Sample records for monitorovaci system biota

  1. Distribution and determination of Pb, Cd, Bi and Cu in the sea brine system: solution--colloidal particles--biota.

    PubMed

    Bozhkov, Ognyan; Tzvetkova, Christina; Russeva, Elena

    2006-01-01

    The distribution of Pb, Cd, Bi, and Cu in Black Sea brine system (solution--colloidal particles--biota) produced in Burgas and Pomorie salterns is studied. The established distribution of the title elements among the brine components is as follows: Pb--25% in the salt solution, 30%--in colloidal particles, 45%--in biota (Halobacterium salinarium and microalgae Dunaliela salina); Cu--30% in the salt solution, 22%--in colloidal particles, 48%--in biota. Cd and Bi are not detected in biota. They are uniformly distributed (50%: 50%) between the salt solution and colloidal particles. Two procedures for analysis are developed. The first one is designed for determination of the total content of the studied metals in brine. It involves elimination of the biota interference by addition of ethanol, extraction and pre-concentration of the metals with NaDDC into CCl4 followed by FAAS determination. The second procedure intends determination of the elements in the separate components of the brine. It involves separation of the colloidal particles through centrifugation, separation of the studied elements from the resulting solution as dithiocarbamate complexes on a Millipore filter, dissolution of the retained metal species and subsequent FAAS analysis. PMID:16948432

  2. Response of soil biota to elevated atmospheric CO 2 in poplar model systems

    Microsoft Academic Search

    John Lussenhop; Amy Treonis; Peter S. Curtis; James A. Teeri; Christoph S. Vogel

    1998-01-01

    We tested the hypotheses that increased belowground allocation of carbon by hybrid poplar saplings grown under elevated atmospheric\\u000a CO2 would increase mass or turnover of soil biota in bulk but not in rhizosphere soil. Hybrid poplar saplings (Populus×euramericana cv. Eugenei) were grown for 5 months in open-bottom root boxes at the University of Michigan Biological Station in northern,\\u000a lower Michigan.

  3. Uncertainties of a Regional Terrestrial Biota Full Carbon Account: A Systems Analysis

    Microsoft Academic Search

    S. Nilsson; A. Shvidenko; M. Jonas; I. McCallum; A. Thomson; H. Balzter

    \\u000a We discuss the background and methods for estimating uncertainty in a holistic manner in a regional terrestrial biota Full\\u000a Carbon Account (FCA) using our experience in generating such an account for vast regions in northern Eurasia (at national\\u000a and macroregional levels). For such an analysis, it is important to (1) provide a full account; (2) consider the relevance of a

  4. Biota of North America Program

    NSDL National Science Digital Library

    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).

  5. Soil biota and exotic plant invasion

    Microsoft Academic Search

    Ragan M. Callaway; Giles C. Thelen; Alex Rodriguez; William E. Holben

    2004-01-01

    Invasive plants are an economic problem and a threat to the conservation of natural systems. Escape from natural enemies might contribute to successful invasion, with most work emphasizing the role of insect herbivores; however, microbial pathogens are attracting increased attention. Soil biota in some invaded ecosystems may promote `exotic' invasion, and plant-soil feedback processes are also important. Thus, relatively rare

  6. Soil biota and exotic plant invasion.

    PubMed

    Callaway, Ragan M; Thelen, Giles C; Rodriguez, Alex; Holben, William E

    2004-02-19

    Invasive plants are an economic problem and a threat to the conservation of natural systems. Escape from natural enemies might contribute to successful invasion, with most work emphasizing the role of insect herbivores; however, microbial pathogens are attracting increased attention. Soil biota in some invaded ecosystems may promote 'exotic' invasion, and plant-soil feedback processes are also important. Thus, relatively rare species native to North America consistently demonstrate negative feedbacks with soil microbes that promote biological diversity, whereas abundant exotic and native species demonstrate positive feedbacks that reduce biological diversity. Here we report that soil microbes from the home range of the invasive exotic plant Centaurea maculosa L. have stronger inhibitory effects on its growth than soil microbes from where the weed has invaded in North America. Centaurea and soil microbes participate in different plant-soil feedback processes at home compared with outside Centaurea's home range. In native European soils, Centaurea cultivates soil biota with increasingly negative effects on the weed's growth, possibly leading to its control. But in soils from North America, Centaurea cultivates soil biota with increasingly positive effects on itself, which may contribute to the success of this exotic species in North America. PMID:14973484

  7. Ediacaran Biota from Sonora, Mexico

    Microsoft Academic Search

    Mark A. S. McMenamin

    1996-01-01

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

  8. Growth ratestoichiometry couplings in diverse biota

    E-print Network

    Markow, Therese

    REPORT Growth rate­stoichiometry couplings in diverse biota J. J. Elser1 *, K. Acharya1 , M. Kyle1 stoichiometry provides a mechanistic theory linking cellular and biochemical features of co-evolving biota : P ratios) of many biota (Elser et al. 2000a,c). The GRH therefore connects the evolution of a major

  9. OBSERVATIONS ON FISHES AND OTHER BIOTA OF

    E-print Network

    344 OBSERVATIONS ON FISHES AND OTHER BIOTA OF EAST LAGOON, GALVESTON ISLAND Marino Biological BIOTA OF EAST LAGOON, GALVESTON ISLAND By Edgar L. Arnold, Jr., Ray S. Wheeler, and Kenneth N. Baxter of plankton sets of culverts. #12;OBSERVATIONS ON FISHES AND OTHER BIOTA OF EAST LAGOON, GALVESTON ISLAND

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

    PubMed

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

    2011-04-01

    Bioaccumulation of key short-lived radionuclides such as (131)I and (32,33)P may be over-estimated since concentration ratios (CRs) are often based on values for the corresponding stable isotope which do not account for radioactive decay during uptake via the food chain. This study presents estimates for bioaccumulation of radioactive phosphorus which account for both radioactive decay and varying ambient levels of stable P in the environment. Recommended interim CR values for radioactive forms of P as a function of bioavailable stable phosphorus in the water body are presented. Values of CR are presented for three different trophic levels of the aquatic food chain; foodstuffs from all three trophic levels may potentially be consumed by humans. It is concluded that current recommended values of the CR are likely to be significantly over-estimated for radioactive phosphorus in many freshwater systems, particularly lowland rivers. Further research is recommended to field-validate these models and assess their uncertainty. The relative importance of food-chain uptake and direct uptake from water are also assessed from a review of the literature. It can be concluded that food-chain uptake is the dominant accumulation pathway in fish and hence accumulation factors for radioactive phosphorus in farmed fish are likely to be significantly lower than those for wild fish. PMID:21324571

  11. Ediacaran biota from Sonora, Mexico.

    PubMed

    McMenamin, M A

    1996-05-14

    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-dwelling animals in this shallow marine community. The body fossils are headless, tailless, and appendageless. Some may be body fossils of animals but others may be fossils of large protoctists. These body and trace fossils, recovered from thinly bedded sandstones and siltstones, occur 75 meters lower in the Sonoran stratigraphic section than a distinctive Clemente Formation oolite. The stratigraphic position of the fossils below this oolite permits long-distance correlation between fossiliferous Proterozoic strata of Mexico and the United States. Correlations utilizing both the Clemente Formation oolite and a trace fossil (Vermiforma antiqua) confirm the antiquity (600 million years or more) of this body fossil-rich community of macroscopic eukaryotes. The recently discovered body fossils are the oldest known remains of the Ediacaran biota. PMID:11607679

  12. The Rhynie hot-spring system: implications for the Devonian timescale, development of Devonian biota, gold mineralization, evolution of the atmosphere and Earth outgassing

    NASA Astrophysics Data System (ADS)

    Mark, D.; Rice, C.; Stuart, F.; Trewin, N.

    2011-12-01

    The Rhynie cherts are hot spring sinters that contain world-renowned plant and animal remains and anomalously high quantities of heavy metals, including gold. The biota in several beds is preserved undeformed with plants in life positions thus establishing that they and the indurating hydrothermal fluids were coeval. Despite the international importance of the Rhynie cherts their age has been poorly constrained for three reasons: (1) lack of a precise radio-isotopic age, (2) low resolution of spore biostratigraphic schemes for Devonian terrestrial deposits, with only one to a few zones per stage, and (3) poor resolution of the early Devonian timescale. Wellman (2004) assigned a Pragian-?earliest Emsian age to the Rhynie cherts on the basis of the spore assemblage. An 40Ar/39Ar dating study targeting Rhynie chert yielded an age of 395 ± 12 Ma (1?) (Rice et al., 1995). This contribution discusses a new high-precision 40Ar/39Ar age (407.1 ± 2.2 Ma, 2?) for the Devonian hot-spring system at Rhynie (Mark et al., 2011) and demonstrates that a proposed U-Pb age (411.5 ± 1.1 Ma, 2?) for the Rhynie cherts (Parry et al., 2011) is inconsistent with both field evidence and our interpretation of the U-Pb data. The 40Ar/39Ar age provides a robust marker for the polygonalis-emsiensis Spore Assemblage Biozone within the Pragian-?earliest Emsian. It also constrains the age of a wealth of flora and fauna preserved in life positions as well as dating gold mineralization. Furthermore, we have now determined the Ar isotope composition of pristine samples of the Rhynie chert using an ARGUS multi-collector mass spectrometer and a low blank laser extraction technique. 40Ar/36Ar are systematically lower than the modern air value (Lee et al., 2006), and are not accompanied by non-atmospheric 38Ar/36Ar ratios. We conclude that the Rhynie chert captured and has preserved Devonian atmosphere-derived Ar. The data indicate that the 40Ar/36Ar of Devonian atmosphere was at least 3 % lower than the modern air value (Lee et al., 2006). Thus the Earth's atmosphere has accumulated at least 5 ± 0.2 x 1016 moles of 40Ar in the last c. 407 Ma, at an average rate of 1.24 ± 0.06 x 108 mol 40Ar/year. This overlaps the 40Ar accumulation rate determined from ice cores for the last 800,000 years (Bender et al. 2008) and implies that there has been no resolvable temporal change in outgassing rate since the mid-Palaeozoic. The new chronological and Ar isotope data provide a unique tie point and dictate outgassing of the Earth's interior early in Earth history. [1] Bender, M. et al. (2008) Proceedings of the National Academy of Sciences, 105, 8232-8237. [2] Wellman, C.H., 2004. Proceedings of the Royal Society of London. Biological Sciences, 271, 985-992. [3] Lee, J.Y. et al. (2006) Geochimica et Cosmochimica Acta, 70, 4507-4512. [4] Mark, D.F. et al. (2011) Geochimica et Cosmochimica Acta, 75, 555-569. [5] Parry, S.F. et al. (2011) Journal of the Geological Society, London, 168, 863-872. [6] Rice, C.M. et al. (1995) Journal of the Geological Society, London, 152, 229-2250.

  13. Factors affecting the organochlorine pollutant load in biota of a rice field ecosystem (Ebro Delta, NE Spain)

    Microsoft Academic Search

    D. Pastor; C. Sanpera; J. González-Sol??s; X. Ruiz; J. Albaigés

    2004-01-01

    The concentrations of PCBs, DDTs, HCHs, HCB and OCS were determined in sediments and associated biota, both invertebrates (Physella acuta, Hirudo medicinalis, chironomid larvae, Hydrous pistaceus, Helochares lividus) and vertebrates (Rana perezi), in a temporary aquatic system, a rice field in the Ebro Delta (NE Spain). The qualitative and quantitative distribution of organochlorine compounds in sediments and aquatic biota has

  14. Biochar effects on soil biota – A review

    Microsoft Academic Search

    Johannes Lehmann; Matthias C. Rillig; Janice Thies; Caroline A. Masiello; William C. Hockaday; David Crowley

    2011-01-01

    Soil amendment with biochar is evaluated globally as a means to improve soil fertility and to mitigate climate change. However, the effects of biochar on soil biota have received much less attention than its effects on soil chemical properties. A review of the literature reveals a significant number of early studies on biochar-type materials as soil amendments either for managing

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

    SciTech Connect

    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

    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.

  16. Redistribution of soil biota by rainfall erosion

    NASA Astrophysics Data System (ADS)

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

    2013-04-01

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

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

    Microsoft Academic Search

    Guy M. Narbonne

    2005-01-01

    The Ediacara biota (575-542 Ma) marks the first appearance of large, architecturally complex organisms in Earth history. Present evidence suggests that the Ediacara biota included a mixture of stem- and crown-group radial animals, stem-group bilaterian animals, \\

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

    SciTech Connect

    NONE

    2004-01-14

    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.

  19. The problem of permissible doses of irradiation for biota

    SciTech Connect

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

    1995-07-01

    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.

  20. Pollution due to volatile halocarbon compounds in biota

    SciTech Connect

    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

    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.

  1. Residues of organochlorine insecticides, polychlorinated biphenyls, and heavy metals in biota from Apalachicola River, Florida, 1978.

    PubMed

    Winger, P V; Sieckman, C; May, T W; Johnson, W W

    1984-01-01

    Seventy-seven composite samples composed of largemouth bass ( Micropterus salmoides ), channel catfish ( Ictaluras punctatus), threadfin shad ( Dorosoma petenense ), Asiatic clam (Corbicula fluminea ), burrowing mayfly ( Hexagenia sp.), water snake ( Natrix spp.), and little green heron ( Butorides virescens ) were collected from upper and lower reaches of the Apalachicola River, Florida, in 1978 for residue analysis of organochlorine insecticides, PCBs (polychlorinated biphenyls), and metals. Compared with data from the National Pesticide Monitoring Program and criteria recommended for the protection of aquatic life, residue concentrations were moderately high in the Apalachicola River. Biota from the upper river generally had higher organic and lower metal residues than those from the lower river. Highest residues in the biota were total DDT, total PCBs, and toxaphene. Although individual mean concentrations were below 2 micrograms/g and total organic contaminant residues never exceeded 5 micrograms/g, residue concentrations of DDT, PCBs, and toxaphene (particularly from the upper river) exceeded recommended permissible levels for the protection of aquatic life. Metal residues were generally below 1 microgram/g. Exceptions were arsenic residues in threadfin shad (1.07 micrograms/g) and Asiatic clams (1.75 micrograms/g), and selenium in eggs of channel catfish (1.39 micrograms/g). The residues observed in the biota, particularly from the upper station, indicated moderate contamination of the Apalachicola River system at the time samples were collected. PMID:6427177

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

    PubMed

    Kryshev, A I; Sazykina, T G

    2012-06-01

    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. PMID:21924530

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

    PubMed

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

    2014-11-01

    A pilot study aimed on possible occurrence of elevated activity of non-exchangable organically bound tritium (NE-OBT) in biota was performed. The first results showed a significant surplus of NE-OBT activity in biota of the valley of Mohelno reservoir and Jihlava river. The liquid releases of HTO from the nuclear power plant Dukovany is the source of tritium in this area. This area can be a source of various types of natural samples for future studies of tritium pathways. PMID:24582481

  4. Becoming New Zealanders: Immigration and the Formation of the Biota

    Microsoft Academic Search

    M. S. McGlone

    Plants and animals have been flying, drifting, swimming and floating to the New Zealand archipelago over the millions of years in which it has been in existence. The continuing interaction of invader and resident has had a powerful influence on the formation of the biota. The current fauna and flora therefore represent the cumulative outcome of many cycles of invasion,

  5. Growth rate-stoichiometry couplings in diverse biota

    Microsoft Academic Search

    J. J. Elser; K. Acharya; M. Kyle; J. Cotner; W. Makino; T. Markow; T. Watts; S. Hobbie; W. Fagan; J. Schade; J. Hood; R. W. Sterner

    2003-01-01

    Biological stoichiometry provides a mechanistic theory linking cellular and biochemical features of co-evolving biota with constraints imposed by ecosystem energy and nutrient inputs. Thus, understanding variation in biomass carbon : nitrogen : phosphorus (C : N : P) stoichiometry is a major priority for integrative biology. Among various factors affecting organism stoichiometry, differences in C : P and N :

  6. Assessing Exposure of Marine Biota and Habitats to Petroleum Compounds

    NSDL National Science Digital Library

    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.

  7. Nitro musk fragrances in biota from freshwater and marine environment

    Microsoft Academic Search

    Gerhard G. Rimkus; Manfred Wolf

    1995-01-01

    The nitro musks - musk xylene, musk ketone, musk ambrette, musk moskene, and musk tibetene - are intensively used as fragrances in cosmetics and detergents. The residue analysis (clean-up and GC\\/ECD analysis) of nitro musks in biota from freshwater and marine environment is described. In particular musk xylene and musk ketone were determined in a total of 145 samples of

  8. Comparing Laboratory and Field Measured Biota-sediment Accumulation Factors

    EPA Science Inventory

    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...

  9. PROTECTION OF CAVE SPRINGS CAVE BIOTA AND GROUNDWATER BASIN

    E-print Network

    Soerens, Thomas

    been quite effective, and this investment is being leveraged to benefit other endangered species, Ozark Underground Laboratory, provided information on the cave's groundwater basin boundary. Cover image of endangered biota and of environmental quality in Cave Springs Cave (CSC), Benton County, Arkansas (Brown et

  10. Empirical Estimation of Biota Exposure Range for Calculation of Bioaccumulation Parameters

    E-print Network

    Empirical Estimation of Biota Exposure Range for Calculation of Bioaccumulation Parameters Aroon R) and biota­sediment accumulation factors (BSAFs) are frequently used to predict contaminant bioaccumulation the spatial scale of contaminant transfer from sediments to biota. We present a simple statistical method

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

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

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

  12. Biota Neotropica is an eletronic journal which is available free at the following site http://www.biotaneotropica.org.br

    E-print Network

    Paiva, Paulo Cesar de

    Biota Neotropica is an eletronic journal which is available free at the following site http://www.biotaneotropica.org.br A Biota Neotropica é uma revista eletrônica e está integral e gratuitamente disponível no endereço http://www.biotaneotropica.org.br Biota Neotropica is an electronic, peer-reviewed journal edited by the Program BIOTA/FAPESP: The Virtual

  13. Molecular Analysis of Human Forearm Superficial Skin Bacterial Biota

    Microsoft Academic Search

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

    2007-01-01

    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

  14. Human colonic biota studied by ribosomal DNA sequence analysis

    Microsoft Academic Search

    KENNETH H. WILSON; R. B. Blitchington

    1996-01-01

    Human colonic biota is a complex microbial ecosystem that serves as a host defense. Unlike most microbial ecosystems, its composition has been studied extensively by relatively efficient culture methods. We have compared an established culture-based method with direct amplification and partial sequencing of cloned 16S rRNAgenesfromahumanfecalspecimen.NinecyclesofPCRwerealsocomparedwith35cycles.Coloniesand clonedampliconswereclassifiedbycomparingtheirribosomalDNA(rDNA;DNAcodingforrRNA)sequences with rDNA sequences of known phylogeny. Quantitative culture recovered 58% of the microscopic

  15. Responses of soil biota to elevated atmospheric carbon dioxide

    Microsoft Academic Search

    Elizabeth G. O'Neill

    1994-01-01

    Increasing concentrations of atmospheric CO2 could have dramatic effects upon terrestrial ecosystems including changes in ecosystem structure, nutrient cycling rates,\\u000a net primary production, C source-sink relationships and successional patterns. All of these potential changes will be constrained\\u000a to some degree by below ground processes and mediated by responses of soil biota to indirect effects of CO2 enrichment. A review of

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

    NASA Astrophysics Data System (ADS)

    Narbonne, Guy M.

    2005-01-01

    The Ediacara biota (575-542 Ma) marks the first appearance of large, architecturally complex organisms in Earth history. Present evidence suggests that the Ediacara biota included a mixture of stem- and crown-group radial animals, stem-group bilaterian animals, "failed experiments" in animal evolution, and perhaps representatives of other eukaryotic kingdoms. These soft-bodied organisms were preserved under (or rarely within) event beds of sand or volcanic ash, and four distinct preservational styles (Flinders-, Fermeuse-, Conception-, and Nama-style) profoundly affected the types of organisms and features that could be preserved. Even the earliest Ediacaran communities (575-565 Ma) show vertical and lateral niche subdivision of the sessile, benthic, filter-feeding organisms, which is strikingly like that of Phanerozoic and modern communities. Later biological and ecological innovations include mobility (>555 Ma), calcification (550 Ma), and predation (<549 Ma). The Ediacara biota abruptly disappeared 542 million years ago, probably as a consequence of mass extinction andor biological interactions with the rapidly evolving animals of the Cambrian explosio

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

    SciTech Connect

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

    1998-09-01

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

  18. Understanding ecosystem dynamics for conservation of biota

    Microsoft Academic Search

    A. R. E. SINCLAIR; ANDREA E. BYROM

    2006-01-01

    Summary 1. Ecosystems have higher-order emerging properties that can affect the conservation of species. We identify some of these properties in order to facilitate a better understanding of them. 2. Nonlinear, indirect effects of food web interactions among species can produce counterintuitive changes in populations. 3. Species differ in their roles and linkages with other species in the system. These

  19. Ecological considerations for possible Martian biota

    NASA Technical Reports Server (NTRS)

    Klingler, June M.; Mancinelli, Rocco L.; White, Melisa R.

