WorldWideScience
 
 
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

Transfers to freshwater biota  

International Nuclear Information System (INIS)

It remains important to monitor the fate of radionuclides, particularly in environmental compartments that comprise human pathways. Therefore, an extensive literature survey has been conducted to compile available data on the transfer of radionuclides and their analogues to edible freshwater biota. Focus was placed on compilation of steady state transfer parameters for two freshwater pathways, including water-to-biota and sediment-to-biota. In general, although in many cases, extensive data were available for fishes and invertebrates, relatively fewer data were available for freshwater primary producers, amphibians and reptiles. To fill in these gaps, data were also compiled on the internal partitioning of elements in the body with respect to tissue masses, which could be used to estimate radionuclide concentrations between compartments in the body. (author)

2009-05-01

3

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

International Nuclear Information System (INIS)

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

2005-08-01

4

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

1975-01-01

5

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

1982-01-01

6

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.

2010-01-01

7

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

Science.gov (United States)

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 (137)Cs, (134)Cs and (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 (137)Cs deposition were applied in the assessment. The dose rates to most species studied were clearly below the screening level of 10 microGy 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. PMID:19828217

Vetikko, Virve; Saxén, Ritva

2010-01-01

8

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

9

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

10

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

International Nuclear Information System (INIS)

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

2011-01-01

11

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

12

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

1993-01-01

13

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

International Nuclear Information System (INIS)

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

1996-07-01

14

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

15

Persistent organic pollutants and metals in the freshwater biota of the Canadian Subarctic and Arctic: an overview.  

Science.gov (United States)

Over 1999-2002, an extensive series of contaminant studies was conducted on freshwater biota of Canada's Arctic and Subarctic regions. The majority of inorganic contaminant studies focused on mercury and fish. While mercury concentrations were low in benthic feeding fish such as whitefish, predatory fish such as lake trout, pike, and walleye frequently had mercury levels which exceeded 0.2 mug/g, the consumption guideline for frequent consumers of fish, and 0.5 microg/g, the guideline for the commercial use of fish. Numerous consumption advisories were issued for lakes along the Mackenzie River. Relatively high mercury levels appear to be due to a combination of relatively old fish populations (because of light fishing pressures) and tend to be more prevalent in smaller lakes where warmer summer water temperatures and watershed influences result in greater mercury and methyl mercury inputs. Mercury levels were substantially lower in char than in lake trout, possibly due to a combination of a less fish-rich diet, a colder environment, and smaller MeHg watershed inputs. Less research has been conducted on other metals but some, such as rubidium, show pronounced variations in concentration that may be related to geological influences. Temporal trend monitoring has revealed little evidence of declining mercury levels in fish that can be attributed to declining atmospheric inputs. Because mercury follows complex pathways in the environment, other factors may operate to counteract reductions in atmospheric mercury sources, e.g., climatic variability, changes in the commercial fishery, and interactions between fish species. Most organochlorine (OC) investigations were based on long term trend monitoring and focused on char (Cornwallis Island), burbot (Great Slave Lake, Yukon lakes, Slave River at Fort Smith, Mackenzie River at Fort Good Hope) and lake trout (Yukon lakes, Great Slave Lake). There was strong evidence of declining OC concentrations in char, particularly SigmaHCH and Sigmachlordane, which may reflect a response to declining atmospheric inputs. Endosulfan concentrations increased, as in the atmosphere. There also was evidence of declining OC concentrations in burbot in the Slave and Mackenzie rivers but not in Great Slave Lake and Yukon lakes. OC concentrations decreased in lake trout in Yukon lakes in the 2000s, most probably because of changes in the fish themselves (i.e., reduced lipid content, condition factor) and possibly climatic variability. Similarly, OCs declined in Great Slave Lake trout. New research on PDBEs and perfluorinated compounds determined that these contaminants are widespread in freshwater fish and concentrations may be increasing. Global warming is a major issue of concern for Arctic and Subarctic waters and may have adverse impacts on contaminant levels in fish and other biota. There is a need for contaminant studies in the north to be broadened to investigate climatic effects. In addition, monitoring studies should be broadened to consider factors affecting other aspects of fish biology. Foremost among these is integrating contaminant monitoring studies on lakes such as Lake Laberge and Great Slave Lake with stock assessment studies. Ecosystem based studies should be conducted on Great Slave Lake and Lake Laberge to more effectively understand contaminant trends and should consider inputs (atmospheric, river inflow, resupension), losses (sedimentation, volatilization), and biological pathways. PMID:16225909

Evans, Marlene S; Muir, Derek; Lockhart, W Lyle; Stern, Gary; Ryan, M; Roach, Pat

2005-12-01

16

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

Energy Technology Data Exchange (ETDEWEB)

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

17

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

International Nuclear Information System (INIS)

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

2012-01-01

18

Terrestrial and freshwater radioecology. A selected bibliography  

International Nuclear Information System (INIS)

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

1975-01-01

19

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

International Nuclear Information System (INIS)

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

2011-04-01

20

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

 
 
 
 
21

Analysis of marine sediment, water and biota for selected organic pollutants  

Energy Technology Data Exchange (ETDEWEB)

The concentrations of various organic pollutants (benzo(a)pyrene (BaP), hexachlorobenzene (HCB) and pentachlorophenol (PCP) were determined in samples of water, sediment and biota (flounder, killifish, shrimp, crabs, and squid) from San Luis Pass, Texas. Sediment was also analyzed for polychlorinated biphenyls (PCBs), phthalic acid esters (PAEs) and various pesticides. Only PCP was detectable in water. In sediment, the relative concentrations were PAEs >> BaP > (PCBs approx. HCB) > PCP. In biota, BaP was not detectable in any animal; HCB was highest in crabs and PCP was highest in all others (flounder, killifish, shrimp and squid). The relative concentrations of HCB and PCP were different in the different organisms. The differences between the relative concentrations in the biota and in sediment are discussed. The results of this study are compared to values measured at other sites. This study is part of a larger effort to identify and quantitate pollutants in various Texas estuaries and to serve as a basis for monitoring marine pollution.

Murray, H.E.; Ray, L.E.; Giam, C.S.

1981-12-01

22

Selecting Reliable and Robust Freshwater Macroalgae for Biomass Applications  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Intensive cultivation of freshwater macroalgae is likely to increase with the development of an algal biofuels industry and algal bioremediation. However, target freshwater macroalgae species suitable for large-scale intensive cultivation have not yet been identified. Therefore, as a first step to identifying target species, we compared the productivity, growth and biochemical composition of three species representative of key freshwater macroalgae genera across a range of cultivation conditi...

Lawton, Rebecca J.; Nys, Rocky; Paul, Nicholas A.

2013-01-01

23

Exposure of biota in the cooling pond of Ignalina NPP: hydrophytes  

International Nuclear Information System (INIS)

The radiological assessment of non-human biota is now accepted by a number of international bodies. In this connection the scientific basis to assess and evaluate biota internal and external radiation exposure is required. This paper presents the comparison of freshwater biota (hydrophyte species) exposure due to discharged anthropogenic radionuclides with that due to natural background radiation. The radionuclides from Ignalina Nuclear Power Plant (Lithuania) are discharged into cooling pond - Druksiai Lake. Submerged hydrophytes were selected as biota exposure indicators because they represent the largest biomass in this lake and have comparatively high radionuclide activity concentrations. The detailed methodology evaluation of the submerged hydrophyte dose rate is presented. The ionizing radiation exposure dose rates to submerged hydrophyte roots and above sediment parts due to the major radionuclides (54Mn, 60Co, 137Cs, 90Sr) discharged into the INPP cooling pond - Druksiai Lake were 0.044 ?Gy h-1 and 0.004 ?Gy h-1, respectively. The internal exposure dose rate due to natural background ?-emitters (210Po,238U, 226Ra) was estimated to be 1.24 ?Gy h-1, as compared with that of anthropogenic ?-emitter 240Pu - 0.04 ?Gy h-1, whereas the external exposure was 0.069 ?Gy h-1. The presented data deeper the knowledge about the concentration of radionuclides and submerged hydrophytes' exposure dose rates in European freshwater ecosystems

2007-10-01

24

A mixture of grass and clover combines the positive effects of both plant species on selected soil biota  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The introduction of N2-fixing white clover (Trifolium repens) in grassland is a management measure that may contribute to sustainable grassland systems by making them less dependent on inorganic fertilizers. However, little is known about the impact of this measure on soil biota and ecosystem services. We investigated earthworms, nematodes, bacteria and fungi in an experiment in which white clover-only and a mixture of grass and white clover without fertilization were compared with grass-only...

Eekeren, N. J. M.; Liere, D.; Vries, F. T.; Rutgers, M.; Goede, R. G. M.; Brussaard, L.

2009-01-01

25

Tissue screening concentrations for use in assessing ecological risks of chemical residues in aquatic biota  

Energy Technology Data Exchange (ETDEWEB)

Ecological risk based screening concentrations for tissue residues have been developed for aquatic biota. Termed tissue screening concentrations (TSCs), they are generally applicable (i.e. non-site specific) to a wide variety of both freshwater and marine biota. Chemical residues in tissues at concentrations below the TSC are presumed to pose little or no risk to aquatic biota, allowing chemicals to be quickly eliminated from further consideration in a risk assessment. To date, relatively few widely applicable screening tools are available to ecological risk assessors. The toxicological basis for TSCs is applicable to both metals and organic compounds. Toxic responses in aquatic biota are directly related to waterborne concentrations of chemicals, and at equilibrium, tissue residues in biota are also proportional to the chemical concentration in water. Therefore, the toxic response in biota is directly related to the tissue residue. A TSC is calculated by multiplying a toxicity value (such as a chronic ambient water quality criterion) by a bioconcentration factor. The selection of the toxicity information and bioconcentration factors for TSC calculation is critical to the success of this screening method, and will be illustrated for cadmium, mercury, and PCB. A literature review comparing whole body tissue residues associated with toxic responses to the TSCs indicated that for most chemicals, the calculated TSCs provide an adequate level of protection so that TSCs can be used as a screening tool in ecological risk assessments. TSCs do not currently provide an accurate assessment of chemicals which are rapidly metabolized to either more or less toxic compounds by biota. The mean safety factor for the 74 chemicals with calculated TSCs is 14. Field tests of the TSCs indicate they identify the same site contaminants of concern as other methods used to assess ecological risks at hazardous waste sites.

Shephard, B.K. [URS Consultants, Seattle, WA (United States)

1995-12-31

26

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

2008-12-01

27

Radioprotection of nonhuman biota  

Energy Technology Data Exchange (ETDEWEB)

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.

Delistraty, Damon [Washington State Department of Ecology, N. 4601 Monroe, Spokane, WA 99205 (United States)], E-mail: ddel461@ecy.wa.gov

2008-12-15

28

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

29

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

Science.gov (United States)

In 2010 and 2011, the U.S. Geological Survey (USGS), in cooperation with the Northeast Texas Municipal Water District and the Texas Commission on Environmental Quality, did a baseline assessment of physical characteristics and aquatic biota (fish and mussels) collected at the mesohabitat scale for reaches of Big Cypress, Black Cypress, and Little Cypress Bayous in the Big Cypress Basin in northeastern Texas, and measured selected water-quality properties in isolated pools in Black Cypress and Little Cypress. All of the data were collected in the context of prescribed environmental flows. The information acquired during the course of the study will support the long-term monitoring of biota in relation to environmental flow prescriptions for Big Cypress Bayou, Black Cypress Bayou, and Little Cypress Bayou. Data collection and analysis were done at mesohabitat- and reach-specific scales, where a mesohabitat is defined as a discrete area within a stream that exhibits unique depth, velocity, slope, substrate, and cover. Biological and physical characteristic data were collected from two sites on Big Cypress Bayou, and one site on both Black Cypress Bayou and Little Cypress Bayou. The upstream reach of Big Cypress Bayou (USGS station 07346015 Big Cypress Bayou at confluence of French Creek, Jefferson, Texas) is hereinafter referred to as the Big Cypress 02 site. The downstream site on Big Cypress Bayou (USGS station 07346017 Big Cypress Bayou near U.S. Highway 59 near Jefferson, Tex.) is hereinafter referred to as the Big Cypress 01 site and was sampled exclusively for mussels. The sites on Black Cypress Bayou (USGS station 07346044 Black Cypress Bayou near U.S. Highway 59 near Jefferson, Tex.) and Little Cypress Bayou (USGS station 07346071 Little Cypress Bayou near U.S. Highway 59 near Jefferson, Tex.) are hereinafter referred to as the Black Cypress and Little Cypress sites, respectively. A small range of streamflows was targeted for data collection, including a period of low flow during July and August 2010 and a period of very low flow during July 2011. This scenario accounts for variability in the abundance and distribution of fish and mussels and in the physical characteristics of mesohabitats present during different flow conditions. Mussels were not collected from the Little Cypress site. However, a quantitative survey of freshwater mussels was conducted at Big Cypress 01. Of the three reaches where physical habitat data were measured in 2010, Big Cypress 02 was both the widest and deepest, with a mean width of 62.2 feet (ft) and a mean depth of 5.5 ft in main-channel mesohabitats. Little Cypress was the second widest and deepest, with a mean width of 49.9 ft and a mean depth of 4.5 ft in main-channel mesohabitats. Black Cypress was by far the narrowest of the three reaches, with a mean width of 29.1 ft and a mean depth of 3.3 ft in main-channel mesohabitats but it had the highest mean velocity of 0.42 feet per second (ft/s). Appreciably more fish were collected from Big Cypress 02 (596) in summer 2010 compared to Black Cypress (273) or Little Cypress (359), but the total number of fish species collected among the three reaches was similar. Longear sunfish was the most abundant fish species collected from all three sites. The total number of fish species was largest in slow run mesohabitats at Big Cypress 02, fast runs at Black Cypress, and slow runs at Little Cypress. The catch-per-unit-effort of native minnows was largest in fast runs at Big Cypress 02. More species of native minnows, including the ironcolor and emerald shiner, were collected from Little Cypress relative to all other mesohabitats at all sites. Fifteen species and 182 individuals of freshwater mussels were collected, with 69.8 percent of the individual mussels collected from Big Cypress 02, 23.6 percent collected from Big Cypress 01, and 6.6 percent collected from Black Cypress. Big Cypress 01was the most species rich site with 13 species, and washboards were the most abundant species overall. Mussels were not collected from Little Cypress because th

Braun, Christopher L.; Moring, James B.

2013-01-01

30

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

2005-06-09

31

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

Science.gov (United States)

The RESRAD-BIOTA code was developed through a partnership among U.S. Department of Energy, the U.S. Environmental Protection Agency, and the U.S. Nuclear Regulatory Commission. RESRAD-BIOTA provides a full spectrum of analysis capabilities, from cost effe...

C. Yu D. LePoire J. Arnish J. -J. Cheng I. Hlohowskij S. Kamboj T. Klett S. Domotor K. Higley R. Graham P. Newkirk T. Harris

2002-01-01

32

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

Science.gov (United States)

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

Braun, Christopher L.; Moring, James B.

2013-01-01

33

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

International Nuclear Information System (INIS)

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

2005-04-15

34

Evidence for selective bacterial community structuring in the freshwater sponge Ephydatia fluviatilis.  

Science.gov (United States)

To understand the functioning of sponges, knowledge of the structure of their associated microbial communities is necessary. However, our perception of sponge-associated microbiomes remains mainly restricted to marine ecosystems. Here, we report on the molecular diversity and composition of bacteria in the freshwater sponge Ephydatia fluviatilis inhabiting the artificial lake Vinkeveense Plassen, Utrecht, The Netherlands. Polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) fingerprints revealed that the apparent diversities within the domain Bacteria and the phylum Actinobacteria were lower in E. fluviatilis than in bulk water. Enrichment of specific PCR-DGGE bands in E. fluviatilis was detected. Furthermore, sponge- and bulk water-derived bacterial clone libraries differed with respect to bacterial community composition at the phylum level. E. fluviatilis-derived sequences were affiliated with six recognized phyla, i.e., Proteobacteria, Planctomycetes, Actinobacteria, Bacteroidetes, Chlamydiae and Verrucomicrobia, in order of relative abundance; next to the uncultured candidate phylum TM7 and one deeply rooted bacterial lineage of undefined taxonomy (BLUT). Actinobacteria, Proteobacteria, and Bacteroidetes were the dominant bacterial phyla in the freshwater clone library whereas sequences affiliated with Planctomycetes, Verrucomicrobia, Acidobacteria and Armatimonadetes were found at lower frequencies. Fine-tuned phylogenetic inference showed no or negligible overlaps between the E. fluviatilis and water-derived phylotypes within bacterial taxa such as Alphaproteobacteria, Bacteroidetes and Actinobacteria. We also ascertained the status of two alphaproteobacterial lineages as freshwater sponge-specific phylogenetic clusters, and report on high distinctiveness of other E. fluviatilis specific phylotypes, especially within the Bacteroidetes, Planctomycetes and Chlamydia taxa. This study supports the contention that the composition and diversity of bacteria in E. fluviatilis is partially driven by the host organism. PMID:22903086

Costa, Rodrigo; Keller-Costa, Tina; Gomes, Newton C M; da Rocha, Ulisses Nunes; van Overbeek, Leo; van Elsas, Jan Dirk

2013-01-01

35

Radiation weighting factors for biota  

International Nuclear Information System (INIS)

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

2005-08-01

36

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

International Nuclear Information System (INIS)

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

2013-12-01

37

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

38

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

39

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

40

A freshwater species wintering in a brackish environment: Habitat selection and diet of Slavonian grebes in the southern Baltic Sea  

Science.gov (United States)

After the breeding season, Slavonian grebes ( Podiceps auritus) leave their freshwater breeding habitats and migrate to wintering grounds in marine or brackish waters. The most important wintering area in northwestern Europe is located in the southern Baltic Sea, with the largest concentrations in the offshore area of the Pommeranian Bight. Analysis of ship-based surveys revealed that the habitat selection of Slavonian grebes in this brackish area is significantly influenced by water depth and bottom sediment type. The grebes prefer shallow waters of 4-14 m depth and occur only over sandy sediments. While the diving depths of endothermic animals is limited due to energetic constraints and thermoregulation, sediment type is regarded to be a proxy for food choice. The diet of Slavonian grebes in the Pomeranian Bight consists mainly of demersal gobies (Gobiidae) that frequently occur over sandy bottom substrates.

