method. The concentration of both the radionuclides was noticed higher in the organs associated with digestion and metabolism. Filter feeding bivalve molluscs registered the maximum activity of 210Po in their whole body compared to grazing gastropods and other crustaceans. The sensitive indicator, 210Po:210Pb ratio was calculated to be greater than unity in most of the analysed tissues. The ecological sensitivity of biota to the radiation exposure and the safeness of the environment was analysed by calculating the external and internal dose rate. The total weighted internal dose rate was higher than the external dose rate. The calculated hazard quotient for molluscs was lesser than the global bench mark dose rate of 10 ?Gy h-1. (author)

313

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

Science.gov (United States)

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

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

2013-07-01

314

Proposal of a weight factor for alpha radiation aiming biota radioprotection  

International Nuclear Information System (INIS)

Several proposals based on the environmental radioprotection of calculating the absorbed dose in biota have been suggested. The absorbed dose expresses the deposition of energy per mass unit. The differences in biological effects of the absorbed dose can be quantified by applying a correction factor to the absorbed dose. The correction factor for radiation is easier to establish, because radiations exist in smaller number (alpha, beta, neutrons and photons) and can be set for groups of organisms. This work aims to propose a correction factor for radiation, in order to adequate the concept of absorbed dose currently used to the concept of equivalent dose. A survey of the literature on correction factors proposed for alpha radiation was carried out and, when possible, the biological endpoint was identified, as well as the radionuclide and the biological target. A variation of the weight factor for alpha radiation from 1 to 377 was observed and a number of biological endpoints, biological target and alpha emitter radionuclide were identified. Finally we propose a weight value for alpha radiation of 40, and we propose also the name of correction factor for radiation alpha as being ecological radiation weighting factor (WRE) the name 'equivalent dose for flora and fauna' (HTFF) to name of the new dose. (author)

315

Cernavoda NPP impact study on terrestrial and aquatic biota. Preliminary results  

International Nuclear Information System (INIS)

Recently, the awareness of the vulnerability of the environment has increased and the need to protect it against industrial pollutants has been recognized. The concept of sustainable development, requires new and developing international policies for environmental protection. See 'Protection of the environment from the effects of ionizing radiation' IAEA-TECDOC-1091, International Atomic Energy Agency, Vienna. As it is recommended in 'Cernavoda Unit No. 2 NPP Environmental Impact Assessment CES-03702-IAD-006', it is Cernavoda NPP responsibility to conduct an Ecological Risk Assessment study, mainly to assess the impact of nuclear power plant operation on terrestrial and aquatic biota. Long records from normal operation of Cernavoda Unit 1, wind pattern, meteorological conditions, and source terms data were used to evaluate areas of interest for environmental impact, conducting to a circle of 20 km radius around mentioned nuclear objective. The screening campaign established tritium level (because Cernavoda NPP is a CANDU type reactor, and tritium is the most important radioisotope evacuated in the environment) in air, water, soil and vegetation, focusing the interest area on particular ecosystem. Using these primary data it was evaluated which are the monitored ecological receptors and which are the measurement endpoints.This paper presents the Ecological Risk Assessment at Cernavoda NPP technical requirements, and the preliminary results of evaluating criteria for renary results of evaluating criteria for representative ecosystem components at Cernavoda NPP. (authors)

316

Delayed Behavioral Effects of Early Life Toxicant Exposures in Aquatic Biota  

Directory of Open Access Journals (Sweden)

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.

Judith S. Weis

2014-05-01

317

Contrasting food web factor and body size relationships with Hg and Se concentrations in marine biota.  

Science.gov (United States)

Marine fish and shellfish are primary sources of human exposure to mercury, a potentially toxic metal, and selenium, an essential element that may protect against mercury bioaccumulation and toxicity. Yet we lack a thorough understanding of Hg and Se patterns in common marine taxa, particularly those that are commercially important, and how food web and body size factors differ in their influence on Hg and Se patterns. We compared Hg and Se content among marine fish and invertebrate taxa collected from Long Island, NY, and examined associations between Hg, Se, body length, trophic level (measured by ?(15)N) and degree of pelagic feeding (measured by ?(13)C). Finfish, particularly shark, had high Hg content whereas bivalves generally had high Se content. Both taxonomic differences and variability were larger for Hg than Se, and Hg content explained most of the variation in Hg:Se molar ratios among taxa. Finally, Hg was more strongly associated with length and trophic level across taxa than Se, consistent with a greater degree of Hg bioaccumulation in the body over time, and biomagnification through the food web, respectively. Overall, our findings indicate distinct taxonomic and ecological Hg and Se patterns in commercially important marine biota, and these patterns have nutritional and toxicological implications for seafood-consuming wildlife and humans. PMID:24019976

Karimi, Roxanne; Frisk, Michael; Fisher, Nicholas S

2013-01-01

318

Composition of the bacterial biota in slime developed in two machines at a Canadian paper mill.  

Science.gov (United States)

During the process of papermaking by pulp and paper plants, a thick and viscous deposits, termed slime, is quickly formed around the paper machines, which can affect the papermaking process. In this study, we explored the composition of the bacterial biota in slime that developed on shower pipes from 2 machines at a Canadian paper mill. Firstly, the composition was assessed for 12 months by DNA profiling with polymerase chain reaction coupled with denaturing gradient gel electrophoresis. Except for short periods (2-3 months), clustered analyses showed that the bacterial composition of the slime varied substantially over the year, with less than 50% similarity between the denaturing gradient gel electrophoresis profiles. Secondly, the screening of 16S rRNA gene libraries derived from 2 slime samples showed that the most abundant bacteria were related to 6 lineages, including Chloroflexi, candidate division OP10, Clostridiales, Bacillales, Burkholderiales, and the genus Deinococcus. Finally, the proportion of 8 bacterial lineages, such as Deinococcus sp., Meiothermus sp., and Chloroflexi, was determined by the Catalyzed Reporter Deposition-Fluorescence In Situ Hybridization in 2 slime samples. The results showed a high proportion of Chloroflexi, Tepidimonas spp., and Schlegelella spp. in the slime samples. PMID:21326351