    1989-01-01

    Current climatic and geological evidence suggests that, like early Earth, conditions on ancient Mars may also have been favorable for the origin and evolution of life. The primordial atmospheres of the two planets were quite similar, composed primarily of CO2, N2, and water vapor at a total atmospheric pressure of approximately 1 bar. Each of these gases are important for the evolution of biological systems. With the exception of nitrogen, there seems to have been a sufficient supply of the biogenic elements C, H, O, P, and S (CHOPS) on early Mars for life to have evolved. It was postulated that primordial Mars contained only 18 mb of nitrogen in the form of N2 given that only fixed nitrogen is utilized by living systems. Laboratory tests performed at a total pressure of 1 bar and various partial pressures of dinitrogen (pN2 1-780 mb) show that nitrogen fixing organisms grow at pN2's of 18 mb or less, although the biomass and growth rates are decreased. The calcualted in vivo Km's ranged from 46 mb to 130 mb. If organisms adapted on Earth to a pH2 of 780 mb are capable of growing at these low partial pressures, it is conceivable that nitrogen was not the limiting factor in the evolution of life on early Mars.

  20. Factors affecting the organochlorine pollutant load in biota of a rice field ecosystem (Ebro Delta, NE Spain).

    PubMed

    Pastor, D; Sanpera, C; González-Solís, J; Ruiz, X; Albaigés, J

    2004-04-01

    The concentrations of PCBs, DDTs, HCHs, HCB and OCS were determined in sediments and associated biota, both invertebrates (Physella acuta, Hirudo medicinalis, chironomid larvae, Hydrous pistaceus, Helochares lividus) and vertebrates (Rana perezi), in a temporary aquatic system, a rice field in the Ebro Delta (NE Spain). The qualitative and quantitative distribution of organochlorine compounds in sediments and aquatic biota has been explained by two mechanisms: equilibrium partitioning and/or biomagnification through the trophic web. Nevertheless, bioaccumulation processes are by far more complex, since several biotic and abiotic factors contribute to the observed pollutant loads in the organisms. In this respect, the biological characteristics of the organisms considered (e.g. species, age, lipid contents, feeding habits, etc.), as well as ecological factors (e.g. the habitat of the species and vertical distribution), have been shown to account for the organochlorine levels observed. PMID:15006509

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

    PubMed

    Muscatello, J R; Janz, D M

    2009-02-01

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

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

    PubMed

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

    2014-08-01

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

  3. Impact of Drainage Channel Improvement Works on Fish Biota

    NASA Astrophysics Data System (ADS)

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

    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.

  4. Status and health of biota at the Rocky Mountain Arsenal

    SciTech Connect

    Macrander, A.M.; Mackey, C.V.; Reagen, D.P.; Tate, D.J.

    1994-12-31

    Field studies have been conducted on the populations and communities of the biota at Rocky Mountain Arsenal (RMA) since the late 1950`s. While earlier studies were primarily documentation of mortality events, a diverse program of studies conducted since 1982 has assessed a number of relevant endpoints. Studies of sedentary species (e.g. plants, earthworm, grasshoppers) focused on contaminated areas within RMA to identify potential contaminant effects. Studies on more mobile species (e.g. deer, great horned owls, kestrels) were conducted throughout RMA to evaluate effects on their RMA-wide populations. Both on- and off-post reference sites were used in some of the studies. Ecological endpoints were selected that were focused upon the population-level effects that could have a causal relationship to the RMA contaminants, such as population abundance and reproductive success, biomarkers, and community organization. Current EPA guidance on conducting ecological risk assessment encourages the use of observational field studies. Although many of these studies were conducted prior to the issuance of this guidance, they are consistent with its scope and intent. Investigators on the effects of contamination at RMA during the past decade indicate that while some effects may still be present in biota at RMA, the wildlife communities and populations are viable and appear healthy.

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

    SciTech Connect

    Yankovich, T.L.; Sharp, K.J.; Benz, M.L.; Carr, J.; Killey, R.W.D. [Atomic Energy of Canada Limited, Chalk River Laboratories, Chalk River, Ontario K0J 1P0 (Canada)

    2008-01-15

    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 ({sup 14}C), a radionuclide with dynamics in natural systems that can be described using a specific activity model; and - To determine whether {sup 14}C 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 {sup 14}C in Duke Swamp, a wetland ecosystem on Atomic Energy of Canada Limited (AECL)'s Chalk River Laboratories (CRL) site that receives {sup 14}C 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 {sup 14}C concentrations. Concentrations of {sup 14}C 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, {sup 14}C 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 {sup 14}C 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 {sup 14}C 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 {sup 14}C 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 {sup 14}C levels in amphibians relative to the environmental media may be due to increased {sup 14}C exposure of aquatic or amphibious animals that occupy systems receiving inputs via groundwater. In such systems, {sup 14}C 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 {sup 14}C in receptor biota in w

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

    EPA Science Inventory

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

  7. Zinc in the sediments, water and biota of Lake Burley Griffin, Canberra

    E-print Network

    Canberra, University of

    HI 235 Zinc in the sediments, water and biota of Lake Burley Griffin, Canberra W.A. Maher, RResearchCentre. Universityo/Canberra. P.O. Box /. BelconnenACT 26/6. Australia ABSTRAcr Zinc concentrations and total amounts in the sediment, water and biota of Lake Burley Griffin were measured to identify where zinc originating from

  8. The importance of the biodiversity of soil biota in arid ecosystems

    Microsoft Academic Search

    Walter G. Whitford

    1996-01-01

    The importance of soil biota in maintaining ecosytem integrity is examined by a review of studies of soil processes and soil biota in arid ecosystems. In decomposition and mineralization processes, there is a temporal succession of microarthropod and nematode species. Tydeid mites are keystone species in the early stages of decomposition. Soil pore neck size variation affects the spatial distribution

  9. Nested biotas and biological conservation: metrics, mechanisms, and meaning of nestedness

    Microsoft Academic Search

    Alan H. Cutler

    1994-01-01

    The biotas of archipelagos and fragmented habitats frequently show a 'nested' structure. That is, the species composition of a small island or fragment tends to be a subset of the next larger island or fragment, and the set of biotas as a whole forms a nested series. Several indices exist that allow 'nestedness' to be quantified and its statistical significance

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

    NASA Astrophysics Data System (ADS)

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

    2014-03-01

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

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

    PubMed

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

    2014-01-01

    Microplastic litter is a pervasive pollutant present in aquatic systems across the globe. A range of marine organisms have the capacity to ingest microplastics, resulting in adverse health effects. Developing methods to accurately quantify microplastics in productive marine waters, and those internalized by marine organisms, is of growing importance. Here we investigate the efficacy of using acid, alkaline and enzymatic digestion techniques in mineralizing biological material from marine surface trawls to reveal any microplastics present. Our optimized enzymatic protocol can digest >97% (by weight) of the material present in plankton-rich seawater samples without destroying any microplastic debris present. In applying the method to replicate marine samples from the western English Channel, we identified 0.27 microplastics m(-3). The protocol was further used to extract microplastics ingested by marine zooplankton under laboratory conditions. Our findings illustrate that enzymatic digestion can aid the detection of microplastic debris within seawater samples and marine biota. PMID:24681661

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

    PubMed Central

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

    2014-01-01

    Microplastic litter is a pervasive pollutant present in aquatic systems across the globe. A range of marine organisms have the capacity to ingest microplastics, resulting in adverse health effects. Developing methods to accurately quantify microplastics in productive marine waters, and those internalized by marine organisms, is of growing importance. Here we investigate the efficacy of using acid, alkaline and enzymatic digestion techniques in mineralizing biological material from marine surface trawls to reveal any microplastics present. Our optimized enzymatic protocol can digest >97% (by weight) of the material present in plankton-rich seawater samples without destroying any microplastic debris present. In applying the method to replicate marine samples from the western English Channel, we identified 0.27 microplastics m?3. The protocol was further used to extract microplastics ingested by marine zooplankton under laboratory conditions. Our findings illustrate that enzymatic digestion can aid the detection of microplastic debris within seawater samples and marine biota. PMID:24681661

  13. Effects of drainage on water, sediment and biota

    USGS Publications Warehouse

    Engberg, Richard A.; Sylvester, Marc A.; Feltz, Herman R.

    1991-01-01

    The U.S. Department of the Interior started a program in 1985 to identify effects of irrigation-induced trace constituents in water, bottom sediment and biota. The program was developed in response to concerns that contamination similar to that found in 1983 at Kesterson Reservoir in California might exist elsewhere. Studies are complete or underway for 26 sites in 15 western States. Selenium is the trace constituent most often found at elevated concentrations in all media. Maximum selenium concentrations in fish from 9 of 20 areas exceeded the threshold concentration for adverse reproductive effects. Maximum selenium concentrations in bird livers from 11 areas exceeded the level at which embryonic deformities are likely; deformed birds were observed in 5 areas. Trace constituent problems may be anticipated if geologic sources such as marine shales occur in an irrigation project area. The potential for problems is increased if closed basins or sinks are present.

  14. The Human Vaginal Bacterial Biota and Bacterial Vaginosis

    PubMed Central

    Srinivasan, Sujatha; Fredricks, David N.

    2008-01-01

    The bacterial biota of the human vagina can have a profound impact on the health of women and their neonates. Changes in the vaginal microbiota have been associated with several adverse health outcomes including premature birth, pelvic inflammatory disease, and acquisition of HIV infection. Cultivation-independent molecular methods have provided new insights regarding bacterial diversity in this important niche, particularly in women with the common condition bacterial vaginosis (BV). PCR methods have shown that women with BV have complex communities of vaginal bacteria that include many fastidious species, particularly from the phyla Bacteroidetes and Actinobacteria. Healthy women are mostly colonized with lactobacilli such as Lactobacillus crispatus, Lactobacillus jensenii, and Lactobacillus iners, though a variety of other bacteria may be present. The microbiology of BV is heterogeneous. The presence of Gardnerella vaginalis and Atopobium vaginae coating the vaginal epithelium in some subjects with BV suggests that biofilms may contribute to this condition. PMID:19282975

  15. Diane Wagner Mark J.F. Brown Deborah M. Gordon Harvester ant nests, soil biota and soil chemistry

    E-print Network

    Gordon, Deborah

    Diane Wagner á Mark J.F. Brown á Deborah M. Gordon Harvester ant nests, soil biota and soil for the soil biota. We ex- amined the eect of harvester ant nests (Pogonomyrmex barbatus) on the soil community. barbatus nests constitute a signi®cant source of spatial heterogeneity in soil biota and soil chemistry

  16. ENANTIOMERIC COMPOSITION OF CHIRAL POLYCHLORINATED BIPHENYL ATROPISOMERS IN AQUATIC AND RIPARIAN BIOTA

    EPA Science Inventory

    The enantiomeric composition of polychlorinated biphenyl (PCB) atropisomers was measured in river and riparian biota (fish, bivalves, crayfish, water snakes, barn swallows) from selected sites throughout the United States by using chiral gas chromatography/mass spectrometry. Nonr...

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

    Microsoft Academic Search

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

    1984-01-01

    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

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

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

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

  19. Linking stormflow hydrology and biota in suburban streams

    NASA Astrophysics Data System (ADS)

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

    2005-12-01

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

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

    SciTech Connect

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

    1995-12-31

    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.

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

    SciTech Connect

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

    1995-12-31

    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.

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

    USGS Publications Warehouse

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

    1988-01-01

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

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

    USGS Publications Warehouse

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

    2015-01-01

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

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

    NASA Astrophysics Data System (ADS)

    Forbes, Matthew; Vogwill, Ryan

    2012-02-01

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

  5. Long-term affects of experimental flows on riverine biota below a reservoir

    NASA Astrophysics Data System (ADS)

    Robinson, Chris; Ortlepp, Johannes

    2010-05-01

    Large dams have altered the flow regime of most rivers on the globe with consequent effects on riverine biota. Experimental flows (multiple floods per year) have been used on the regulated Spöl River below Livigno Reservoir for over 9 years to enhance the ecological condition of the river. The flow program has improved the brown trout fishery in the river as indicated by an increased number of redds. Floods have reset periphyton assemblages from a moss-dominated streambed to one dominated by diatoms and patches of filamentous algae. Zoobenthic assemblages have shown dramatic shifts in benthic structure in line with predictions from altered state models. Ecosystem regime shifts have been characterized with increases in parameter variances followed by periods of stable states. The system appears to be entering a second zoobenthic regime shift after year 8, perhaps in response to biotic interactions due to changes in the fishery. The response patterns clearly show that a long-term perspective must be in place when assessing biotic responses to changes in physical habitat properties resulting from flow experiments.

  6. Mass extinction of the marine biota at the Ordovician-Silurian transition due to environmental changes

    NASA Astrophysics Data System (ADS)

    Barash, M. S.

    2014-11-01

    The terminal Ordovician was marked by one of five great mass extinction events of the Phanerozoic (445.6-443.0 Ma ago), when up to 86% of the marine species became extinct. The rapid onset of the continental glaciation on Gondwana determined by its position in the South Pole area; the cooling; the hydrodynamic changes through the entire water column in the World Ocean; and the corresponding sea level fall, which was responsible for the reduction of shelf areas and shallow-water basins, i.e., the main ecological niche of the Ordovician marine biota, were main prerequisites of the stress conditions. Similar to other mass extinction events, these processes were accompanied by volcanism, impact events, a corresponding reduction of the photosynthesis and bioproductivity, the destruction of food chains, and anoxia. The appearance and development of terrestrial plants and microphytoplankton, which consumed atmospheric carbon dioxide, thus, diminishing the greenhouse effect and promoting the transition of the climatic system to the glacial mode, played a unique role in that period.

  7. Interaction of the reasons for the mass biota extinctions in the Phanerozoic

    NASA Astrophysics Data System (ADS)

    Barash, M. S.

    2013-11-01

    The consideration of the conditions during the mass extinctions has shown that a series of factors, including mutually independent tectonic movements, variations in the sea level and climate, volcanism, asteroid impacts, changes in the composition of the atmosphere and hydrosphere, the dimming of the atmosphere by aerosols at volcanism and impact events, etc., had a harmful affect during some periods of time (a hundred thousand years to millions of years). Some of the listed events occurred for a long period of time and could not have caused the abrupt catastrophic death of organisms on a global scale. The examination of the hierarchy of the major events allows us to distinguish the primary terrestrial (volcanism) and cosmic (impact events) reasons for the mass extinctions. The coeval mutually independent events testify to the common external reasons for the higher order beyond the solar system. These events are suggested to be related with the orbital movement of the solar system around the galaxy's center, the intersection of the galactic branches, and the oscillations of the solar system's position relative to the galactic plane. These reasons influence the processes on the Earth, including the internal and external geospheres, and activate the impacts of asteroids and comets. Under their effect, two main subsequences of events are developed: terrestrial, leading to intense volcanism, and cosmic impact events. In both cases, harmful chemical elements and aerosols are vented to the atmosphere, thus resulting in the greenhouse effect, warming, the dimming of the atmosphere, the prevention of photosynthesis, the ocean's stagnation, and anoxia with the following reduction of the bioproductivity, the destruction of the food chains, and the extinction of a significant part of the biota.

  8. When the Fog Clears: Long-Term Monitoring of Fog and Fog-Dependent Biota in the Namib Desert

    NASA Astrophysics Data System (ADS)

    Logan, J. R. V.

    2014-12-01

    The Gobabeb Research and Training Centre in western Namibia is currently undertaking several efforts to enhance long-term atmospheric and fog monitoring in the central Namib Desert and to measure how fog-dependent biota are responding to global change. In an environment that receives regular sea fog and a mean annual rainfall of only 25 mm, Gobabeb is ideally situated to study the drivers and ecological role of fog in arid environments. Currently more than ten meteorological projects perform measurements at or close to Gobabeb. These projects include continuous trace gas measurements, fog isotope sampling, in situ surface radiation measurements, land surface temperature and other satellite validation studies, and multiple aerosol/dust monitoring projects; most of these projects are also components in other global monitoring networks. To these projects, Gobabeb has recently added a network of nine autonomous weather stations spanning the central Namib that will continuously collect basic meteorological data over an area of approximately 70x70 km. Using this data in conjunction with modeling efforts will expand our understanding of fog formation and the linkages between fog and the Benguela Current off Namibia's coast. Historical weather data from previous meteorological stations and satellite observations will also enable development of a fog time series for the last 50 years to determine climate variability driven by possible changes in the Benguela Current system. To complement these efforts, Gobabeb is also expanding its decades-old ecological research programs to explore the impacts of the fog on the region's biota at various time and spatial scales. Gobabeb's long-term, multidisciplinary projects can serve as a prototype for monitoring in other fog-affected systems, together increasing our understanding of coastal fog dynamics, land-atmosphere-ocean connections, and the impacts of fog-related global change.

  9. EVALUATION OF THE USE OF LANDSCAPE CLASSIFICATIONS FOR THE PREDICTION OF FRESHWATER BIOTA: SYNTHESIS AND RECOMMENDATIONS

    EPA Science Inventory

    This paper summarizes and synthesizes the collective results that emerged from the series of papers published in this issue of J-NABS, and places these results in the context of previously published literature describing variation in aquatic biota at landscape spatial scales. Cla...

  10. A Preliminary Study of the Marine Biota at Navassa Island, Caribbean Sea

    E-print Network

    A Preliminary Study of the Marine Biota at Navassa Island, Caribbean Sea MARK GRACE, MELISSA.gov]. ABSTRACT--A preliminary study of reef fish and sharks was conducted at Navassa Island in the Caribbean Sea remote loca tion (southwest of the Windward Passage, Caribbean Sea) and lack of human habi tation. Reef

  11. Project EARTH09-MDB2: ECOLOGY AND TAPHONOMY OF THE EDIACARA BIOTA

    Microsoft Academic Search

    Martin Brasier; Duncan McIlroy

    The transition from a thoroughly alien Ediacaran world to a fully formed and recognisable modern ecological structure by the Middle Cambrian presents palaeobiologists with a series of major puzzles. Not least of these puzzles is the enigma of the Ediacara biota, which contains the oldest known macroscopic 'animal' fossil remains. The Oxford group has a major project on the evolution

  12. SOME BIOACCUMULATION FACTORS AND BIOTA-SEDIMENT ACCUMULATION FACTORS FOR POLYCYCLIC AROMATIC HYDROCARBONS IN LAKE TROUT

    EPA Science Inventory

    Bioaccumulation factors (BAFs) and biota-sediment accumulation factors (BSAFs) for phenanthrene, fluoranthene, pyrene, benz[a]anthracene, and chrysene/triphenylene were calculated using the tissue data of Zabik et al. for Salvelinus namaycush siscovet with 20.5% lipid content, th...

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

    EPA Science Inventory

    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 ...

  14. Chlorinated hydrocarbons in marine biota and coastal sediments from the Gulf and Gulf of Oman

    Microsoft Academic Search

    Stephen de Mora; Scott W. Fowler; Imma Tolosa; Jean-Pierre Villeneuve; Chantal Cattini

    2005-01-01

    The spatial distribution of various organochlorinated compounds was investigated in the Gulf and Gulf of Oman based on marine biota (fish and various bivalves) and coastal sediment collected in Bahrain, Oman, Qatar and the United Arab Emirates (UAE) during 2000–2001. Several potential organic contaminants from agricultural (e.g., DDT and its breakdown products, lindane, endrin, dieldrin, endosulfan) and industrial (PCBs) sources

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

    PubMed Central

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

    2014-01-01

    In this paper we analyse the degree of concordance in species richness and taxonomic distinctness (diversity) patterns among different freshwater taxonomic groups in order to test three long held patterns described in Mexican freshwater biogeography: 1. The aquatic biota of Mexico includes two distinct faunas, a rich Neotropical component in the south and a south-eastern region and a less rich Nearctic component towards central and northern latitudes of the country. 2. A hotspot of species richness and diversity has been recorded in the Usumacinta, including the Yucatan Peninsula. 3. The presence of two distinct biotas in Mexico, an eastern one distributed along the Gulf of Mexico slope, and a western one associated to the Pacific versant. We use species richness and taxonomic distinctness to explore patterns of diversity and how these patterns change between zoogeographical regions. This paper points out a clear separation between Neotropical and Nearctic drainage basins but also between eastern (Gulf of Mexico) and western (Pacific) drainage basins. Present data gives additional empirical support from freshwater biota for three long held beliefs regarding distributional patterns of the Mexican biota. The neotropical basins of Mexico are generally host to a richest and more diversified fauna, that includes more families, genera and species, compared to the less rich and less diverse fauna in the nearctic basins. PMID:25136979

  16. Radiological dose conversion factors for generic non-human biota used for screening potential ecological impacts

    Microsoft Academic Search

    B. D. Amiro

    1997-01-01

    Protection of non-human biota from radionuclides in the environment is an important aspect of many environmental assessments. Biosphere transport models can be used to estimate radionuclide concentrations in plants and animals, and the radiological dose is calculated as the product of concentration and a dose-rate conversion factor (DCF). Here, we calculate and present DCF values for 99 radionuclides that can

  17. A polychlorinated biphenyl (Aroclor 1254) in the water, sediment, and biota of escambia bay, Florida

    Microsoft Academic Search

    T. W. Duke; J. I. Lowe; A. J. Wilson

    1970-01-01

    We have detected a polychlorinated biphenyl (PCB), Aroclor 1254, in the biota, sediment, and water of estuarine areas near Pensacola, Florida~ 0nly one source of the chemical, an industrial plant on the Escambia River, has been located~ However, the chemical occurs in tissues of pelagic and sessile organisms that are widely distributed within the estuary. This distribution of Aroclor 1254

  18. Plantsoil biota interactions and spatial distribution of black cherry in its native and invasive ranges

    E-print Network

    Packer, Alissa A.