Sonntag, Nicole; Garthe, Stefan; Adler, Sven

2009-09-01

 
 
 
 
41

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

Science.gov (United States)

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

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

2013-12-01

42

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

1986-01-01

43

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

1990-01-01

44

RESRAD-BIOTA: A Tool for Implementing a Graded Approach to Biota Dose Evaluation.  

Science.gov (United States)

This Interagency Steering Committee on Radiation Standards (ISCORS) Technical Report provides a User's Guide for the RESRAD-BIOTA code. The RESRAD-BIOTA code is a tool for implementing a graded approach to biota dose evaluation. The RESRAD-BIOTA code was ...

2004-01-01

45

Baseline Assessment of Physical Characteristics, Aquatic Biota, and Selected Water-Quality Properties at the Reach and Mesohabitat Scale for Reaches of Big Cypress, Black Cypress, and Little Cypress Bayous, Big Cypress Basin, Northeastern Texas, 2010-11.  

Science.gov (United States)

In 2010 and 2011, the U.S. Geological Survey (USGS), in cooperation with the Northeast Texas Municipal Water District and the Texas Commission on Environmental Quality, did a baseline assessment of physical characteristics and aquatic biota (fish and muss...

C. L. Braun J. B. Moring

2013-01-01

46

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 T...

Banu, A. N. H.; Khan, M. H.

2004-01-01

47

Biota and biological principles of the aquatic environment  

Energy Technology Data Exchange (ETDEWEB)

The first of several compilations of briefing papers on water quality prepared by the U.S. Geological Survey is presented. Each briefing paper is prepared in a simple, nontechnical, easy to understand manner. This U.S. Geological Survey Circular contains papers on selected biota and biological principles of the aquatic environment. Briefing papers are included on Why biology in water quality studies , Stream biology, Phytoplankton, Periphyton, Drift organisms in streams, Family Chironomidae (Diptera), Influences of water temperature on aquatic biota, and Stream channelization: Effects on stream fauna.

Greeson, P.E.

1982-01-01

48

Biota and biological principles of the aquatic environment  

International Nuclear Information System (INIS)

The first of several compilations of briefing papers on water quality prepared by the U.S. Geological Survey is presented. Each briefing paper is prepared in a simple, nontechnical, easy to understand manner. This U.S. Geological Survey Circular contains papers on selected biota and biological principles of the aquatic environment. Briefing papers are included on Why biology in water quality studies , Stream biology, Phytoplankton, Periphyton, Drift organisms in streams, Family Chironomidae (Diptera), Influences of water temperature on aquatic biota, and Stream channelization: Effects on stream fauna

1982-01-01

49

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

50

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)

2003-05-01

51

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." (JAWRA) (Copyright ?? 2005).

Westra, J. V.; Zimmerman, J. K. H.; Vondracek, B.

2005-01-01

52

Ediacaran biota from Sonora, Mexico.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

Mcmenamin, M. A.

1996-01-01

53

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

54

Biota of North America Program  

Science.gov (United States)

The goal of the Biota of North America Program (BONAP) is to develop a unified digital system for assessing the North American biota. BONAP's database now includes assessment for all vascular plants and vertebrate animals (native, naturalized, and adventive) of North America north of Mexico, and it maintains the most current taxonomy, nomenclature, and biogeographic data for all members of the biota. The Synthesis of the North American Flora, published in 1999, is available for purchase as a CD-ROM (ordering information is provided); a 1mb demonstration version for Windows is available through the BONAP site. The Synthesis includes taxonomic, nomenclatural, and biogeographic data and images, enabling users to produce species checklists, distribution summaries, and species assessments for morphology, rarity, endemism, nativity, and other biological attributes. It consists of three parts: the "Lexicon," which provides the underlying nomenclature and taxonomy; the "Atlas," which displays distribution maps for each of the accepted taxa; and the "Biological Attributes," which provides summaries of morphological and other specialized data (rarity and endemism, nativity, weediness, habit, habitat, and others).

55

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

1997-01-01

56

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

57

Tissue screening concentration values for assessing ecological risks of chemical residues in aquatic biota  

Energy Technology Data Exchange (ETDEWEB)

Ecological risk based screening concentrations for aquatic biota tissue residues have been developed for 74 chemicals. These tissue screening concentrations (TSC`s) are non-site specific and applicable to a wide variety of both freshwater and marine biota. Chemical residues in tissues at concentrations below the TSC are presumed to pose little or no risk to aquatic biota, allowing chemicals to be quickly eliminated from further consideration in an ecological risk assessment. Compared with human health risk assessments, relatively few screening tools are available to ecological risk assessors which allow them to quickly reduce the number of chemicals which need to be carried through the complete risk assessment process. To date, only ambient water quality criteria and sediment quality guidelines have been widely used as screening tools in ecological risk assessment. It is believed that the tissue screening concentrations described will provide ecological risk assessors with another tool for rapidly identifying contaminants of concern to aquatic biota, while allowing those chemicals which do not pose significant risks to aquatic biota to be eliminated from the risk assessment. Computational methods for deriving TSC`s will be shown, and the TSC`s for 74 chemicals, covering a wide range of chemicals, both metals and organic compounds, will be presented. The results of a literature survey for over 40 chemicals, comparing whole body tissue residues associated with toxic responses to the calculated TSC`s will be shown. This review indicates that for most chemicals, the TSC`s describe tissue residues for aquatic biota which, if not exceeded, are indicative of chemical concentrations which pose little or no risks to aquatic biota.

Shephard, B.K. [URS Consultants, Seattle, WA (United States)

1995-12-31

58

Taxonomical notes on selected freshwater fish species described from northern and central Vietnam (Cypriniformes: Balitoridae, Cobitidae, Cyprinidae, Nemacheilidae; Perciformes: Channidae, Osphronemidae; Synbranchiformes: Mastacembelidae).  

Science.gov (United States)

Selected, little known taxa of northern and central Vietnamese freshwater fish species are reviewed. Nomenclatural acts are taken: Hemibarbus lehoai is placed in synonymy of H. maculatus, Paracobitis hagiangensis in synonymy of Schistura caudofurca. A neotype of Micronemacheilus bacmeensis is assigned. The name Channa hanamensis is treated as a nomen nudum. Two labeonine species described from China are nomenclaturally affected: Garra findolabium is transferred to Vinagarra and its specific epithet is treated as a noun in apposition; the specific epithet of Sinigarra napoense is corrected to napoensis. PMID:24668657

Endruweit, Marco

2014-03-18

59

Inventory of selected freshwater-ecology studies from the New England Coastal Basins (Maine, New Hampshire, Massachusetts, Rhode Island), 1937-97  

Science.gov (United States)

An inventory of published studies that address freshwater ecology within the New England Coastal Basins was created through computerized bibliographic literature searches and consultation with environmental agencies. Assembled papers were classified to associate their contents with one or more states, ecoregions, river basins, and ecological topics. Full references and their classifications were entered into a bibliographic software program and then exported to a data-base application to generate a checklist summary of study contents. This report presents a listing and classification of 154 selected studies, published between 1937 and 1997, that provide background knowledge and serve as general aquatic-ecology references for the New England Coastal Basins study area.

Tessler, Steven; Coles, J. F.; Beaulieu, K. M.

1999-01-01

60

Environmental pathways and radiological dosimetry for biota  

Energy Technology Data Exchange (ETDEWEB)

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

Blaylock, B.G. [SENES Oak Ridge Inc., Center for Risk Analysis, Oak Ridge, TN (United States)

1997-07-01

 
 
 
 
61

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

International Nuclear Information System (INIS)

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

2012-06-01

62

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

63

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

1986-01-01

64

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

65

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

International Nuclear Information System (INIS)

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

2004-12-01

66

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

Energy Technology Data Exchange (ETDEWEB)

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

Batlle, J Vives i [Westlakes Scientific Consulting Ltd, Westlakes Science and Technology Park, Moor Row, Cumbria CA24 3LN (United Kingdom); Jones, S R [Westlakes Scientific Consulting Ltd, Westlakes Science and Technology Park, Moor Row, Cumbria CA24 3LN (United Kingdom); Gomez-Ros, J M [Radiation Dosimetry Group, CIEMAT, Avenida Complutense 22, E-28040 Madrid (Spain)

2004-12-01

67

Vulnerability of stream biota to climate change in mediterranean climate regions: a synthesis of ecological responses and conservation challenges  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Freshwater species worldwide are experiencing dramatic declines partly attributable to ongoing climate change. It is expected that the future effects of climate change could be particularly severe in mediterranean climate (med-) regions, which host many endemic species already under great stress from the high level of human development. In this article, we review the climate and climate-induced changes in streams of med-regions and the responses of stream biota, focusing on both observed and ...

Filipe, A. F.; Lawrence, J. E.; Bonada I Caparro?s, Nu?ria

2013-01-01

68

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

International Nuclear Information System (INIS)

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

2008-01-01

69

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)

2005-08-01

70

Review of the impact of copper released into freshwater environments  

International Nuclear Information System (INIS)

The concentrations of copper in the abiotic and biotic compartments of freshwater ecosystems, and the effects on biota of increased amounts of copper in the water and sediments are reviewed. Data compiled and discussed include the quantities and physicochemical forms of copper in the water column, the concentrations of copper in the bed-load sediments and interstitial waters, and the concentrations of copper in primary producers, molluscs, crustacea, aquatic insects, other invertebrates, and fishes. In addition, the acute and sublethal effects of copper on the same groups of biota are presented, as well as data on copper concentration factors. This information can be used to: (1) determine the ranges of copper concentrations that occur in nature for different types of ecosystems; (2) identify ecosystems that are or may be impacted by copper released from industrial and urban sources; and (3) assess the effects of biota of the use of copper alloys in nuclear power station cooling systems

1983-01-01

71

Freshwater fish of the Wilderness National Park  

Directory of Open Access Journals (Sweden)

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

I.A. Russell

1999-01-01

72

Comparative Hydrology, Water Quality, and Ecology of Selected Natural and Augmented Freshwater Wetlands in West-Central Florida  

Science.gov (United States)

Comparing altered wetlands to natural wetlands in the same region improves the ability to interpret the gradual and cumulative effects of human development on freshwater wetlands. Hydrologic differences require explicit attention because they affect nearly all wetland functions and are an overriding influence on other comparisons involving wetland water quality and ecology. This study adopts several new approaches to quantify wetland hydrologic characteristics and then describes and compares the hydrology, water quality, and ecology of 10 isolated freshwater marsh and cypress wetlands in the mantled karst landscape of central Florida. Four of the wetlands are natural, and the other six have water levels indirectly lowered by ground-water withdrawals on municipally owned well fields. For several decades, the water levels in four of these altered wetlands have been raised by adding ground water in a mitigation process called augmentation. The two wetlands left unaugmented were impaired because their water levels were lowered. Multifaceted comparisons between the altered and natural wetlands are used to examine differences between marshes and cypress wetlands and to describe the effects of augmentation practices on the wetland ecosystems. In the karstic geologic setting, both natural and altered wetlands predominantly lost water to the surficial aquifer. Water leaking out of the wetlands created water-table mounds below the wetlands. The smallest mounds radiated only slightly beyond the vegetated area of the wetlands. The largest and steepest mounds occurred below two of the augmented wetlands. There, rapid leakage rates regenerated a largely absent surficial aquifer and mounds encompassed areas 7-8 times as large as the wetlands. Wetland leakage rates, estimated using a daily water-budget analysis applied over multiple years and normalized as inches per day, varied thirtyfold from the slowest leaking natural wetland to the fastest leaking augmented wetland. Leakage rates increased as the size of the flooded area decreased and as the downward head difference between the wetland and the underlying Upper Floridan aquifer increased. Allowing one of the augmented wetlands to dry up for about 2.5 months in the spring of 2004, and then refilling it, generated a net savings of augmentation water despite the amount of water required to recreate the water-table mound beneath the wetland. Runoff from the surrounding uplands was an important component of the water budget in all of the unaugmented wetlands and two of the augmented wetlands. At a minimum, runoff contributed from half (45 percent) to twice (182 percent) as much water as direct rainfall at individual wetlands. Wetland flooded areas, derived using wetland water levels and bathymetric data and presented as a percentage of total wetland area, were used to compare and contrast hydrologic conditions among the 10 wetlands. The percentages of the natural wetland areas that flooded during the study were comparable, despite differences in the sizes of the wetlands. The percent flooded area in each wetland was calculated daily over the study period and monthly for up to 16 years using historical water-level data. Historical flooding in the natural wetlands spanned a greater range in area and had more pronounced seasonality than historical flooding at either the impaired or augmented wetlands. Flooding in the impaired and natural wetlands was similar, however, during 2 years of the study with substantially reduced well-field pumping and above average rainfall. Comparisons indicated several hydrologic differences between the marsh and cypress wetlands in this study. The natural and impaired marshes leaked at about half the rate of the natural and impaired cypress wetlands, and the marshes collectively were underlain by geologic material with lower vertical leakance values than the cypress wetlands. The natural marshes had higher evaporation rates compared to cypress

Lee, T.M.; Haag, K.H.; Metz, P.A.; Sacks, L.A.

2009-01-01

73

Molecular analysis of human forearm superficial skin bacterial biota  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The microbial ecology of human skin is complex, but little is known about its species composition. We examined the diversity of the skin biota from the superficial volar left and right forearms in six healthy subjects using broad-range small subunit rRNA genes (16S rDNA) PCR-based sequencing of randomly selected clones. For the initial 1,221 clones analyzed, 182 species-level operational taxonomic units (SLOTUs) belonging to eight phyla were identified, estimated as 74.0% [95% confidence inte...

Gao, Zhan; Tseng, Chi-hong; Pei, Zhiheng; Blaser, Martin J.

2007-01-01

74

Manipulation of soil biota in ecological research  

Directory of Open Access Journals (Sweden)

Full Text Available Manipulation of soil biota, such as soil sterilization, may have complex effects as they alter soil properties as well as microorganism communities. To assess the effects of such manipulation, we conducted an experiment using three sterilizing approaches, two soil types, and two plant species to identify the problems that may occur when different sterilizing approaches are used. The sterilizing treatments decreased growth of plants and resulted in large changes in soil nutrients and pH. Such effects varied with the approach followed. Our data suggest that studied effects on soil biota may be misleading if we fail to consider such changes in the soil.

W.-M. He

2009-12-01

75

The RESRAD-BIOTA code for application in biota dose assessment  

International Nuclear Information System (INIS)

The RESRAD-BIOTA code was developed through a partnership involving offices of the U.S. Department of Energy, the U.S. Environmental Protection Agency, and the U.S. Nuclear Regulatory Commission. RESRAD-BIOTA is designed to provide a full spectrum of analysis capabilities, from practical conservative screening methods to more realistic organism-specific dose assessments. The RESRAD-BIOTA code has many advanced features such as dose conversion factors for eight ellipsoid organism geometries, sensitivity analysis capability for studying parameter sensitivities, and text and graphic reports for easy interpretation of results. An improved version of the RESRAD-BIOTA code is currently available for test and evaluation. (author)

2003-09-01

76

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

77

Inventory of Selected Freshwater-Ecology Studies From the New England Coastal Basins (Maine, New Hampshire, Massachusetts, Rhode Island), 1937-1997.  

Science.gov (United States)

An inventory of published studies that address freshwater ecology within the New England Coastal Basins was created through computerized bibliographic literature searches and consultation with environmental agencies. Assembled papers were classified to as...

S. Tessler J. F. Coles K. M. Beaulieu

1999-01-01

78

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

79

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

80

Manipulation of soil biota in ecological research  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Manipulation of soil biota, such as soil sterilization, may have complex effects as they alter soil properties as well as microorganism communities. To assess the effects of such manipulation, we conducted an experiment using three sterilizing approaches, two soil types, and two plant species to identify the problems that may occur when different sterilizing approaches are used. The sterilizing treatments decreased growth of plants and resulted in large changes in soil nutrients and pH. Such ...

-m He, W.; -g Cui, Q.

2009-01-01

 
 
 
 
81

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

Energy Technology Data Exchange (ETDEWEB)

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

Yu, C.; LePoire, D.; Arnish, J.; Cheng, J.-J.; Hlohowskij, I.; Kamboj, S.; Klett, T.; Domotor, S.; Higley, K.; Graham, R.; Newkirk, P.; Harris, T.