Disnard, Julie; Beaulieu, Carole; Villemur, Richard

2011-02-01

319

Studies on natural and anthropogenic radionuclides in sediment and biota of Mumbai Harbour Bay  

International Nuclear Information System (INIS)

Mumbai Harbour Bay (MHB) is a recipient of low level treated effluents from BARC, Trombay and its also a recipient of domestic and industrial wastes from the city of Mumbai and adjoining areas. Sediment samples were collected from various locations of MHB to determine the concentrations of naturally occurring radionuclides like 226Ra, 228Ra and 40K which varied between 4.0 and 26.0, 5.5 and 19.9, 249.6 and 557.6 Bq kg(dry)-1 respectively and are comparable to the worldwide average concentration. The mean value ratio of 228Ra/226Ra in sediment was found to be 1.4, indicating a relatively higher mobility of 238U compared to 232Th. The concentration of anthropogenic radionuclide 137Cs in sediment and biota ranged between 3.6 and 54.5 Bq kg(dry)-1, (wet)-1 respectively. The ingestion dose to 'General Public' due to 137Cs intake is 0.02 ?Sv years-1 which is negligible compared to the internationally accepted limit of 1,000 ?Sv years-1 to 'members of public'. (author)

320

High level of natural radioactivity in biota from deep sea hydrothermal vents  

International Nuclear Information System (INIS)

Hydrothermal vent ecosystems are associated with virtually every area of tectonic activities throughout the deep sea an are thus enriched in natural primitive radionuclides characterizing the magma source i. e. uranium-thorium series. However, the amount of data on radionuclide content in hydrothermal vent biota is very scarce. Various organisms were sampled on the East Pacific Rise and the Mid-Atlantic Ridge in 1996-2001 and 2002. All the samples were analysed through ICP-MS in order to determine their uranium (''238U, ''235U and ''234U) and thorium (''230Th, ''232 Th) contents. In addition''210 Po-Pb were determined in 3 of the samples collected in 2002. Vent organisms are characterized by high levels of U, Th and Pb compared to what is generally encountered in organisms from outside hydrothermal vent ecosystems. ''210 Po appears to be entirely supported by ''210 Pb. These are the first results of a series of on-going work on this topic. Indeed, determination of vent organism concentrations for key elements in the uranium-thorium families has to be carried out in order to precisely determine the radiation exposure they are subject to. This appears especially important at the time where international bodies aim at promoting the development of criteria on the protection of the environment from effects arising from exposures to ionizing radiation. (Author)

 
 
 
 
321

Eramosa Lagerstätte—Exceptionally preserved soft-bodied biotas with shallow-marine shelly and bioturbating organisms (Silurian, Ontario, Canada)  

Science.gov (United States)

The middle Silurian Eramosa Lagerstätte of Ontario, Canada, preserves taxonomically and taphonomically diverse biotas including articulated conodont skeletons and heterostracan fish, annelids and arthropods with soft body parts, and a diverse marine flora. Soft tissues are preserved as calcium phosphate and carbon films, the latter possibly stabilized by early diagenetic sulfurization. It is significant that the biotas also include a decalcified, autochthonous shelly marine fauna, and trace fossils. This association of exceptionally preserved and more typical fossils distinguishes the Eramosa from other Silurian shallow-marine Lagerstätten, such as the Waukesha Lagerstätte, and suggests that the Eramosa is not the product of exceptional preservation in an atypical environment, a bias claimed for many post-Cambrian Lagerstätten. The Eramosa Lagerstätte may provide a more reliable, balanced measure of what has been lost from the Silurian fossil record.

von Bitter, Peter H.; Purnell, Mark A.; Tetreault, Denis K.; Stott, Christopher A.

2007-10-01

322

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

International Nuclear Information System (INIS)

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

323

Polychlorinated naphthalenes in soil, sediment, and biota collected near a former chloralkali plant in coastal Georgia, USA.  

Science.gov (United States)

Concentrations of total polychlorinated naphthalenes (PCNs) as high as 23 micrograms/g, dry wt, were found in sediments contaminated by the disposal of wastes from chlor-alkali processes. Concentrations of total PCNs in blue crab, fish and birds were 3- to 5-orders of magnitude less than that in sediments. The profile of PCN congeners in biota was predominated by tetra- or penta-chloronaphthalenes, while hepta- and octa-chloronaphthalenes were dominant in sediments. The 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TEQs) estimated for PCNs in sediments and biota were greater than those reported for PCBs, PCDDs or PCDFs. These results suggest that chlor-alkali process is a source of PCNs found in the environment. PMID:10943435

Kannan, K; Blankenship, A L; Giesy, J P; Imagawa, T

2000-07-01

324

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

International Nuclear Information System (INIS)

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

325

Persistent organic pollutants and mercury in marine biota of the Canadian Arctic: an overview of spatial and temporal trends.  

Science.gov (United States)