    LETTER Plant­soil biota interactions and spatial distribution of black cherry in its native investigated. Here we present evidence showing that the invasion of black cherry (Prunus serotina) into north that develops near black cherry inhibits the establishment of neighbouring conspecifics and reduces seedling

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

    EPA Science Inventory

    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...

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

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

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

  1. http://www.biotaneotropica.org.br/v13n3/en/abstract?article+bn03613032013 http://www.biotaneotropica.org.br Biota Neotrop., vol. 13, no. 3

    E-print Network

    Penz, Carla

    ://www.biotaneotropica.org.br Biota Neotrop., vol. 13, no. 3 Wing pattern diversity in Brassolini butterflies (Nymphalidae, Satyrinae). Biota Neotrop. 13(3): http://www.biotaneotropica.org.br/v13n3/en/abstract?article+bn03613032013 Abstract. Diversidade de padrão das asas em Brassolini (Nymphalidae, Satyrinae). Biota Neotrop. 13(3): http

  2. A method to assess longitudinal riverine connectivity in tropical streams dominated by migratory biota

    USGS Publications Warehouse

    Crook, K.E.; Pringle, C.M.; Freeman, Mary C.

    2009-01-01

    1. One way in which dams affect ecosystem function is by altering the distribution and abundance of aquatic species. 2. Previous studies indicate that migratory shrimps have significant effects on ecosystem processes in Puerto Rican streams, but are vulnerable to impediments to upstream or downstream passage, such as dams and associated water intakes where stream water is withdrawn for human water supplies. Ecological effects of dams and water withdrawals from streams depend on spatial context and temporal variability of flow in relation to the amount of water withdrawn. 3. This paper presents a conceptual model for estimating the probability that an individual shrimp is able to migrate from a stream's headwaters to the estuary as a larva, and then return to the headwaters as a juvenile, given a set of dams and water withdrawals in the stream network. The model is applied to flow and withdrawal data for a set of dams and water withdrawals in the Caribbean National Forest (CNF) in Puerto Rico. 4. The index of longitudinal riverine connectivity (ILRC), is used to classify 17 water intakes in streams draining the CNF as having low, moderate, or high connectivity in terms of shrimp migration in both directions. An in-depth comparison of two streams showed that the stream characterized by higher water withdrawal had low connectivity, even during wet periods. Severity of effects is illustrated by a drought year, where the most downstream intake caused 100% larval shrimp mortality 78% of the year. 5. The ranking system provided by the index can be used as a tool for conservation ecologists and water resource managers to evaluate the relative vulnerability of migratory biota in streams, across different scales (reach-network), to seasonally low flows and extended drought. This information can be used to help evaluate the environmental tradeoffs of future water withdrawals. ?? 2008 John Wiley & Sons, Ltd.

  3. Levels and spatial and temporal trends of contaminants in Greenland biota: an updated review.

    PubMed

    Riget, F; Dietz, R; Vorkamp, K; Johansen, P; Muir, D

    2004-09-20

    Knowledge of contaminant levels in Greenland biota has increased substantially in recent years, particularly for persistent organic pollutants. This paper reviews and updates knowledge of spatial and temporal trends of Cd, Hg and organochlorines (PCBs, DDTs, HCHs, HCB and chlordane-related compounds) in Greenland terrestrial, freshwater and marine biota. The most comprehensive studies of spatial trends of Cd and Hg in the terrestrial ecosystem concern lichens, with relatively complete coverage, and caribou (Rangifer tarandus), with coverage mainly in different regions of central West Greenland and Southwest Greenland. The Arctic char (Salvelinus alpinus) is the only freshwater organism for which studies of spatial trends of Hg levels have been completed. Information on spatial trends of Cd and Hg in the marine environment is available from studies of fish, seabirds, ringed seals (Phoca hispida) and polar bears (Ursus maritimus). Geographical patterns of Cd and Hg in Greenland biota were not always consistent among different species or different studies. In landlocked Arctic char the concentrations of Hg decreased from south to north. In marine animals levels of Hg tended to be higher in East Greenland than in West Greenland and Cd levels were highest in biota from Disko Island in central West Greenland. The observed regional differences are difficult to explain but in most cases the causes appear to be natural rather than anthropogenic. Only a few time series covering the last 20 years exist for Cd and Hg. The one time series indicating a temporal change is for ringed seals in Northwest Greenland, which shows an increasing trend of Hg and a decreasing trend of Cd since 1984. Whether the changes reflect anthropogenic inputs, seal behaviour or other environmental factors is unknown. The most significant new insights have concerned organochlorines. In general, levels of these compounds were very low in terrestrial biota compared to marine species. Concentrations in landlocked Arctic char were highest in Southeast Greenland and lowest in Northwest and Northeast Greenland. Marine species from East Greenland had consistently higher levels of SigmaPCB, SigmaDDT and SigmaHCH than marine species from West Greenland. Very few data exist to evaluate temporal changes of organochlorine levels in Greenland biota, and this is the most significant knowledge gap at present. The most pronounced change observed was a decrease of 78% in SigmaPCB levels in polar bears from East Greenland from 1990 to 2000. Levels of SigmaHCH in shorthorn sculpins (Myoxocephalus scorpius) and seals from both central West Greenland and central East Greenland appear to have decreased since 1994. Increasing trends of SigmaDDT from 1994 until now were found in both sexes of seals as well as in male sculpins from central West Greenland. PMID:15325140

  4. Methodology for Estimating Radiation Dose Rates to Freshwater Biota Exposed to Radionuclides in the Environment

    SciTech Connect

    Blaylock, B.G.

    1993-01-01

    The purpose of this report is to present a methodology for evaluating the potential for aquatic biota to incur effects from exposure to chronic low-level radiation in the environment. Aquatic organisms inhabiting an environment contaminated with radioactivity receive external radiation from radionuclides in water, sediment, and from other biota such as vegetation. Aquatic organisms receive internal radiation from radionuclides ingested via food and water and, in some cases, from radionuclides absorbed through the skin and respiratory organs. Dose rate equations, which have been developed previously, are presented for estimating the radiation dose rate to representative aquatic organisms from alpha, beta, and gamma irradiation from external and internal sources. Tables containing parameter values for calculating radiation doses from selected alpha, beta, and gamma emitters are presented in the appendix to facilitate dose rate calculations. The risk of detrimental effects to aquatic biota from radiation exposure is evaluated by comparing the calculated radiation dose rate to biota to the U.S. Department of Energy's (DOE's) recommended dose rate limit of 0.4 mGy h{sup -1} (1 rad d{sup -1}). A dose rate no greater than 0.4 mGy h{sup -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). The literature identifies the developing eggs and young of some species of teleost fish as the most radiosensitive organisms. DOE recommends that if the results of radiological models or dosimetric measurements indicate that a radiation dose rate of 0.1 mGy h{sup -1} will be exceeded, then a more detailed evaluation of the potential ecological consequences of radiation exposure to endemic populations should be conducted. Dose rates have been calculated for biota in aquatic ecosystems associated with three national laboratories and one uranium mining and milling facility (NCRP 1991). At all sites, the dose rates were two orders of magnitude less than the value recommended by DOE for the protection of populations of aquatic biota. Therefore, it is highly unlikely that aquatic organisms will encounter dose rates in aquatic ecosystems that will be detrimental at the population level other than in man-made bodies of water associated with waste management activities or from accidental releases of radionuclides.

  5. Impacts of Extreme Weather and Climate on Terrestrial Biota

    Microsoft Academic Search

    Camille Parmesan; Terry L. Root; Michael R. Willig

    2000-01-01

    Climate is a driver of biotic systems. It affects individual fitness, population dynamics, distribution and abundance of species, and ecosystem structure and function. Regional variation in climatic regimes creates selective pressures for the evolution of locally adapted physiologies, morphological adaptations (e.g., color patterns, surface textures, body shapes and sizes), and behavioral adaptations (e.g., foraging strategies and breeding systems). In the

  6. Understanding Human Culture as an Event in the Biota

    ERIC Educational Resources Information Center

    Hartley, Peter E.

    1974-01-01

    The role of human feelings as well as physiologicalfacts in ecological concerns is considered. New terms are proposed to facilitate thinking about the ecosystem - the entire system of relationships on which life is contingent. (LS)

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

    SciTech Connect

    Garten, C.T. Jr.; Bondietti, E.A.; Walker, R.L.

    1981-04-01

    The uptake of /sup 238/U, /sup 232/Th, and /sup 239/Pu from soil by fescue, grasshoppers, and small mammals was compared at the contaminated White Oak Creek floodplain in East Tennessee. Comparisons of actinide uptake were based on analyses of radionuclide ratios (U/Pu and Th/Pu) in soil and biota. U:Pu ratios in small mammal carcasses (shrews, mice, and rats) and bone samples from larger mammals (rabbit, woodchuck, opossum, and raccoon) were significantly greater (P less than or equal to 0.05) than U/Pu ratios in soil (based on 8M HNO/sub 3/ extractable). There was no significant difference between Th/Pu ratios in animals and soil. The order of actinide accumulation by biota from the site relative to contaminated soil was U > Th approx. = Pu.

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

    NASA Astrophysics Data System (ADS)

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

    2014-02-01

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

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

    PubMed

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

    2014-01-01

    The lower Cretaceous Yixian and Jiufotang formations contain numerous exceptionally well-preserved invertebrate, vertebrate and plant fossils that comprise the Jehol Biota. Freshwater and terrestrial fossils of the biota usually occur together within some horizons and have been interpreted as deposits of mass mortality events. The nature of the events and the mechanisms behind the exceptional preservation of the fossils, however, are poorly understood. Here, after examining and analysing sediments and residual fossils from several key horizons, we postulate that the causal events were mainly phreatomagmatic eruptions. Pyroclastic density currents were probably responsible for the major causalities and for transporting the bulk of the terrestrial vertebrates from different habitats, such as lizards, birds, non-avian dinosaurs and mammals, into lacustrine environments for burial. Terrestrial vertebrate carcasses transported by and sealed within the pyroclastic flows were clearly preserved as exceptional fossils through this process. PMID:24495913

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

    PubMed

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

    2015-04-01

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

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

    SciTech Connect

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

    2003-06-06

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

  12. Selenium, selected inorganic elements, and organochlorine pesticides in bottom material and biota from the Colorado River delta

    USGS Publications Warehouse

    Garcia-Hernandez, J.; King, K.A.; Velasco, A.L.; Shumilin, E.; Mora, M.A.; Glenn, E.P.

    2001-01-01

    Concentrations of selenium (Se) in bottom material ranged from 0.6 to 5.0 ??g g-1, and from 0.5 to 18.3 ??g g-1 in biota; 23% of samples exceeded the toxic threshold. Concentrations of DDE in biota exceeded the toxic threshold in 30% of the samples. Greater concentrations of selenium in biota were found at sites with strongly reducing conditions, no output, alternating periods of drying and flooding or dredging activities, and at sites that received water directly from the Colorado River. The smallest Se concentrations in biota were found at sites where an outflow and exposure or physical disturbance of the bottom material were uncommon. ?? 2001 Academic Press.

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

    SciTech Connect

    NONE

    1988-07-01

    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.

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

    SciTech Connect

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

    1993-08-01

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

  15. The bacterial biota on crustose (nonarticulated) coralline algae from Tasmanian waters

    Microsoft Academic Search

    Thomas E. Lewis; Christian D. Garland; Thomas A. McMeekin

    1985-01-01

    The bacterial biota associated with the cuticle surface of healthy benthic samples of crustose nonarticulated coralline algae from the east coast of Tasmania (Australia) was examined by bacteriological cultivation and electron microscopy. In 32 samples studied, the viable count on Zobell's marine agar (supplemented with vitamins) was 3.3×106 bacteria g?1 wet wt. (range 2.9×104–2.7×107). Of 732 strains isolated from 16

  16. The biota and environment of fumaroles on Mt Melbourne, northern Victoria Land

    Microsoft Academic Search

    Paul Broady I; David Given; Laurence Greenfield; Keith Thompson

    1987-01-01

    The aim of this investigation was to provide a general description of the biota and environment of fumarolic ground close to the summit (2733 m) of Mt Melbourne. Heat flow through the ground was examined and analyses made of the physico-chemical properties of the soil. Bryophyte vegetation comprisedCampylopus pyriformis (K.F. Schultz) Brid. andCephaloziella exiliflora (Tayl.) Steph. The former is a

  17. Soil organic matter, biota and aggregation in temperateand tropical soils - Effects of no-tillage

    Microsoft Academic Search

    Johan Six; Christian Feller; Karolien Denef; Stephen M. Ogle; Joao Carlos de Moraes; Alain Albrecht

    2002-01-01

    The long-term stabilization of soil organic matter (SOM) in tropical and temperate regions is mediated by soil biota (e.g. fungi, bacte- ria, roots and earthworms), soil structure (e.g. aggregation) and their interactions. On average, soil C turnover was twice as fast in tropical com- pared with temperate regions, but no major differences were observed in SOM quality between the two

  18. A Modelling Framework to Assess the Effect of Pressures on River Abiotic Habitat Conditions and Biota

    PubMed Central

    Kail, Jochem; Guse, Björn; Radinger, Johannes; Schröder, Maria; Kiesel, Jens; Kleinhans, Maarten; Schuurman, Filip; Fohrer, Nicola; Hering, Daniel; Wolter, Christian

    2015-01-01

    River biota are affected by global reach-scale pressures, but most approaches for predicting biota of rivers focus on river reach or segment scale processes and habitats. Moreover, these approaches do not consider long-term morphological changes that affect habitat conditions. In this study, a modelling framework was further developed and tested to assess the effect of pressures at different spatial scales on reach-scale habitat conditions and biota. Ecohydrological and 1D hydrodynamic models were used to predict discharge and water quality at the catchment scale and the resulting water level at the downstream end of a study reach. Long-term reach morphology was modelled using empirical regime equations, meander migration and 2D morphodynamic models. The respective flow and substrate conditions in the study reach were predicted using a 2D hydrodynamic model, and the suitability of these habitats was assessed with novel habitat models. In addition, dispersal models for fish and macroinvertebrates were developed to assess the re-colonization potential and to finally compare habitat suitability and the availability / ability of species to colonize these habitats. Applicability was tested and model performance was assessed by comparing observed and predicted conditions in the lowland Treene River in northern Germany. Technically, it was possible to link the different models, but future applications would benefit from the development of open source software for all modelling steps to enable fully automated model runs. Future research needs concern the physical modelling of long-term morphodynamics, feedback of biota (e.g., macrophytes) on abiotic habitat conditions, species interactions, and empirical data on the hydraulic habitat suitability and dispersal abilities of macroinvertebrates. The modelling framework is flexible and allows for including additional models and investigating different research and management questions, e.g., in climate impact research as well as river restoration and management. PMID:26114430

  19. THE NEOGENE MARINE BIOTA OF TROPICAL AMERICA (“NMITA”) DATABASE: ACCOUNTING FOR BIODIVERSITY IN PALEONTOLOGY

    Microsoft Academic Search

    ANN F. BUDD; CHARLES T. FOSTER Jr.; JOHN P. DAWSON; KENNETH G. JOHNSON

    2001-01-01

    ABSTRACT—The reliability of any survey of biodiversity through geologic time depends on the rigor and consistency by which taxa are recognized and samples are identified. The main goal of the Neogene Marine Biota of Tropical America (‘NMITA’) project is to create an online biotic database (http:\\/\\/nmita.geology.uiowa.edu) containing images and synoptic taxonomic information that are essential to collecting and disseminating high-quality

  20. Living Landscapes: Present and Past Interactions Between Coastal Sediments and Biota

    NASA Astrophysics Data System (ADS)

    Mariotti, G.

    2014-12-01

    Since the dawn of life, sedimentary landscapes have been interacting with biota. This is particularly evident in coastal environments, where sediment transport and production are strongly influenced by microbes, plants and animals. Here I will discuss examples ranging from erosion of modern coastal wetlands to evidence of early life in sedimentary rocks. Using mathematical models and laboratory experiments I will investigate processes and present new perspectives at the border between geomorphology, ecology and paleontology.

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

    PubMed Central

    He, Xunyang; Liu, Lu; Wang, Kelin

    2014-01-01

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

  2. Trace organic contamination in biota collected from the Pearl River Estuary, China: a preliminary risk assessment.

    PubMed

    Wei, S; Lau, R K F; Fung, C N; Zheng, G J; Lam, J C W; Connell, D W; Fang, Z; Richardson, B J; Lam, P K S

    2006-12-01

    The marine ecosystem of the Pearl River Delta, located on the southern coast of China, has been heavily exploited following the rapid economic growth that has occurred since the 1980s. This investigation aimed to elucidate trace organic contamination in marine biota inhabiting the Pearl River Delta area. Biota samples, including green-lipped mussels (Perna viridis), oysters (Crassostrea rivularis) and shrimp (Penaeus orientalis) were sampled from 16 stations fringing the Estuary. Elevated concentrations (on a dry weight basis) of polycyclic aromatic hydrocarbons (27.8-1041.0 ng/g), petroleum hydrocarbons (1.7-2345.4 microg/g), polychlorinated biphenyls (2.1-108.8 ng/g), DDTs (1.9-79.0 ng/g), and hexachlorocyclohexanes (n.d.-38.4 ng/g) were recorded. A human health risk assessment was conducted to estimate the risk to local residents associated with the consumption of biota collected from the Pearl River Estuary. The results indicated that PCBs were at levels that may cause deleterious health effects in populations that consume large amounts of seafood. However, it would be instructive to establish health criteria for trace organic contaminants that are specific to the local populations, in order to derive a more accurate and relevant health risk assessment. PMID:16908034

  3. Enantiomeric composition of chiral polychlorinated biphenyl atropisomers in aquatic and riparian biota

    USGS Publications Warehouse

    Wong, C.S.; Garrison, A.W.; Smith, P.D.; Foreman, W.T.

    2001-01-01

    The enantiomeric composition of polychlorinated biphenyl (PCB) atropisomers was measured in river and riparian biota (fish, bivalves, crayfish, water snakes, barn swallows) from selected sites throughout the United States by using chiral gas chromatography/mass spectrometry. Nonracemic enantiomeric fractions (EFs) were observed for PCBs 91, 95, 136, and 149 for aquatic and riparian biota from Lake Hartwell, SC, a reservoir heavily contaminated with PCBs, and for these congeners and PCBs 132, 174, 176, and 183 in river fish and bivalves nationwide. Fish and bivalves showed marked differences in EFs as compared to sediment found at the same sampling sites, thus suggesting that PCBs are bioprocessed in biota in a different manner from those found in sediment (e.g., reductive dechlorination). Species-dependent patterns in PCB EFs were observed, which suggest differences in the ability of different species to bioprocess PCBs enantioselectively, most likely by metabolism. The presence of nonracemic PCBs in fish and bivalves suggests greater metabolic degradation of PCBs in these organisms than indicated from previous achiral studies and underscores the powerful potential of chiral analysis as a tracer of environmental bioprocesses.

  4. Climate Change Effects on Aquatic Biota, Ecosystem Structure and Function

    Microsoft Academic Search

    Frederick J. Wrona; Terry D. Prowse; James D. Reist; John E. Hobbie; Lucie M. J. Lévesque; Warwick F. Vincent

    2006-01-01

    Climate change is projected to cause significant alter- ations to aquatic biogeochemical processes, (including carbon dynamics), aquatic food web structure, dynamics and biodiversity, primary and secondary production; and, affect the range, distribution and habitat quality\\/quantity of aquatic mammals and waterfowl. Projected enhanced permafrost thawing is very likely to increase nutrient, sediment, and carbon loadings to aquatic systems, resulting in both

  5. Australian salt lakes: their history, chemistry, and biota — a review

    Microsoft Academic Search

    Patrick De Deckker

    1983-01-01

    A vast number of large lakes (» 100 km2) are typically very old features of the Australian landscape; they occupy areas which have changed little tectonically (e.g., they occupy ancient drainage systems in Western Australia or lie in deep depressions such as the Great Artesian Basin: Lake Eyre) and have not been transgressed by the sea since at least the

  6. The Response of Marine Biota to OAE 1b

    NASA Astrophysics Data System (ADS)

    Herrle, J. O.

    2006-12-01

    The latest Aptian to earliest Albian is characterized by the first appearance of a distinctly modern phytoplankton community accompanied by a cold episode during a generally extreme greenhouse climate. Massive burial of organic matter caused the formation of the black shale `Niveaus' Jacob, Kilian, Paquier and Leenhardt in the Vocontian Basin (SE France). This interval is reported as the Oceanic Anoxic Event 1b (OAE1b) following the definition of Leckie et al. (2002). Lasting about four million years, OAE1b facilitates analysis of rapid climate change in a greenhouse world, and crucial for understanding climate change. During latest Aptian angiosperms and diatoms became abundant in the terrestrial and marine environments (Gersonde & Haywood 1990; Heimhofer et al. 2005). Planktic foraminifera experienced their greatest turnover rates since their first appearance, accompanied by a decrease in test size and changes of the ultrastructures of their shells (Leckie et al. 2002). Calcareous nannoplankton show a major change characterized by the influx of the boreal cool water indicator Repagulum parvidentatum into the Tethyan Realm (Herrle & Mutterlose 2003). Moreover, ammonite faunas became more cosmopolitan at the expense of Tethyan taxa during this period. Both the influx of boreal nannoplankton taxa and the trend to more cosmopolitian ammonite assemblages in the Tethyan Realm was probably favored by a long-term sea level rise accompanied by a global cooling during the late Aptian to early Albian interval. Most dramatic changes of the marine carbonate system are reflected by the stepwise decrease of nannoconids and carbonate platform drowning accompanied by a positive carbon isotope excursion which is similar to the biocalcification crisis associated with the early Aptian OAE1a (Erba 1994, Weissert et al., 1998). The massive change in the global carbon cycle is probably linked to a major change in global marine productivity from a calcareous system (nannoconids, foraminifera, carbonate platforms) to a siliceous system (diatoms, sponge spicules), and may reflect the transition to the modern marine ecosystem. However, causes and consequences of these changes remain to be enigmatic and may be linked to changes in the global circulation system, nutrient partitioning, ocean chemistry, global sea- level change, and cooler climate during the Late Aptian to early Albian interval.