2002-07-09

82

The RESRAD-BIOTA code for application in biota dose evaluation  

International Nuclear Information System (INIS)

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

2002-07-22

83

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

84

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

International Nuclear Information System (INIS)

The United States Department of Energy (DOE) currently has in place a radiation dose limit for the protection of aquatic organisms, and has considered dose limits for terrestrial biota. These limits are: 10 mGy/d for aquatic animals, 10 mGy/d for terrestrial plants, and 1 mGy/d for terrestrial animals. Guidance on suitable approaches to implementation of these and other proposed limits for protection of biota is needed. In response to this need, we have developed methods, models and guidance within a graded approach for evaluating radiation doses to biota. DOE's multi-tiered process is described in a technical standard document. Methods are encoded in a series of electronic spreadsheets termed the RAD-BCG Calculator to assist the user in progressing through the evaluation process. A key component of the graded approach is a screening methodology that provides limiting concentrations of radionuclides, termed Biota Concentration Guides (BCGs), for use in screening water, sediment, and soil media to determine if dose limits for biota are likely to be exceeded. The graded approach provides flexibility and the ability to iterate through the evaluation process. User-selected biota dose limits can be entered in place of default dose limits. Parameter values, radiation weighting factors, and organism residence times can be modified within site-specific screening and site-specific analysis phases of the graded approach. The methodology, available since 2000, was developed using an interdisciplinary team approach that included both 'developers' and 'users' through the Department's Biota Dose Assessment Committee (BDAC). DOE's graded approach framework provides a practical and effective tool for demonstrating protection of biota relative to Dose Rate Guidelines, and for conducting ecological screening assessments of radiological impact. It provides a needed evaluation tool that can be employed within an international framework for protection of the environment. (author)

2003-05-01

85

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

International Nuclear Information System (INIS)

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

2013-02-01

86

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

87

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

International Nuclear Information System (INIS)

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

2008-08-01

88

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

International Nuclear Information System (INIS)

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

2013-12-01

89

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

90

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

International Nuclear Information System (INIS)

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

2008-06-15

91

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2003-07-01

92

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

International Nuclear Information System (INIS)

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

2003-01-01

93

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)

1997-04-01

94

Declines of biomes and biotas and the future of evolution.  

Science.gov (United States)

Although panel discussants disagreed whether the biodiversity crisis constitutes a mass extinction event, all agreed that current extinction rates are 50-500 times background and are increasing and that the consequences for the future evolution of life are serious. In response to the on-going rapid decline of biomes and homogenization of biotas, the panelists predicted changes in species geographic ranges, genetic risks of extinction, genetic assimilation, natural selection, mutation rates, the shortening of food chains, the increase in nutrient-enriched niches permitting the ascendancy of microbes, and the differential survival of ecological generalists. Rates of evolutionary processes will change in different groups, and speciation in the larger vertebrates is essentially over. Action taken over the next few decades will determine how impoverished the biosphere will be in 1,000 years when many species will suffer reduced evolvability and require interventionist genetic and ecological management. Whether the biota will continue to provide the dependable ecological services humans take for granted is less clear. The discussants offered recommendations, including two of paramount importance (concerning human populations and education), seven identifying specific scientific activities to better equip us for stewardship of the processes of evolution, and one suggesting that such stewardship is now our responsibility. The ultimate test of evolutionary biology as a science is not whether it solves the riddles of the past but rather whether it enables us to manage the future of the biosphere. Our inability to make clearer predictions about the future of evolution has serious consequences for both biodiversity and humanity. PMID:11344296

Woodruff, D S

2001-05-01

95

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.

Lyudmila Koren

2011-03-01

96

ACCUMULATION OF HEAVY METALS IN BIOTA OF VYRLYTSA LAKE  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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.

Bilyk, Tetiana; Tsurkan, Katerina; Koren, Lyudmila

2011-01-01

97

Whole-body to tissue concentration ratios for use in biota dose assessments for animals.  

Science.gov (United States)

Environmental monitoring programs often measure contaminant concentrations in animal tissues consumed by humans (e.g., muscle). By comparison, demonstration of the protection of biota from the potential effects of radionuclides involves a comparison of whole-body doses to radiological dose benchmarks. Consequently, methods for deriving whole-body concentration ratios based on tissue-specific data are required to make best use of the available information. This paper provides a series of look-up tables with whole-body:tissue-specific concentration ratios for non-human biota. Focus was placed on relatively broad animal categories (including molluscs, crustaceans, freshwater fishes, marine fishes, amphibians, reptiles, birds and mammals) and commonly measured tissues (specifically, bone, muscle, liver and kidney). Depending upon organism, whole-body to tissue concentration ratios were derived for between 12 and 47 elements. The whole-body to tissue concentration ratios can be used to estimate whole-body concentrations from tissue-specific measurements. However, we recommend that any given whole-body to tissue concentration ratio should not be used if the value falls between 0.75 and 1.5. Instead, a value of one should be assumed. PMID:20931337

Yankovich, Tamara L; Beresford, Nicholas A; Wood, Michael D; Aono, Tasuo; Andersson, Pål; Barnett, Catherine L; Bennett, Pamela; Brown, Justin E; Fesenko, Sergey; Fesenko, J; Hosseini, Ali; Howard, Brenda J; Johansen, Mathew P; Phaneuf, Marcel M; Tagami, Keiko; Takata, Hyoe; Twining, John R; Uchida, Shigeo

2010-11-01

98

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

99

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)

2004-09-06

100

Effect of chronic selenium exposure on the freshwater bivalve Corbicula fluminea  

Energy Technology Data Exchange (ETDEWEB)

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 (SeO{sub 4}{sup 2-}) and selenite (SeO{sub 3}{sup 2-}) 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)

Fournier, E.; Adam, C.; Massabuau, J.C.; Garnier-Laplace, J. [CEA Cadarache (DEI/SECRE/LRE), Laboratory of Radioecology and Ecotoxicology, Institute for Radioprotection and Nuclear Safety, 13 - Saint-Paul-lez-Durance (France)

2004-07-01

 
 
 
 
101

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

1980-01-01

102

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

International Nuclear Information System (INIS)

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

2013-12-01

103

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

Science.gov (United States)

The RESRAD-BIOTA Level 1 default Biota Concentration Guides (BCGs) are generic screening environmental medium concentrations based on reasonably conservative concentration ratios (CRs). These CRs had been identified from available literature for a variety of biota organisms. The International Atomic Energy Agency (IAEA) Technical Report Series (TRS) handbook on radionuclide transfer to wildlife was recently published with data that can be compared with the RESRAD-BIOTA values. In addition, previous IAEA Environmental Modeling for Radiation Safety (EMRAS) II Biota Working Group model comparison results are examined by comparing them with those obtained using the new TRS CR values for wildlife. Since the CR affects only internal doses, the effect on the overall dose depends on the relative contribution from internal and external exposure pathways. PMID:23455002

Yu, C; Cheng, J-J; Kamboj, S

2013-12-01

104

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

Immediate conservation measures for world-wide freshwater resources are of eminent importance. This is particularly true for so-called ancient lakes. While these lakes are famous for being evolutionary theatres, often displaying an extraordinarily high degree of biodiversity and endemism, in many cases these biota are also experiencing extreme anthropogenic impact.

Lake Ohrid, a major European biodiversity hotspot situated in a trans-frontier setting on the Balkans, is a ...

2010-01-01

105

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

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

2011-01-01

106

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

1116-01-00

107

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

Energy Technology Data Exchange (ETDEWEB)

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.

Chambers, Douglas B. [SENES Consultants Limited, 121 Granton Drive, Unit 12, Richmond Hill, Ontario L4B 3N4 (Canada)]. E-mail: dchambers@senes.ca; Osborne, Richard V. [Ranasara Consultants Inc., P.O. Box 1116, 7 Pine Point Close, Deep River, Ontario K0J 1P0 (Canada); Garva, Amy L. [SENES Consultants Limited, 121 Granton Drive, Unit 12, Richmond Hill, Ontario L4B 3N4 (Canada)

2006-07-01

108

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

International Nuclear Information System (INIS)

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

2003-01-01

109

User's guide, version 1 RESRAD-BIOTA : a tool for implementing a graded approach to biota dose evaluation  

International Nuclear Information System (INIS)

This Interagency Steering Committee on Radiation Standards (ISCORS) Technical Report provides a User's Guide for the RESRAD-BIOTA code. The RESRAD-BIOTA code is a tool for implementing a graded approach to biota dose evaluation. The RESRAD-BIOTA code was principally sponsored and developed by the U.S. Department of Energy (DOE), with support from the U.S. Environmental Protection Agency (EPA) and the U.S. Nuclear Regulatory Commission (NRC), through the informal interagency Ecological Radiological Work Group (ECORAD-WG). The work group was led by DOE and coordinated under the oversight of ISCORS. The RESRAD-BIOTA code provides a complete spectrum of biota dose evaluation capabilities, from methods for general screening, to comprehensive receptor-specific dose estimation. The code was designed to be consistent with and provide a tool for implementing the DOE ''Graded Approach for Evaluating Radiation Doses to Aquatic and Terrestrial Biota'' (DOE voluntary consensus Technical Standard DOE-STD-1153-2002), and to provide advanced analysis capabilities in a manner that will support the anticipated needs of DOE and other agencies. These advanced analysis capabilities were generally developed through a consensus-based process among the participating agency representatives of the ECORAD-WG

2004-01-01

110

Establishing a database of radionuclide transfer parameters for freshwater wildlife  

International Nuclear Information System (INIS)

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

2013-12-01

111

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

International Nuclear Information System (INIS)

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

2003-05-01

112

The problem of permissible doses of irradiation for biota  

Energy Technology Data Exchange (ETDEWEB)

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

Korogodin, V.I. [Joint Institute for Nuclear Research, Moscow (Russian Federation)

1995-07-01

113

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)

2008-09-01

114

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

115

Testing for evolutionary trends of Europan biota  

Science.gov (United States)

The present work was stimulated by the possibility of designing an advanced lander mission that may melt through the ice layer above the Europan ocean, in order to deploy a tethered submersible. We devote our attention to the determination of the degree of evolution of the biota, and the determination of the Europan environments that should be probed. As the most likely microorganisms in the Europa ocean are archaebacteria, we argue that evolution should have occurred, as hydrothermal vents are assumed to be present at the bottom of the ocean and such environments are known not to be refuges against evolution. We argue that a factor in interpreting the lack of uniformity in surface brightness and color of the Europan surface may be the presence of microorganisms. This hypothesis can be tested by spectroscopic search for not only the precursors of biomolecules (as has already been confirmed by the Galileo Mission in the case of Ganymede and Callisto), but a spectroscopic search should also be conducted for the biomolecules themselves, such as nucleotides, aminoacids, lipids and polysaccharides. The submersible seems to be the most appropriate means for a program in the search for extraterrestrial eukaryotes (SETE), but we also discuss SETE in the context of another proposal.

Chela-Flores, Julian

1997-07-01

116

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

International Nuclear Information System (INIS)

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

2003-10-22

117

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

118

Plant communtiy development is affected by nutrients and soil biota  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

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

2004-01-01

119

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

Science.gov (United States)

In March 2004, the Ecological Risk Assessment Forum (ERAF) submitted a request to ORDs Ecological Risk Assessment Center (ERASC) relating to the estimation of Biota-Sediment Accumulation Factors (BSAFs). BSAF is a parameter describing bioaccumulation of s...

L. Burkhard

2009-01-01

120

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

Directory of Open Access Journals (Sweden)

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

Pedro Ribeiro Piffer

2011-06-01

 
 
 
 
121

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

1981-07-31

122

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

Energy Technology Data Exchange (ETDEWEB)

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

Blaylock, B.G.; Frank, M.L.

1981-01-01

123

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

International Nuclear Information System (INIS)

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

1981-07-31

124

Approaches to estimating the transfer of radionuclides to arctic biota  

Energy Technology Data Exchange (ETDEWEB)

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 {sup 137}Cs and {sup 90}Sr 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)

Beresford, N.A.; Wright, S.M.; Barnett, C.L.; Golikov, V.; Shutov, V.; Kravtsova, O. [Centre for Ecology and Hydrology, Lancaster Environment Centre, Bailrigg, Lancaster (United Kingdom)

2004-07-01

125

Freshwater and fish  

Energy Technology Data Exchange (ETDEWEB)

Severe radioactive contamination of the freshwater environment could have serious consequences for both drinking water and fish. Most of the Nordic countries have an abundance of freshwater lakes and rivers. Finland alone has about 56,000 lakes, each with a surface area of 1 hectare or more. Nearly 10% of Finland`s surface is covered with lakes and rivers. In Sweden, about 9% of the surface area is freshwater, in Norway about 5%, and in Denmark only about 2%. Freshwater plays a minor role in Iceland, but even there numerous rivers discharge from the volcanic soils to the Ocean. Cs-137 and {sup 90}Sr are likely to be the most important radionuclides with respect to long term radioactive contamination of freshwater. If radioactive deposition occurs in the absence of snow and ice radionuclides will contaminate the surface water directly and may rapidly enter the aquatic food chain. Fish which eat contaminated plankton become contaminated almost immediately. Deposition during summer increases the transfer for radionuclides to fish since fish metabolism is faster during the warm season. During the cold period, fish metabolism is slow and thus uptake and excretion of radiocaesium are also slow. (EG). 18 refs.

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

1997-10-01

126

Freshwater and fish  

International Nuclear Information System (INIS)

Severe radioactive contamination of the freshwater environment could have serious consequences for both drinking water and fish. Most of the Nordic countries have an abundance of freshwater lakes and rivers. Finland alone has about 56,000 lakes, each with a surface area of 1 hectare or more. Nearly 10% of Finland's surface is covered with lakes and rivers. In Sweden, about 9% of the surface area is freshwater, in Norway about 5%, and in Denmark only about 2%. Freshwater plays a minor role in Iceland, but even there numerous rivers discharge from the volcanic soils to the Ocean. Cs-137 and "9"0Sr are likely to be the most important radionuclides with respect to long term radioactive contamination of freshwater. If radioactive deposition occurs in the absence of snow and ice radionuclides will contaminate the surface water directly and may rapidly enter the aquatic food chain. Fish which eat contaminated plankton become contaminated almost immediately. Deposition during summer increases the transfer for radionuclides to fish since fish metabolism is faster during the warm season. During the cold period, fish metabolism is slow and thus uptake and excretion of radiocaesium are also slow. (EG)

1997-10-01

127

Pollution due to volatile halocarbon compounds in biota  

Energy Technology Data Exchange (ETDEWEB)

In recent years, volatile halocarbon compounds (VHCs) in drinking water have elicited increasing social concern and health problems. Further, it was reported that carcinogenic and/or mutagenic effects have been induced in animals by several VHCs. These substances were also detected in biota, sediment, and human food. Several methods were developed for the determination of VHCs in these types of samples. In each case, VHCs were eventually measured by gas chromatography. One of the pretreatment techniques involves the fairly simple procedure where samples are extracted with isooctane and subsequently isolated by micro florisil column. However, this method is susceptible to low recovery. Ferrario et al. (1985) reported that ecosystems in Lake Pontchartrain were polluted based on the fact that VHCs were detected by the purge and trap method, using a pretreatment method slightly different from the ones mentioned above. Nevertheless, no report about an evaluation of the amount of pollutants in biota as human food was found. In this report, the substantially improved Daft method for VHC analysis was applied to environmental biota and sediments, and an attempt was made to clarify the cause of pollution due to VHCs in biota. Furthermore, we found several interesting phenomena concerning the movement of VHCs in biota. 8 refs., 1 fig., 3 tabs.

Gotoh, Masayuki (Ube College (Japan)); Sekitani, Yoshiko; Aramaki, Teruyo; Kobayashi, Haruo; Ogino, Keiki; Hobara, Tatsuya (Yamaguchi Univ. School of Medicine, Ube (Japan))

1992-08-01

128

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

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

2004-01-01

129

Ecodosimetry weighting factor (e{sub R}) for non-human biota  

Energy Technology Data Exchange (ETDEWEB)

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, w{sub R} 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 w{sub R} 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 'e{sub R}' for biota to fulfill a role equivalent to that occupied by w{sub R} in human radiation protection. RBE values for deterministic effects such as reproduction, fecundity and survival in biota are the critical bases for selection of e{sub R} values. These deterministic effects in populations are far more relevant to the assessment endpoints in ecological risk assessment than are stochastic effects, to which RBE values in human radiation protection relate. For tritium {beta}-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 w{sub R} of 1 to all electrons and all photons, including tritium beta-rays. Therefore, if e{sub R} 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 e{sub R} for {alpha}-emitters is not the larger, limiting value of RBE value observed at low doses, but rather a value around 5. (author)

Trivedi, A.; Gentner, N.E. [Atomic Energy of Canada Limited, Ontario (Canada)

2000-05-01

130

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)

2003-05-01

131

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

International Nuclear Information System (INIS)

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

1989-01-01

132

Biomes: Freshwater and Seawater  

Science.gov (United States)

This lesson plan is part of the DiscoverySchool.com lesson plan library for grades 6-8. Students conduct research by sampling organisms in a nearby freshwater habitat to determine how an organism's behavior and adaptation relate to its habitat, and how freshwater habitats have different characteristics depending on whether water is still or moving. Included are objectives, materials, procedures, discussion questions, evaluation ideas, suggested readings, and vocabulary. There are videos available to order which complement this lesson, an audio-enhanced vocabulary list, and links to teaching tools for making custom quizzes, worksheets, puzzles and lesson plans.