This review summarizes and synthesizes the significant amount of data which was generated on mercury (Hg) and persistent organic pollutants (POPs) in Canadian Arctic marine biota since the first Canadian Arctic Contaminants Assessment Report (CACAR) was published in 1997. This recent body of work has led to a better understanding of the current levels and spatial and temporal trends of contaminants in biota, including the marine food species that northern peoples traditionally consume. Compared to other circumpolar countries, concentrations of many organochlorines (OCs) in Canadian Arctic marine biota are generally lower than in the European Arctic and eastern Greenland but are higher than in Alaska, whereas Hg concentrations are substantially higher in Canada than elsewhere. Spatial coverage of OCs in ringed seals, beluga and seabirds remains a strength of the Arctic contaminant data set for Canada. Concentrations of OCs in marine mammals and seabirds remain fairly consistent across the Canadian Arctic although subtle differences from west to east and south to north are found in the proportions of various chemicals. The most significant development since 1997 is improvement in the temporal trend data sets, thanks to the use of archived tissue samples from the 1970s and 1980s, long-term studies using archeological material, as well as the continuation of sampling. These data cover a range of species and chemicals and also include retrospective studies on new chemicals such as polybrominated diphenyl ethers. There is solid evidence in a few species (beluga, polar bear, blue mussels) that Hg at some locations has significantly increased from pre-industrial times to the present; however, the temporal trends of Hg over the past 20-30 years are inconsistent. Some animal populations exhibited significant increases in Hg whereas others did not. Therefore, it is currently not possible to determine if anthropogenic Hg is generally increasing in Canadian Arctic biota. It is also not yet possible to evaluate whether the recent Hg increases observed in some biota may be due solely to increased anthropogenic inputs or are in part the product of environmental change, e.g., climate warming. Concentrations of most "legacy" OCs (PCBs, DDT, etc.) significantly declined in Canadian Arctic biota from the 1970s to the late 1990s, and today are generally less than half the levels of the 1970s, particularly in seabirds and ringed seals. Chlorobenzenes and endosulfan were among the few OCs to show increases during this period while summation operatorHCH remained relatively constant in most species. A suite of new-use chemicals previously unreported in Arctic biota (e.g., polybrominated diphenyl ethers (PBDEs), short chain chlorinated paraffins (SCCPs), polychlorinated naphthalenes (PCNs), perfluoro-octane sulfonic acid (PFOS) and perfluorocarboxylic acids (PFCAs)) has recently been found, but there is insufficient information to assess species differences, spatial patterns or food web dynamics for these compounds. Concentrations of these new chemicals are generally lower than legacy OCs, but there is concern because some are rapidly increasing in concentration (e.g., PBDEs), while others such as PFOS have unique toxicological properties, and some were not expected to be found in the Arctic because of their supposedly low potential for long-range transport. Continuing temporal monitoring of POPs and Hg in a variety of marine biota must be a priority. PMID:16109439

Braune, B M; Outridge, P M; Fisk, A T; Muir, D C G; Helm, P A; Hobbs, K; Hoekstra, P F; Kuzyk, Z A; Kwan, M; Letcher, R J; Lockhart, W L; Norstrom, R J; Stern, G A; Stirling, I

2005-12-01

326

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

International Nuclear Information System (INIS)

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 ?g 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 ?g Cu L-1 as the pH decreased from 6.5 to 5.7. The 72 h EC50 for U increased from 44 to 78 ?g 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 ?g 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

327

Anthropogenic PAHs in Sediment-Dwelling Biota from Mangrove Areas of the Calabar River, SE Niger Delta, Nigeria  

Directory of Open Access Journals (Sweden)

Full Text Available Polycyclic aromatic hydrocarbons (PAHs in mangrove sediment-dwelling biota (crabs and molluscs from the Calabar River, SE Niger Delta of Nigeria were analyzed using GC-MS in order to assess the degree of contamination of the river by anthropogenic activity. The associated sediment samples (where these biota were collected showed much higher total PAH (TPAH concentration (16,028.3 ng/g dry weight (dw at the upper mangrove area (UMA than that found toward the river mouth (MR; 1,667.5 ng/g dw. However, the mean TPAH levels were higher in molluscs (16,749.8 ng/g ww and crabs (29,325.1 ng/g ww at theMR, and in molluscs (28,580.8 ng/g ww and crabs (71,782.6 ng/g ww at the UMA than in the associated sediments, indicating occurrence of bio-accumulation/bio-concentration of PAHs in tissues of these organisms. The results revealed that molluscs are safer to consume than crabs. One way analysis of variance (ANOVA indicated no significant relationship between lipid content or body size of organisms and contaminant load probably because of non-equilibrium situation: smaller animals accumulated more PAHs than their larger counterparts, suggesting different uptake and elimination rates for these compounds. Biota-sediment accumulation factors (BSAFs varied among the organisms (4.84-14.98 and were generally lower for highly polluted site (UMA; fresh water area and higher for area of low anthropogenic pressure (MR- brackish water area. Risk assessment against USEPA standard show the biota to be highly contaminated with carcinogenic PAHs and may pose life-time cancer risk, especially to residents of the riverine/coastal communities who often consume more of these organisms than those living hinterland.

Bassey O. Ekpo

2012-08-01

328

Assessment of doses to non-human biota: Review of developments and demonstration assessment for Olkiluoto repository  

International Nuclear Information System (INIS)

This report provides a summary of work commissioned by Posiva Oy and undertaken by Enviros Consulting Ltd to support the development of a strategy for the assessment of environmental impacts from ionising radiation associated with the Olkiluoto waste repository, Finland, as part of the development of the Posiva Safety Case Portfolio. This project included a review of the development of international policies and standards related to protection of biota from the effects of ionizing radiation and of biota assessment methodologies, paying particular attention to those that have been applied to waste repository performance assessments. On the basis of this review, recommendations were developed on the most appropriate methodology to apply in order to assess the impact of radioactive releases from the planned spent fuel repository in Olkiluoto. A test-case was developed, in collaboration with staff from Posiva and Facilia AB, and an assessment was performed. The results and experience of which were analysed and summarised to develop recommendations for a future strategy. The test case highlighted some significant data gaps related to the assessment of impacts to both generic biota types and to interest species. In particular, concentration ratios for generic carnivorous mammals and migratory species such as moose that may consume food from multiple ecosystems and dose conversion factors for large burrowing (i.e. hibernating) mammals. However, in general terms, the dose rates predicted for all organism types were several orders of magnitude below those at which population effects would be expected to be observed and those at which effects on the individual may be anticipated. There would therefore be scope for simplifying the approach applied, although there would be value in performing a sensitivity analysis to ensure that the simplification is applied appropriately. There would also be value in ensuring consistency of the developing approach for non-human biota with that applied for human protection. (orig.)

329

Biota: sediment partitioning of aluminium smelter related PAHs and pulp mill related diterpenes by intertidal clams at Kitimat, British Columbia.  