  7. Soil biota and agriculture production in conventional and organic farming

    NASA Astrophysics Data System (ADS)

    Schrama, Maarten; de Haan, Joj; Carvalho, Sabrina; Kroonen, Mark; Verstegen, Harry; Van der Putten, Wim

    2015-04-01

    Sustainable food production for a growing world population requires a healthy soil that can buffer environmental extremes and minimize its losses. There are currently two views on how to achieve this: by intensifying conventional agriculture or by developing organically based agriculture. It has been established that yields of conventional agriculture can be 20% higher than of organic agriculture. However, high yields of intensified conventional agriculture trade off with loss of soil biodiversity, leaching of nutrients, and other unwanted ecosystem dis-services. One of the key explanations for the loss of nutrients and GHG from intensive agriculture is that it results in high dynamics of nutrient losses, and policy has aimed at reducing temporal variation. However, little is known about how different agricultural practices affect spatial variation, and it is unknown how soil fauna acts this. In this study we compare the spatial and temporal variation of physical, chemical and biological parameters in a long term (13-year) field experiment with two conventional farming systems (low and medium organic matter input) and one organic farming system (high organic matter input) and we evaluate the impact on ecosystem services that these farming systems provide. Soil chemical (N availability, N mineralization, pH) and soil biological parameters (nematode abundance, bacterial and fungal biomass) show considerably higher spatial variation under conventional farming than under organic farming. Higher variation in soil chemical and biological parameters coincides with the presence of 'leaky' spots (high nitrate leaching) in conventional farming systems, which shift unpredictably over the course of one season. Although variation in soil physical factors (soil organic matter, soil aggregation, soil moisture) was similar between treatments, but averages were higher under organic farming, indicating more buffered conditions for nutrient cycling. All these changes coincide with pronounced shifts in soil fauna composition (nematodes, earthworms) and an increase in earthworm activity. Hence, more buffered conditions and shifts in soil fauna composition under organic farming may underlie the observed reduction in spatial variation of soil chemical and biological parameters, which in turn correlates positively with a long-term increase in yield. Our study highlights the need for both policymakers and farmers alike to support spatial stability-increasing farming.

  8. BIOGEOCHEMICAL STUDIES OF PHOTOSYNTHETIC MICROBIAL MATS AND THEIR BIOTA

    NASA Technical Reports Server (NTRS)

    DesMarais, David; Discipulo, M.; Turk, K.; Londry, K. L.

    2005-01-01

    Photosynthetic microbial mats offer an opportunity to define holistic functionality at the millimeter scale. At the same time. their biogeochemistry contributes to environmental processes on a planetary scale. These mats are possibly direct descendents of the most ancient biological communities; communities in which oxygenic photosynthesis might have been invented. Mats provide one of the best natural systems to study how microbial populations associate to control dynamic biogeochemical gradients. These are self- sustaining, complete ecosystems in which light energy absorbed over a dial (24 hour) cycle drives the synthesis of spatially-organized, diverse biomass. Tightly-coupled microorganisms in the mat have specialized metabolisms that catalyze transformations of carbon, nitrogen, sulfur, and a host of other elements.

  9. Climate Warming and Disease Risks for Terrestrial and Marine Biota

    NASA Astrophysics Data System (ADS)

    Harvell, C. Drew; Mitchell, Charles E.; Ward, Jessica R.; Altizer, Sonia; Dobson, Andrew P.; Ostfeld, Richard S.; Samuel, Michael D.

    2002-06-01

    Infectious diseases can cause rapid population declines or species extinctions. Many pathogens of terrestrial and marine taxa are sensitive to temperature, rainfall, and humidity, creating synergisms that could affect biodiversity. Climate warming can increase pathogen development and survival rates, disease transmission, and host susceptibility. Although most host-parasite systems are predicted to experience more frequent or severe disease impacts with warming, a subset of pathogens might decline with warming, releasing hosts from disease. Recently, changes in El Niño-Southern Oscillation events have had a detectable influence on marine and terrestrial pathogens, including coral diseases, oyster pathogens, crop pathogens, Rift Valley fever, and human cholera. To improve our ability to predict epidemics in wild populations, it will be necessary to separate the independent and interactive effects of multiple climate drivers on disease impact.

  10. Climate warming and disease risks for terrestrial and marine biota

    USGS Publications Warehouse

    Harvell, C.D.; Mitchell, C.E.; Ward, J.R.; Altizer, S.; Dobson, A.P.; Ostfeld, R.S.; Samuel, M.D.

    2002-01-01

    Infectious diseases can cause rapid population declines or species extinctions. Many pathogens of terrestrial and marine taxa are sensitive to temperature, rainfall, and humidity, creating synergisms that could affect biodiversity. Climate warming can increase pathogen development and survival rates, disease transmission, and host susceptibility. Although most host-parasite systems are predicted to experience more frequent or severe disease impacts with warming, a subset of pathogens might decline with warming, releasing hosts from disease. Recently, changes in El Niño–Southern Oscillation events have had a detectable influence on marine and terrestrial pathogens, including coral diseases, oyster pathogens, crop pathogens, Rift Valley fever, and human cholera. To improve our ability to predict epidemics in wild populations, it will be necessary to separate the independent and interactive effects of multiple climate drivers on disease impact.

  11. Identifying drivers of biodiversity change from fossil long-lived lakes: lessons for risk and resilience of todays long-lived lake biota.

    NASA Astrophysics Data System (ADS)

    Wesselingh, Frank

    2015-04-01

    Several fossil long-lived lake systems exist that have a very good spatiotemporal geological and faunal record enabling us to study timeseries of biodiversity change. These complexes, such as the Miocene Pannonian and Quaternary Pontocaspian systems of Europe, Quaternary Lake Biwa in Japan and the Miocene Pebas System in South America enable us to assess the impact of environmental stability and pertubation on component processes of turnover, e.g. migration, speciation and extinction/ extirpation. Also, the temporal dimensions of such processes can be clarified and compared to the nature and rates of current turnover in long-lived lake systems. Our studies suggest that we are currently witnessing dramatic biodiversity loss caused mostly by habitat degradation and destruction in smaller lakes and invasives in larger lakes that may exceed the potential of endemic lake biota to recover. Long-live lakes should serve as an excellent illustration of the magnitude of the current anthropogenic-induced biodiversity crisis.

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

    NASA Technical Reports Server (NTRS)

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

    1995-01-01

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

  13. Isolation and characterization of platelet-activating factor receptor binding antagonists from Biota orientalis.

    PubMed

    Yang, H O; Suh, D Y; Han, B H

    1995-02-01

    The leaf extract of Biota orientalis showed potent PAF receptor binding antagonistic activity in our previous screening studies on 234 Korean medicinal plants using rabbit platelet receptor binding tests. The activity-guided purification of the plant extract resulted in the isolation of six compounds, including two active substances. The chemical structures of the compounds isolated were established by chemical and spectrometric analyses as dotriacontane, totarol, 8 beta-hydroxy-3-oxopimar-15-ene, cedrol (IC50 = 1.3 x 10(-5) M), pinusolide (IC50 = 2.52 x 10(-7) M), and 5-hydroxy-7,4'-dimethoxyflavone. PMID:7700989

  14. Antifibrotic activity of diterpenes from Biota orientalis leaves on hepatic stellate cells.

    PubMed

    Lee, Mi Kyeong; Yang, Hyekyung; Yoon, Jeong Seon; Jeong, Eun Ju; Kim, Do Yoon; Ha, Na Ry; Sung, Sang Hyun; Kim, Young Choong

    2008-07-01

    Antifibrotic effect of twelve diterpenes (1-12) from the 90% methanolic fraction of Biota orientalis leaves was evaluated employing HSC-T6 cells by assessing cell proliferation and morphological change. Among these diterpenes, totarol (8) and isopimara-8(14),15-dien-19-oic acid (9) dramatically reduced cell proliferation in dose-and time-dependent manner. Furthermore, treatment with these compounds resulted in the different pattern of morphological changes of HSC-T6 cells. Taken together, antiproliferative activity of diterpenes from B. orientalis might suggest therapeutic potentials against liver fibrosis. PMID:18704328

  15. [A comparative analysis of the impact on biota and man in the 30 km zone of the Chernobyl NPP].

    PubMed

    Fesenko, S V; Aleksakhin, P M; Geras'kin, S A; Sanzharova, N I; Spirin, E V; Spiridonov, S I; Gontarenko, I A; Strand, P

    2004-01-01

    A methodological approach is described for a comparative assessment of ionizing radiation effects on man and biota, based on the use of indices of radiation impact--ratios of actual exposure doses to environmental objects (including humans) and critical ones. As such doses, standards limiting radiation exposure and doses at which phenotypical effects were absent after the Chernobyl accident were employed, respectively for man and biota. For the test site chosen within the 30 km ChNPP zone (region of the Borshchovka settlement), dose burdens to reference biota species and the population (with and without evacuation) and the corresponding radiation impact indices were calculated. For the long term period after the accident radiation safety standards for man are shown to ensure radiation safety for biota as well. At the same time in the early period after the accident the emergency regulations do not guarantee adequate protection of nature, some species of which can be subject to irradiation more than man, even if countermeasures like evacuation are not applied. A conclusion has been made on the necessity of a more detailed and comprehensive analysis of situations when the anthropocentric principle "if radiation standards protect man then biota are also adequately protected" is violated. PMID:15700800

  16. Partitioning behavior of perfluorinated compounds between sediment and biota in the Pearl River Delta of South China.

    PubMed

    Zhao, Y G; Wan, H T; Wong, M H; Wong, Chris K C

    2014-06-15

    Surface sediment and biota were collected from 12 sampling sites - seven along the Pearl River Delta and five along the Hong Kong coastline. Perfluorinated compound (PFC) concentrations were detected using a high-performance-liquid-chromatogram-tandem-mass-spectrometry system. Analytical results indicated that the total PFC concentrations were in the range of 0.15-3.11 ng/g dry weight in sediments, while the total PFC concentrations in oyster and mussel samples were between 0.46-1.96 and 0.66-3.43 ng/g wet weight, respectively. The major types of PFCs detected in the sediment samples were perfluorooctanesulfonic acid (PFOS) and perfluorobutanoic acid (PFBA), with concentrations ranging from low limits of quantification to 0.86±0.12 ng/g dry weight and 1.50±0.26 ng/g dry weight, respectively. In bivalve samples, PFOS was the dominant contaminant with concentrations ranging from 0.25±0.09 to 0.83±0.12 ng/g wet weight in oysters and 0.41±0.14 to 1.47±0.25 ng/g wet weight in mussels. An increase in PFC concentration was found to be correlated with increased human population density in the study areas. PMID:24775068

  17. Soil Biota

    NSDL National Science Digital Library

    Katherine McCarville

    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.

  18. Threatened biotas: \\

    Microsoft Academic Search

    Norman Myers

    1988-01-01

    The mass-extinction episode underway is largely centred on tropical forests, insofar as they contain at least half of all Earth's species and they are being depleted faster than any other biome. But species distributions and depletion patterns are anything but uniform throughout the biome. This paper identifies 10 areas that, a) are characterised by exceptional concentrations of species with high

  19. Occurrence of platinum and additional traffic related heavy metals in sediments and biota.

    PubMed

    Haus, N; Zimmermann, S; Wiegand, J; Sures, B

    2007-01-01

    Non-point sources play an important role in metal emissions into surface waters. One of the most important non-point sources is automobile traffic. Recent studies determining traffic related heavy metals in surface waters have concentrated mainly on worst case scenarios by analyzing heavy metal loads in waters and sediments close to storm-water overflow inlets. The present study aims at identifying traffic related heavy metals in moderately polluted sites, as they occur in highly urbanized regions. Therefore, the concentrations of eight traffic related metals (Pt, Sb, Mo, Cd, Pb, Cu, Cr and Zn) were determined in sediment and crustacean samples from eight different aquatic habitats in the Ruhr district, Germany. Traffic related heavy metals could be identified in sediment and biota samples as a combination of heavy metals (Pt, Sb, Cd, Pb for sediments and Pt and Sb for crustacean samples). Pt concentrations received special attention due to the relatively recent occurrence of anthropogenically emitted Pt in the environment. At six sampling sites, Pt was detected in sediment and/or biota samples. The uptake of Pt compared to other traffic related heavy metals by Asellus aquaticus and Gammarus pulex is relatively high and can be compared with the uptake rates of essential metals like Zn. PMID:16996105

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

    PubMed

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

    2014-01-01

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

  1. Persistence of spilled oil on shores and its effects on biota

    USGS Publications Warehouse

    Irvine, G.V.

    2000-01-01

    Over two million tonnes of oil are estimated to enter the world's oceans every year. A small percentage, but still a large volume, of this oil strands onshore, where its persistence is governed primarily by the action of physical forces. In some cases, biota influence the persistence of stranded oil or the rate of its weathering. Oil's deleterious effects on biota are frequently related to the persistence and degree of weathering of the oil, with long-lasting effects in low-energy environments such as salt marshes and coastal mangroves, or in higher-energy environments where oil is sequestered. However, an oil spill can have disproportionately large biological effects when it affects key species or processes (e.g., structurally important species, predators, prey, recruitment, or succession). In these cases, the continuing presence of oil is not always a prerequisite for continuing biological effects. There are relatively few long-term studies of the effects of oil spills; data from these suggest that oil can persist for decades in some environments or situations, and that biological effects can be equally persistent. Broad-based, integrated studies have been the most revealing in terms of the importance of direct and indirect effects, spillover effects between different parts of the environment, and continuing linkages between residual oil and biologic effects. Clean-up and treatment techniques applied to spilled or stranded oil can also have significant, long-lasting effects and need to be carefully evaluated prior to use.

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

    PubMed

    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

    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

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

    SciTech Connect

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

    2003-06-06

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

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

    SciTech Connect

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

    2008-01-01

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

  5. The remarkable fossils from the Early Cretaceous Jehol Biota of China and how they have changed our knowledge of Mesozoic life

    E-print Network

    Benton, Michael

    The remarkable fossils from the Early Cretaceous Jehol Biota of China and how they have changed our. & KEARNS, S. L. 2008. The remarkable fossils from the Early Cretaceous Jehol Biota of China and how and others have been repeatedly amazed by reports of spectacularly well-preserved fossils from China, and one

  6. Application of Biota Dose Assessment Committee Methodology to Assess Radiological Risk to Salmonids in the Hanford Reach of the Columbia River

    Microsoft Academic Search

    Ted M. Poston; Ernest J. Antonio; Robert E. Peterson

    2002-01-01

    Protective guidance for biota in the U.S. Department of Energy's Graded Approach for Evaluating Radiation Doses to Aquatic and Terrestrial Biota is based on population level protection guides of 10 or 1 mGy.d-1, respectively. Several \\

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

    PubMed

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

    2015-07-01

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

  8. Polycyclic aromatic hydrocarbons and trace metal contamination of coastal sediment and biota from Togo.

    PubMed

    Gnandi, Kissao; Musa Bandowe, Benjamin A; Deheyn, Dimitri D; Porrachia, Magali; Kersten, Michael; Wilcke, Wolfgang

    2011-07-01

    The state of contamination of tropical environments, particularly in Africa, remains a relatively under explored subject. Here, we determined polycyclic aromatic hydrocarbon (PAH) and trace metal concentrations in coastal sediment and biota samples (fish and mussels) from Togo (West Africa). In the sediments, the ?21 PAH concentrations ranged from <4 ng g(-1) to 257 ng g(-1), averaging 92 ng g(-1). Concentration ratios of low molecular weight PAHs (2-3 rings) versus high molecular weight PAHs (?4 rings) were always lower than 1 (ranging from 0.08 to 0.46) indicating that high molecular weight PAHs were dominant in all sediment samples, and that PAHs originated mainly from anthropogenic combustion activities. The sediments were also analyzed for major elements and a total of 15 trace metals, which were found in elevated concentrations. The calculated enrichment factor (EF) values relative to the Earth's crust show that the contamination is extremely severe for Cd (EF = 191), severe for Cr (EF = 18) and U (EF = 17.8), moderately severe for Zr (EF = 8.8), for Ni (EF = 6.8), Sr (EF = 5.9) and Ba (EF = 5.4), and moderate for V (EF = 3.6) and Zn (EF = 3.4). Sediments sampled in areas affected by the dumping of phosphorite mine tailings showed particularly high concentrations of trace metals. Overall, concentrations of both PAHs and trace metals in sediment tend to increase from the coastline to the open sea (2 km offshore). This is attributable to the increasingly finer texture of coastal sediment found offshore, which has a terrigenous origin and appears loaded with various contaminants through adsorption processes. Such high loads of trace metals were also found in the biota (fish and mussels). The ratio of measured trace metal concentrations in biota to threshold limits set by the World Health Organization herein defined as relative health factor (RHF) was high. Average RHF values in fish were highest for Se (470), As (250), Ag (97), Ni (78), Mn (63), Fe (53), Pb (36), Cd (10), and Cr (7) while lowest for Cu (0.08) and Zn (0.03). Cd and Al did not bioaccumulate in the analyzed fish species. In mussels, the RHF values were highest for Fe (9,108), As (295), Pb (276), Se (273), Mn (186), Ni (71), Ag (70), Cd (14), and Cu (4). PMID:21655572

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

    USGS Publications Warehouse

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

    2015-01-01

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

  10. Environmental Setting and the Effects of Natural and Human-Related Factors on Water Quality and Aquatic Biota, Oahu, Hawaii

    USGS Publications Warehouse

    Oki, Delwyn S.; Brasher, Anne M.D.

    2003-01-01

    The island of Oahu is the third largest island of the State of Hawaii, and is formed by the eroded remnants of the Waianae and Koolau shield volcanoes. The landscape of Oahu ranges from a broad coastal plain to steep interior mountains. Rainfall is greatest in the mountainous interior parts of the island, and lowest near the southwestern coastal areas. The structure and form of the two volcanoes in conjunction with processes that have modified the original surfaces of the volcanoes control the hydrologic setting. The rift zones of the volcanoes contain dikes that tend to impede the flow of ground water, leading to high ground-water levels in the dike-impounded ground-water system. In the windward (northeastern) part of the island, dike-impounded ground-water levels may reach the land surface in stream valleys, resulting in ground-water discharge to streams. Where dikes are not present, the volcanic rocks are highly permeable, and a lens of freshwater overlies a brackish-water transition zone separating the freshwater from saltwater. Ground water discharges to coastal springs and streams where the water table in the freshwater-lens system intersects the land surface. The Waianae and Koolau Ranges have been deeply dissected by numerous streams. Streams originate in the mountainous interior areas and terminate at the coast. Some streams flow perennially throughout their entire course, others flow perennially over parts of their course, and the remaining streams flow during only parts of the year throughout their entire course. Hawaiian streams have relatively few native species compared to continental streams. Widespread diverse orders of insects are absent from the native biota, and there are only five native fish, two native shrimp, and a few native snails. The native fish and crustaceans of Hawaii's freshwater systems are all amphidromous (adult lives are spent in streams, and larval periods as marine or estuarine zooplankton). During the 20th century, land-use patterns on Oahu reflected increases in population and decreases in large-scale agricultural operations over time. The last two remaining sugarcane plantations on Oahu closed in the mid-1990's, and much of the land that once was used for sugarcane now is urbanized or used for diversified agriculture. Although two large pineapple plantations continue to operate in central Oahu, some of the land previously used for pineapple cultivation has been urbanized. Natural and human-related factors control surface- and ground-water quality and the distribution and abundance of aquatic biota on Oahu. Natural factors that may affect water quality include geology, soils, vegetation, rainfall, ocean-water quality, and air quality. Human-related factors associated with urban and agricultural land uses also may affect water quality. Ground-water withdrawals may cause saltwater intrusion. Pesticides and fertilizers that were used in agricultural or urban areas have been detected in surface and ground water on Oahu. In addition, other organic compounds associated with urban uses of chemicals have been detected in surface and ground water on Oahu. The effects of urbanization and agricultural practices on instream and riparian areas in conjunction with a proliferation of nonnative fish and crustaceans have resulted in a paucity of native freshwater macrofauna on Oahu. A variety of pesticides, nutrients, and metals are associated with urban and agricultural land uses, and these constituents can affect the fish and invertebrates that live in the streams.