133

Radioactive radium and lead isotopes determinations in biota samples  

International Nuclear Information System (INIS)

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

2009-11-01

134

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

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

2012-01-01

135

Radiation protection of humans and biota in the environment  

Energy Technology Data Exchange (ETDEWEB)

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

Alexakhin, R.M. [Russian Inst. of Agricultural Radiology and Agroecology, Obninsk, Kaluga (Russian Federation)

2000-05-01

136

(The effects of ionizing radiation on terrestrial and freshwater organisms and ecosystems)  

Energy Technology Data Exchange (ETDEWEB)

The traveler was invited by the International Atomic Energy Agency (IAEA) to attend an Advisory Group Meeting on The Effects of Ionizing Radiation on Terrestrial and Freshwater Organisms and Ecosystems.'' The traveler and Dr. Ward F. Whicker of Colorado State University had prepared a draft document on the subject that was to be reviewed by the Advisory Group. The purpose of the document was to address the statement that by protecting humans with radiological standards, we are automatically protecting natural populations of terrestrial and aquatic organisms and ecosystems. In addition, the document was to include a review of the literature on the effects of radiation on terrestrial and aquatic organisms and populations. Recommendations of the Advisory Group were that because of the abundance of reviews and methodologies for dose calculations for aquatic biota, with a few revisions, the section on aquatic biota would be complete. For the section on terrestrial biota, the Advisory Group recommended that the literature review include results of laboratory and domestic animal studies and that the dosimetry calculations be reviewed by other experts in the field. The Scientific Secretary concluded that the document would not be completed for at least one year because of the time required to complete the review on terrestrial biota.

Blaylock, B.G.

1988-02-04

137

Final Report: Biota Survey for Devils Lake, ND., Conducted July 25-30, 2005.  

Science.gov (United States)

This biota survey was undertaken to help address recognized data gaps about aquatic biota of concern in Devils Lake, North Dakota. This effort stems from a collaborative process that involved interested jurisdictions that could be affected by the operatio...

B. Arroyo

2005-01-01

138

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

139

Assessing Exposure of Marine Biota and Habitats to Petroleum Compounds  

Science.gov (United States)

This publication, reprinted from Analytical Chemistry News & Features (March 1, 1998; pp. 186 A-192) describes methods that "accurately and rapidly measure aromatic components of oil spills in marine biota and habitats." In addition to full-text, the report includes color photographs, tables, chromatograms, and references.

140

Global satellite monitoring of spatial and temporal changes of biota  

Energy Technology Data Exchange (ETDEWEB)

Various aspects of the study of global changes of biota are examined. It is suggested that such changes can be effectively studied by combining satellite observations with ground measurements and theoretical investigations. The basic requirements concerning satellite-borne scientific payloads and observing strategies are discussed. 42 refs.

Izakov, M.N.; Zhukov, B.S. (RAN, Inst. Kosmicheskikh Issledovanii, Moscow (Russian Federation))

1992-12-01

 
 
 
 
141

Comparing Laboratory and Field Measured Biota-sediment Accumulation Factors  

Science.gov (United States)

The report presents a review of studies where biota-sediment accumulation factors (BSAFs) were measured in the field, and the same sediment samples were tested in the laboratory using sediment bioaccumulation testing protocols. The focus of this review was to document the extent...

142

Assessment of doses to biota in the river system  

Energy Technology Data Exchange (ETDEWEB)

Doses to aquatic biota in the hydrological system Techa - Ob are estimated.The following water bodies with different levels of radioactive contamination are considered: industrial reservoirs, Techa, Iset, Tobol and Irtysh Rivers. Doses to biota are calculated using the observed data on the content of radionuclides in various ennmental components, with consideration for geometric characteristics of the organisms and the exposure sources. The following groups of the river biota are considered: aquatic plants, mollusks and fish. Simplified geometric models (ellipsoids) are used in the internal dose calculations for fish and mollusks. Aquatic plants are approximated either with spheres or with a layer of finite depth. For the external doses assessment the water was considered as an infinite source with the uniform distribution of radionuclides. Sediments were represented as a source with the uniformly distributed activity. Concentration factor of scattered radiation was taken into account for gamma emitters. Sources and levels of radioactive contamination of the Techa - Ob system are analyzed. Data on the activity concentration of radionuclides in water, bottom sediments and aquatic biota are used for the dose assessment. Assessment of doses to biota in the Techa -Ob river system in the period from 1949 to the present time are performed.The highest doses (over 0.01 Gy/day) were received by aquatic organisms in the upper reaches of the Techa River in the period of maximum discharges of radionuclides (1950-1951). In that period, a major contribution to the dose to aquatic organisms was due to the incorporated radionuclides: 89 Sr, 90 Sr, 106 Ru,137 Cs, 144 Ce and others. During 1950-1951, the doses to aquatic organisms were estimated, on average, at 0.003-0.1 Gy/day. After the cessation of intensive radioactive discharges and the construction of a system of protective water bodies, the doses to aquatic biota noticeably decreased. Current levels of exposure to fish in the Techa River are estimated as 3 x 10-4 Gy/day in the upper reaches of Techa River, 6 x 10-6 Gy/day in the Techa River mouth, 9 x 10-7 Gy/day in the Iset River, 10-7 Gy/day in the Tobol River and 6 x 10-8 Gy/day in the Irtysh River; the major contributors to the doses are 90 Sr and 137 Cs. It is shown that exposure to aquatic biota noticeably decreased with distance frhe site of discharges. (authors)

Kryshev, I.; Kryshev, A.; Sazykina, T. [SPA ' Typhoon' , Obninsk (Russian Federation)

2006-07-01

143

Assessment of doses to biota in the river system  

International Nuclear Information System (INIS)

Doses to aquatic biota in the hydrological system Techa - Ob are estimated.The following water bodies with different levels of radioactive contamination are considered: industrial reservoirs, Techa, Iset, Tobol and Irtysh Rivers. Doses to biota are calculated using the observed data on the content of radionuclides in various environmental components, with consideration for geometric characteristics of the organisms and the exposure sources. The following groups of the river biota are considered: aquatic plants, mollusks and fish. Simplified geometric models (ellipsoids) are used in the internal dose calculations for fish and mollusks. Aquatic plants are approximated either with spheres or with a layer of finite depth. For the external doses assessment the water was considered as an infinite source with the uniform distribution of radionuclides. Sediments were represented as a source with the uniformly distributed activity. Concentration factor of scattered radiation was taken into account for gamma emitters. Sources and levels of radioactive contamination of the Techa - Ob system are analyzed. Data on the activity concentration of radionuclides in water, bottom sediments and aquatic biota are used for the dose assessment. Assessment of doses to biota in the Techa -Ob river system in the period from 1949 to the present time are performed.The highest doses (over 0.01 Gy/day) were received by aquatic organisms in the upper reaches of the Techa River in the period of maximum discharges of radionuclides (1950-1951). In that period, a major contribution to the dose to aquatic organisms was due to the incorporated radionuclides: 89 Sr, 90 Sr, 106 Ru,137 Cs, 144 Ce and others. During 1950-1951, the doses to aquatic organisms were estimated, on average, at 0.003-0.1 Gy/day. After the cessation of intensive radioactive discharges and the construction of a system of protective water bodies, the doses to aquatic biota noticeably decreased. Current levels of exposure to fish in the Techa River are estimated as 3 x 10-4 Gy/day in the upper reaches of Techa River, 6 x 10-6 Gy/day in the Techa River mouth, 9 x 10-7 Gy/day in the Iset River, 10-7 Gy/day in the Tobol River and 6 x 10-8 Gy/day in the Irtysh River; the major contributors to the doses are 90 Sr and 137 Cs. It is shown that exposure to aquatic biota noticeably decreased with distance from the site of discharges. (authors)

2006-05-15

144

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)

2010-05-24

145

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

146

Acidification of freshwaters  

Energy Technology Data Exchange (ETDEWEB)

This volume gives an account that draws not only on the main branches of chemistry but also on soil physics, chemistry, hydrology, meteorology, geography, geology, plant physiology, soil microbiology and zoology. The author examine the numerous interacting physical, chemical, and biological, processes that regulate the acidity of freshwaters, a phenomenon that has various causes, including precipitation; acidifying pollutions; and the interaction of plants, soils and water. The relative importance of the different processes is examined.

Cresser, M.S.; Edwards, A.C.

1987-01-01

147

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

2008-09-01

148

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

149

Determination of methylmercury in marine biota samples: Method validation.  

Science.gov (United States)

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

Carrasco, Luis; Vassileva, Emilia

2014-05-01

150

Analytical Methods for Measuring Mercury in Water, Sediment and Biota  

Energy Technology Data Exchange (ETDEWEB)

Mercury (Hg) exists in a large number of physical and chemical forms with a wide range of properties. Conversion between these different forms provides the basis for mercury's complex distribution pattern in local and global cycles and for its biological enrichment and effects. Since the 1960’s, the growing awareness of environmental mercury pollution has stimulated the development of more accurate, precise and efficient methods of determining mercury and its compounds in a wide variety of matrices. During recent years new analytical techniques have become available that have contributed significantly to the understanding of mercury chemistry in natural systems. In particular, these include ultra sensitive and specific analytical equipment and contamination-free methodologies. These improvements allow for the determination of total mercury as well as major species of mercury to be made in water, sediments and soils, and biota. Analytical methods are selected depending on the nature of the sample, the concentration levels of mercury, and what species or fraction is to be quantified. The terms “speciation” and “fractionation” in analytical chemistry were addressed by the International Union for Pure and Applied Chemistry (IUPAC) which published guidelines (Templeton et al., 2000) or recommendations for the definition of speciation analysis. "Speciation analysis is the analytical activity of identifying and/or measuring the quantities of one or more individual chemical species in a sample. The chemical species are specific forms of an element defined as to isotopic composition, electronic or oxidation state, and/or complex or molecular structure. The speciation of an element is the distribution of an element amongst defined chemical species in a system. In case that it is not possible to determine the concentration of the different individual chemical species that sum up the total concentration of an element in a given matrix, meaning it is impossible to determine the speciation, it is a useful practice to do fractionation instead. Fractionation is the process of classification of an analyte or a group of analytes from a certain sample according to physical (e.g. size, solubility) or chemical (e.g. bonding, reactivity) properties."

Lasorsa, Brenda K.; Gill, Gary A.; Horvat, Milena

2012-06-07

151

Invasive alien freshwater snail species in the Kruger National Park, South Africa  

Digital Repository Infrastructure Vision for European Research (DRIVER)

An account is given of all invasive alien freshwater snail species samples found in the Kruger National Park currently on record in the National Freshwater Snail Collection(NFSC) database. This report mainly focuses on samples collected during surveys of selected water bodies in the Kruger National Park (KNP) during 1964, 1995, 2001 and 2006. The progress made by four alien invasive freshwater snail species, Lymnaea columella, Physa acuta, Aplexa marmorata and T...

Kock, Kenne? N.; Wolmarans, Cornelius T.

2008-01-01

152

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

153

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

International Nuclear Information System (INIS)

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

2009-01-01

154

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

155

Robust monomer-distribution biosignatures in evolving digital biota  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Because organisms synthesize component molecules at rates that reflect those molecules' adaptive utility, we expect a population of biota to leave a distinctive chemical signature on their environment that is anomalous given the local (abiotic) chemistry. We observe the same effect in the distribution of computer instructions used by an evolving population of digital organisms, and characterize the robustness of the evolved signature with respect to a number of different cha...

Dorn, Evan D.; Adami, Christoph

2011-01-01

156

Functionally and phylogenetically diverse plant communities key to soil biota  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Recent studies assessing the role of biological diversity for ecosystem functioning indicate that the diversity of functional traits and the evolutionary history of species in a community, not the number of taxonomic units, ultimately drives the biodiversity–ecosystem-function relationship. Here, we simultaneously assessed the importance of plant functional trait and phylogenetic diversity as predictors of major trophic groups of soil biota (abundance and diversity), six years from the onse...

2013-01-01

157

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 < 0.1 Sv helps to maintain the Atlantic-Pacific salinity difference. However, proportionally large variations in the small Bering Strait transport can only marginally impact NADW salinity, whose freshening relative to saline surface water is mainly due to air-sea/runoff fluxes in the subpolar North Atlantic and Arctic. In contrast, Bering Strait freshwater export has proportionally much greater impact on North Pacific salinity balances, including NPIW salinity, because the Pacific has a much smaller overturning rate than the Atlantic.

Talley, L.

2008-12-01

158

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

159

Soil biota reduce allelopathic effects of the invasive Eupatorium adenophorum.  

Science.gov (United States)

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

Zhu, Xunzhi; Zhang, Jintun; Ma, Keping

2011-01-01

160

Radionuclides in air, water, and biota  

International Nuclear Information System (INIS)

Air, water, and biological samples collected before and after the 1965, 1969, and 1971 underground nuclear detonations at Amchitka Island were analyzed for natural and fallout radionuclides by gamma spectrometry. Selected samples were also analyzed for tritium, 55Fe, and 90Sr. The objectives were to search for and identify radionuclides of Amchitka origin in the samples and to contribute to the general knowledge of the distribution of radionuclides in the environment. The studies showed that there has been no escape of radionuclides from the underground sites of the three nuclear detonations at Amchitka Island except for trace quantities of radionuclides, principally tritium, in water and soil gas samples from the immediate vicinity of the surface ground zero for the 1965 event. Two naturally occurring radionuclides, 40K and 7Be, were the most abundant radionuclides in the samples, usually by a factor of 10 or more, except for 137Cs in lichen samples. All levels were well below applicable Radiation Protction Guides, often being near the statistical limit of detection

1977-09-01

 
 
 
 
161

United Nations Environment Programme: Freshwater  

Science.gov (United States)

This portal provides access to information on equitable and sustainable management of freshwater resources around the world. Topics include water scarcity, irrigated agriculture, water and sanitation, water quality, groundwater, transboundary water management, water and ecosystems, floods and droughts, and urban water. There are also case studies, global assessments of freshwater resources, policy documents, and information on conferences and other events.

162

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

International Nuclear Information System (INIS)

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

2003-05-01

163

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

2005-01-01

164

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

2004-01-01

165

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

Energy Technology Data Exchange (ETDEWEB)

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.

Chambers, D. B.; Muller, E.; Saint-Pierre, S.; Le bar, S.

2004-07-01

166

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...

2000-01-01

167

Choosing a Weighting Factor for Doses to Biota from Alpha Particles  

International Nuclear Information System (INIS)

The potential risks to non-human biota from exposure to ionizing radiation is an area of considerable current interest, both in Canada and internationally. It is well known that the effects of exposure to ionizing radiation depend not only on the physical quantity absorbed dose, appropriately averaged over a relevant target volume, but also on the type of radiation. It is common to multiply the absorbed dose of a particular type of radiation by a factor to account for the relative biological effectiveness (RBE) of the radiation type. for non-human biota, this factor has also been referred to as an eco dosimetric weighting factor or more simple, the radiation weighting factor. There have been many experimental studies of the RBE of doses from internally deposited alpha emitters for a variety of effects and organisms. Estimated values of RBE range over two orders of magnitude. Selection of the most appropriate value (or values) to apply as a radiation weighting factor is very judgmental and, not too surprisingly, different reviewers have made different selections. currently recommended values range from 5 to 50. This paper reports, on a review of relevant published literature discussing experimental RBE data for internally deposited alpha emitting radionuclides. However, rather than simply adding to that plethora of reviews, we first attempt here to lay out the questions that might be asked during and assessment of the data from experimental studies before coming to our own conclusions. In the end, some 66 relevant papers were identified and reviewed. Recommendations for alpha radiation weighting factors are provided. (Author) 26 Refs

2004-01-01

168

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

International Nuclear Information System (INIS)

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

1977-06-01

169

User's guide, version 1 RESRAD-BIOTA : a tool for implementing a graded approach to biota dose evaluation.  

Energy Technology Data Exchange (ETDEWEB)

This Interagency Steering Committee on Radiation Standards (ISCORS) Technical Report provides a User's Guide for the RESRAD-BIOTA code. The RESRAD-BIOTA code is a tool for implementing a graded approach to biota dose evaluation. The RESRAD-BIOTA code was principally sponsored and developed by the U.S. Department of Energy (DOE), with support from the U.S. Environmental Protection Agency (EPA) and the U.S. Nuclear Regulatory Commission (NRC), through the informal interagency Ecological Radiological Work Group (ECORAD-WG). The work group was led by DOE and coordinated under the oversight of ISCORS. The RESRAD-BIOTA code provides a complete spectrum of biota dose evaluation capabilities, from methods for general screening, to comprehensive receptor-specific dose estimation. The code was designed to be consistent with and provide a tool for implementing the DOE ''Graded Approach for Evaluating Radiation Doses to Aquatic and Terrestrial Biota'' (DOE voluntary consensus Technical Standard DOE-STD-1153-2002), and to provide advanced analysis capabilities in a manner that will support the anticipated needs of DOE and other agencies. These advanced analysis capabilities were generally developed through a consensus-based process among the participating agency representatives of the ECORAD-WG.