Science.gov (United States)

The question of polycyclic aromatic hydrocarbon (PAH) bioavailability and its relationship to specific PAH sources with different PAH binding characteristics is an important one, because bioavailability drives PAH accumulation in biota and ultimately the biochemical responses to the PAH contaminants. The industrial harbour at Kitimat (British Columbia, Canada) provides an ideal location to study the bioavailability and bioaccumulation of sediment hydrocarbons to low trophic level biota. Samples of soft shell clams (Mya arenaria) and intertidal sediment collected from multiple sites over six years at various distances from an aluminium smelter and a pulp and paper mill were analysed for 106 PAHs, plant diterpenes and other aromatic fraction hydrocarbons. Interpretation using PAH source ratios and multivariate data analysis reveals six principal hydrocarbon sources: PAHs in coke, pitch and emissions from anode combustion from the aluminium smelter, vascular plant terpenes and aromatised terpenes from the pulp and paper mill, petroleum PAHs from shipping and other anthropogenic activities and PAHs from natural plant detritus. Harbour sediments predominantly contain either pitch or pyrogenic PAHs from the smelter, while clams predominantly contain plant derived PAHs and diterpenes from the adjacent pulp mill. PAHs from the smelter have low bioavailability to clams (Biota-Sediment Accumulation Factors; BSAFs 500). Thus while most of the smelter associated PAHs in sediments may not be bioavailable to benthic organisms, the plant terpenes (including retene, totarol, ferruginol, manool, dehydroabietane and other plant terpenes that form the chemical defence mechanism of conifers) released by pulp mills are bioavailable and possess demonstrated toxic properties. The large scale release of plant terpenes by some of the many pulp mills located in British Columbia and elsewhere represents a largely undocumented risk to aquatic biota. PMID:21788067

Yunker, Mark B; Lachmuth, Cara L; Cretney, Walter J; Fowler, Brian R; Dangerfield, Neil; White, Linda; Ross, Peter S

2011-09-01

330

Natural populations of plants and animals as test objects in ecological and genetic assessment of STS biota and population  

International Nuclear Information System (INIS)

Anthropogenic activities result in degradation of natural landscapes and biota impoverishment, disturb historical biocenoses relationships and thus unbalance the ecological system. Rare and few in number plant and animal species vanish and simplify the structure of plant and animal communities. Under unstable landscape conditions and growing impact of stress-inducing anthropogenic factors, populations of living organisms fall into several small isolated sub-populations that impoverishes the gene pool. (author)

331

Baseline assessment of doses and risk due to natural radionuclides in edible biota of Domiasiat, Meghalaya, India  

International Nuclear Information System (INIS)

Radiation dose-risk assessment was carried out for cereal species Brassica compestris var. dichotoma, Oryza sativa var. Shalum1, Zea mays, Lactuca indica, Cumunis sativum, and Clocasia esculanta due to naturally available radionuclides 40K, 238U and 232Th in Domiasiat area. The activity in biota and corresponding soil was measured by precipitation method using NaI(TI) detector. Transfer factor (TF) was for Oryza spp. (1.00E-01-40K, 8.76E-05-232Th, and 9.11E-05-238U), for Brassica spp. (5.39E-01-40K, 8.17E-04-232Th and 2.96E-04-238U) and for Zea spp. (3.41E-01-40K, 5.84E-05-232Th, 8.87E-05-238U) etc., respectively. A detailed physio-morphological study of the biota and extensive investigation of ecosystem was carried out for assessment. The data was modeled using FASSET for dose estimation and obtained total dose was 1.58E-04 ?Gy h-1 in Oryza spp., 2.87E-04 ?Gy h-1 Brassica spp. and 6.90E-03 ?Gy h-1 in Zea spp. etc. The dose was compared with the UNSCEAR dataset for screening level dose for biota. Zea spp. was more susceptible for the chronic radiation exposure. (author)

332

Baseline survey on air, water, soil quality, radioactivity and aquatic biota in and around the project site on new uranium mining site, Tummalapalle, Andhra Pradesh  

International Nuclear Information System (INIS)

In this study four ecological parameters of the environment ie. water, air, soil and biota were monitored at the new uranium mining site of Tummalapalle, Andhra Pradesh. The water quality was assessed by estimating trace metals, natural uranium, physical and chemical parameters. Air quality was assessed through PM10, TSP, PM2.5, SOx and NOx parameters. Soil samples were analysed for trace metals, metal oxides and natural radionuclides. Similarly biota samples were analysed for trace metals and radionuclides

333

Microsoft Word - Rationale for Water Framework Directive Freshwater-Classification-JG- ...  

1 Draft River Basin Management Plans Rationale for Water Framework Directive (WFD) Freshwater Classification December 2008 2 Rationale for Water Framework Directive (WFD) Freshwater Classification RIVER AND LAKES ...

334

Freshwater flux to Sermilik Fjord, SE Greenland  

Directory of Open Access Journals (Sweden)

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.

S. H. Mernild

2010-07-01

335

Radiological benchmarks for screening contaminants of potential concern for effects on aquatic biota at Oak Ridge National Laboratory, Oak Ridge, Tennessee  

International Nuclear Information System (INIS)

A hazardous waste site may contain hundreds of contaminants; therefore, it is important to screen contaminants of potential concern for the ecological risk assessment. Often this screening is done as part of a screening assessment, the purpose of which is to evaluate the available data, identify data gaps, and screen contaminants of potential concern. Screening may be accomplished by using a set of toxicological benchmarks. These benchmarks are helpful in determining whether contaminants warrant further assessment or are at a level that requires no further attention. Unlike exposures to chemicals, which are expressed as the concentration in water or sediment, exposures to radionuclides are expressed as the dose rate received by the organism. The recommended acceptable dose rate to natural populations of aquatic biota is 1 rad d-1. Blaylock, Frank, and O'Neal provide formulas and exposure factors for estimating the dose rates to representative aquatic organisms. Those formulas were used herein to calculate the water and sediment concentrations that result in a total dose rate of 1 rad d-1 to fish for selected radionuclides. These radiological benchmarks are intended for use at the US Department of Energy's (DOE's) Oak Ridge Reservation and at the Portsmouth and Paducah gaseous diffusion plants as screening values only to show the nature and extent of contamination and identify the need for additional site-specific investigation

336

A bioaccumulation bioassay for freshwater sediments  

Science.gov (United States)

A laboratory bioassay is described for determining the bioavailability of contaminants from freshwater sediments. The bioassay consists of 10-d exposures to whole sediments under flow-through conditions. After testing five species, the fathead minnow (Pimephales promelas) and the earthworm (Lubricus terrestris) were recommended for use in the test. When the availability of polychlorinated biphenyls (PCBs), Hg and Zn from Great Lakes sediments was examined in laboratory exposures, only the PCBs were accumulated. A field validation study demonstrated that the magnitude of accumulation in laboratory exposures was similar to that in organisms caged in the field. A protocol is recommended for using the test as a standardized bioaccumulation bioassay.