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

    Microsoft Academic Search

    S. V. Fesenko; R. M. Alexakhin; S. A. Geras'kin; N. I. Sanzharova; Ye. V. Spirin; S. I. Spiridonov; I. A. Gontarenko; P. Strand

    2005-01-01

    A methodological approach for a comparative assessment of ionising radiation effects on man and non-human species, based on the use of Radiation Impact Factor (RIF) – ratios of actual exposure doses to biota species and man to critical dose is described. As such doses, radiation safety standards limiting radiation exposure of man and doses at which radiobiological effects in non-human

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  13. idly, had immediate, major, and visible impacts on the island_s biota and physical landscape, and

    E-print Network

    Bear, Mark

    14, 801 (2004). 8. C. Smith, in The Archaeology of Easter Island, Vol. 1, T. Heyerdahl, E. Ferdon (1971). 11. J. Flenley, in Easter Island Studies: Contributions to the History of Rapanui in Memoryidly, had immediate, major, and visible impacts on the island_s biota and physical landscape

  14. Bioaccumulation and trophic transfer of polybrominated diphenyl ethers (PBDEs) in biota from the Pearl River Estuary, South China.

    PubMed

    Yu, Mei; Luo, Xiao-Jun; Wu, Jiang-Ping; Chen, She-Jun; Mai, Bi-Xian

    2009-10-01

    Two hundred and fifty-four biota samples (four species of invertebrates and ten species of fish) were collected from the Pearl River Estuary between 2005 and 2007 and one hundred and twenty four individual or composite samples were analyzed for polybrominated diphenyl ethers (PBDEs). The concentrations of PBDEs in organisms varied from 6.2 to 208ng/g lipid weight. This PBDE level was significantly lower than those collected in 2004, showing a decreasing trend of PBDEs in biota in the study area. Trophic magnification factors (TMFs) for nine BDE congeners were calculated with values ranging from 0.78 to 3.0. TMFs of BDE47, 66, 100, 99, 154, and 153 were statistically greater than one, indicating a biomagnifcation potential for these congeners. Significant positive correlations were also found between concentrations of the total PBDEs, BDE28, 47, 66, 100, 99, 154, and153 and lipid content in biota, indicating the that bioconcentration also played an important role in the accumulation of PBDEs. No correlation between trophic level and lipid content was found, suggesting that biomagnification was not the result of lipid content effect but indeed occurred. The concentration ratios of BDE99 to BDE100 were much lower in biota than that in water implying that potential congener-specific biotransformation of PBDEs occurred and influenced the biomagnification of BDE congeners. PMID:19616300

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

    PubMed

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

    2014-04-01

    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

  16. Soil and Biota of Serpentine: A World View 2009 Northeastern Naturalist 16(Special Issue 5):2138

    E-print Network

    Boyd, Robert S.

    challenging substrates for plant growth (Brooks 1987). In California, serpentine soils form ecological islandsSoil and Biota of Serpentine: A World View 2009 Northeastern Naturalist 16(Special Issue 5 yellow undulate sepals (U). In this study, we raised plants from ten populations (five Y, three P, one Y

  17. Vegetation and soil biota response to experimentally-changed nitrogen inputs in coniferous forest ecosystems of the NITREX project

    Microsoft Academic Search

    Andries W. Boxman; Kai Blanck; Tor-Erik Brandrud; Bridget A. Emmett; Per Gundersen; Rene F. Hogervorst; O. Janne Kjønaas; Hans Persson; Volkmar Timmermann

    1998-01-01

    Enhancement of the atmospheric N deposition is a serious threat for the structure and function of ecosystems. Here we evaluate the ecological effects of excess N with respect to changes in vegetation and soil biota in a series of experiments along a N gradient across Europe. The aim of this project (NITREX: N saturation EXperiments) is to assess the risk

  18. Investigations of water quality, bottom sediment, and biota associated with irrigation drainage in the western United States

    Microsoft Academic Search

    HERMAN R. EELTZ; RICHARD A. ENGBERG; MARC A. SYLVESTER

    1990-01-01

    In response to concerns expressed by the US Congress over contamination at the Kesterson National Wildlife Refuge in California, the US Department of the Interior started a programme in 1985 to identify the nature and extent of irrigation-induced water-quality problems that might exist in other areas of the western United States. Surface and ground water, bottom sediment, and biota were

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

    Microsoft Academic Search

    Nicholas A. Beresford; Mikhail Balonov; Karine Beaugelin-Seiller; Justin Brown; David Copplestone; Joanne L. Hingston; Jan Horyna; Ali Hosseini; Brenda J. Howard; Sunita Kamboj; Tatjana Nedveckaite; Geert Olyslaegers; Tatiana Sazykina; Jordi Vives i Batlle; Tamara L. Yankovich; Charley Yu; SCK CEN; SPA-Typhoon

    2008-01-01

    Over the last decade a number of models and approaches have been developed for the estimation of the exposure of non-human biota to 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

  20. Soil and Biota of Serpentine: A World View 2009 Northeastern Naturalist 16(Special Issue 5):93110

    E-print Network

    Boyd, Robert S.

    Soil and Biota of Serpentine: A World View 2009 Northeastern Naturalist 16(Special Issue 5):93­110 Elemental Concentrations of Eleven New Caledonian Plant Species from Serpentine Soils: Elemental plant species from serpentine soils of New Caledonia. Species were classified into four catego- ries

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

    PubMed Central

    Ren, Dong; Shih, ChungKun; Labandeira, Conrad C.

    2011-01-01

    Abstract 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. PMID:21998553

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

    SciTech Connect

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

    2000-05-01

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

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

    SciTech Connect

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

    2003-06-06

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

  4. Effects of causeway construction on environment and biota of subtropical tidal flats in Okinawa, Japan.

    PubMed

    Reimer, James Davis; Yang, Sung-Yin; White, Kristine N; Asami, Ryuji; Fujita, Kazuhiko; Hongo, Chuki; Ito, Shingo; Kawamura, Iori; Maeda, Isshu; Mizuyama, Masaru; Obuchi, Masami; Sakamaki, Takashi; Tachihara, Katsunori; Tamura, Maiko; Tanahara, Akira; Yamaguchi, Aika; Jenke-Kodama, Holger

    2015-05-15

    Okinawa, Japan is known for its high marine biodiversity, yet little work has been performed on examining impacts of numerous large-scale coastal development projects on its marine ecosystems. Here, we examine apparent impacts of the construction of the Kaichu-Doro causeway, which was built over 40years ago. The causeway is a 4.75km long embankment that divides a large tidal flat and has only two points of water exchange along its entire length. We employed quadrats, transects, sampling, visual surveys, and microbial community analyses combined with environmental, water quality data, and 1m cores, at five stations of two paired sites each (one on each side of Kaichu-Doro) to investigate how the environment and biota have changed since the Kaichu-Doro was built. Results indicate reduction in water flow, and site S1 was particularly heavily impacted by poor water quality, with low diversity and disturbed biotic communities. PMID:25865345

  5. http://www.biotaneotropica.org.br/v8n4/pt/abstract?short-communication+bn01708042008 http://www.biotaneotropica.org.br Biota Neotrop., vol. 8, no. 4, Out./Dez. 2008

    E-print Network

    Simões-Lopes, Paulo César

    ://www.biotaneotropica.org.br Biota Neotrop., vol. 8, no. 4, Out./Dez. 2008 Notas sobre a distribuição, tamanho de grupo e. Biota Neotrop. 8(4): http://www.biotaneotropica. org.br/v8n4/en Catarina, sul do Brasil. Biota Neotrop. 8(4): http://www.biotaneotropica.org.br/v8n4/pt/ abstract

  6. Distribution characteristics of polycyclic aromatic hydrocarbons in sediments and biota from the Zha Long Wetland, China.

    PubMed

    Li, Jinchunzi; Liu, Guangmin; Yin, Lili; Xue, Jianliang; Qi, Hong; Li, Yifan

    2013-04-01

    In this paper, the concentrations of polycyclic aromatic hydrocarbons (PAHs) were measured in biota (reed, grass, mussel, fish, and red-crowned crane) and sediments collected from seven locations in the Zha Long Wetland. PAHs were recovered from the sediments and biota by ultrasonic extraction and then analyzed by means of gas chromatography-mass spectrometry. The total PAH concentrations were 244-713 ng/g dw in sediments, 82.8-415 ng/g dw in plants and 207-4,780 ng/g dw in animals. The total sediment PAH concentrations were categorized as lower to moderate contamination compared with other regions of China and the world. In the plant samples, the accumulation abilities of reed roots and stems for PAHs were higher than those of grass roots. In addition, the concentration of individual PAHs in mussel muscles was the highest in all of the animal samples, followed by fish, feeding crane fetuses, and wild crane fetuses. Compositional analysis suggests that the PAHs in the sediments from the Zha Long Wetland were derived from incomplete biomass combustion. Risk assessment shows that the levels of PAHs in sediments are mostly lower than the effects range mean value (effects range mean), whereas only naphthalene in all sample sites was higher than the effects range low value. It is worthwhile to note that benzo(b)fluoranthene, benzo(k)fluoranthene, indeno(1,2,3-cd)pyrene and benzo(ghi)perylene were detected in crane fetal, which have potential carcinogenicity for organisms from the Zha Long Wetland. PMID:22821325

  7. General Relationships between Abiotic Soil Properties and Soil Biota across Spatial Scales and Different Land-Use Types

    PubMed Central

    Birkhofer, Klaus; Schöning, Ingo; Alt, Fabian; Herold, Nadine; Klarner, Bernhard; Maraun, Mark; Marhan, Sven; Oelmann, Yvonne; Wubet, Tesfaye; Yurkov, Andrey; Begerow, Dominik; Berner, Doreen; Buscot, François; Daniel, Rolf; Diekötter, Tim; Ehnes, Roswitha B.; Erdmann, Georgia; Fischer, Christiane; Foesel, Bärbel; Groh, Janine; Gutknecht, Jessica; Kandeler, Ellen; Lang, Christa; Lohaus, Gertrud; Meyer, Annabel; Nacke, Heiko; Näther, Astrid; Overmann, Jörg; Polle, Andrea; Pollierer, Melanie M.; Scheu, Stefan; Schloter, Michael; Schulze, Ernst-Detlef; Schulze, Waltraud; Weinert, Jan; Weisser, Wolfgang W.; Wolters, Volkmar; Schrumpf, Marion

    2012-01-01

    Very few principles have been unraveled that explain the relationship between soil properties and soil biota across large spatial scales and different land-use types. Here, we seek these general relationships using data from 52 differently managed grassland and forest soils in three study regions spanning a latitudinal gradient in Germany. We hypothesize that, after extraction of variation that is explained by location and land-use type, soil properties still explain significant proportions of variation in the abundance and diversity of soil biota. If the relationships between predictors and soil organisms were analyzed individually for each predictor group, soil properties explained the highest amount of variation in soil biota abundance and diversity, followed by land-use type and sampling location. After extraction of variation that originated from location or land-use, abiotic soil properties explained significant amounts of variation in fungal, meso- and macrofauna, but not in yeast or bacterial biomass or diversity. Nitrate or nitrogen concentration and fungal biomass were positively related, but nitrate concentration was negatively related to the abundances of Collembola and mites and to the myriapod species richness across a range of forest and grassland soils. The species richness of earthworms was positively correlated with clay content of soils independent of sample location and land-use type. Our study indicates that after accounting for heterogeneity resulting from large scale differences among sampling locations and land-use types, soil properties still explain significant proportions of variation in fungal and soil fauna abundance or diversity. However, soil biota was also related to processes that act at larger spatial scales and bacteria or soil yeasts only showed weak relationships to soil properties. We therefore argue that more general relationships between soil properties and soil biota can only be derived from future studies that consider larger spatial scales and different land-use types. PMID:22937029

  8. Irrigation-induced contamination of water, sediment, and biota in the western United States-synthesis of data from the National Irrigation Water Quality Program

    USGS Publications Warehouse

    Seiler, Ralph L.; Skorupa, Joseph P.; Naftz, David L.; Nolan, B. Thomas

    2003-01-01

    In October 1985 the U.S. Department of the Interior (DOI), through the National Irrigation Water Quality Program (NIWQP), began a series of field investigations at 26 areas in the Western United States to determine whether irrigation drainage has had harmful effects on fish, wildlife, and humans or has reduced beneficial uses of water. In 1992 NIWQP initiated the Data Synthesis Project to evaluate data collected during the field investigations. Geologic, climatologic, and hydrologic data were evaluated and water, sediment, and biota from the 26 areas were analyzed to identify commonalities and dominant factors that result in irrigation-induced contamination of water and biota. Data collected for the 26 area investigations have been compiled and merged into a common data base. The structure of the data base is designed to enable assessment of relations between contaminant concentrations in water, sediment, and biota. The data base is available to the scientific community through the World Wide Web at URL http://www.usbr.gov/niwqp. Analysis of the data base for the Data Synthesis included use of summary statistics, factor analysis, and logistic regression. A Geographic Information System was used to store and analyze spatially oriented digital data such as land use, geology and evaporation rates. In the U.S. Department of the Interior (DOI) study areas, samples of water, bottom sediment, and biota were collected for trace-element and pesticide analysis. Contaminants most commonly associated with irrigation drainage were identified by comparing concentrations in water with established criteria. For surface water, the criteria used were typically chronic criteria for the protection of freshwater aquatic life. Because ground water can discharge to the surface where wildlife can be exposed to it, the criteria used for ground water were both the maximum contaminant levels (MCL's) for drinking water and the chronic criteria for the protection of freshwater aquatic life. Data collected by the NIWQP studies indicated that, in surface water, filtered and unfiltered samples had nearly the same concentrations of arsenic, boron, molybdenum, and selenium for concentrations greater than about 10 micrograms per liter. Therefore, in this concentration range, filtered concentrations can be directly compared to biological-effect levels developed for unfiltered samples. In the range of 1 to 10 micrograms per liter there may be a tendency for unfiltered arsenic concentrations to be greater than filtered concentrations. For selenium, however, the data suggest differences from equality in that range result from analytical imprecision and not a general tendency for unfiltered concentrations to be greater than filtered concentrations. This relation may not be true in lentic, nutrient-rich waters because in such settings algae can bioaccumulate large amounts of selenium and other trace elements. Selenium was the trace element in surface water that most commonly exceeded chronic criteria for the protection of freshwater aquatic life; more than 40 percent of the selenium concentrations in surface-water samples exceeded the U.S. Environmental Protection Agency (USEPA) aquatic-life chronic criterion (5 micrograms per liter). In 12 of the 26 areas at least 25 percent of the surface water-samples had selenium concentrations that either equaled or exceeded the chronic criterion (5 micrograms per liter). More than 28 percent of boron concentrations and almost 17 percent of the molybdenum concentrations exceeded the aquatic life criteria established by the State of California (550 and 19 micrograms per liter, respectively). In ground water, more than 22 percent of the arsenic concentrations and more than 35 percent of the selenium concentrations exceeded the MCL (10 and 50 micrograms per liter, respectively). Few samples of uranium in surface water exceeded a criterion for the protection of aquatic life (300 micrograms per liter), but 44 percent

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

    PubMed

    Kryshev, I I; Kryshev, A I; Sazykina, T G

    2012-12-01

    Estimates of radiation dose rates are presented for marine biota in March-May 2011 in the coastal zone near Fukushima NPP, and in the open sea. Calculations of fish contamination were made using two methods: a concentration factor approach, and a dynamic model. For representative marine organisms (fish and molluscs) the radiation dose rates did not exceed the reference level of 10 mGy/day. At a distance 30 km from the NPP, in the open sea the radiation doses for marine biota were much lower than those in the coastal zone near the NPP. Comparative estimates are presented for radiation doses to aquatic organisms in the exclusion zones of the Eastern Urals Radioactive Trail, and the Chernobyl NPP. PMID:22647507

  10. Biomonitoring aquatic pollution with feral eel ( Anguilla anguilla) I. Bioaccumulation: biota-sediment ratios of PCBs, OCPs, PCDDs and PCDFs

    Microsoft Academic Search

    Ron van der Oost; Antoon Opperhuizen; Karel Satumalay; Henk Heida; Nico P. E. Vermeulen

    1996-01-01

    Samples of sediments and eel taken from six Amsterdam freshwater sites were analyzed for polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), polychlorinated dibenzofurans (PCDFs) and polychlorinated dibenzo-p-dioxins (PCDDs). Biota-sediment accumulation factors (BSAFs) were determined from levels in sediments [ng\\/g organic matter (OM)] and eel muscle tissues [ng\\/g lipid weight (LW)]. Bioaccumulation patterns were both site- and analyte-specific. Bioaccumulation of these persistent

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

    Microsoft Academic Search

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

    1995-01-01

    The relationship between total concentrations of hexachlorocyclohexane (?HCH), ?DDT, and chlorinated bornanes (toxaphene, ?CHB) and the trophic position of biota from a subarctic lake was investigated using stable isotope ratios of nitrogen (15N\\/14N). Zooplankton, benthic invertebrates, and forage and piscivorous fishes were analysed for 15N\\/14N and organochlorines using mass spectrometry and high resolution capillary gas chromatography (GC-ECD), respectively. The trophic

  12. PCB congeners and hexachlorobenzene biota sediment accumulation factors for Macoma nasuta exposed to sediments with different total organic carbon contents

    Microsoft Academic Search

    Bruce L. Boese; H. II Lee; R. Randall; M. Winsor; S. Echols; J. Pelletier

    1995-01-01

    Deposit-feeding marine clams (Macoma nasuta) were exposed for 119 d to three sediment types that varied in total organic carbon (TOC) from 0.8 to 2.5%. Sediments were spiked with equal concentrations of 13 polychlorinated biphenyl congeners and hexachlorobenzene. Tissue residues were measured, and steady-state bioaccumulation factors (BAFs), the corresponding lipid, and TOC-normalized biota sediment accumulation factors (BSAFs) were determined. The

  13. Early embryogenesis of potential bilaterian animals with polar lobe formation from the Ediacaran Weng’an Biota, South China

    Microsoft Academic Search

    Zongjun Yin; Maoyan Zhu; Paul Tafforeau; Junyuan Chen; Pengju Liu; Gang Li

    Exquisite phosphatized eggs and embryos from the Ediacaran Doushantuo Formation (Weng’an biota, ca.580Ma) of Guizhou, southwestern China have greatly expanded our knowledge of the diversity and palaeobiology of early multicellular animals, and contributed to our understanding of the origins of sponge, cnidarian and other potential eumetazoans. However, the key question of whether triploblastic bilaterian animals are present in the Weng’an

  14. Metal Pollution by Old Lead-Zinc Mines in Urumea River Valley (Basque Country, Spain). Soil, Biota and Sediment

    Microsoft Academic Search

    J. Sánchez; N. Marino; M. C. Vaquero; J. Ansorena; I. Legórburu

    1998-01-01

    Soil, aquatic biota (moss: Brachythecium rivulare; aquatic macrophytes: Juncus effusus, Potamogeton crispus; fish: Salmo trutta fario, Anguilla anguilla, Phoxinus phoxinus, Chelon labrosus) and sediment samples from the Urumea river valley were analysed for metals by acid digestion and atomic absorption spectroscopy. The sediments show the presence of metal pollution (Cd: 2.5–24 mg kg-1; Pb: 125–1,150 mg kg-1; Zn: 125–2,500 mg

  15. Assessment of radiological risk for marine biota and human consumers of seafood in the coast of Qingdao, China.

    PubMed

    Yang, Baolu; Ha, Yiming; Jin, Jing

    2015-09-01

    This paper reports the levels of (226)Ra, (232)Th, (40)K and (137)Cs in the edible parts of 11 different marine species collected from the Qingdao coast of China. The activities of (226)Ra, (232)Th and (40)K ranged from 0.08±0.03 to 1.65±0.60Bqkg(-1) w.w., 0.09±0.02 to 1.44±0.10Bqkg(-1) w.w., 26.89±1.25 to 219.25±5.61Bqkg(-1) w.w., respectively. Artificial (137)Cs was undetectable or close to the detection limit in the biota sampled. To link radioactivity to possible impact on health, we calculated radiation doses to both the marine biota and human beings. We showed that doses in all cases were dominated by naturally occurring (40)K and that (137)Cs doses were negligible compared with (40)K-derived doses. The total doses to marine biota ranged between 16.55 and 62.41nGyh(-1) among different biota species, which were below the benchmark level of aquatic organism. The committed effective dose to humans through seafood consumption varied from 10.55 to 36.17?Svy(-1), and the associated lifetime cancer risks ranged from 5.93E-05 to 9.49E-05 for different age and gender groups. Both the dose and cancer risk to humans were at the acceptable range. Despite the significant amount of radionuclides released as a result of the Fukushima accident, their impact on the seafood in Qingdao coast appears to be negligible based on our measurements of concentrations of radionuclide activity and internal dose estimates. PMID:25985213

  16. Distribution, abundance, and habitat use of introduced Boa constrictor threatening the native biota of Cozumel Island, Mexico

    Microsoft Academic Search

    Irene Romero-Nájera; Alfredo D. Cuarón; Cristopher González-Baca

    2007-01-01

    Species introductions are among the most pervasive types of disturbance, seriously affecting island biota and ecosystem dynamics.\\u000a The management of introduced generalist species, which may live in a wide range of environmental conditions, can be particularly\\u000a difficult and is a major challenge for the conservation of native insular species. Boa constrictor was introduced onto Cozumel Island, Mexico, in 1971. The

  17. Distribution, abundance, and habitat use of introduced Boa constrictor threatening the native biota of Cozumel Island, Mexico

    Microsoft Academic Search

    Irene Romero-Nájera; Alfredo D. Cuarón; Cristopher González-Baca

    Species introductions are among the most pervasive types of disturbance, seriously affecting island biota and ecosystem dynamics.\\u000a The management of introduced generalist species, which may live in a wide range of environmental conditions, can be particularly\\u000a difficult and is a major challenge for the conservation of native insular species. Boa constrictor was introduced onto Cozumel Island, Mexico, in 1971. The

  18. Acute toxicity to Daphnia pulex of six classes of chemical compounds potentially hazardous to Great Lakes aquatic biota

    Microsoft Academic Search

    Stephen B. Smith; Jacqueline F. Savino; Marc A. Blouin

    1988-01-01

    Of the six classes of chemicals potentially hazardous to Great Lakes aquatic biota, derivatives of polyaromatic hydrocarbons (PAHs) were the most acutely toxic (48-h EC 50) to Daphnia pulex. The other classes, listed in order of decreasing toxicity, were alkyl halides, nitrogen-containing compounds, cyclic alkanes, heterocyclic nitrogen compounds, silicon-containing compounds. Of the 41 compounds representing the six chemical classes, 6

  19. Biological studies of atmospheric deposition impact on biota in Kola North Mountain Lakes, Russia

    SciTech Connect

    Yakovlev, V.; Sharov, A.; Vandysh, O. [Institute of the North Industrial Ecology Problems, Murmansk (Russian Federation)

    1996-12-31

    In the framework of the AL:PE projects, biological studies of phyto-, zooplankton and zoobenthos communities of a small lakes situated in Chuna tundra and Chibiny mountains in Murmansk region were performed in 1993-1995. The lakes are the typical oligotrophic mountain lakes. In the Chibiny lake phytoplankton were presented mostly by species from rock catchment area. Summer phytoplankton state in the lakes showed no acidification in 1993-1995. However, the great number dead cells of acid tolerance diatoms, such as Tabellaria flocculosa found in the Chuna lake in summer period, may indicate a presence of acid episodes. Zooplankton of the lakes is typical for high oligotrophic mountain lakes. However, lack of the acid sensitive daphniidae cladocerans seems to be a result of acidification effects. There were no significant relationships between benthic invertebrates species composition and present water acidity of the lakes. The typical for mountain lakes taxa (Prodiamesinae chironomids, stone flies and mayflies) were found in lake shore and streams. Despite the only little evidence of damage in biota, the further biological studies would be useful for long-term monitoring of the mountain lakes.