NONE

2004-01-14

170

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.

Gaines, Robert R.; Droser, Mary L.

2012-01-01

171

Effect of oil on salt marsh biota: methods for restoration  

Energy Technology Data Exchange (ETDEWEB)

South Louisiana crude was applied to replicated plots in a Louisiana Spartina alterniflora salt marsh. Various marsh restoration methods were evaluated for mitigating the impact of crude oil on the marsh biota. Oiling the marsh caused no reduction in macrophyte production as compared with the non-oiled plots. Thus the cleanup treatment showed no beneficial effects to S. alterniflora. Likewise, there was no oil-induced mortality for the marsh macrofauna or meiofauna. In Louisiana Gulf Coast salt marshes, which have a low sensitivity to oil as shown in this study, the best response is no cleanup action at all. 37 references, 8 figures, 5 tables.

DeLaune, R.D.; Smith, C.J.; Patrick, W.H. Jr.; Fleeger, J.W.; Tolley, M.D.

1984-01-01

172

Anthropogenic radionuclides in biota samples from the Caspian Sea  

International Nuclear Information System (INIS)

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

2004-10-25

173

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

2003-04-01

174

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

175

Extensive Behavioural Divergence following Colonisation of the Freshwater Environment in Threespine Sticklebacks  

Science.gov (United States)

Colonisation of novel environments means facing new ecological challenges often resulting in the evolution of striking divergence in phenotypes. However, little is known about behavioural divergence following colonisation, despite the predicted importance of the role of behavioural phenotype-environment associations in adaptive divergence. We studied the threespine stickleback (Gasterosteus aculeatus), a model system for postglacial colonisation of freshwater habitats largely differing in ecological conditions from the ones faced by the descendants of the marine ancestor. We found that common-environment reared freshwater juveniles were less social, more active and more aggressive than their marine counterparts. This behavioural divergence could represent the result of natural selection that acted on individuals following freshwater colonisation, with predation as a key selection agent. Alternatively, the behavioural profile of freshwater juveniles could represent the characteristics of individuals that preferentially invaded freshwater after the glacial retreat, drawn from the standing variation present in the marine population.

Di-Poi, Carole; Lacasse, Jennyfer; Rogers, Sean M.; Aubin-Horth, Nadia

2014-01-01

176

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.

2012-06-01

177

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

178

Nearctic freshwater tardigrades: a review  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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, groundwa...

Mcfatter, Mitchell M.; Meyer, Harry A.; Hinton, Juliana G.

2007-01-01

179

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

2011-01-01

180

Interactions between marine biota and ENSO: a conceptual model analysis  

Directory of Open Access Journals (Sweden)

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

 
 
 
 
181

Impact of Drainage Channel Improvement Works on Fish Biota  

Science.gov (United States)

Impact of concrete lining of channel bed with eco-friendly works, i.e. fish pools and fish habitat blocks on fish biota in Ooe drainage channel is discussed based on the ecological, hydraulic and water quality investigations from 2003 through 2007. The effectiveness of these eco-friendly technologies is also evaluated. As a result, the followings become apparent; 1) Several species which are suitable for improved channels, especially in their spawning, e.g. Pseudorasbora parva, Gambusia affinis affinis, Squalidus chankaensis sp. and Rhinogobius sp. tend to increase relatively and the species e.g. Oryzias latipes and Channa argus decrease oppositely. 2) Fish biota settles down to a certain level after 3 or 4 years after improvement of channel. 3) Fish show their preference to eco-friendly technologies like fish habitat block and fish pool and also utilize them as their habitat during non irrigation period, and 4) the total number of fish tends to somewhat decrease at large, but the number of species tends to increase contrarily in the channel through improvement with eco-friendly works.

Hiramatsu, Ken; Nishimura, Shinichi; Shimizu, Hideyoshi; Nakane, Yoshinobu; Ichion, Eiji

182

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)

2010-05-01

183

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)

2008-10-19

184

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

International Nuclear Information System (INIS)

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

1993-04-01

185

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

186

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

International Nuclear Information System (INIS)

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

2011-01-01

187

Radiation protection of natural ecosystems: Primary and secondary dose limits to biota  

Energy Technology Data Exchange (ETDEWEB)

A methodological approach is proposed for developing criteria for the radiation protection of natural ecosystems, based on establishing the general (primary) and site-specific (secondary) limits of chronic radiation dose rates to biota. The screening procedure is described for the radiation protection of biota on the territories with the increased levels of radioactive contamination 9 refs.

Sazykina, T.G.; Kryshev, I.I. [Scientific and Production Association `TYPHOON`, Obninsk (Russian Federation)

1999-04-01

188

Population Dynamics of Biota on the Roots of Azolla microphylla Kaulfuss  

Directory of Open Access Journals (Sweden)

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

189

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

Science.gov (United States)

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

190

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

191

Temporal and spatial variation in landscape connectivity for a freshwater turtle in a temporally dynamic wetland system.  

Science.gov (United States)

Inter-wetland connectivity, defined here as the movement of biota among discrete water bodies, can have important population- and community-level consequences in aquatic systems. We examined inter-wetland connectivity in a southeastern Australian national park by intensively monitoring the movements of freshwater turtles (Chelodina longicollis) via capture-mark-recapture over a three-year period, and more sporadically for 25 years. A high percentage (33%) of turtles moved between wetlands, suggesting that single wetlands should not represent the minimum habitat unit harboring a C. longicollis population. Distance was the only structural landscape metric correlated with inter-patch transition probability, with probability declining as inter-wetland distance increased. Movements also appear to be strongly influenced by shifting resource quality gradients between temporary wetlands and permanent lakes according to drought and flood cycles, a pattern more consistent with migration between critical resource patches than occasional interpopulational dispersal. Rare dispersal events of up to 5.2 km were known to occur. Captures at a terrestrial drift fence suggest that small and immature turtles moved between wetlands more frequently than our aquatic sampling indicated. We caution that measures of actual (or functional) connectivity can be biased by sampling methods and the temporal scale of sampling and must also be interpreted in the context of factors that motivate animal movements. This requires some understanding of spatial and temporal variation in intra-patch processes (e.g., quality and extent) and the expected movement responses of animals (e.g., habitat selection) over extended time frames, information that can potentially yield more important insight on connectivity than measures of landscape structural features alone. PMID:19688935

Roe, John H; Brinton, Alicia C; Georges, Arthur

2009-07-01

192

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

193

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.

194

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  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 po...

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

2008-01-01

195

Freshwater Ecology. LC Science Tracer Bullet.  

Science.gov (United States)

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

Niskern, Diana, Comp.

196

Inhabitants of the Fresh-Water Community.  

Science.gov (United States)

This learner's guide is designed to assist middle school students in studying freshwater organisms. Following a brief introduction to freshwater ecology, simple line drawings facilitate the identification of plants and animals common to Florida's freshwater ecosystems. Emphasis of the short text which accompanies each illustration is upon the…

Jorgensen, Joseph; Schroeder, Marlene

197

Incipient toxicity of lithium to freshwater organisms representing a salmonid habitat  

International Nuclear Information System (INIS)

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

1981-01-01

198

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2003-04-01

199

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

International Nuclear Information System (INIS)

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

2003-04-01

200

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

Science.gov (United States)

Background The formation of the East African Rift System has decisively influenced the distribution and evolution of tropical Africa’s biota by altering climate conditions, by creating basins for large long-lived lakes, and by affecting the catchment and drainage directions of river systems. However, it remains unclear how rifting affected the biogeographical patterns of freshwater biota through time on a continental scale, which is further complicated by the scarcity of molecular data from the largest African river system, the Congo. Results We study these biogeographical patterns using a fossil-calibrated multi-locus phylogeny of the gastropod family Viviparidae. This group allows reconstructing drainage patterns exceptionally well because it disperses very poorly in the absence of existing freshwater connections. Our phylogeny covers localities from major drainage basins of tropical Africa and reveals highly disjunct sister-group relationships between (a) the endemic viviparids of Lake Malawi and populations from the Middle Congo as well as between (b) the Victoria region and the Okavango/Upper Zambezi area. Conclusions The current study testifies to repeated disruptions of the distribution of the Viviparidae during the formation of the East African Rift System, and to a central role of the Congo River system for the distribution of the continent’s freshwater fauna during the late Cenozoic. By integrating our results with previous findings on palaeohydrographical connections, we provide a spatially and temporarily explicit model of historical freshwater biogeography in tropical Africa. Finally, we review similarities and differences in patterns of vertebrate and invertebrate dispersal. Amongst others we argue that the closest relatives of present day viviparids in Lake Malawi are living in the Middle Congo River, thus shedding new light on the origin of the endemic fauna of this rift lake.

2014-01-01

 
 
 
 
201

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

International Nuclear Information System (INIS)

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

2005-12-01

202

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2005-12-01

203

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

204

Magnetite in freshwater magnetotactic bacteria.  

Science.gov (United States)

A previously undescribed magnetotactic spirillum isolated from a freshwater swamp was mass cultured in the magnetic as well as the nonmagnetic state in chemically defined culture media. Results of Mossbauer spectroscopic analysis applied to whole cells identifies magnetite as a constituent of these magnetic bacteria. PMID:17780480

Frankel, R B; Blakemore, R P; Wolfe, R S

1979-03-30

205

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

206

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

207

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

International Nuclear Information System (INIS)

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

2003-05-01

208

Background and anthropogenic radionuclide derived dose rates to freshwater ecosystem - Nuclear power plant cooling pond - Reference organisms  

Energy Technology Data Exchange (ETDEWEB)

The radiological assessment of non-human biota to demonstrate protection is now accepted by a number of international and national bodies. Therefore, it is necessary to develop a scientific basis to assess and evaluate exposure of biota to ionizing radiation. Radionuclides from the Ignalina Nuclear Power Plant (Lithuania) were discharged into Lake Druksiai cooling pond. Additional radionuclide migration and recharge to this lake from a hypothetical near-surface, low-level radioactive waste disposal, to be situated 1.5 km from the lake, had been simulated using RESRAD-OFFSITE code. This paper uses ERICA Integrated Approach with associated tools and databases to compare the radiological dose to freshwater reference organisms. Based on these data, it can be concluded that background dose rates to non-human biota in Lake Druksiai far exceed those attributable to anthropogenic radionuclides. With respect the fishery and corresponding annual committed effective human dose as a result of this fish consumption Lake Druksiai continues to be a high-productivity water body with intensive angling and possible commercial fishing. - Highlights: > Dose rates to the reference organisms are lower than expected from the background radioactivity. > Pelagic fish part of adult human annual committed effective dose would be as small as a few {mu}Sv y{sup -1}. > With respect the fishery Lake Druksiai continues to be a high-productivity water body.

Nedveckaite, T., E-mail: tatjana@cablenet.lt [Institute of Physics of the Center of Physical Science and Technology, Savanoriu av, 231, LT-02300, Vilnius (Lithuania); Filistovic, V. [Institute of Physics of the Center of Physical Science and Technology, Savanoriu av, 231, LT-02300, Vilnius (Lithuania); Marciulioniene, D. [Institute of Botany, Zaliuju ezeru 49, LT-08406, Vilnius (Lithuania); Prokoptchuk, N.; Plukiene, R.; Gudelis, A.; Remeikis, V. [Institute of Physics of the Center of Physical Science and Technology, Savanoriu av, 231, LT-02300, Vilnius (Lithuania); Yankovich, T. [AREVA Resources Canada Inc., P.O. Box 9204, 817-45th Street West, Saskatoon, SK S7K 3X5 (Canada); Beresford, N.-A. [Centre for Ecology and Hydrology, Lancaster Environment Centre, Library Av., Bailrigg, Lancaster, LA1 4AP (United Kingdom)

2011-08-15

209

Background and anthropogenic radionuclide derived dose rates to freshwater ecosystem: nuclear power plant cooling pond: reference organisms.  

Science.gov (United States)

The radiological assessment of non-human biota to demonstrate protection is now accepted by a number of international and national bodies. Therefore, it is necessary to develop a scientific basis to assess and evaluate exposure of biota to ionizing radiation. Radionuclides from the Ignalina Nuclear Power Plant (Lithuania) were discharged into Lake Druksiai cooling pond. Additional radionuclide migration and recharge to this lake from a hypothetical near-surface, low-level radioactive waste disposal, to be situated 1.5 km from the lake, had been simulated using RESRAD-OFFSITE code. This paper uses ERICA Integrated Approach with associated tools and databases to compare the radiological dose to freshwater reference organisms. Based on these data, it can be concluded that background dose rates to non-human biota in Lake Druksiai far exceed those attributable to anthropogenic radionuclides. With respect the fishery and corresponding annual committed effective human dose as a result of this fish consumption Lake Druksiai continues to be a high-productivity water body with intensive angling and possible commercial fishing. PMID:21601320

Nedveckaite, T; Filistovic, V; Marciulioniene, D; Prokoptchuk, N; Plukiene, R; Gudelis, A; Remeikis, V; Yankovich, T; Beresford, N-A

2011-08-01

210

Background and anthropogenic radionuclide derived dose rates to freshwater ecosystem - Nuclear power plant cooling pond - Reference organisms  

International Nuclear Information System (INIS)

The radiological assessment of non-human biota to demonstrate protection is now accepted by a number of international and national bodies. Therefore, it is necessary to develop a scientific basis to assess and evaluate exposure of biota to ionizing radiation. Radionuclides from the Ignalina Nuclear Power Plant (Lithuania) were discharged into Lake Druksiai cooling pond. Additional radionuclide migration and recharge to this lake from a hypothetical near-surface, low-level radioactive waste disposal, to be situated 1.5 km from the lake, had been simulated using RESRAD-OFFSITE code. This paper uses ERICA Integrated Approach with associated tools and databases to compare the radiological dose to freshwater reference organisms. Based on these data, it can be concluded that background dose rates to non-human biota in Lake Druksiai far exceed those attributable to anthropogenic radionuclides. With respect the fishery and corresponding annual committed effective human dose as a result of this fish consumption Lake Druksiai continues to be a high-productivity water body with intensive angling and possible commercial fishing. - Highlights: ? Dose rates to the reference organisms are lower than expected from the background radioactivity. ? Pelagic fish part of adult human annual committed effective dose would be as small as a few ?Sv y-1. ? With respect the fishery Lake Druksiai continues to be a high-productivity water body.

2011-08-01

211

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

Directory of Open Access Journals (Sweden)

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

212

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

2001-01-01

213

Differential concentration of plutonium isotopes in Rocky Flats Biota  

International Nuclear Information System (INIS)

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

1978-12-01

214

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

Macoma biota Arruda & Domaneschi, 2005, is a recently described species known only from the intertidal zone of Praia da Cidade, Caraguatatuba Bay, in the state of São Paulo, southeastern Brazil. The main purpose of the present paper is to describe the biology of M. biota, beginning with a detailed analysis of its anatomy and functional morphology and how these attributes are correlated with its habitat and life history. The morphology of the organs in the pallial cavity and their sorting dev...

Pedro Ribeiro Piffer; Eliane Pintor de Arruda; Flávio Dias Passos

2011-01-01

215

Soil biota community structure and abundance under agricultural intensification and extensification  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

Postma-blaauw, M. B.; Goede, R. G. M.; Bloem, J.; Faber, J. H.; Brussaard, L.

2010-01-01

216

Dissimilar response of plant and soil biota communities to long-term nutrient adition in grasslands  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The long-term effect of fertilizers on plant diversity and productivity is well known, but long-term effects on soil biota communities have received relatively little attention. Here, we used an exceptional long-lasting (>40 years) grassland fertilization experiment to investigate the long-term effect of Ca, N, PK, and NPK addition on the productivity and diversity of both vegetation and soil biota. Whereas plant diversity increased by liming and decreased by N and NPK, the diversity of nemat...

Wal, A.; Geerts, R. H. E. M.; Korevaar, H.; Schouten, A. J.; Jagers Op Akkerhuis, G. A. J. M.; Rutgers, M.; Mulder, C.

2009-01-01

217

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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, cr...

Candeiro, C. R. A.

2007-01-01

218

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 ac...

Defossez, Emmanuel; Courbaud, Benoi?t; Marcais, Benoi?t; Thuiller, Wilfried; Granda, Elena; Kunstler, Georges

2011-01-01

219

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

Directory of Open Access Journals (Sweden)

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

Katherin Maritza Vanegas Berrouet

2011-12-01

220

Determination of polybrominated diphenyl ethers in freshwater fishes from a river polluted by e-wastes.  

Science.gov (United States)

Analytical method using mass spectrometric techniques was applied for the determination of polybrominated diphenyl ethers (PBDEs) in freshwater fishes. Fish samples collected from Nanyang River contaminated by the recycling electron-wastes (e-wastes) materials were prepared by using Soxhlet extraction and multiple-step column chromatographic clean-up. PBDEs were determined by gas chromatography (GC) coupled with ion trap mass spectrometry (for mono- to hepta-BDEs) and quadrupole mass spectrometry (for BDE-209). The method performance was evaluated with the recovery of (13)C-labeled internal standards and with the analysis of certified reference biota. The obtained recoveries ranged from 75 to 125% with a relative standard deviation of lower than 10% for 16 PBDE congeners. The total PBDE (SigmaPBDE) concentrations in fishes showed the following trend: grass carpGuiyu. PMID:19071810

Luo, Qian; Wong, Minghung; Cai, Zongwei

2007-07-31

 
 
 
 
221

Changing Arctic Ocean freshwater pathways.  