Mac, Michael J.; Noguchi, George E.; Hesselberg, Robert J.; Edsall, Carol C.; Shoesmith, John A.; Bowker, James D.

1990-01-01

337

Radiation dose assessment for the biota of terrestrial ecosystems in the shoreline zone of the Chernobyl nuclear power plant cooling pond.  

Science.gov (United States)

Radiation exposure of the biota in the shoreline area of the Chernobyl Nuclear Power Plant Cooling Pond was assessed to evaluate radiological consequences from the decommissioning of the Cooling Pond. This paper addresses studies of radioactive contamination of the terrestrial faunal complex and radionuclide concentration ratios in bodies of small birds, small mammals, amphibians, and reptiles living in the area. The data were used to calculate doses to biota using the ERICA Tool software. Doses from 90Sr and 137Cs were calculated using the default parameters of the ERICA Tool and were shown to be consistent with biota doses calculated from the field data. However, the ERICA dose calculations for plutonium isotopes were much higher (2-5 times for small mammals and 10-14 times for birds) than the doses calculated using the experimental data. Currently, the total doses for the terrestrial biota do not exceed maximum recommended levels. However, if the Cooling Pond is allowed to draw down naturally and the contaminants of the bottom sediments are exposed and enter the biological cycle, the calculated doses to biota may exceed the maximum recommended values. The study is important in establishing the current exposure conditions such that a baseline exists from which changes can be documented following the lowering of the reservoir water. Additionally, the study provided useful radioecological data on biota concentration ratios for some species that are poorly represented in the literature. PMID:21878760

Oskolkov, Boris Ya; Bondarkov, Mikhail D; Gaschak, Sergey P; Maksimenko, Andrey M; Hinton, Thomas G; Coughlin, Daniel; Jannik, G Timothy; Farfán, Eduardo B

2011-10-01

338

RADIATION DOSE ASSESSMENT FOR THE BIOTA OF TERRESTRIAL ECOSYSTEMS IN THE SHORELINE ZONE OF THE CHERNOBYL NUCLEAR POWER PLANT COOLING POND  

Energy Technology Data Exchange (ETDEWEB)

Radiation exposure of the biota in the shoreline area of the Chernobyl Nuclear Power Plant Cooling Pond was assessed to evaluate radiological consequences from the decommissioning of the Cooling Pond. The article addresses studies of radioactive contamination of the terrestrial faunal complex and radionuclide concentration ratios in bodies of small birds, small mammals, amphibians, and reptiles living in the area. The data were used to calculate doses to biota using the ERICA Tool software. Doses from {sup 90}Sr and {sup 137}Cs were calculated using the default parameters of the ERICA Tool and were shown to be consistent with biota doses calculated from the field data. However, the ERICA dose calculations for plutonium isotopes were much higher (2-5 times for small mammals and 10-14 times for birds) than the doses calculated using the experimental data. Currently, the total doses for the terrestrial biota do not exceed maximum recommended levels. However, if the Cooling Pond is allowed to drawdown naturally and the contaminants of the bottom sediments are exposed and enter the biological cycle, the calculated doses to biota may exceed the maximum recommended values. The study is important in establishing the current exposure conditions such that a baseline exists from which changes can be documented following the lowering of the reservoir water. Additionally, the study provided useful radioecological data on biota concentration ratios for some species that are poorly represented in the literature.

Farfan, E.; Jannik, T.

2011-10-01

339

Using macroinvertebrates to identify biota-land cover optima at multiple scales in the Pacific Northwest, USA  

Science.gov (United States)

Macroinvertebrate assemblages and environmental variables were evaluated at 45 stream sites throughout the Puget Sound Basin, Washington, USA. Environmental variables were measured at 3 spatial scales: reach, local, and whole watershed. Macroinvertebrate distributions were related to environmental variables using canonical correspondence analysis to determine which variables and spatial scales best explained the observed community composition and to identify biota-land cover optima. The calculation of a biota-land cover optimum was a 2-step process. First, an individual taxon's optimum was estimated for a particular land cover by weighting the mean value for that land cover by the abundance of that taxon at all sites. Second, the biota-land cover optimum was determined as the point at which the greatest numbers of taxa, at their calculated optima, appeared for a particular land cover. Sampling reaches were located on streams in watersheds with varying levels of forest, agriculture, and urban/suburban land cover that represented the full range of physical conditions typically found in Puget Sound streams. At the reach scale, taxa composition was correlated with conductivity and mean velocity. At the local and whole-watershed scales, taxa composition was correlated with % forest and agricultural land cover and % forest and bedrock land cover, respectively. For all of the scales, the dominant environmental variables represented an anthropogenic gradient. There was little difference in the amount of variability explained by each spatial scale. At the local-watershed scale, a biota-land cover optimum of ???80 to 90% forest land cover was identified. The total number of taxa at their optima declined rapidly as forest land cover within the local scale declined below 80 to 90%. At the whole-watershed scale, a biota-land cover optimum of 70 to 80% forest land cover was identified. The total number of taxa at their optima declined rapidly as forest land cover within the whole watershed declined below 70 to 80%. Our results suggest that macroinvertebrates can be used both as quantitative indicators of environmental conditions at multiple scales and indicators of land cover optima. Further examination of these optima could be used to establish priorities for conservation and restoration efforts.

Black, R. W.; Munn, M. D.; Plotnikoff, R. W.

2004-01-01

340

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

Directory of Open Access Journals (Sweden)

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.