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

    PubMed

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

    2013-07-01

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

  1. Determining the response of African biota to climate change: using the past to model the future.

    PubMed

    Willis, K J; Bennett, K D; Burrough, S L; Macias-Fauria, M; Tovar, C

    2013-01-01

    Prediction of biotic responses to future climate change in tropical Africa tends to be based on two modelling approaches: bioclimatic species envelope models and dynamic vegetation models. Another complementary but underused approach is to examine biotic responses to similar climatic changes in the past as evidenced in fossil and historical records. This paper reviews these records and highlights the information that they provide in terms of understanding the local- and regional-scale responses of African vegetation to future climate change. A key point that emerges is that a move to warmer and wetter conditions in the past resulted in a large increase in biomass and a range distribution of woody plants up to 400-500 km north of its present location, the so-called greening of the Sahara. By contrast, a transition to warmer and drier conditions resulted in a reduction in woody vegetation in many regions and an increase in grass/savanna-dominated landscapes. The rapid rate of climate warming coming into the current interglacial resulted in a dramatic increase in community turnover, but there is little evidence for widespread extinctions. However, huge variation in biotic response in both space and time is apparent with, in some cases, totally different responses to the same climatic driver. This highlights the importance of local features such as soils, topography and also internal biotic factors in determining responses and resilience of the African biota to climate change, information that is difficult to obtain from modelling but is abundant in palaeoecological records. PMID:23878343

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

    PubMed

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

    2015-08-01

    Molecular clock analyses estimate that crown-group animals began diversifying hundreds of millions of years before the start of the Cambrian period. However, the fossil record has not yielded unequivocal evidence for animals during this interval. Some of the most promising candidates for Precambrian animals occur in the Weng'an biota of South China, including a suite of tubular fossils assigned to Sinocyclocyclicus, Ramitubus, Crassitubus and Quadratitubus, that have been interpreted as soft-bodied eumetazoans comparable to tabulate corals. Here, we present new insights into the anatomy, original composition and phylogenetic affinities of these taxa based on data from synchrotron radiation X-ray tomographic microscopy, ptychographic nanotomography, scanning electron microscopy and electron probe microanalysis. The patterns of deformation observed suggest that the cross walls of Sinocyclocyclicus and Quadratitubus were more rigid than those of Ramitubus and Crassitubus. Ramitubus and Crassitubus specimens preserve enigmatic cellular clusters at terminal positions in the tubes. Specimens of Sinocyclocyclicus and Ramitubus have biological features that might be cellular tissue or subcellular structures filling the spaces between the cross walls. These observations are incompatible with a cnidarian interpretation, in which the spaces between cross walls are abandoned parts of the former living positions of the polyp. The affinity of the Weng'an tubular fossils may lie within the algae. PMID:26180072

  3. Determining the response of African biota to climate change: using the past to model the future

    PubMed Central

    Willis, K. J.; Bennett, K. D.; Burrough, S. L.; Macias-Fauria, M.; Tovar, C.

    2013-01-01

    Prediction of biotic responses to future climate change in tropical Africa tends to be based on two modelling approaches: bioclimatic species envelope models and dynamic vegetation models. Another complementary but underused approach is to examine biotic responses to similar climatic changes in the past as evidenced in fossil and historical records. This paper reviews these records and highlights the information that they provide in terms of understanding the local- and regional-scale responses of African vegetation to future climate change. A key point that emerges is that a move to warmer and wetter conditions in the past resulted in a large increase in biomass and a range distribution of woody plants up to 400–500 km north of its present location, the so-called greening of the Sahara. By contrast, a transition to warmer and drier conditions resulted in a reduction in woody vegetation in many regions and an increase in grass/savanna-dominated landscapes. The rapid rate of climate warming coming into the current interglacial resulted in a dramatic increase in community turnover, but there is little evidence for widespread extinctions. However, huge variation in biotic response in both space and time is apparent with, in some cases, totally different responses to the same climatic driver. This highlights the importance of local features such as soils, topography and also internal biotic factors in determining responses and resilience of the African biota to climate change, information that is difficult to obtain from modelling but is abundant in palaeoecological records. PMID:23878343

  4. A new middle eocene whale (Mammalia: Cetacea: Archaeoceti) and associated biota from Georgia

    USGS Publications Warehouse

    Hulbert, R.C., Jr.; Petkewich, R.M.; Bishop, G.A.; Bukry, D.; Aleshire, D.P.

    1998-01-01

    A shallow-marine fossil biota was recovered from the Blue Bluff unit (formerly part of the McBean Formation) in the Upper Coastal Plain of eastern Georgia. Biochronologically significant mollusks (e.g., Turritella nasuta, Cubitostrea sellaeformis, Pteropsella lapidosa) and calcareous nannoplankton (e.g., Chiasmolithus solitus, Reticulofenestra umbilica, Cribocentrum reticulatum) indicate a latest Lutetian-earliest Bartonian age, or about 40 to 41 Ma. Georgiacetus vogtlensis new genus and species is described from a well-preserved, partial skeleton. Georgiacetus is the oldest known whale with a true pterygoid sinus fossa in its basicranium and a pelvis that did not articulate directly with the sacral vertebrae, two features whose acquisitions were important steps toward adaptation to a fully marine existence. The posterior four cheek teeth of G. vogtlensis form a series of carnassial-like shearing blades. These teeth also bear small, blunt accessory cusps, which are regarded as being homologous with the larger, sharper accessory cusps of basilosaurid cheek teeth.

  5. Influence of 2,4,6-trichlorophenol and pentachlorophenol on the biota of aquatic systems

    SciTech Connect

    Schauerte, W.; Lay, J.P.; Klein, W.; Korte, F.

    1982-01-01

    Effects of the chemicals 2,4,6-trichlorophenol (TCP) and pentachlorophenol (PCP) on population dynamics of several species were studied in a short-term experiment in separated compartments of an experimental pond. TCP and PCP were applied at single doses of 5 mg/1 and 1 mg/1 respectively in duplicates into compartments of a natural experimental pond. The chemicals showed the following influences on population dynamics and on the physicochemistry of the compartments: 1. A rapid decline of Daphnia concentrations to zero after about three days for PCP and eight days for TCP. 2. A decrease of autotrophic phytoplankton (blue-algae and diatoms). 3. A continuous increase of contamination indicators like flagellates and microorganisms. 4. A significant decrease in oxygen concentration as secondary effect of the changed balance between autotrophic and heterotrophic populations.

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

    PubMed

    Fesenko, S V; Alexakhin, R M; Geras'kin, S A; Sanzharova, N I; Spirin, Ye V; Spiridonov, S I; Gontarenko, I A; Strand, P

    2005-01-01

    A methodological approach for a comparative assessment of ionising radiation effects on man and non-human species, based on the use of Radiation Impact Factor (RIF) - ratios of actual exposure doses to biota species and man to critical dose is described. As such doses, radiation safety standards limiting radiation exposure of man and doses at which radiobiological effects in non-human species were not observed after the Chernobyl accident, were employed. For the study area within the 30km ChNPP zone dose burdens to 10 reference biota groups and the population (with and without evacuation) and the corresponding RIFs were calculated. It has been found that in 1986 (early period after the accident) the emergency radiation standards for man do not guarantee adequate protection of the environment, some species of which could be affected more than man. In 1991 RIFs for man were considerably (by factor of 20.0-1.1 x 10(5)) higher compared with those for selected non-human species. Thus, for the long term after the accident radiation safety standards for man are shown to ensure radiation safety for biota as well. PMID:15653184

  7. The Luoping biota: exceptional preservation, and new evidence on the Triassic recovery from end-Permian mass extinction.

    PubMed

    Hu, Shi-xue; Zhang, Qi-yue; Chen, Zhong-Qiang; Zhou, Chang-yong; Lü, Tao; Xie, Tao; Wen, Wen; Huang, Jin-yuan; Benton, Michael J

    2011-08-01

    The timing and nature of biotic recovery from the devastating end-Permian mass extinction (252 Ma) are much debated. New studies in South China suggest that complex marine ecosystems did not become re-established until the middle-late Anisian (Middle Triassic), much later than had been proposed by some. The recently discovered exceptionally preserved Luoping biota from the Anisian Stage of the Middle Triassic, Yunnan Province and southwest China shows this final stage of community assembly on the continental shelf. The fossil assemblage is a mixture of marine animals, including abundant lightly sclerotized arthropods, associated with fishes, marine reptiles, bivalves, gastropods, belemnoids, ammonoids, echinoderms, brachiopods, conodonts and foraminifers, as well as plants and rare arthropods from nearby land. In some ways, the Luoping biota rebuilt the framework of the pre-extinction latest Permian marine ecosystem, but it differed too in profound ways. New trophic levels were introduced, most notably among top predators in the form of the diverse marine reptiles that had no evident analogues in the Late Permian. The Luoping biota is one of the most diverse Triassic marine fossil Lagerstätten in the world, providing a new and early window on recovery and radiation of Triassic marine ecosystems some 10 Myr after the end-Permian mass extinction. PMID:21183583

  8. Recruitment of marine biota onto hard and soft artificially created subtidal habitats in Sabah Al-Ahmad Sea City, Kuwait.

    PubMed

    Jones, David A; Nithyanandan, Manickam

    2013-07-30

    Remediation of coastal habitats from impacts such as dredging and excavation in Gulf coastal waters is hampered by a lack of information on natural recolonisation rates and recruitment patterns of subtidal biota. For soft substrate habitats recovery information is only available for severely polluted sites where recovery takes many years (Jones et al., 2008). Construction of the Sabah Al-Ahmad Sea City provides a unique opportunity to follow benthic recruitment and community development on a range of artificially created benthic habitats over time. The three phases completed were each flooded by the sea separately and annual ecological surveys allow comparison of colonisation patterns and community development rates over time. Species diversity similar to that seen in comparable natural open sea habitats is reached within 2-5 years for mixed sand/rock biota, but longer (2-6 years) for sand biota. Biotic abundance exceeds open sea levels within 1-2 years due to settlement of opportunistic species. Coral recruitment occurred within 3 years. Present data provides a reference point for recovery rates into none polluted benthic habitats for the Gulf. PMID:23199731

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

    PubMed

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

    2011-10-01

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

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

    SciTech Connect

    Farfan, E.; Jannik, T.

    2011-10-01

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

  11. Use of the Biotic Ligand Model to predict metal toxicity to aquatic biota in areas of differing geology

    USGS Publications Warehouse

    Smith, Kathleen S.

    2005-01-01

    This work evaluates the use of the biotic ligand model (BLM), an aquatic toxicity model, to predict toxic effects of metals on aquatic biota in areas underlain by different rock types. The chemical composition of water, soil, and sediment is largely derived from the composition of the underlying rock. Geologic source materials control key attributes of water chemistry that affect metal toxicity to aquatic biota, including: 1) potentially toxic elements, 2) alkalinity, 3) total dissolved solids, and 4) soluble major elements, such as Ca and Mg, which contribute to water hardness. Miller (2002) compiled chemical data for water samples collected in watersheds underlain by ten different rock types, and in a mineralized area in western Colorado. He found that each rock type has a unique range of water chemistry. In this study, the ten rock types were grouped into two general categories, igneous and sedimentary. Water collected in watersheds underlain by sedimentary rock has higher mean pH, alkalinity, and calcium concentrations than water collected in watersheds underlain by igneous rock. Water collected in the mineralized area had elevated concentrations of calcium and sulfate in addition to other chemical constituents. Miller's water-chemistry data were used in the BLM (computer program) to determine copper and zinc toxicity to Daphnia magna. Modeling results show that waters from watersheds underlain by different rock types have characteristic ranges of predicted LC 50 values (a measurement of aquatic toxicity) for copper and zinc, with watersheds underlain by igneous rock having lower predicted LC 50 values than watersheds underlain by sedimentary rock. Lower predicted LC 50 values suggest that aquatic biota in watersheds underlain by igneous rock may be more vulnerable to copper and zinc inputs than aquatic biota in watersheds underlain by sedimentary rock. For both copper and zinc, there is a trend of increasing predicted LC 50 values with increasing dissolved organic carbon (DOC) concentrations. Predicted copper LC 50 values are extremely sensitive to DOC concentrations, whereas alkalinity appears to have an influence on zinc toxicity at alkalinities in excess of about 100 mg/L CaCO 3 . These findings show promise for coupling the BLM (computer program) with measured water-chemistry data to predict metal toxicity to aquatic biota in different geologic settings and under different scenarios. This approach may ultimately be a useful tool for mine-site planning, mitigation and remediation strategies, and ecological risk assessment.

  12. Screening level dose assessment of aquatic biota downstream of the Marcoule nuclear complex in southern France.

    PubMed

    St-Pierre, S; Chambers, D B; Lowe, L M; Bontoux, J G

    1999-09-01

    Aquatic biota in the Rhone River downstream of the Marcoule nuclear complex in France are exposed to natural sources of radiation and to radioactivity released from the Marcoule complex. A simple conservative screening level model was used to estimate the range of concentrations in aquatic media (water, sediments, and aquatic organisms) of both artificial and natural radionuclides and the consequent absorbed (whole body) dose rates for aquatic organisms. Five categories of aquatic organisms were studied, namely, submerged aquatic plants (phanerogam), non-bottom-feeding fish, bottom-feeding fish, mollusca, and fish-eating birds. The analysis was based on the radionuclide concentrations reported in four consecutive annual radioecological monitoring reports published by French agencies with nuclear regulatory responsibilities. The results of this assessment were used to determine, qualitatively, the magnitude of any potential health impacts on each of the five categories of aquatic organisms studied. The range of dose rate estimates ranged over three orders of magnitude, with maximum dose rates estimated to be in the order of 1 to 10 microGy h(-1). These maximum dose rates are a factor 40 or more below the international guideline intended to ensure the protection of aquatic populations (about 400 microGy h(-1)), and a factor ten or more below the level which may trigger the need for a more detailed evaluation of potential ecological consequences to the exposed populations (about 100 microGy h(-1)). As a result, chronic levels of radioactivity, artificial and natural, measured in aquatic media downstream of Marcoule are unlikely to result in adverse health impacts on the categories and species of aquatic organisms studied. Thus, based on the screening level analysis discussed in this paper, a more detailed evaluation of the dose rates does not appear to be warranted. PMID:10456504

  13. Enantioselective determination of persistent and partly degradable toxaphene congeners in high trophic level biota.

    PubMed

    Vetter, W; Luckas, B

    2000-08-01

    Enantiomer separation of chiral toxaphene components in biological samples was studied by application of different chiral stationary phases based on modified cyclodextrins. Several pairs of enantiomers were resolved on permethylated beta-cyclodextrin (beta-PMCD), among them 2-endo,3-exo,5-endo,6-exo,8,8,9,10-octachlorobornane (B8-1412), which was not enantiomerically resolved on tert-butyldimethylsilylated beta-cyclodextrin (beta-BSCD). The latter column was applied to determine the enantiomer ratios (ERs) of 2-endo,3-exo,5-endo,6-exo,8,8,10,10-octachlorobornane (B8-1413 or P-26) in brain tissue of three seal species. The ER of B8-1413 (P-26) in brain was virtually racemic as well as those of the two persistent and chiral components of technical chlordane, 1-exo,2,2,4,5,6,7,8,8-octachloro-3a,4,7,7a-tetrahydro-4,7-metha noindane (trans-nonachlor III or MC 6) and 1-exo,2-endo,3-exo,4,5,6,8,8-octachloro-3a,7,7a-tetrahydro-4,7- methanoindane (U82). In contrast, B8-1412 and 2-exo,5,5,8,9,9,10,10-octachlorobornane (B8-2229 or P-44) were significantly enantiomerically enriched in several samples of high trophic level biota. 2,2,5,5,8,9,9,10,10-Nonachlorobornane (B9-1025 or P-62), a chlorobornane metabolisable by seals and the presumable precursor of B8-2229 (P-44), was also enantiomerically enriched in seal blubber. These results confirm the assumption that some less persistent toxaphene components may be significantly degraded in biological samples. Enantioselective gas chromatography provides the information that such a degradation is happening by the characteristic change of the ratio of the two enantiomers in the respective tissues. PMID:10819220

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

    PubMed

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

    2012-02-01

    Biological entities and gradients of selected chemicals within the seemingly barren ice layers covering Lake Baikal were investigated. Ice cores 40-68 cm long were obtained from in shore and offshore sites of Southern Lake Baikal during the cold period of a year (March-April) in 2007 and 2008. In microscopic observations of the melted ice, both algae and bacteria were found in considerable numbers (>10(3) cells/L and >10(4) cells/ml, respectively). Among all organisms found, diatom was generally the most predominant taxon in the ice. Interestingly, both planktonic and benthic algae were present in considerable numbers (2-4×10(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

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

    PubMed

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

    2012-01-01

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

  16. Soil biota can change after exotic plant invasion: Does this affect ecosystem processes?

    USGS Publications Warehouse

    Belnap, J.; Phillips, S.L.; Sherrod, S.K.; Moldenke, A.

    2005-01-01

    Invasion of the exotic annual grass Bromus tectorum into stands of the native perennial grass Hilaria jamesii significantly reduced the abundance of soil biota, especially microarthropods and nematodes. Effects of invasion on active and total bacterial and fungal biomass were variable, although populations generally increased after 50+ years of invasion. The invasion of Bromus also resulted in a decrease in richness and a species shift in plants, microarthropods, fungi, and nematodes. However, despite the depauperate soil fauna at the invaded sites, no effects were seen on cellulose decomposition rates, nitrogen mineralization rates, or vascular plant growth. When Hilaria was planted into soils from not-invaded, recently invaded, and historically invaded sites (all currently or once dominated by Hilaria), germination and survivorship were not affected. In contrast, aboveground Hilaria biomass was significantly greater in recently invaded soils than in the other two soils. We attributed the Hilaria response to differences in soil nutrients present before the invasion, especially soil nitrogen, phosphorus, and potassium, as these nutrients were elevated in the soils that produced the greatest Hilaria biomass. Our data suggest that it is not soil biotic richness per se that determines soil process rates or plant productivity, but instead that either (1) the presence of a few critical soil food web taxa can keep ecosystem function high, (2) nutrient loss is very slow in this ecosystem, and/or (3) these processes are microbially driven. However, the presence of Bromus may reduce key soil nutrients over time and thus may eventually suppress native plant success. ?? 2005 by the Ecological Society of America.