Science.gov (United States)

Freshening in the Canada basin of the Arctic Ocean began in the 1990s and continued to at least the end of 2008. By then, the Arctic Ocean might have gained four times as much fresh water as comprised the Great Salinity Anomaly of the 1970s, raising the spectre of slowing global ocean circulation. Freshening has been attributed to increased sea ice melting and contributions from runoff, but a leading explanation has been a strengthening of the Beaufort High--a characteristic peak in sea level atmospheric pressure--which tends to accelerate an anticyclonic (clockwise) wind pattern causing convergence of fresh surface water. Limited observations have made this explanation difficult to verify, and observations of increasing freshwater content under a weakened Beaufort High suggest that other factors must be affecting freshwater content. Here we use observations to show that during a time of record reductions in ice extent from 2005 to 2008, the dominant freshwater content changes were an increase in the Canada basin balanced by a decrease in the Eurasian basin. Observations are drawn from satellite data (sea surface height and ocean-bottom pressure) and in situ data. The freshwater changes were due to a cyclonic (anticlockwise) shift in the ocean pathway of Eurasian runoff forced by strengthening of the west-to-east Northern Hemisphere atmospheric circulation characterized by an increased Arctic Oscillation index. Our results confirm that runoff is an important influence on the Arctic Ocean and establish that the spatial and temporal manifestations of the runoff pathways are modulated by the Arctic Oscillation, rather than the strength of the wind-driven Beaufort Gyre circulation. PMID:22222749

Morison, James; Kwok, Ron; Peralta-Ferriz, Cecilia; Alkire, Matt; Rigor, Ignatius; Andersen, Roger; Steele, Mike

2012-01-01

222

Natural radioactivity in some specimens of the marine biota  

International Nuclear Information System (INIS)

Marine environment contamination by natural radionuclides (uranium and "2"3"8U daughters) is evaluated using marine -fauna and flora elements concentrating fission - and radioactivated products released by nuclear facilities. Total alpha and beta radiometry is done in the the biota to determine the radionuclide concentration. Uranium, "2"2"6Ra and "2"1"0PO assay is done to estimate their contribution to natural radioactivity in the chosen biological indicators. Several analytical techniques required by each radionuclide are used. Potassium assay is done to evaluate the contribution of "4"0K to the natural radioactivity, and calcium assay to determine Ra/Ca and U/Ca ratios in the samples. For total alpha radiometry in algae the higher average value is detected in Phaeophyta (84.1 pCi/kg fresh weight); maximum concentration in animals is registered in Bunodosoma caissarum (43.1 pCi/kg fresh weight). For algae, the higher average total beta radiometry detected is in Chlorophyta (6.9 nCi/kg fresh weight); the maximum value found in animals refers to Thais Haemastoma (7.54 nCi/kg fresh weight). Potassium higher average ratio for algae occurs in Chlorophyta (12.77% ashes); for animals, the maximum value is found in Bunodosoma caissarum (13.80% ashes). The uranium concentration factor is maximum in Perna perna bissus (684) while the minimum is registered in Thais haemastoma and Sargassum vulgare (44). The "2"2"6Ra concentration factor is maximum in Sargassum vulgare (2143) and minimum in Bunodosoma caissarum (32). Maximum average ratio for "2"1"0PO in algae occurs in Phaephyta (11.5 pCi/g dry weight) and the maximum concentration for animals in Perna perna (31.5 pCi/g dry weight). The techniques employed proved to be efficient for the objectives aimed at. (Author)

1980-01-01

223

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

224

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)

2003-05-01

225

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

226

Adiciones a la Biota de Uredinales (fungi) de Colombia / Addictions to the Uredinales Biota (fungi) in Colombia  

Scientific Electronic Library Online (English)

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

Katherin Maritza, Vanegas Berrouet; Mauricio, Salazar Yepes.

227

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)

2008-07-16

228

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

International Nuclear Information System (INIS)

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

2003-05-01

229

Significance of the air pathway in contributing radiation dose to biota  

International Nuclear Information System (INIS)

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

2003-05-01

230

Contamination of estaurine water, biota, and sediment by halogenated organic compounds: a field study  

Energy Technology Data Exchange (ETDEWEB)

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 and bottom sediment increased with increasing octanol/estuarine water partition coefficients (K/sub ow*/), maximizing at log K/sub ow*/ 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 (K/sub tw/).

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

1988-07-01

231

Toxicity of soil iodine to terrestrial biota, with implications for {sup 129}I  

Energy Technology Data Exchange (ETDEWEB)

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

Sheppard, S.C.; Evenden, W.G. [Atomic Energy of Canada Ltd., Pinawa, MB (Canada). Whiteshell Labs.

1995-08-01

232

Toxicity of soil iodine to terrestrial biota, with implications for "1"2"9I  

International Nuclear Information System (INIS)

The environmental impact of "1"2"9I has traditionally been assessed by its radiological effects on human health; however, protection of human health does not ensure protection of other biota. Because of the very long half-life of "1"2"9I, there is a relatively high molar concentration of I associated with any specified level of radioactivity. The potential exists for chemical toxicity to non-human biota to exceed radiological toxicity in importance. The authors reviewed the literature and conducted laboratory bioassays to obtain information on the chemical toxicity of inorganic I to terrestrial biota. Levels as low as 5 mg I kg"-"1 soil may have detrimental effects. If this were as "1"2"9I, the corresponding radiological effects to non-human biota may not be as important as the chemical toxicity. However, because of the very low risk factor applied to protect humans, levels of "1"2"9I in the environment acceptable for human health appear to be acceptable for other biota at the higher risk levels commonly used for them. (author)

1995-01-01

233

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

234

Plutonium and americium concentration along fresh-water food chains of the Great Lakes, U.S.A. Progress report, July 1976--September 30, 1977  

International Nuclear Information System (INIS)

The primary purpose of studying the biogeochemical behavior of transuranic radionuclides in large freshwater lakes began with studies of the distribution of these radionuclides, essentially introduced from the fallout of atmospheric nuclear weapons tests, in Lake Ontario. The recognition that an additional source of supply of these nuclides to Lake Ontario (subsequent to their release into Lake Erie) existed in the form of leakage from the Nuclear Fuel Services reprocessing plant at Springville, New York, led to expansion of the program to include sampling at the eastern end of Lake Erie. Much of the program is devoted to studies of the distribution of these nuclides in the lake sediments as they appear to be a major repository for transuranics in freshwater lakes. The extent to which this is a temporary or permanent repository is illuminated by studies of transuranic distributions in the lake waters and biota

1977-01-01

235

Freshwater Scarcity in the Nile River Basin.  

Science.gov (United States)

According to a growing body of literature, scarcity of freshwater to meet the many needs of Third World countries is rapidly escalating. Furthermore, many of the remaining exploitable sources of freshwater are in river basins shared by two or more soverei...

K. F. Ubbelohde

2000-01-01

236

Environmental assessment for Bruce Restart: calculating doses to non-human biota  

International Nuclear Information System (INIS)

An environmental assessment of returning Units 1 and 2 of Bruce A nuclear generating station to service from their temporary lay-up was carried out in 2005 and should be completed by mid-2006. It included an assessment of effects of environmental concentrations of radionuclides on aquatic and terrestrial biota. A method of assessing doses to individual species of biota using data available for reference organisms was applied to conduct this assessment. This method is consistent with the draft proposals published by ICRP in November 2005. Even though the regulatory bodies and scientific community have not achieved a full consensus on the regulatory limits on, or methodology for assessing doses to, biota, this paper demonstrates that a practical approach based on most recent research can be used successfully for the purposes of environmental assessments. (author)

2006-06-11

237

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

238

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)

2013-12-01

239

K-BIOTA: A Computer Program for Assessing Radiation Doses to Non-human Species  

Energy Technology Data Exchange (ETDEWEB)

Recently, the Internal Commission on Radiological Protection (ICRP) stressed the importance of the environmental protection from the ionizing radiation and subsequently proposed the reference animal and plant (RAPs) concept, and the methodology to evaluate non-human species radiation dose. In order to apply an integrated methodology of addressing the international recent issue for the protection of the environment from the ionizing radiation to the Korean ecological environment, the K-BIOTA, a computer program for assessing radiation doses to non-human species, is presently being developed. This paper describes the components and methodologies that are considered in the K-BIOTA

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

2010-05-15

240

K-BIOTA: A Computer Program for Assessing Radiation Doses to Non-human Species  

International Nuclear Information System (INIS)

Recently, the Internal Commission on Radiological Protection (ICRP) stressed the importance of the environmental protection from the ionizing radiation and subsequently proposed the reference animal and plant (RAPs) concept, and the methodology to evaluate non-human species radiation dose. In order to apply an integrated methodology of addressing the international recent issue for the protection of the environment from the ionizing radiation to the Korean ecological environment, the K-BIOTA, a computer program for assessing radiation doses to non-human species, is presently being developed. This paper describes the components and methodologies that are considered in the K-BIOTA

2010-05-01

 
 
 
 
241

Potential kinetic availability of metals in sulphidic freshwater sediments  

Energy Technology Data Exchange (ETDEWEB)

The insolubility of metal sulphides is believed to limit the bioavailability of trace metals in sulphidic sediments. However, if non-equilibrium conditions are important, metals may be more available than simple thermodynamic calculations suggest. To investigate the possible dynamic supply of Cu, Ni and Zn in a sulphidic freshwater sediment, they were measured, along with iron, manganese and sulphide, by the technique of diffusive gradients in thin-films (DGT). DGT measures the supply of solute from sediment to solution in response to a local solute sink. Release of Mn, Cu, Zn and Ni was observed at the sediment surface and attributed to the supply from reductive dissolution of manganese oxides. The depth profile of simultaneously extractable metals (SEM) for Cu and Ni followed the shape of the Mn profile more closely than the profiles of either acid volatile sulphur (AVS) or Fe, again consistent with supply from Mn oxides. Solubility calculations for a mesocosm of homogenised sediment indicated supersaturation with respect to the sulphides of Fe, Cu, Ni and Zn, yet DGT measurements demonstrated a substantial supply of both trace metals and sulphide from the solid phase to the pore waters. Ratios of metals measured in pore waters by DGT were consistent with their release from iron and manganese oxides, indicating that supply, as much as removal processes, determines the pseudo-steady state concentrations in the pore waters. The observations suggest that trace metals are not immediately bound in an insoluble, inert form when they are in contact with sulphide. This has consequences for modelling metal processes in sediment, as well as for uptake by some biota.

Naylor, C. [IENS, ES, Lancaster University, Lancaster LA1 4YQ (United Kingdom); Davison, W. [IENS, ES, Lancaster University, Lancaster LA1 4YQ (United Kingdom)]. E-mail: w.davison@lancaster.ac.uk; Motelica-Heino, M. [IENS, ES, Lancaster University, Lancaster LA1 4YQ (United Kingdom); Berg, G.A. van den [KIWA Water Research, P.O. Box 1072, 3430 BB Nieuwegein (Netherlands); Heijdt, L.M. van der [Ministry of Transport, Public Works and Water Management, Water Management Inspectorate, P.O. Box 61, 8200 AB Lelystad (Netherlands)

2006-03-15

242

Potential kinetic availability of metals in sulphidic freshwater sediments  

International Nuclear Information System (INIS)

The insolubility of metal sulphides is believed to limit the bioavailability of trace metals in sulphidic sediments. However, if non-equilibrium conditions are important, metals may be more available than simple thermodynamic calculations suggest. To investigate the possible dynamic supply of Cu, Ni and Zn in a sulphidic freshwater sediment, they were measured, along with iron, manganese and sulphide, by the technique of diffusive gradients in thin-films (DGT). DGT measures the supply of solute from sediment to solution in response to a local solute sink. Release of Mn, Cu, Zn and Ni was observed at the sediment surface and attributed to the supply from reductive dissolution of manganese oxides. The depth profile of simultaneously extractable metals (SEM) for Cu and Ni followed the shape of the Mn profile more closely than the profiles of either acid volatile sulphur (AVS) or Fe, again consistent with supply from Mn oxides. Solubility calculations for a mesocosm of homogenised sediment indicated supersaturation with respect to the sulphides of Fe, Cu, Ni and Zn, yet DGT measurements demonstrated a substantial supply of both trace metals and sulphide from the solid phase to the pore waters. Ratios of metals measured in pore waters by DGT were consistent with their release from iron and manganese oxides, indicating that supply, as much as removal processes, determines the pseudo-steady state concentrations in the pore waters. The observations suggest that trace metals are not immediately bound in an insoluble, inert form when they are in contact with sulphide. This has consequences for modelling metal processes in sediment, as well as for uptake by some biota

2006-03-15

243

The freshwater reservoir effect in radiocarbon dating  

DEFF Research Database (Denmark)

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

Philippsen, Bente

2014-01-01

244

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...

245

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)

2008-09-01

246

Concentration factors 226Ra, 210Pb and 90Sr in the biota of the Sava river  

International Nuclear Information System (INIS)

This work presents the results of identification of the concentration factor in the biota of the river Sava. Organisms of the water system have different abilities of concentration of radio nuclide. This ability is most highly expressed in plancton as the first link on the trophic chain. As the length of trat chain increases, the concentration of radionuclide in the organisms diminishes

1977-06-03

247

LEVELS OF SYNTHETIC MUSK COMPOUNDS IN MUNICIPAL WASTEWATER FOR ESTIMATING BIOTA EXPOSURE IN RECEIVING WATER  

Science.gov (United States)

To test the ruggedness of a newly developed analytical method for synthetic musks, a 1-year monthly monitoring of synthetic musks in water and biota was conducted for Lake Mead (near Las Vegas, Nevada) as well as for combined sewage-dedicated effluent streams feeding Lake ...

248

Textured organic surfaces associated with the Ediacara biota in South Australia  

Science.gov (United States)

The Ediacaran Period takes its name from the fossils of the Ediacara biota, which represent the first appearance of large and diverse assemblages of organisms in the fossil record. Although the global record of these distinctive body fossils is now well known, a previously unrecognized megascopic organic record of textured organic surfaces (TOS) occurs in the Ediacara biota. However, TOS is also a feature over a wider range of paleoenvironmental settings, where body fossils are unknown, in Ediacaran siliciclastic successions that have been studied in Australia, Namibia and western North America. Paleoecological analysis of successive bedding planes of strata from the late Ediacaran Rawnsley Quartzite in the Flinders Ranges of South Australia, reveals that TOS represent the most common organic features in bedding-surface assemblages of the Ediacara biota. The TOS consist of preserved, patterned assemblages of textured organic mats, fibers and simple tubular body fossils. Complex Ediacara body fossils while striking for their distinctive body plans, and dominating some of the beds, are relatively minor components of combined overall surface area. Many elements of TOS have previously been miss-diagnosed as trace fossils, which are in practice limited to two or at most three morphotypes that indicate the presence of Bilateria. Although TOS represent a simpler grade of organismic construction than discrete and more complex Ediacara body fossils, they were preserved in a similar manner. Marked variability in all components of the biota between successive surfaces suggests that Ediacara ecologies fluctuated at short intervals despite an apparently consistent sedimentary regime.

Gehling, James G.; Droser, Mary L.

2009-10-01

249

Climate changes: effects of secondary salinisation in freshwater organisms  

Digital Repository Infrastructure Vision for European Research (DRIVER)

As global climate patterns change, so will freshwater availability. Specially, salinisation of freshwater costal ecosystem is a major point of concern; either by surface flooding or by groundwater intrusions of seawater. This may be potentiated by the decrease of freshwater availability provoked by longer drought periods, evaporation, and increased freshwater extraction (for example for agriculture and other human uses). According, the present work aimed at evaluating how freshwater organi...

Leita?o, Joa?o Lui?s Vieira

2011-01-01

250

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

Energy Technology Data Exchange (ETDEWEB)

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

Yankovich, T.L.; Cornett, R.J.J. [Atomic Energy of Canada Limited, Environmental Technologies Branch, Chalk River Lab., Chalk River, Ontario (Canada)

2004-07-01

251

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

International Nuclear Information System (INIS)

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

2004-09-06

252

Freshwater Biology and Pollution Ecology: Training Manual.  

Science.gov (United States)

The manual includes specific teaching outlines on biology and identification of major plant and animal groups, effects of pollution, biological indices of pollution, and methods of collection and analysis of freshwater communities.

R. M. Sinclair

1975-01-01

253

Practical Implementation of Freshwater Pearl Mussel Measures  

...FAQsAccess KeysPractical Implementation of Freshwater Pearl Mussel MeasuresLast updated: 17...undertake a programme of works involving the practical implementation of measures to support the restoration of...

254

Freshwater fish of the Wilderness National Park  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The study aimed to determine the distribution and relative abundance of freshwater fish in the Wilderness National Park. Fish assemblages in the Touw and Duiwe rivers were sampled in 1997 and 1998, with a total of 327 fish from nine species recorded. Indigenous species included two freshwater species (Pseudobarbus afer, Sandelia capensis), two catadromous species (Anguilla mossambicus, Myxus capensis), and two estuarine species (Monodactylusfalciformis, Caffrogobius multifasciatus). Three of ...

Russell, I. A.

1999-01-01

255

CROATIAN FRESHWATER FISHERY IN 2001 and 2002  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 fres...