Arun Kumar MS* and A Jawahar Ali

2014-08-01

 
 
 
 
341

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

Science.gov (United States)

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 few invaded ecosystems are free from habitat degradation, and that both factors may interact in different ways. Here we analyze the relative importance of habitat degradation and invasive species in the decline of native fish assemblages in the Guadiana River basin (southwestern Iberian Peninsula) using an information theoretic approach to evaluate interaction pathways between invasive species and habitat degradation (structural equation modeling, SEM). We also tested the possible changes in the functional relationships between invasive and native species, measured as the per capita effect of invasive species, using ANCOVA. We found that the abundance of invasive species was the best single predictor of natives' decline and had the highest Akaike weight among the set of predictor variables examined. Habitat degradation neither played an active role nor influenced the per capita effect of invasive species on natives. Our analyses indicated that downstream reaches and areas close to reservoirs had the most invaded fish assemblages, independently of their habitat degradation status. The proliferation of invasive species poses a strong threat to the persistence of native assemblages in highly fluctuating environments. Therefore, conservation efforts to reduce native freshwater fish diversity loss in Mediterranean rivers should focus on mitigating the effect of invasive species and preventing future invasions. PMID:21516896

Hermoso, Virgilio; Clavero, Miguel; Blanco-Garrido, Francisco; Prenda, José

2011-01-01

342

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

Scientific Electronic Library Online (English)

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

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

343

Biota-sediment accumulation and trophic transfer factors for extremely hydrophobic polychlorinated biphenyls  

Energy Technology Data Exchange (ETDEWEB)

Polychlorinated biphenyls (PCBs) in fish, invertebrates, and sediment from a contaminated tidal creek system in coastal Georgia (USA) were traced to Aroclor 1268, a mixture of hepta through decachlorinated homologs used at a former chlor/alkali plant adjacent to the study site. The base 10 logarithm of the octanol/water partition coefficient (K{sub ow}) for the 15 most abundant Aroclor 1268 components in these samples ranged from 6.7 to >9. The composite mean biota-sediment accumulation factor (BSAF) for these congeners was 3.1, 0.81, and 0.28 for yearling striped mullet, spotted sea trout, and grass shrimp, respectively, species representing three trophic levels of the local food web. Individual congener BSAFs were negatively correlated with log K{sub ow} for all three species. The composite mean trophic transfer factor (TTF{sub lip}), defined as the ratio of lipid-normalized PCB concentrations in fish to grass shrimp, was higher for mullet (12) than for sea trout (2.9). Individual TTF{sub lip} values were two to three times higher for Cl{sub 7} and Cl{sub 8} homologs that were substituted at all four ortho positions, suggesting a difference in PCB retention based on chlorine substitution patterns. The relative magnitude of BSAFs and TTF{sub lip} values indicated that sediment-ingesting forage species like mullet efficiently accumulate PCBs and are an important link in the food web transfer of sediment-ingesting forage in this system. The negative linear relationships between BSAF and log K{sub ow} established in this study are among the first to be reported in the field for extremely hydrophobic PCBs.

Maruya, K.A.; Lee, R.F. [Skidaway Inst. of Oceanography, Savannah, GA (United States)

1998-12-01

344

Scientific drilling and the evolution of the earth system: climate, biota, biogeochemistry and extreme systems  

Science.gov (United States)

A US National Science Foundation-funded workshop occurred 17-19 May 2013 at the University of Oklahoma to stimulate research using continental scientific drilling to explore earth's sedimentary, paleobiological and biogeochemical record. Participants submitted 3-page "pre-proposals" to highlight projects that envisioned using drill-core studies to address scientific issues in paleobiology, paleoclimatology, stratigraphy and biogeochemistry, and to identify locations where key questions can best be addressed. The workshop was also intended to encourage US scientists to take advantage of the exceptional capacity of unweathered, continuous core records to answer important questions in the history of earth's sedimentary, biogeochemical and paleobiologic systems. Introductory talks on drilling and coring methods, plus best practices in core handling and curation, opened the workshop to enable all to understand the opportunities and challenges presented by scientific drilling. Participants worked in thematic breakout sessions to consider questions to be addressed using drill cores related to glacial-interglacial and icehouse-greenhouse transitions, records of evolutionary events and extinctions, records of major biogeochemical events in the oceans, reorganization of earth's atmosphere, Lagerstätte and exceptional fossil biota, records of vegetation-landscape change, and special sampling requirements, contamination, and coring tool concerns for paleobiology, geochemistry, geochronology, and stratigraphy-sedimentology studies. Closing discussions at the workshop focused on the role drilling can play in studying overarching science questions about the evolution of the earth system. The key theme, holding the most impact in terms of societal relevance, is understanding how climate transitions have driven biotic change, and the role of pristine, stratigraphically continuous cores in advancing our understanding of this linkage. Scientific drilling, and particularly drilling applied to continental targets, provides unique opportunities to obtain continuous and unaltered material for increasingly sophisticated analyses, tapping the entire geologic record (extending through the Archean), and probing the full dynamic range of climate change and its impact on biotic history.

Soreghan, G. S.; Cohen, A. S.

2013-11-01

345

Secondary UV radiation from biota as a proof of radiation hormesis and Gurwitsch phenomena  

International Nuclear Information System (INIS)

High (large) and low (small) doses of ionizing radiation consistently induce opposite physiologic effects in biological systems. The effects of low doses cannot be inferred by interpolation between the result from groups exposed to high doses and controls irradiated only by Natural Background Radiation. Stimulation NBR ('bio-positive') effects by low-level doses of ionizing radiation is called radiation hormesis. It is still a controversial idea; however it was found that some biological objects (yeast, sees, animals) after ?-irradiation by low-level doses (10-50 times more NBR) can increase their development. The results of the researches demonstrate that the excitation of living systems by ionizing radiation (high energy, low doses) produces among other hydrogen peroxide which initiates prolonged secondary emission that can influence biota and activate many important processes in biological systems. On the other hand it is well known that after water irradiation by ionizing radiation as the product of radiolysis concentration of hydrogen peroxide has been received. The spectral analysis of this secondary emission confirmed the contribution of the UV component to the total emission. This secondary radiation can play a very important role in the intercellular communication. The influence of hydrogen peroxide on glycine has been examined. I have measured secondary emission from Gly using the Single Photon Counting device SPC. The data obtained made possible at least a partial understanding of the radiation hormesis phenomenon and suggest closer relationship to mitogenetic radiation. I propose deexcitation processes in biomolecules as a common denominator of UV and ionizing radiation interacting with living cells, underlying both radiation hormesis and mitogenetic effect. Based on the above experiments and other authors' reports it is postulated that low-level doses of ionizing radiation through radiolysis products (among others hydrogen peroxide) generate UV photons which can create mitogenetic radiation from cells

346

Comparing laboratory- and field-measured biota-sediment accumulation factors.  