  17. The effect of native and introduced biofuel crops on the composition of soil biota communities

    NASA Astrophysics Data System (ADS)

    Hed?nec, Petr; Ustak, Sergej; Novotný, David; Frouz, Jan

    2015-04-01

    Biofuel crops are an accepted alternative to fossil fuels, but little is known about the ecological impact of their production. The aim of this contribution is to study the effect of native (Salix viminalis and Phalaris arundinacea) and introduced (Helianthus tuberosus, Reynoutria sachalinensis and Silphium perfoliatum) biofuel crop plantations on the soil biota in comparison with cultural meadow vegetation used as control. The study was performed as part of a split plot field experiment of the Crop Research Institute in the city of Chomutov (Czech Republic). The composition of the soil meso- and macrofauna community, composition of the cultivable fraction of the soil fungal community, cellulose decomposition (using litter bags), microbial biomass, basal soil respiration and PLFA composition (incl. F/B ratio) were studied in each site. The C:N ratio and content of polyphenols differed among plant species, but these results could not be considered significant between introduced and native plant species. Abundance of the soil meso- and macrofauna was higher in field sites planted with S. viminalis and P. arundinacea than those planted with S. perfoliatum, H. tuberosus and R. sachalinensis. RDA and Monte Carlo Permutation Test showed that the composition of the faunal community differed significantly between various native and introduced plants. Significantly different basal soil respiration was found in sites planted with various energy crops; however, this difference was not significant between native and introduced species. Microbial biomass carbon and cellulose decomposition did not exhibit any statistical differences among the biofuel crops. The largest statistically significant difference we found was in the content of actinobacterial and bacterial (bacteria, G+ bacteria and G- bacteria) PLFA in sites overgrown by P. arundinacea compared to introduced as well as native biofuel crops. In conclusion, certain parameters significantly differ between various native and introduced species of biofuel crops; however, the functional importance of these differences requires further research.

  18. Fukushima-derived radionuclides in the ocean and biota off Japan

    PubMed Central

    Buesseler, Ken O.; Jayne, Steven R.; Fisher, Nicholas S.; Rypina, Irina I.; Baumann, Hannes; Baumann, Zofia; Breier, Crystaline F.; Douglass, Elizabeth M.; George, Jennifer; Macdonald, Alison M.; Miyamoto, Hiroomi; Nishikawa, Jun; Pike, Steven M.; Yoshida, Sashiko

    2012-01-01

    The T?hoku earthquake and tsunami of March 11, 2011, resulted in unprecedented radioactivity releases from the Fukushima Dai-ichi nuclear power plants to the Northwest Pacific Ocean. Results are presented here from an international study of radionuclide contaminants in surface and subsurface waters, as well as in zooplankton and fish, off Japan in June 2011. A major finding is detection of Fukushima-derived 134Cs and 137Cs throughout waters 30–600 km offshore, with the highest activities associated with near-shore eddies and the Kuroshio Current acting as a southern boundary for transport. Fukushima-derived Cs isotopes were also detected in zooplankton and mesopelagic fish, and unique to this study we also find 110mAg in zooplankton. Vertical profiles are used to calculate a total inventory of ?2 PBq 137Cs in an ocean area of 150,000 km2. Our results can only be understood in the context of our drifter data and an oceanographic model that shows rapid advection of contaminants further out in the Pacific. Importantly, our data are consistent with higher estimates of the magnitude of Fukushima fallout and direct releases [Stohl et al. (2011) Atmos Chem Phys Discuss 11:28319–28394; Bailly du Bois et al. (2011) J Environ Radioact, 10.1016/j.jenvrad.2011.11.015]. We address risks to public health and marine biota by showing that though Cs isotopes are elevated 10–1,000× over prior levels in waters off Japan, radiation risks due to these radionuclides are below those generally considered harmful to marine animals and human consumers, and even below those from naturally occurring radionuclides. PMID:22474387

  19. Radionuclides in the adriatic sea and related dose-rate assessment for marine biota.

    PubMed

    Petrinec, Branko; Strok, Marko; Franic, Zdenko; Smodis, Borut; Pavicic-Hamer, Dijana

    2013-01-01

    Artificial and natural radionuclides were determined in the Adriatic Sea in the seawater and sediment samples in the period from 2007 to 2011. The sampling areas were coastal waters of Slovenia, Croatia and Albania, together with the deepest part of the Adriatic in South Adriatic Pit and Otranto strait. Sampling locations were chosen to take into account all major geological and geographical features of this part of the Adriatic Sea and possible coastal influences. After initial sample preparation steps, samples were measured by gamma-ray spectrometry. In the seawater ??K activity concentrations were in the range from 6063 to 10519 Bq m?³, ¹³?Cs from 1.6 to 3.8 Bq m?³, ²²?Ra from 23 to 31 Bq m?³, ²²?Ra from 1 to 25 Bq m?³ and ²³?U from 64 to 490 Bq m?³. The results of sediment samples showed that ??K was in the range from 87 to 593 Bq kg?¹, ¹³?Cs from 0.8 to 7.3 Bq kg?¹, ²²?Ra from 18 to 35 Bq kg?¹, ²²?Ra from 4 to 29 Bq kg?¹ and ²³?U from 14 to 120 Bq kg?¹. In addition, the ERICA Assessment Tool was used for the assessment of dose rates for reference marine organisms using the activity concentrations of the determined radionuclides in seawater. The assessment showed that for the most of the organisms, the dose rates were within the background levels, indicating that the determined values for seawater does not pose a significant risk for the most of marine biota. In the study, the results are critically discussed and compared with other similar studies worldwide. Generally, the activity concentrations of the examined radionuclides did not differ from those reported for the rest of the Mediterranean Sea. PMID:22927659

  20. Occurrence, distribution and bioaccumulation of endocrine disrupting compounds in water, sediment and biota samples from a European river basin.

    PubMed

    Salgueiro-González, N; Turnes-Carou, I; Besada, V; Muniategui-Lorenzo, S; López-Mahía, P; Prada-Rodríguez, D

    2015-10-01

    The occurrence, distribution and bioaccumulation of five endocrine disrupting compounds (4-tert-octylphenol, 4-n-octylphenol, 4-n-nonylphenol, nonylphenol and bisphenol A) in water, sediment and biota (Corbicula fluminea) collected along the Minho River estuary (NW Iberian Peninsula) were examined. Samples were collected in two campaigns (May and November, 2012) and analyzed by different extraction procedures followed by liquid chromatography tandem mass spectrometry determination. The presence of linear isomers (4-n-octylphenol and 4-n-nonylphenol) was scarcely observed whereas branched isomers (4-tert-octylphenol and nonylphenol) were measured in almost all samples. Wastewater treatment plant effluents and nautical, fishing and agricultural activities are considered the primary source of pollution of the river by alkylphenols. The presence of bisphenol A in the river could be mainly associated to punctual sources of contamination from industrial discharges. A decrease in the total concentration of phenolic compounds in water was observed from spring to autumn (from 0.888?gL(-1) in May to 0.05?gL(-1) in November), while similar values were shown in C. fluminea samples from the two campaigns (1388 and 1228ngg(-1) dw in spring and autumn, respectively). In sediments, the total concentration of the target compounds varied between 13 and 4536ngg(-1) dw (average of 1041ngg(-1) dw). Sediment-water partition coefficient (Kd), bioaccumulation factor (BAF) and biota-sediment accumulation factor (BSAF) were estimated and highest values were obtained for nonylphenol. Calculated risk quotients showed low and moderate risk for the aquatic environment from the presence of the target compounds at all sampling points. The estimation of the daily intake of the studied compounds via water and biota ingestion indicated no risk for human health. PMID:26005755

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

    PubMed

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

    2011-09-01

    The question of polycyclic aromatic hydrocarbon (PAH) bioavailability and its relationship to specific PAH sources with different PAH binding characteristics is an important one, because bioavailability drives PAH accumulation in biota and ultimately the biochemical responses to the PAH contaminants. The industrial harbour at Kitimat (British Columbia, Canada) provides an ideal location to study the bioavailability and bioaccumulation of sediment hydrocarbons to low trophic level biota. Samples of soft shell clams (Mya arenaria) and intertidal sediment collected from multiple sites over six years at various distances from an aluminium smelter and a pulp and paper mill were analysed for 106 PAHs, plant diterpenes and other aromatic fraction hydrocarbons. Interpretation using PAH source ratios and multivariate data analysis reveals six principal hydrocarbon sources: PAHs in coke, pitch and emissions from anode combustion from the aluminium smelter, vascular plant terpenes and aromatised terpenes from the pulp and paper mill, petroleum PAHs from shipping and other anthropogenic activities and PAHs from natural plant detritus. Harbour sediments predominantly contain either pitch or pyrogenic PAHs from the smelter, while clams predominantly contain plant derived PAHs and diterpenes from the adjacent pulp mill. PAHs from the smelter have low bioavailability to clams (Biota-Sediment Accumulation Factors; BSAFs <1 for pitch and coke; <10 for anode combustion, decreasing to ?0.1 for the mass 300 and 302 PAHs), possibly due to binding to pitch or soot carbon matrices. Decreases in PAH isomer ratios between sediments and clams likely reflect a combination of variation in uptake kinetics of petroleum PAHs and compound specific metabolism, with the importance of petroleum PAHs decreasing with increasing molecular weight. Plant derived compounds exhibit little natural bioaccumulation at reference sites, but unsaturated and aromatised diterpenes released from resins by industrial pulping processes are readily accumulated by the clams (BSAFs >500). Thus while most of the smelter associated PAHs in sediments may not be bioavailable to benthic organisms, the plant terpenes (including retene, totarol, ferruginol, manool, dehydroabietane and other plant terpenes that form the chemical defence mechanism of conifers) released by pulp mills are bioavailable and possess demonstrated toxic properties. The large scale release of plant terpenes by some of the many pulp mills located in British Columbia and elsewhere represents a largely undocumented risk to aquatic biota. PMID:21788067

  2. Geochemistry, biota and natural background levels in an arsenic naturally contaminated volcanic aquifer

    NASA Astrophysics Data System (ADS)

    Preziosi, Elisabetta; Amalfitano, Stefano; Di Lorenzo, Tiziana; Parrone, Daniele; Rossi, David; Ghergo, Stefano; Lungarini, Silvia; Zoppini, Anna Maria

    2015-04-01

    The tight links between chemical and ecological status are largely acknowledged as for surface water bodies, while aquifers are still considered as hidden groundwater reservoirs, rather than ecosystems to be preserved. Geochemical and biological interactions play a key role in all subterranean processes, including the dynamics of the fate of anthropogenic contaminants. Studies on groundwater dependent ecosystems (GDE) were mainly focused on karst aquifers so far, but an increased awareness on the importance of water-rock interactions and methodological improvements in microbial ecology are rapidly increasing the level of characterization of groundwater ecosystems in various hydrogeological contexts. Similarly, knowledge about groundwater biodiversity is still limited, especially if porous habitats are concerned. Yet, groundwater and GDEs are populated by a diverse and highly adapted biota, dominated by crustaceans, which provide important ecosystem services and act as biological indicators of chemical and quantitative impact on groundwater resources. In a previous research (Amalfitano et al. 2014), we reported that the microbial community heterogeneity may reflect the lithological and hydrogeological complexity within volcanic and alluvial facies transition in a groundwater body. The quantitative tracking of the microbial community structure allowed disentangling the natural biogeochemical processes evolving within the aquifer flow path. The analyses of groundwater crustaceans assemblages may contribute to shed more light upon the state and dynamics of such ecosystems. In the present research, a comprehensive study of a water table aquifer flowing through a quaternary volcanic district is being performed, including the geochemical (inorganic) composition, the microbial composition, and the analysis of crustacean assemblages . Groundwater samples are periodically collected from private wells and springs under a low anthropic impact. The key issues within the sampling area are related to occurrence of arsenic from natural sources, fluoride and coliforms, which make the water resource unsuitable for human consumption. The aim of this work is to present the first outcomes of this activity. References Amalfitano S, Del Bon A, Zoppini AM, Ghergo S, Fazi S, Parrone D, Casella P, Stano F, Preziosi E (2014) Groundwater geochemistry and microbial community structure in the aquifer transition from volcanic to alluvial areas. Water Research, 65 (2014) 384-394. Doi http://dx.doi.org/10.1016/j.watres.2014.08.004

  3. Distribution of PCB congeners in seven lake systems: Interactions between sediment and food-web transport

    SciTech Connect

    MacDonald, C.R.; Metcalfe, C.D.; Balch, G.C.; Metcalfe, T.L. (Trent Univ., Peterborough, Ontario (Canada). Environmental and Resource Studies)

    1993-11-01

    A study was conducted to examine the role of two processes, partitioning of PCBs between sediment and biota and food-web transport, in determining the concentration of PCB congeners in the biota of seven lakes. Biota PCB concentration (lipid)-to-sediment PCB concentration (organic carbon), or BSF, ratios were calculated as markers of the partitioning of PCBs between biota and sediment, and biota PCB concentration (lipid)-to-zooplankton PCB concentration (lipid), or BAS, ratios were calculated as markers of the transport of PCBs through food webs. The lakes ranged from a shallow, well-mixed lake with a historic input of Aroclor technical mixtures to deeper, oligotrophic systems in which atmospheric deposition was the only known source. BSF ratios ranged from approximately one in cyprinids and zooplankton in all lakes to 30 in yellow perch in one lake. A significant correlation between lake maximum depth and combined BSF ratios for all biota indicated that PCBs were generally more available for accumulation in the shallower lakes, regardless of the PCB source. Principal component analysis (PCA) showed that the biota in the shallower lakes had higher ratios of higher chlorinated congeners, suggesting that predictions of equal concentrations of hydrophobic contaminants on a lipid basis in sediment and lower trophic levels may significantly underestimate the accumulation of very hydrophobic compounds in the organisms of some lake systems. BAF ratios ranged from approximately one in the lower trophic levels to approximately 10 in lake trout.

  4. Assessing radiation impact at a protected coastal sand dune site: an intercomparison of models for estimating the radiological exposure of non-human biota.

    PubMed

    Wood, Michael D; Beresford, Nicholas A; Barnett, Catherine L; Copplestone, David; Leah, Richard T

    2009-12-01

    This paper presents the application of three publicly available biota dose assessment models (the ERICA Tool, R&D128/SP1a and RESRAD-BIOTA) to an assessment of the Drigg coastal sand dunes. Using measured (90)Sr, (99)Tc, (137)Cs, (238)Pu, (239+240)Pu and (241)Am activity concentrations in sand dune soil, activity concentration and dose rate predictions are made for a range of organisms including amphibians, birds, invertebrates, mammals, reptiles, plants and fungi. Predicted biota activity concentrations are compared to measured data where available. The main source of variability in the model predictions is the transfer parameters used and it is concluded that developing the available transfer databases should be a focus of future research effort. The value of taking an informed user approach to investigate the way in which models may be expected to be applied in practice is highlighted and a strategy for the future development of intercomparison exercises is presented. PMID:19447531

  5. LEAD (Pb) IN BIOTA AND PERCEPTIONS OF Pb EXPOSURE AT A RECENTLY DESIGNATED SUPERFUND BEACH SITE IN NEW JERSEY

    PubMed Central

    Burger, Joanna; Gochfeld, Michael; Jeitner, Christian; Donio, Mark; Pittfield, Taryn

    2014-01-01

    The Raritan Bay Slag Site (New Jersey) was designated a Superfund site in 2009 because the seawall, jetties, and sediment contained lead (Pb). Our objective was to compare Pb and mercury (Hg) levels in biota and public perceptions of exposure at the Superfund and reference sites. Samples (algae, invertebrates, fish) were collected from the Raritan Bay Slag Site and reference sites and analyzed for Pb and Hg. Waterfront users were interviewed using a standard questionnaire. Levels of Pb in aquatic organisms were compared to ecological and human health safety standards. Lead levels were related to location, trophic level, and mobility. Lead levels in biota were highest at the western side of the West Jetty. Mean Pb levels were highest for algae (Fucus = 53,600 ± 6990 ng/g = ppb [wet weight], Ulva = 23,900 ± 2430 ppb), intermediate for grass shrimp (7270 ± 1300 ppb, 11,600 ± 3340 ppb), and lowest for fish (Atlantic silversides 218 ± 44 ppb). Within species, Pb levels varied significantly across the sampling sites. Lead levels in algae, sometimes ingested by individuals, were sufficiently high to exceed human safety levels. Mercury levels did not differ between the Superfund and reference sites. Despite the fence and warnings, people (1) used the Superfund and reference sites similarly, (2) had similar fish consumption rates, and (3) were not concerned about Pb, although most individuals knew the metal was present. The fish sampled posed no apparent risk for human consumers, but the algae did. PMID:22409490

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

    SciTech Connect

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

    2008-10-09

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

  7. Acute toxicity of Daphnia pulex to six classes of chemical compounds potentially hazardous to Great Lakes aquatic biota

    USGS Publications Warehouse

    Smith, Stephen B.; Savino, Jacqueline F.; Blouin, Marc A.

    1988-01-01

    Of the six classes of chemicals potentially hazardous to Great Lakes aquatic biota, derivatives of polyaromatic hydrocarbons (PAHs) were the most acutely toxic (48-h EC 50) to Daphnia pulex. The other classes, listed in order of decreasing toxicity were alkyl halides, nitrogen-containing compounds, cyclic alkanes, heterocyclic nitrogen compounds, silicon-containing compounds. O f the 41 compounds representing the six chemical classes, 6 were extremely toxic (> 0.01 - 0.1 mg/L), 11 highly toxic (> 01. - 1.0 mg/L), 20 moderately toxic (> 1.0 - 10.0 mg/L), and 4 slightly toxic (>10 - 100 mg/L). The reference compound, p, p'DDT, was super toxic (< 0.01 mg/L). Based on toxicity and relative abundance (hazard ranking) of the 21 compounds that were detected in tissue of Great Lakes fishes, the classes of compounds that present the greatest threat to Great Lakes aquatic biota are PAH derivatives, alkyl halides, and cyclic aklanes.

  8. Temporal and spatial trends of PCBs, DDTs, HCHs, and HCB in Swedish marine biota 1969-2012.

    PubMed

    Nyberg, Elisabeth; Faxneld, Suzanne; Danielsson, Sara; Eriksson, Ulla; Miller, Aroha; Bignert, Anders

    2015-06-01

    In the 1960s, the Baltic Sea was severely polluted by organic contaminants such as PCBs, HCHs, HCB, and DDTs. Elevated concentrations caused severe adverse effects in Baltic biota. Since then, these substances have been monitored temporally and spatially in Baltic biota, primarily in herring (Clupea harengus) and in guillemot (Uria aalge) egg, but also in cod (Gadus morhua), perch (Perca fluviatilis), eelpout (Zoarces viviparous), and blue mussel (Mytilus edulis). These chemicals were banned in Sweden in the late 1970s/early 1980s. Since the start of monitoring, overall significant decreases of about 70-90 % have been observed. However, concentrations are still higher in the Baltic Sea than in, for example, the North Sea. CB-118 and DDE exceed the suggested target concentrations (24 µg kg(-1) lipid weight and 5 µg kg(-1) wet weight, respectively) at certain sites in some of the monitored species, showing that concentrations may still be too high to protect the most sensitive organisms. PMID:26022330

  9. Non-effect of water hardness on the accumulation and toxicity of copper in a freshwater macrophyte ( Ceratophyllum demersum): How useful are hardness-modified copper guidelines for protecting freshwater biota?

    Microsoft Academic Search

    Scott J. Markich; Angus R. King; Scott P. Wilson

    2006-01-01

    Several nations have adopted hardness-modified copper (Cu) guidelines for protecting freshwater biota. However, there is a lack of good quality data and mechanistic understanding on the effects of true water hardness (calcium (Ca) and magnesium (Mg)) on the bioavailability and toxicity of Cu to freshwater biota, particularly macrophytes. This study determined the effect of true water hardness (35, 90 and

  10. Vertical fluxes of biogenic particles and associated biota in the eastern North Pacific: Implications for biogeochemical cycling and productivity

    NASA Astrophysics Data System (ADS)

    Taylor, Gordon T.; Karl, David M.

    1991-09-01

    Previously published data on vertical fluxes of particulate carbon (PC), nitrogen (PN), organisms (MICRO), and extracted adenosine triphosphate (ATP) into screened sediment traps (335 ?m) from the VERTEX 5 and ADIOS I programs are reexamined as they relate to biogeochemical cycling and oceanic productivity. The four stations discussed represent an oligotrophic to mesotrophic gradient in total primary production (PT), ranging from 245 to 1141 mg Cm-2 d-1 and a gradient in PC flux from the euphotic zone, ranging from 12 to 164 mg Cm-2 d-1 for particles <335 ?m in diameter. Vertical fluxes of PC, PN, MICRO, and ATP decreased as negative power functions of depth with significantly higher depth-dependent losses for ATP fluxes. The flux of intact biota (free, particle-associated, and some active "swimmers," measured microscopically and by extracted ATP) decreased rapidly in the upper 200 m, contributing as much as 52.4% at the most productive station and as little as 1.6% to the flux of PC at oligotrophic stations, remaining relatively constant or increasing slightly (to 3.4 - 9.6% PC flux) between 200 and 2000 m. Multiple regression analyses, expressing fluxes as functions of depth and PT or new production, PN, demonstrated that MICRO and ATP fluxes were more dependent on PT, PN, and depth than bulk PC or PN fluxes. The present analysis illustrates that while sinking particulate organic matter (POM) undergoes rapid attrition in the upper water column, the fluxes of sedimenting biota decrease at even higher rates. Findings support the hypothesis that in oceanic waters, POM sinking from the euphotic zone rapidly becomes a poor habitat for associated microbes, and mechanisms other than remineralization by attached microbes must be invoked to explain observed fluxes and attrition rates. This study also supports the hypothesis that the vertical flux of intact organisms is a more sensitive and less ambiguous record of upper ocean processes than bulk flux measurements of total mass, PC, or PN. Therefore time-resolved measurement of the flux of biota may be useful in estimating PT and PN in the overlying waters.