Irena Jahutka; Zlatko Homen

2003-01-01

256

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

257

Toxicity of metallic oxides nanoparticle suspensions to a freshwater sludge worm Tubifex tubifex Müller.  

Science.gov (United States)

Toxic effects of selected metallic oxides nanoparticles were studied using the short-term static bioassays. Nanoparticles were more toxic than comparable bulk metallic oxides. Freshwater sludge worm Tubifex tubifex can be used as suitable test model for nanoecotoxicological studies in future studies. PMID:21485877

Verma, Surabhi; Das, Sangita; Khangarot, B S

2011-02-01

258

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)

1998-01-01

259

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

260

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

Directory of Open Access Journals (Sweden)

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

David Edward Bignell

2009-08-01

 
 
 
 
261

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

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

1995-01-01

262

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

Ku?hn, Ingolf; Kowarik, Ingo; Kollmann, Johannes; Starfinger, Uwe; Bacher, Sven; Blackburn, Tim M.; Bustamante, Ramiro O.; Celesti-grapow, Laura; Chytry?, Milan; Colautti, Robert I.; Essl, Franz; Foxcroft, Llewellyn C.; Garci?a-berthou, Emili; Gollasch, Stephan; Hierro, Jose?

2011-01-01

263

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

Ku?hn, Ingolf; Kowarik, Ingo; Kollmann, Johannes; Starfinger, Uwe; Bacher, Sven; Blackburn, Tim; Bustamante, Ramiro; Celesti-grapow, Laura; Chytry?, Milan; Colautti, Robert; Essl, Franz; Foxcroft, Llewellyn; Garci?a-berthou, Emili; Gollasch, Stephan; Hierro, Jose?

2011-01-01

264

Evolution of the freshwater eels.  

Science.gov (United States)

The freshwater anguillid eels have an unusual life history and world-wide distribution. Questions about the phylogenetic relationships of this group and how their long spawning migrations and larval phase may contribute to their global distribution have not been addressed. This paper is first presentation of molecular phylogeny of Anguilla species, and based on this phylogenetic tree we suggest new aspect of the evolution of this group. Namely, ancestral eels originated during the Eocene or earlier, in the western Pacific Ocean near present-day Indonesia. A group derived from this ancestor dispersed westward, probably by larval transport in the global circum-equatorial current through the northern edge of the Tethys Sea. This group split into the ancestor of the European and American eels, which entered into the Atlantic Ocean, and a second group, which dispersed southward and split into the east African species and Australian species. Thus the world-wide distribution of the eel family can be understood from knowledge of continental drift, ocean currents, a specialized larva and evolutionary forces favoring dispersal and speciation of segregated gene pool. PMID:9050003

Aoyama, J; Tsukamoto, K

1997-01-01

265

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

266

Inland oil spills: Options for minimizing environmental impacts of freshwater spill response  

Energy Technology Data Exchange (ETDEWEB)

Selecting appropriate protection, response, and cleanup techniques, both before and following an oil spill, affects the ultimate environmental impact and cost resulting from a spill. The American Petroleum Institute (API) and the National Oceanic and Atmospheric Administration (NOAA) jointly developed this guide as a tool for contingency planners and field responders to identify response techniques that have minimal ecological impacts and also minimize the impact of the oil. The guide provides information on 29 response methods and classifies their relative environmental impact for combinations of four oil types and twelve freshwater environments and habitats. Spill topics of special concern in freshwater settings are also discussed, including public health, conditions under which oil might sink in freshwater, oil behavior in ice conditions, permafrost, and use of firefighting foams.

1994-09-01

267

Histopathological changes in two potential indicator fish species from a hyper-eutrophic freshwater ecosystem in South Africa : a baseline study  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Histopatholigical changes were identified in selected target organs from two freshwater fish species, Clarias gariepinus and Oreochromis mossambicus, inhabiting a hyper-eutrophic freshwater aquatic system. The approach was to use a histology-based fish health assessment protocol which included a semi-quantitative histopathological assessment of six target organs (gills, liver, ovaries, testes, kidney, and heart). Results of water quality analysis showed selected variables to be above the reco...

Marchand, M. J.; Dyk, Jacobus C.; Barnhoorn, Irene E. J.; Wagenaar, G. M.

2012-01-01

268

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.

269

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

270

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2003-06-06

271

210Pb and 210Po in Venice Lagoon Biota and their contribution to population dose  

International Nuclear Information System (INIS)

Phosphogypsum is a by-product resulting from the processes applied in phosphoric acid or phosphate fertilizer production. The phosphate ore used in these chemical processes contains the naturally occurring radioactive materials U, and Th, along with their decay products. Large volumes of solid waste products were discharged from a phosphoric acid production plant on the edge of the Venice lagoon (Italy). Water, suspended matter, and biota were monitored in the Venice lagoon, since this aquatic environment can be considered to represent the final area of deposition for the radionuclides transported from inland. The present paper reports data on the activity concentrations of 210Po and 210Pb determined in biota living in the lagoon, and an estimation of the contribution to internal dose to man from the ingestion of food originating in the investigated area. (orig.)

2002-03-01

272

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

2008-09-01

273

KERAGAMAN AKTIVITAS ANTIFUNGI BIOTA LAUT TERHADAP Fusarium oxysporum f.sp. vanillae, PENYEBAB BUSUK BATANG VANILI  

Directory of Open Access Journals (Sweden)

Full Text Available The diversity of marine biota resources is very high, therefore it is necessary to be recovered for our life need. The objective of this research is to know the antifungal ability of marine biota derived from Bali Island against Fusarium oxysporum f. sp. vanillae. Samples were collected at the intertidal zone of seven beaches around Bali. Extraction of antifungal substance of raw material extract was conducted using various organic solvents until the best ability was obtained. The dry material extract was then screened using well diffusion method. The method was also used to determine the inhibition indicators to Fusarium. The methanolic extract of Aglaophenia sp. marine animal was able to suppress the Fusarium effectively, with minimum inhibition concentration (MIC of 0.05%. The extract inhibited the colony growth, total of conidial forming, total of growing colony, total of mycelial dry weight, total of mycelial protein, however, increased fusaric acid production of the pathogen.

I Ketut Suada

2012-02-01

274

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

275

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

...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 ...

276

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

International Nuclear Information System (INIS)

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

2000-05-01

277

Biota assessment. Phases 1 and 2, task 9, final technical plan. Version 3.2. Final report  

Energy Technology Data Exchange (ETDEWEB)

The biota assessment will fulfill the general need for comprehensive information on the plants and animals on and near RMA in relation to chemical contamination. The primary objective of Task 915 to provide information on: (1) migration of contaminants through the food web; (2) injury to environmental resources. Phase I involves the compilation of existing information on the presence and distribution of RMA contaminants in the biota a brief field survey documents present conditions and recent changes. Phase II consists of any field and laboratory studies needed. Sections of the two technical plans detail information on the following programs: evaluation of existing information, quantitative biota studies, chemical analysis, quality control, safety, sampling, and data management. Other information in the plan includes: contamination sites and sources, contaminants of concern, contaminant levels in biota, injuries and deaths, food webs, species lists.

NONE

1988-07-01

278

Contribution to the lichen biota of the Pogórze Wi?nickie foothills (Carpathians  

Directory of Open Access Journals (Sweden)

Full Text Available The Pogórze Wi?nickie foothills are situated in close vicinity to the Kraków agglomeration and is highly influenced by human activity. Lichen studies in the area revealed 163 species so far. A current checklist of the lichen biota of the territory is provided with numerous new regional records, e.g. Bacidina sulphurella, Evernia prunastri, Fuscidea pusilla, Lecanora albellula, Lepraria ecorticata, Mycobilimbia epixanthoides, Ramalina farinacea, R.. fastigiata, Ropalospora viridis, Verrucaria praetermissa and V. tectorum.

Lucyna ?liwa

2010-12-01

279

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

International Nuclear Information System (INIS)

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 m3, 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.

2010-06-07

280

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

Senicovscaia, Irina

2012-01-01

 
 
 
 
281

Cryptic vicariance in the historical assembly of a Baja California Peninsular Desert biota  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We use analyses of phylogeographic population structure across a suite of 12 mammalian, avian, amphibian, and reptilian species and species-groups to assess the role of Late Miocene to Pleistocene geological history in the evolution of a distinct Baja California Peninsular Desert biota. Comparative examination of phylogroup distributions provides support for previously hypothesized vicariant events produced by: a middle Pleistocene midpeninsular seaway, a late Plio...

Riddle, Brett R.; Hafner, David J.; Alexander, Lois F.; Jaeger, Jef R.

2000-01-01

282

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

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

2012-01-01

283

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

284

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

285

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

286

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

International Nuclear Information System (INIS)

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

2004-09-06

287

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...

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

2010-01-01

288

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

289

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

Energy Technology Data Exchange (ETDEWEB)

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

Beresford, N.A.; Copplestone, D.; Kryshev, I.I.; Sazykina, T.G.; Prohl, G.; Arkhipov, A.; Wright, S.M.; Howard, B.J. [Centre for Ecology and Hydrology, Lancaster Environment Centre, Bailrigg, Lancaster (United Kingdom)

2004-07-01

290

Radioactivity in produced water from oil and gas installations - doses to biota and humans  

International Nuclear Information System (INIS)

Substantial amounts of produced water containing elevated levels of 226Ra and 228Ra are discharged into the sea as a result of oil and gas production on the Norwegian continental shelf. The average concentration in the discharges is 3.3 and 2.8 Bq/L of 226Ra and 228Ra, respectively. The main objective of the project described in the paper is to establish radiological safe discharge limits for radium, lead and polonium in produced water produced by oil and gas installations on the Norwegian continental shelf. One of the objectives of the study is to provide information to enable risk assessment based on doses from ionizing radiation to marine biota and man. Reference organisms for the North Sea area have been chosen for calculation of absorbed dose to biota. The dose calculations rely on specific knowledge of activity concentration in the reference organism, activity concentration in seawater and sediments, dose conversion factors and time spent at different locations relative to the point of discharge. Based on the calculated doses to marine biota, 'potential no effect concentrations' are recommended. (author)

2008-08-01

291

The Empire Knight: Patterns of mercury contamination in sediment and biota at a marine site  

Energy Technology Data Exchange (ETDEWEB)

The Empire Knight, a merchant ship carrying approximately 7.3 metric tons of elemental mercury in its cargo, sank in a storm off the Maine coast in 1 944. Unique attributes of the site include the deep water marine conditions (80 m) and mercury originally in elemental form. Recent evaluations of the site were undertaken to determine environmental risk of the remaining mercury and possible remedial actions. Data collected in 1993 for this risk evaluation included sediment core samples, and a variety of biota samples. Biota were analyzed for total and methylmercury, and the following patterns examined: percent methylmercury, variability between species groups, and spatial patterns related to sediment contamination. Sediment contamination was largely confined to the immediate area near the wreck, with levels decreasing to background within 60 m. Invertebrates within this area had elevated levels of mercury in tissue. Most contamination was in an inorganic form, with percentages of methyl to total mercury below 20%, except for crab and lobster. Most of the residual mercury appears to be largely unavailable to biota, with local invertebrates comprising the main biological receptors. Evidence of bioaccumulation of mercury in higher trophic level organisms was not found, thus mercury did not appear to be a source of contamination beyond the immediate area the wreck.

Hoff, R.Z. [NOAA Hazmat, Seattle, WA (United States)

1995-12-31

292

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

293

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

International Nuclear Information System (INIS)

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

2010-01-01

294

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

295

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

International Nuclear Information System (INIS)

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

2004-09-06

296

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

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

2007-01-01

297

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

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

2000-01-01

298

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 rati...

2008-01-01

299

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 "2"3"3 "2"3"4U, "2"3"8U, "2"3"8Pu, "2"3"9 "2"4"0Pu, "2"4"1Am, and "2"4"4Cm 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 "2"3"9 "2"4"0Pu; 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, "2"4"1Am/"2"3"9Pu, "2"4"4Cm/"2"3"9Pu, and "2"3"8U/"2"3"9Pu ratios were greater than the respective ratio in sediment while "2"3"3 "2"3"4U/"2"3"8U, and "2"3"9 "2"4"0Pu/"2"3"8Pu 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

1981-07-31

300

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

 
 
 
 
301

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.

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

2014-01-01

302

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

303

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

304

Sulfate reduction in freshwater peatlands  

International Nuclear Information System (INIS)

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

1996-01-01

305

Macrophytes: Freshwater Forests of Lakes and Rivers.  

Science.gov (United States)

Physical, chemical, and biological effects on macrophytes (aquatic plants) on the freshwater ecosystem are discussed. Research questions and issues related to these organisms are also discussed, including adaptations for survival in a wet environment, ecological consequences of large-scale macrophyte eradication, seasonal changes in plant…

McDermid, Karla J.; Naiman, Robert J.

1983-01-01

306

RNA interference in marine and freshwater sponges  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Background: The marine sponge Tethya wilhelma and the freshwater sponge Ephydatia muelleri are emerging model organisms to study evolution, gene regulation, development, and physiology in non-bilaterian animal systems. Thus far, functional methods (i.e., loss or gain of function) for these organisms have not been available.

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

2011-01-01

307

2008 NWFSC Tidal Freshwater Genetics Results  

Energy Technology Data Exchange (ETDEWEB)

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

David Teel

2009-05-01

308

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

309

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

310

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

Science.gov (United States)

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

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

2012-07-01

311

Accumulation and toxicokinetics of fluoranthene in sediment bioassays with freshwater amphipods  

Energy Technology Data Exchange (ETDEWEB)

Two freshwater amphipods, Hyalella azteca and Diporeia sp., were exposed to sediment spiked with radiolabeled fluoranthene at nominal concentrations of 0.1 (trace) to 1,270 nmol fluoranthene/g dry weight. In two experiments, uptake kinetics and mortality were determined over 30-d exposures. Concentrations of fluoranthene in sediment and pore water were also measured. Mean survival of H. azteca was generally high, greater than 90% after 10 or 16 d, and greater than 74% after 30 d. Mean survival was lower for Diporeia, 14% after a 30-d exposure to the highest sediment concentration in experiment 1, and 53% in experiment 2. Tissue concentrations in Diporeia were as high as 2 to 4 {micro}mol/g wet weight, a body burden that could be expected to result in death by narcosis. Hyalella azteca did not typically accumulate more than 1 {micro}mol/g wet weight, which is consistent with the lower observed mortality. Apparent steady-state biota-sediment accumulation factors (BSAFs, lipid- and organic-carbon-normalized) for sediment concentrations other than trace level tended to be higher for Diporeia than for H. azteca. The BSAFs for trace levels tended to be lower for both species in comparison to higher sediment concentrations. For both organisms, the internal concentration based on body residue was a more reliable indicator of toxicity than were equilibrium partitioning predictions.

Driscoll, S.K.; Harkey, G.A.; Landrum, P.F. [National Oceanic and Atmospheric Administration, Ann Arbor, MI (United States). Great Lakes Environmental Research Lab.

1997-04-01

312

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

Enongene, Agnes Debime

2013-01-01

313

REVIEW OF FRESHWATER BIOASSAY PROCEDURES FOR SELECTED AMPHIPODS  

Science.gov (United States)

Methods previously used for performing gammarid bioassays and several important life-cycle requirements are reviewed. The discussion is largely based on methodology for the amphipods Gammarus fasciatus, Gammarus lacustris, and Gammarus pseudolimnaeus, but additional evidence, gat...

314

Selected bibliography of terrestrial freshwater, and marine radiation ecology  

International Nuclear Information System (INIS)

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

1975-01-01

315

Investigation of manganese in salt- and freshwater pearls  

International Nuclear Information System (INIS)

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

2001-07-01

316

Investigation of manganese in salt- and freshwater pearls  

Energy Technology Data Exchange (ETDEWEB)

The trace element distribution in natural and cultured pearls is analysed by micro-PIXE, cathodoluminescence (CL) microscopy and spectroscopy and electron spin resonance (ESR) spectroscopy to develop a new method to distinguish cultured from natural pearls. These different kinds of pearls can be identified by their manganese content and its distribution in aragonite and calcite structure, respectively. Manganese content of natural freshwater pearls from Persian Gulf was compared to that of natural freshwater pearls from the Mississippi river (USA). Moreover manganese content of tissue-graft freshwater pearls from Chansu (China) was compared to that of natural freshwater pearls from the Mississippi river (USA). It was proved that the Chinese freshwater tissue-graft cultured pearls generally contain domains of calcite, emitting orange Mn{sup 2+}-activated CL which are almost absent in the natural freshwater pearls from the Mississippi river. Freshwater pearls showing much higher Mn concentrations build in calcitic and aragonitic parts compared to saltwater pearls.

Habermann, D. E-mail: dirk.habermann@physik.tu-freiberg.de; Banerjee, A.; Meijer, J.; Stephan, A

2001-07-01

317

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

318

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 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)

2003-05-01

319

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

International Nuclear Information System (INIS)

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

2013-01-01

320

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 "9"0Sr, "1"3"7Cs 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)

1980-10-10

 
 
 
 
321

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 (<250 K) environment would not have racemized significantly over the lifetime of the planet. Racemization would have taken place in environments where liquid water was present even for time periods of only a few million years following biotic extinction. The best preservation of both amino acid homochirality and nucleic acid genetic information associated with extinct martian life would be in the polar regions.