Science.gov (United States)

Standardized laboratory protocols for measuring the accumulation of chemicals from sediments are used in assessing new and existing chemicals, evaluating navigational dredging materials, and establishing site-specific biota-sediment accumulation factors (BSAFs) for contaminated sediment sites. The BSAFs resulting from the testing protocols provide insight into the behavior and risks associated with individual chemicals. In addition to laboratory measurement, BSAFs can also be calculated from field data, including samples from studies using in situ exposure chambers and caging studies. The objective of this report is to compare and evaluate paired laboratory and field measurement of BSAFs and to evaluate the extent of their agreement. The peer-reviewed literature was searched for studies that conducted laboratory and field measurements of chemical bioaccumulation using the same or taxonomically related organisms. In addition, numerous Superfund and contaminated sediment site study reports were examined for relevant data. A limited number of studies were identified with paired laboratory and field measurements of BSAFs. BSAF comparisons were made between field-collected oligochaetes and the laboratory test organism Lumbriculus variegatus and field-collected bivalves and the laboratory test organisms Macoma nasuta and Corbicula fluminea. Our analysis suggests that laboratory BSAFs for the oligochaete L. variegatus are typically within a factor of 2 of the BSAFs for field-collected oligochaetes. Bivalve study results also suggest that laboratory BSAFs can provide reasonable estimates of field BSAF values if certain precautions are taken, such as ensuring that steady-state values are compared and that extrapolation among bivalve species is conducted with caution. PMID:21538837

Burkhard, Lawrence P; Arnot, Jon A; Embry, Michelle R; Farley, Kevin J; Hoke, Robert A; Kitano, Masaru; Leslie, Heather A; Lotufo, Guilherme R; Parkerton, Thomas F; Sappington, Keith G; Tomy, Gregg T; Woodburn, Kent B

2012-01-01

347

Chemical analysis and genotoxicity of high molecular mass PAH in sediment samples and biota  

International Nuclear Information System (INIS)

A normal phase liquid chromatography (NPLC) method was used to fractionate the organic extracts of prepared from coal tar-contaminated sediments from hamilton Harbor in Ontario and from Sydney Harbor in Nova Scotia into molecular mass classes. Each PAH fraction up to 302 amu was analyzed by GC-MS and fractions containing PAH with molecular masses greater than 302 amu were analyzed by atmospheric pressure chemical ionization (APCI) LC-MS.Each fraction was also subjected to Ames bioassays using a TA100-like strain of Salmonella typhimurium (YG1025 + S9). The 300/302 amu, 326/328 and 350/352 amu PAH fractions accounted for 25% of the total genotoxic response of the extract; these PAH constitute a substantial genotoxic burden. A number of 300, 302, 326, 350, 374 and 400 amu PAH were identified using APCI LC-MS and comparison with authentic standards. The non-polar aromatic extracts of bottom sediments, suspended sediments and zebra mussels from Hamilton Harbor were also examined by GC-MS, APCI LC-MS and genotoxicity bioassays. The profiles of the priority and high mass PAH in these samples were identical showing that all PAH up to and exceeding 400 amu were readily bioavailable to biota such as Zebra mussels. In addition, the pseudo faeces of the Zebra mussels and amphipod detritivores which fed on the pseudo faeces had chemical profiles identical to the Zebra mussels. Since many sport fish prize amphipods as food, this observation demonstrates a pathway for organic contaminants adsorbed to suspended sediments to enter the food chain of non-bottom-feeding fish in areas infested by Zebra mussels

348

Impacts of new highways and subsequent landscape urbanization on stream habitat and biota  

Science.gov (United States)

New highways are pervasive, pernicious threats to stream ecosystems because of their short- and long-term physical, chemical, and biological impacts. Unfortunately, standard environmental impact statements (EISs) and environmental assessments (EAs) focus narrowly on the initial direct impacts of construction and ignore other long-term indirect impacts. More thorough consideration of highway impacts, and, ultimately, better land use decisions may be facilitated by conceptualizing highway development in three stages: initial highway construction, highway presence, and eventual landscape urbanization. Highway construction is characterized by localized physical disturbances, which generally subside through time. In contrast, highway presence and landscape urbanization are characterized by physical and chemical impacts that are temporally persistent. Although the impacts of highway presence and landscape urbanization are of similar natures, the impacts are of a greater magnitude and more widespread in the urbanization phase. Our review reveals that the landscape urbanization stage is clearly the greatest threat to stream habitat and biota, as stream ecosystems are sensitive to even low levels (urban development. Although highway construction is ongoing, pervasive, and has severe biological consequences, we found few published investigations of its impacts on streams. Researchers know little about the occurrence, loading rates, and biotic responses to specific contaminants in highway runoff. Also needed is a detailed understanding of how highway crossings, especially culverts, affect fish populations via constraints on movement and how highway networks alter natural regimes (e.g., streamflow, temperature). Urbanization research topics that may yield especially useful results include a) the relative importance and biological effects of specific components of urban development - e.g., commercial or residential; b) the scenarios under which impacts are reversible; and c) the efficacy of mitigation measures - e.g., stormwater retention or treatment and forested buffers. Copyright ?? Taylor & Francis Inc.

Wheeler, A. P.; Angermeier, P. L.; Rosenberger, A. E.

2005-01-01

349

The small-sized benthic biota of the Håkon Mosby Mud Volcano (SW Barents Sea slope)  

Science.gov (United States)

R/V POLARSTERN expedition ARK XVIII/1 in summer 2002 provided the opportunity to carry out a sampling programme to assess the activity, biomass and composition of the small-sized benthic biota (size range: bacteria to meiofauna) around the active mud-oozing and methane-seeping Håkon Mosby Mud Volcano (HMMV) on the SW Barents Sea slope, Northern North-Atlantic. A total of 11 stations, covering different areas (e.g., bacterial mat sites, and pogonophoran fields) within the crater, and sites outside the caldera were sampled using a multiple corer. Subsamples were analyzed for various biogenic compounds to estimate the flux of organic matter to the seafloor (sediment-bound chloroplastic pigments indicating phytodetritus), activities (bacterial exo-enzymatic turnover rates) and the total biomass [from bulk parameters, like phospholipid (PL) concentrations in the sediments] of the smallest sediment-inhabiting organisms (range: bacteria to meiofauna). Direct investigations of bacterial numbers and biomasses as well as on meiofauna densities and composition completed our investigations at HMMV. As expected for a comparable small deep-sea area with only minor disparity in water depth between sampling sites, our investigations revealed generally no significant differences in organic matter input from phytodetritus sedimentation between sampling sites inside and outside HMMV. Bacterial exo-enzymatic activities as well as total microbial biomass (TMB) and meiofauna densities, however, exhibited generally higher values at HMMV, compared to sites outside the mud volcano. Enhanced benthic life at HMMV is based on chemosynthetic processes, making the mud volcano a "chemosynthetic oasis" in an otherwise oligotrophic deep-sea environment. As we did not find any indication for bacterial symbioses in the meiofauna, comparably rich meiofaunal assemblages at HMMV are presumably indirectly related to a general enhanced biological production.

Soltwedel, Thomas; Portnova, Daria; Kolar, Ingrid; Mokievsky, Vadim; Schewe, Ingo

2005-04-01

350

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

Science.gov (United States)

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

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

2014-11-01

351

Steroid catabolism in marine and freshwater fish.  

Science.gov (United States)

Steroids play important roles in regulating many physiological functions in marine and freshwater fish. Levels of active steroid in blood and tissues are determined by the balance between synthetic and catabolic processes. This review examines what is known about pathways of catabolism of steroids, primarily sex steroids, in marine and freshwater fish. Cytochrome P450 (P450) isoforms present in hepatic microsomes catalyze steroid hydroxylation to metabolites with lower or no activity at estrogen or androgen receptors. Important pathways of steroid catabolism to readily excreted metabolites are glucuronidation and sulfonation of hydroxyl groups. Estradiol, testosterone, DHEA and hydroxylated metabolites of these and other steroids readily form glucuronide and sulfate conjugates in those fish species where these pathways have been examined. Little is known, however, of the structure and function of the UDP-glucuronosyltransferase (UGT) and sulfotransferase (SULT) enzymes involved in steroid conjugation in fish. Glucuronide and sulfate conjugates of steroids may be transported into and out of cells by organic anion transporter proteins and multi-drug resistance proteins, and there is growing evidence that these proteins play important roles in steroid conjugate transport and elimination. Induction or inhibition of any of these pathways by environmental chemicals can result in alteration of the natural balance of steroid hormones and could lead to disruption of the endocrine system. Recent studies in this area are presented, with particular focus on phase II (conjugative) pathways. PMID:20955793

James, Margaret O

2011-11-01

352

Reclaiming freshwater sustainability in the Cadillac Desert  

Science.gov (United States)

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%.

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

353

Freshwater fishes of Tsitsikamma National Park  

Directory of Open Access Journals (Sweden)

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.

I.A. Russell

2002-12-01

354

Freshwater fishes of Bontebok National Park  

Directory of Open Access Journals (Sweden)

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.

I.A. Russell

2001-08-01

355

Tritium kinetics in a freshwater marsh  

International Nuclear Information System (INIS)

Ten curies (Ci) of tritium (as tritiated water) were applied to a 2-ha Lake Erie marsh in northwestern Ohio on 29 October 1973. Tritium kinetics in the marsh water, bottom sediment, crayfish (Procambarus blandingi), and fish (Lepomis macrochirus) were determined over an 8 to 12-month period. Tritium half-life in the water was 64.5 days. Approximately 3 percent of the initial tritium present in the water remained after 332 days. Following application, peak tritium levels in the sediment were observed on day 13 in the top 1-cm layer, on day 27 at 5-cm depth and on day 64 at a 10-cm depth. Tritium uptake in the biota was rapid. After the initial uptake, loss of tritium from unbound (body-water) compartments paralleled marsh water activity. Loss of bound (tissue structure) tritium from bluegill muscle was similar to loss of tritium from the marsh water. Loss of bound tritium from crayfish muscle was slower than loss of tritium from the marsh water. A model based on diffusion theory described tritium movement through the sediment. Tritium uptake and loss by the crayfish and bluegills were described by a set of simple linear differential equations.nt through the sediment. Tritium uptake and loss by the crayfish and bluegills were described by a set of simple linear differential equations

356

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

Science.gov (United States)

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

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

2009-06-01

357

Arsenic contamination in the freshwater fish ponds of Pearl River Delta: bioaccumulation and health risk assessment.  

Science.gov (United States)

This study investigated the extent of arsenic (As) contamination in five common species of freshwater fish (northern snakehead [Channa argus], mandrarin fish [Siniperca chuatsi], largemouth bass [Lepomis macrochirous], bighead carp [Aristichthys nobilis] and grass carp [Ctenopharyngodon idellus]) and their associated fish pond sediments collected from 18 freshwater fish ponds around the Pearl River Delta (PRD). The total As concentrations detected in fish muscle and sediment in freshwater ponds around the PRD were 0.05-3.01 mg kg(-1) wet weight (w. wt) and 8.41-22.76 mg kg(-1) dry weight (d. wt), respectively. In addition, the As content was positively correlated (p aquaculture ponds were selected for investigation: (1) omnivorous food chain (zooplankton, grass carp and bighead carp) and (2) predatory food chain (zooplankton, mud carp and mandarin fish). Significant linear relationships were obtained between log As and ? (15)N. The slope of the regression (-0.066 and -0.078) of the log transformed As concentrations and ? (15)N values, as biomagnifications power, indicated there was no magnification or diminution of As from lower trophic levels (zooplankton) to fish in the aquaculture ponds. Consumption of largemouth bass, northern snakehead and bighead carp might impose health risks of Hong Kong residents consuming these fish to the local population, due to the fact that its cancer risk (CR) value exceeded the upper limit of the acceptable risk levels (10(-4)) stipulated by the USEPA. PMID:23247527

Cheng, Zhang; Chen, Kun-Ci; Li, Kai-Bin; Nie, Xiang-Ping; Wu, Sheng Chun; Wong, Chris Kong-Chu; Wong, Ming-Hung

2013-07-01