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

1995-01-01

322

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

International Nuclear Information System (INIS)

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

1994-08-01

323

Soil Biota  

Science.gov (United States)

In teams of two, students collect samples from one or two different environments -- agricultural fields, sports turf areas, lawns, forest floor, wetland/pond margin, greenhouse, etc. They construct a Berlese funnel apparatus, process their two samples, identify and photograph (under a microscope) the organisms they isolate. The class aggregates their data from all the different environments, calculates a Simpson's diversity index for each environment, and uses this value to compare the diversity of the different environments.

Mccarville, Katherine

324

Applying DoE's Graded Approach for assessing radiation impacts to non-human biota at the Incl  

International Nuclear Information System (INIS)

In July 2002, The US Department of Energy (DOE) released a new technical standard entitled A Graded Approach for Evaluating Radiation Doses to Aquatic and Terrestrial Biota. DOE facilities are annually required to demonstrate that routine radioactive releases from their sites are protective of non-human receptors and sites are encouraged to use the Graded Approach for this purpose. Use of the Graded Approach requires completion of several preliminary steps, to evaluate the degree to which the site environmental monitoring program is appropriate for evaluating impacts to non-human biota. We completed these necessary activities at the Idaho National Laboratory (INL) using the following four tasks: (1) develop conceptual models and evaluate exposure pathways; (2) define INL evaluation areas; (3) evaluate sampling locations and media; (4) evaluate data gaps. All of the information developed in the four steps was incorporated, data sources were identified, departures from the Graded Approach were justified, and a step-by-step procedure for biota dose assessment at the INL was specified. Finally, we completed a site-wide biota dose assessment using the 2002 environmental surveillance data and an offsite assessment using soil and surface water data collected since 1996. These assessments demonstrated the environmental concentrations of radionuclides measured on and near the INL do not present significant risks to populations of non-human biota

2006-01-01

325

Applying DoE's Graded Approach for assessing radiation impacts to non-human biota at the Incl  

Energy Technology Data Exchange (ETDEWEB)

In July 2002, The US Department of Energy (DOE) released a new technical standard entitled A Graded Approach for Evaluating Radiation Doses to Aquatic and Terrestrial Biota. DOE facilities are annually required to demonstrate that routine radioactive releases from their sites are protective of non-human receptors and sites are encouraged to use the Graded Approach for this purpose. Use of the Graded Approach requires completion of several preliminary steps, to evaluate the degree to which the site environmental monitoring program is appropriate for evaluating impacts to non-human biota. We completed these necessary activities at the Idaho National Laboratory (INL) using the following four tasks: (1) develop conceptual models and evaluate exposure pathways; (2) define INL evaluation areas; (3) evaluate sampling locations and media; (4) evaluate data gaps. All of the information developed in the four steps was incorporated, data sources were identified, departures from the Graded Approach were justified, and a step-by-step procedure for biota dose assessment at the INL was specified. Finally, we completed a site-wide biota dose assessment using the 2002 environmental surveillance data and an offsite assessment using soil and surface water data collected since 1996. These assessments demonstrated the environmental concentrations of radionuclides measured on and near the INL do not present significant risks to populations of non-human biota.

Morris, Randall C. [North Wind, Inc., PO Box 51174, Idaho Falls, ID 83405-1174 (United States)]. E-mail: rmorris@nwindenv.com

2006-07-01

326

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

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

2000-01-01

327

Geological dates and molecular rates: rapid divergence of rivers and their biotas.  

Science.gov (United States)

We highlight a novel molecular clock calibration system based on geologically dated river reversal and river capture events. Changes in drainage pattern may effect vicariant isolation of freshwater taxa, and thus provide a predictive framework for associated phylogeographic study. As a case in point, New Zealand's Pelorus and Kaituna rivers became geologically isolated from the larger Wairau River system 70 to 130 kyr BP. We conducted mitochondrial DNA phylogeographic analyses of two unrelated freshwater-limited fish taxa native to these river systems (Gobiomorphus breviceps, n = 63; Galaxias divergens, n = 95). Phylogenetic analysis of combined control region and cytochrome b sequences yielded reciprocally monophyletic clades of Pelorus-Kaituna and Wairau haplotypes for each species. Calibrated rates of molecular change based on this freshwater vicariant event are substantially faster than traditionally accepted rates for fishes but consistent with other recent inferences based on geologically young calibration points. A survey of freshwater phylogeographic literature reveals numerous examples in which the ages of recent evolutionary events may have been substantially overestimated through the use of "accepted" calibrations. We recommend that--wherever possible--biologists should start to reassess the conclusions of such studies by using more appropriate molecular calibrations derived from recent geological events. PMID:17464882

Waters, Jonathan M; Rowe, Diane L; Apte, Smita; King, Tania M; Wallis, Graham P; Anderson, Leigh; Norris, Richard J; Craw, Dave; Burridge, Christopher P

2007-04-01

328

CROATIAN FRESHWATER FISHERY IN 2001 and 2002  

Directory of Open Access Journals (Sweden)

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

329

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

330

Ontogenesis and functional morphology of the digestive system of the freshwater prawn, Macrobrachium amazonicum (Decapoda: Palaemonidae)  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The appropriate feeding regime for larvae and post-larvae of crustacean decapods is essential for successful larval culture. Reports on the development and morphology of the mouthparts and foregut of these crustaceans have aided in the selection of appropriate larval foodstuffs and consequently increased larval survival and growth rate during development. In the present study, the functional morphology of foregut and mouthparts was investigated in larvae and post-larvae of the freshwater praw...

Queiroz, Luciano D.; Abrunhosa, Fernando A.; Maciel, Cristiana R.

2011-01-01

331

Influence of Substratum Wettability on Attachment of Freshwater Bacteria to Solid Surfaces  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We studied the attachment of a number of freshwater bacteria from River Sowe, Coventry, England, to test substrata. The attachment of each organism to hydrophobic and hydrophilic surfaces was evaluated, and further studies evaluated the attachment of selected isolates to a number of substrata with a range of water wettabilities. The wettability of each substratum was determined by contact angle measurements and was expressed as the work of adhesion (WA). No generic pattern of attachment to th...

Pringle, James H.; Fletcher, Madilyn

1983-01-01

332

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

1984-09-11

333

Physical processes in freshwater ecosystems  

International Nuclear Information System (INIS)

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

2009-05-01

334

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.

2010-05-01

335

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

336

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

Directory of Open Access Journals (Sweden)

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

E. de la Peña

2009-01-01

337

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 "6"0Co in seston, periphyton and invertebrates did not decrease to the degree that the other radionuclides did. Levels of "6"0Co 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, "6"5Zn 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)

1981-01-01

338

Some aspects of interrelations between fungi and other biota in forest soil.  

Science.gov (United States)

Interrelations of fungal mycelium with other soil biota are of paramount importance in forestry and soil ecology. Here we present the results of statistical analysis of a comprehensive data set collected in the first (and the only) British fungus sanctuary over a period of four months. The variables studied included a number of soil properties, bacteria, protozoan flagellates, ciliates and amoebae, microbial and plant feeding nematodes, various microarthropods, and two fungal biomarkers--glomalin and ergosterol. One way ANOVA showed that the dynamics of the microbiota studied was influenced by seasonal changes. Superimposed on these changes, however, was variability due to biological interactions and habitat characteristics. Two fungal biomarkers, ergosterol and glomalin, were differently influenced by other biota and abiotic variables. The results indicate that the dynamics of soil fungi is influenced not only by soil microarthropods, but also by those found in forest litter. The overall outcome, therefore, is likely to be very complex and will depend upon specific conditions of any particular ecosystem. PMID:15449599

Krivtsov, Vladimir; Griffiths, Bryan S; Salmond, Ross; Liddell, Keith; Garside, Adam; Bezginova, Tanya; Thompson, Jacqueline A; Staines, Harry J; Watling, Roy; Palfreyman, John W

2004-08-01

339

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.

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, Francois; 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

340

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

International Nuclear Information System (INIS)

The Yenisei is a large river situated in Central Siberia (Russia). It flows northwards to the Yenisei Bay of the Kara Sea. The length of the Yenisei River is 3840 km, the average annual water discharge is 591 km3. Since 1958, the Yenisei River is contaminated by the routine releases of radionuclides from the Krasnoyarsk Mining and Chemical Industrial Complex (KMCIC). Among the radionuclides presented in liquid discharges from KMCIC, radioisotopes of phosphorus, caesium and zinc are of major radioecological importance, since they are easily assimilated by the aquatic biota. Yenisei River is characterized by low concentrations of stable nutrients in water, particularly of phosphorus. This may be the reason for the intensive bioassimilation of radioactive phosphorus by organisms in the Yenisei River. The subject of this paper is reconstruction of accumulation of artificial radionuclides (32P, 137Cs, 65Zn, 51Cr, 54Mn) by the Yenisei River biota during the 25-years period (1975 - 2000), and estimation of the internal dose rates to the river organisms. Among the radionuclides presented in the releases, 32P is of particular importance. Reconstruction of the radionuclide assimilation by the Yenisei biota was performed using the ECOMOD model approach. The model considers a radionuclide as a tracer, identical in its properties to a stable (analogous) element participated in the metabolism of aquatic organism. Radionuclide assimilated by an organism goes to the production of new biomass, and to compensation of metabolic losses of the analogous bioelement. Basic equations of the general ECOMOD approach were described in paper. The model was adapted to the conditions of the Yenisei River and applied to calculate the dynamics of 3'2P, 137Cs, 65Zn, 51Cr, 54Mn in the most typical Yenisei fish species: roach (non-predatory) and pike (predatory). The reconstructed activity concentrations in roach and pike at the distances 16-80 km downstream the KMCIC are shown. 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 III. Annual average dose rates from incorporated radionuclides to the Yenisei biota are presented in Table IV. 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%)

2006-02-01

 
 
 
 
341

Freshwater biodiversity and aquatic insect diversification.  

Science.gov (United States)

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

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

2014-01-01

342

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

343

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

344

The use of multiple tracers for tracking wastewater discharges in freshwater systems.  

Science.gov (United States)

The assessment of potential impacts of wastewater effluent discharges in freshwater systems requires an understanding of the likely degrees of dilution and potential zones of influence. In this study, four tracers commonly present in wastewater effluents were monitored to compare their relative effectiveness in determining areas in freshwater systems that are likely to be impacted by effluent discharges. The four tracers selected were the human pharmaceutical carbamazepine, anthropogenic gadolinium, fluorescent-dissolved organic matter (fDOM), and electrical conductivity (EC). The four tracers were monitored longitudinally in two distinct freshwater systems receiving wastewater effluents, where one site had a high level of effluent dilution (effluent <1% of total flow) and the other site had a low level of effluent dilution (effluent ?50% of total flow). At both sites, the selected tracers exhibited a similar pattern of response intensity downstream of discharge points relative to undiluted wastewater effluent, although a number of anomalies were noted between the tracers. Both EC and fDOM are non-specific to human influences, and both had a high background response, relative to the highly sensitive carbamazepine and anthropogenic gadolinium responses, although the ease of measuring EC and fDOM would make them more adaptable in highly variable systems. However, the greater sensitivity and selectivity of carbamazepine and gadolinium would make their combination with EC and fDOM as tracers of wastewater effluent discharges highly desirable to overcome potential limitations of individual tracers. PMID:23729161

Williams, Mike; Kumar, Anupama; Ort, Christoph; Lawrence, Michael G; Hambly, Adam; Khan, Stuart J; Kookana, Rai

2013-11-01

345

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

346

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,...

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

2012-01-01

347

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

International Nuclear Information System (INIS)

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

2008-11-01

348

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

International Nuclear Information System (INIS)

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

2011-03-01

349

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

International Nuclear Information System (INIS)

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

1999-12-01

350

Assessing the freshwater distribution of yellow eel  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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) ...

Lasne, Emilien; Laffaille, Pascal

2009-01-01

351

Methylotrophy in Freshwater Beggiatoa alba Strains ?  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Two freshwater strains of the gammaproteobacterium Beggiatoa alba, B18LD and OH75-2a, are able to use methanol as a sole carbon and energy source under microoxic conditions. Genes encoding a methanol dehydrogenase large-subunit homolog and four enzymes of the tetrahydromethanopterin-dependent C1 oxidation pathway were identified in B18LD. No evidence of methanotrophy was detected.

Jewell, Talia; Huston, Sherry L.; Nelson, Douglas C.

2008-01-01

352

Predicting spatial similarity of freshwater fish biodiversity  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A major issue in modern ecology is to understand how ecological complexity at broad scales is regulated by mechanisms operating at the organismic level. What specific underlying processes are essential for a macroecological pattern to emerge? Here, we analyze the analytical predictions of a general model suitable for describing the spatial biodiversity similarity in river ecosystems, and benchmark them against the empirical occurrence data of freshwater fish species collected in the Mississip...

Azaele, Sandro; Muneepeerakul, Rachata; Maritan, Amos; Rinaldo, Andrea; Rodriguez-iturbe, Ignacio

2009-01-01

353

Predicting spacial similarity of freshwater fish biodiversity  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A major issue in modern ecology is to understand how ecological complexity at broad scales is regulated by mechanisms operating at the organismic level. What specific underlying processes are essential for a macroecological pattern to emerge? Here, we analyze the analytical predictions of a general model suitable for describing the spatial biodiversity similarity in river ecosystems, and benchmark them against the empirical occurrence data of freshwater fish species collected in the Mississip...

Azaele, S.; Muneepeerakul, R.; Marian, A.; Rinaldo, A.; Rodriguez-iturbe, I.

2009-01-01

354

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

355

Reclaiming freshwater sustainability in the Cadillac Desert  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

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

356

Coal ash basin effects (particulates, metals, acidic pH) upon aquatic biota: an eight-year evaluation. [Gambusia affinis; Plathemis lydia; Libellula spp  

Energy Technology Data Exchange (ETDEWEB)

Coal ash effluent effects including particulates, acidic pH excursions, elemental concentrations and bioconcentration in selected organisms have been studied as changes in water quality and densities of benthic macroinvertebrate and mosquitofish (Gambusia affinis) populations in a swanmp drainage system over an eight-year period. Initial density of the aquatic biota was altered severely by heavy ash siltation, followed by acidic pH excursions, and perhaps overall by elemental concentrations and bioaccumulation. Heavy ash siltation, followed by acidic pH excursions after the addition of fly ash to the original settling basin system, had the most profound effect on biota. Dipterans (chironomids) and some odonates (Plathemis lydia and Libellula spp.) were resistant to heavy ash siltation, while mosquitofish, which showed no discernible responses to ash siltation, were absent at acidic pH along with the few previously surviving invertebrate populations. Elemental concentrations of arsenic, cadmium, chromium, copper, selenium, and zinc did not appear to limit aquatic flora and fauna on a short-term, acute basis. Long-chronic elemental exposures may have been instrumental in retarding the recovery of all forms of aquatic life in the receiving system. Elemental concentrations (except for arsenic and selenium) in the receiving system were generally one to two orders of magnitude higher than the Water Quality Criteria set by the US Environmental Protection Agency (1980) for protection of aquatic life for the minimum and 24-hour mean values. By 1978, when the new settling basin systems were operating effectively, invertebrate populations were largely recovered, and mosquito-fish populations recovered within one year afterward.

Cerry, D.S.; Guthrie, R.K.; Davis, E.M.; Harvey, R.S.

1984-08-01

357

Monitoring Global Freshwater Resources with GRACE  

Science.gov (United States)

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

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

2011-01-01

358

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)

2008-09-00

359

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

Energy Technology Data Exchange (ETDEWEB)

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)

Lopez-Lopez, E.; Sedeno-Diaz, J. E.

2009-07-01

360

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

International Nuclear Information System (INIS)

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

2008-01-01

 
 
 
 
361

Viral Loop Dynamics in Temperate and Polar Freshwaters  

Digital Repository Infrastructure Vision for European Research (DRIVER)

All cellular organisms in aquatic environments are susceptible to virus attack. Viruses are the smallest but most abundant biological entities in freshwaters. This thesis describes interactions between viruses and bacteria in temperate and polar freshwaters with particular emphasis on Arctic and Antarctic aquatic systems. Free virus-like particles in freshwaters are vulnerable and exposed and as parasites their survival is dependent on the existence of a suitable host. I found that high conce...

Sa?wstro?m, Christin

2006-01-01

362

A Complete Guide to the Freshwater Fishes of Southern Africa  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

Skelton, P. H.

2012-01-01

363

Implications of dam obstruction for global freshwater fish diversity  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Dams are obstructing rivers worldwide, impairing habitat and migration opportunities for many freshwater fish species; however, global data linking dam and fish distributions have been limited. Here, we quantify dam obstruction at the biogeographic scale of freshwater ecoregion, which provides the spatial framework necessary to assess the risk of fish species loss due to dams and allows us to identify both ecoregions and genera at risk. Nearly 50% of the 397 assessed freshwater ecoregions are...

Reidy Liermann, Catherine; Nilsson, Christer; Robertson, James; Ng, Rebecca

2012-01-01

364

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

365

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

366

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)

2009-01-01

367

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

1994-01-01

368

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

369

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

International Nuclear Information System (INIS)

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

2004-12-01

370

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)

1999-11-22

371

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

372

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

373

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

International Nuclear Information System (INIS)

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

2004-10-25