  11. An Integrated Case Study for Evaluating the Impacts of an Oil Refinery Effluent on Aquatic Biota in the Delaware River: Introduction, Study Approach, and Objectives

    Microsoft Academic Search

    Lenwood W. Hall Jr; Dennis T. Burton

    2005-01-01

    This is the first in a series of article presenting results from a case study designed to assess the impacts of an oil refinery effluent [primarily polynuclear aromatic hydrocarbons (PAHs)] on aquatic biota in the Delaware River. During the course of the study, the oil refinery was owned by Motiva Enterprises LLC. This article provides background information on the study

  12. Exceptional vertebrate biotas from the Triassic of China, and the expansion of marine ecosystems after the Permo-Triassic mass extinction

    E-print Network

    Benton, Michael

    Exceptional vertebrate biotas from the Triassic of China, and the expansion of marine ecosystems Systematics of Vertebrates, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy formations. New work shows the richness of the faunas of fishes and reptiles, and that recovery of vertebrate

  13. Comparison of streambed sediment and aquatic biota as media for characterizing trace elements and organochlorine compounds in the Willamette Basin, Oregon

    USGS Publications Warehouse

    Wentz, D.A.; Waite, I.R.; Rinella, F.A.

    1998-01-01

    During 1992-93, 27 organochlorine compounds (pesticides plus total PCB) and 17 trace elements were analyzed in bed sediment and aquatic biota from 20 stream sites in the Willamette Basin as part of the U.S. Geological Survey's National Water-Quality Assessment Program. Data from each medium were compared to evaluate their relative effectiveness for assessing occurrence (broadly defined as documentation of important concentrations) of these constituents. Except for Cd, Hg, Se, and Ag, trace element concentrations generally were higher in bed sediment than in biota. Conversely, although frequencies of detection for organochlorine compounds in biota were only slightly greater than in bed sediment, actual concentrations in biota (normalized to lipid) were as much as 19 times those in sediment (normalized to organic carbon). Sculpin (Cottus spp.) and Asiatic clams (Corbicula fluminea), found at 14 and 7 sites, respectively, were the most widespread taxa collected during the study. Concentrations of trace elements, particularly As and Cu, were typically greater in Asiatic clams than in sculpin. In contrast, almost half of the organochlorine compounds analyzed were found in sculpin, but only DDT and its degradation products were detected in Asiatic clams; this may be related to the lipid content of sculpin, which was about three times higher than for clams. Thus, the medium of choice for assessing occurrence depends largely on the constituent(s) of interest.

  14. Non-radiological consequences to the aquatic biota and fisheries of the Susquehanna River from the 1979 accident at Three Mile Island Nuclear Station

    Microsoft Academic Search

    C. R. Jr. Hickey; R. B. Samworth

    1979-01-01

    The non-radiological consequences to the aquatic biota and fishes of the Susquehanna River from the March 28, 1979 accident at Three Mile Island Nuclear Station were assessed through the post-accident period of July 1979. Thermal and chemical discharges during the period did not exceed required effluent limitations. Several million gallons of treated industrial waste effluents were released into the river

  15. Supplementary Online Material Medium-term effects of corn biochar addition on soil biota activities and functions in a temperate soil cropped to corn

    E-print Network

    Lehmann, Johannes

    Supplementary Online Material Medium-term effects of corn biochar addition on soil biota activities and treatments, all expressed on a dry weight basis. Biochar Plot Sand Silt Clay Moisture pH EC SOC P-PO4 Cl N highlighted in bold and asterisks indicating the significance (*=p0.05, **=p0.01); n=15. Biochar rate Fauna

  16. Medium-term effects of corn biochar addition on soil biota activities and functions in a temperate soil cropped to corn

    E-print Network

    Lehmann, Johannes

    Medium-term effects of corn biochar addition on soil biota activities and functions in a temperate in revised form 19 November 2013 Accepted 29 January 2014 Available online 11 February 2014 Keywords: Biochar Microorganisms Soil fauna Litter Decomposition Mineralization a b s t r a c t Biochar addition to soil has been

  17. Reconnaissance investigation of water quality, bottom sediment, and biota associated with irrigation drainage in and near Stillwater Wildlife Management Area, Churchill County, Nevada, 1986-87

    USGS Publications Warehouse

    Hoffman, R.J.; Hallock, R.J.; Rowe, T.G.; Lico, M.S.; Burge, H.L.; Thompson, S.P.

    1990-01-01

    A reconnaissance was initiated in 1986 to determine whether the quality of irrigation-drainage water in and near the Stillwater Wildlife Management Area, Nevada, has caused or has potential to cause harmful effects on human health, fish, wildlife, or other beneficial uses of water. Samples of surface and groundwater, bottom sediment, and biota were collected from sites upstream and downstream from the Fallon agricultural area in the Carson Desert, and analyzed for potentially toxic trace elements. Other analysis included radioactive substances, major dissolved constituents, and nutrients in water, and pesticide residues in bottom sediment and biota. In areas affected by irrigation drainage, the following constituents were found to commonly exceed baseline concentrations or recommended criteria for protection of aquatic life or propagation of wildlife: In water, arsenic, boron, dissolved solids, molybdenum, sodium, and un-ionized ammonia; in bottom sediments, arsenic, lithium, mercury, molybdenum, and selenium; and in biota, arsenic, boron, chromium, copper, mercury, selenium, and zinc. In some wetlands, selenium and mercury appeared to be biomagnified, and arsenic bioaccumulated. Pesticides contamination in bottom sediments and biota was insignificant. Adverse biological effects observed during this reconnaissance included gradual vegetative changes and species loss, fish die-offs, waterfowl disease epidemics, and persistent and unexplained deaths of migratory birds. (USGS)

  18. Distribution of Polycyclic Aromatic Hydrocarbons in Soils and Terrestrial Biota After a Spill of Crude Oil in Trecate, Italy

    SciTech Connect

    Brandt, Charles A. (BATTELLE (PACIFIC NW LAB)); Becker, James M. (BATTELLE (PACIFIC NW LAB)); Porta, Augusto C. (BATTELLE GENEVA RESEARCH)

    2001-12-01

    Following a large blowout of crude oil in northern Italy in 1994, the distribution of polyaromatic hydrocarbons (PAHs) was examined over time and space in soils, uncultivated wild vegetation, insects, mice, and frogs in the area. Within 2 y of the blowout, PAH concentrations declined to background levels over much of the area where initial concentrations were within an order of magnitude above background, but had not declined to background in areas where starting concentrations exceeded background by two orders of magnitude. Octanol-water partitioning and extent of alkylation explained much of the variance in uptake of PAHs by plants and animals. Lower Kow PAHs and higher-alkylated PAHs had higher soil-to-biota accumulation factors (BSAFs) than did high-Kow and unalkylated forms. BSAFs for higher Kow PAHs were very low for plants, but much higher for animals, with frogs accumulating more of these compounds than other species.

  19. Distribution of petroleum hydrocarbons and organochlorinated contaminants in marine biota and coastal sediments from the ROPME Sea Area during 2005.

    PubMed

    de Mora, Stephen; Tolosa, Imma; Fowler, Scott W; Villeneuve, Jean-Pierre; Cassi, Roberto; Cattini, Chantal

    2010-12-01

    The composition and spatial distribution of various petroleum hydrocarbons (PHs), comprising both aliphatic and polycyclic aromatic hydrocarbons (PAHs), and selected chlorinated pesticides and PCBs were measured in biota and coastal sediments from seven countries in the Persian Gulf and the Gulf of Oman (Bahrain, Iran, Kuwait, Oman, Qatar, Saudi Arabia and the United Arab Emirates). Evidence of extensive marine contamination with respect to organochlorinated compounds and PHs was not observed. Only one site, namely the BAPCO oil refinery in Bahrain, was considered to be chronically contaminated. Comparison of the results from this survey for ? DDTs and ? PCBs in rock oysters from the Gulf of Oman with similar measurements made at the same locations over the past two decades indicates a temporal trend of overall decreasing ? PCB concentrations in oysters, whereas ? DDTs levels have little changed during that period. PMID:20965523

  20. Simulation of radioactive cesium transfer in the southern Fukushima coastal biota using a dynamic food chain transfer model.

    PubMed

    Tateda, Yutaka; Tsumune, Daisuke; Tsubono, Takaki

    2013-10-01

    The Fukushima Dai-ichi Nuclear Power Plant (1F NPP) accident occurred on 11 March 2011. The accident introduced (137)Cs into the coastal waters which was subsequently transferred to the local coastal biota thereby elevating the concentration of this radionuclide in coastal organisms. In this study, the radioactive cesium levels in coastal biota from the southern Fukushima area were simulated using a dynamic biological compartment model. The simulation derived the possible maximum radioactive cesium levels in organisms, indicating that the maximum (137)Cs concentrations in invertebrates, benthic fish and predator fish occurred during late April, late May and late July, respectively in the studied area where the source was mainly the direct leakage of (137)Cs effluent from the 1F NPP. The delay of a (137)Cs increase in fish was explained by the gradual food chain transfer of (137)Cs introduced to the ecosystem from the initial contamination of the seawater. The model also provided the degree of radionuclide depuration in organisms, and it demonstrated the latest start of the decontamination phase in benthic fish. The ecological half-lives, derived both from model simulation and observation, were 1-4 months in invertebrates, and 2-9 months in plankton feeding fish and coastal predator fish from the studied area. In contrast, it was not possible to similarly calculate these parameters in benthic fish because of an unidentified additional radionuclide source which was deduced from the biological compartment model. To adequately reconstruct the in-situ depuration of radiocesium in benthic fish in the natural ecosystem, a contamination source associated with the bottom sediments is necessary. PMID:23639689

  1. Do reclamation speed up recovery of soil and soil biota on post mining sites along climatic gradient across continental USA?

    NASA Astrophysics Data System (ADS)

    Frouz, Jan

    2015-04-01

    Soil biota community (macrofauna, nematodes and microbial community studied by PLFA) was studied together with soil development in post-mining chronosequences along climatic gradient in the USA, covering hardwood forest (TN, IN), tallgrass prairie (IL), or shortgrass prairie (WY). Post mining sites reclaimed according recent regulation which includes topsoil application and vegetation establishment were compared to local climax. Both young and old restoration sites were much closer to the climax condition in shortgrass prairie than in the other sites. The shortgrass prairie soil community contained abundant root-feeding organisms, which may establish quicker than the saprophagous fauna that was abundant at the other sites. Absence of saprophagous groups, and especially earthworms, resulted in the absence of bioturbation in shortgrass prairie sites while in chronosequences other than the one in shortgrass prairie, bioturbation played an important role in topsoil formation resulting in more complex soil profile development compare to shortgrass prairie. This may contribute to faster recovery communities in shortgrass prairie in comparison with tallgrass prairie and forest as At the same time sites that were reclaimed according recent regulation (topsoil application and vegetation establishment) were compare to unreclaimed sites both about 30 years old in TN IL and WY. It TN soil and soil biota seems to approach fasted to climax in unreclaimed than reclaimed sites. In IL this differences between reclaimed and unreclaimed sites was not so clear. While in WY reclaimed sites seems to approach to climax community fasted than unreclaimed one. This suggests that effect of reclamation vary along climatic gradient. In drier sites, formation of soil matrix from parent material is probably much slower and topsoil application speed up soil community recovery substantially while this effect is less pronounces in more wet sites, where soil compaction due to restoration may in some cases even slow recovery.

  2. Identifying sources and biomagnification of persistent organic contaminants in biota from mountain streams of southwestern British Columbia, Canada.

    PubMed

    Morrissey, Christy A; Bendell-Young, Leah I; Elliott, John E

    2005-10-15

    We assessed whether biota occupying mountain streams accumulate and biomagnify remotely derived organic pollutants originating from atmospheric inputs to snowpack and glacial runoff and from marine sources introduced by migrating anadromous salmon. Several persistent organic pollutants including polychlorinated biphenyls (PCBs), p,p'-dichloro-diphenyl-dichloroethylene, hexachlorobenzene, and trans-nonachlor were commonly detected in benthic invertebrates, salmon fry (Oncorhynchus spp.), and eggs of an aquatic passerine, the American dipper (Cinclus mexicanus) from the Chilliwack River watershed, British Columbia, Canada. Total PCBs and several organochlorines (OCs) biomagnified from benthic invertebrate composites to salmon fry to dipper eggs. Invertebrate samples generally did not differ significantly in contaminant burdens between the river main stem where salmon are more abundant and higher-elevation tributaries where the salmon density is lower. Concentrations of total OCs and total PCBs in dipper eggs were positively related to drainage basin area and collection year but not to elevation. No differences in PCB congener patterns existed between dipper egg samples from the Chilliwack watershed and other watersheds in southwestern British Columbia. However, principal component analysis revealed significant spatial differences in egg PCB congener patterns between the main Chilliwack River and the higher-elevation tributaries. This difference was primarily due to a greater occurrence of lower chlorinated PCB congeners (66 and 105) in dipper eggs collected from the tributaries and higher loadings of the more stable and persistent congeners (153, 138, 130, and 128) in eggs from the river main stem. The results suggest that atmospheric sources are the main contributor of contaminants detected in biota from the region and that biomagnification is a common pathway for accumulation in lotic predators such as the American dipper. PMID:16295880

  3. Coupling between phytodetritus deposition and the small-sized benthic biota in the deep Arabian Sea: analyses of biogenic sediment compounds

    NASA Astrophysics Data System (ADS)

    Pfannkuche, Olaf; Sommer, Stefan; Kähler, Anja

    As part of the large-scale, interdisciplinary deep-sea study "BIGSET", the relationship between the monsoon-induced regional and temporal variability of POC deposition and the small-sized benthic community was investigated at several sites 2316-4420 m deep in the Arabian Sea during four cruises between 1995 and 1998. Vertical and horizontal distribution patterns of chloroplastic pigments (a measure of phytodetritus deposition), readily soluble protein and activity, and biomass parameters of the small-sized benthic community (Electron Transport System Activity (ETSA); bacterial ectoenzymatic activity (FDA turnover) and DNA concentrations) were measured concurrently with the vertical fluxes of POC and chloroplastic pigments. Sediment chlorophyll a (chl. a) profiles were used to calculate chl. a flux rates and to estimate POC flux across the sediment water interface using two different transport reaction models. These estimates were compared with corresponding flux rates determined in sediment traps. Regional variability of primary productivity and POC deposition at the deep-sea floor creates a trophic gradient in the Arabian Basin from the NW to the SE, which is primarily related to the activity of monsoon winds and processes associated with the topography of the Arabian Basin and the vicinity of land masses. Inventories of sediment chloroplastic pigments closely corresponded to this trophic gradient. For ETSA, FDA and DNA, however, no clear coupling was found, although stations WAST (western Arabian Sea) and NAST (northern Arabian Sea) were characterised by high concentrations and activities. These parameters exhibited high spatial and temporal variability, making it impossible to recognise clear mechanisms controlling temporal and spatial community patterns of the small-sized benthic biota. Nevertheless, the entire Arabian Basin was recognised as being affected by monsoonal activity. Comparison of two different transport reaction models indicates that labile chl. a buried in deeper sediment layers may escape rapid degradation in Arabian deep-sea sediments.

  4. Validation of a screening method based on liquid chromatography coupled to high-resolution mass spectrometry for analysis of perfluoroalkylated substances in biota.

    PubMed

    Berger, Urs; Haukås, Marianne

    2005-07-22

    A screening method for analysis of perfluoroalkylated substances (PFAS) in biota samples has been developed and validated using liver samples from polar cod (Boreogadus saida) and glaucous gull (Larus hyperboreus). The method was based on extraction of target compounds from homogenised samples into the solvent mixture used as mobile phase in high-performance liquid chromatography (HPLC), i.e. methanol/water (50:50; 2 mM ammonium acetate). The extract was filtered and directly injected into a HPLC/time-of-flight mass spectrometry (TOF-MS) system. Quantification was performed using 7H-perfluoroheptanoic acid as internal standard and a calibration standard solution dissolved in sample extract for each matrix type (matrix-matched calibration standard). The method is very time and cost efficient. Except for long-chain compounds and perfluorooctane sulfonamide (which cannot be covered by this method), recoveries were between 60% and 115% and method detection limits were in the range 0.04-1.3 ng/g wet weight. Blank values could be neglected with the exception of perfluorooctane sulfonate (PFOS), perfluorohexanoic acid (PFHxA) and perfluorooctanoic acid (PFOA). One of the major challenges in PFAS analysis is ionisation disturbance by co-eluting matrix in the ion source of the mass spectrometer. Both matrix and analyte specific signal enhancement and suppression was observed and quantified. Repeated extractions (n = 3) gave relative standard deviations (RSD) <35% for all PFAS. Accuracy was examined by comparing the screening method to the generally applied ion pair extraction (IPE) method. PFAS concentration values of a glaucous gull liver sample deviated by less than 30% for the two methods, provided that matrix-matched calibration standards were employed in both methods. PMID:16038211

  5. BiodivERsA project VineDivers: Analysing interlinkages between soil biota and biodiversity-based ecosystem services in vineyards across Europe

    NASA Astrophysics Data System (ADS)

    Zaller, Johann G.; Winter, Silvia; Strauss, Peter; Querner, Pascal; Kriechbaum, Monika; Pachinger, Bärbel; Gómez, José A.; Campos, Mercedes; Landa, Blanca; Popescu, Daniela; Comsa, Maria; Iliescu, Maria; Tomoiaga, Liliana; Bunea, Claudiu-Ioan; Hoble, Adela; Marghitas, Liviu; Rusu, Teodor; Lora, Ángel; Guzmán, Gema; Bergmann, Holger

    2015-04-01

    Essential ecosystem services provided by viticultural landscapes result from diverse communities of above- and belowground organisms and their interactions. For centuries traditional viticulture was part of a multifunctional agricultural system including low-input grasslands and fruit trees resulting in a high functional biodiversity. However, in the last decades intensification and mechanisation of vineyard management caused a separation of production and conservation areas. As a result of management intensification including frequent tilling and/or use of pesticides several ecosystem services are affected leading to high rates of soil erosion, degradation of soil structure and fertility, contamination of groundwater and high levels of agricultural inputs. In this transdisciplinary BiodivERsA project we will examine to what extent differently intensive managed vineyards affect the activity and diversity of soil biota (e.g. earthworms, collembola, soil microorganisms) and how this feed back on aboveground biodiversity (e.g. weeds, pollinators). We will also investigate ecosystem services associated with soil faunal activity and biodiversity such as soil structure, the formation of stable soil aggregates, water infiltration, soil erosion as well as grape quality. These effects will become increasingly important as more extreme precipitation events are predicted with climate change. The socio-economic part of the project will investigate the role of diversely structured, species-rich viticultural landscapes as a cultural heritage providing aesthetic values for human well-being and recreation. The project objectives will be analysed at plot, field (vineyard) and landscape scales in vineyards located in Spain, France, Romania and Austria. A detailed engagement and dissemination plan for stakeholder at the different governance levels will accompany scientific research and will contribute to the implementation of best-practice recommendations for policy and farmers.

  6. GROUP REPORT: INTERACTIONS AMONG ACIDIFICATION, PHOSPHOROUS, CONTAMINANTS, AND BIOTA IN FRESHWATER ECOSYSTEMS

    EPA Science Inventory

    Scientific investigations over the last two decades have examined the processes and effects of acidic deposition on surface waters and their catchments. hese studies have been performed on various scales: laboratory benchtop, mesocosm/plot studies, whole system manipulations, and...

  7. Validation of a screening method based on liquid chromatography coupled to high-resolution mass spectrometry for analysis of perfluoroalkylated substances in biota

    Microsoft Academic Search

    Urs Berger; Marianne Haukås

    2005-01-01

    A screening method for analysis of perfluoroalkylated substances (PFAS) in biota samples has been developed and validated using liver samples from polar cod (Boreogadus saida) and glaucous gull (Larus hyperboreus). The method was based on extraction of target compounds from homogenised samples into the solvent mixture used as mobile phase in high-performance liquid chromatography (HPLC), i.e. methanol\\/water (50:50; 2mM ammonium

  8. Persistence and transfer of ³⁶Cl-DDT in the soil and biota of an old-field ecosystem: a six-year balance study

    Microsoft Academic Search

    D. J. Forsyth; T. J. Peterle; L. W. Bandy

    1983-01-01

    The fate of a 1 kg\\/ha application of granular chlorine-36-labeled DDT made by helicopter on 10 June 1969 to a 4-ha old-field study area near Urbana, Ohio was traced and quantified in soil and biota through November 1974. Between 1970 and 1974, residues of DDT (DDTR, includes DDT plus metabolites) declined from 22.0 to 3.8 mg\\/kg tissue in earthworms (Lumbricus

  9. Distinguishing geology from biology in the Ediacaran Doushantuo biota relaxes constraints on the timing of the origin of bilaterians.

    PubMed

    Cunningham, John A; Thomas, Ceri-Wyn; Bengtson, Stefan; Kearns, Stuart L; Xiao, Shuhai; Marone, Federica; Stampanoni, Marco; Donoghue, Philip C J

    2012-06-22

    The Ediacaran Doushantuo biota has yielded fossils that include the oldest widely accepted record of the animal evolutionary lineage, as well as specimens with alleged bilaterian affinity. However, these systematic interpretations are contingent on the presence of key biological structures that have been reinterpreted by some workers as artefacts of diagenetic mineralization. On the basis of chemistry and crystallographic fabric, we characterize and discriminate phases of mineralization that reflect: (i) replication of original biological structure, and (ii) void-filling diagenetic mineralization. The results indicate that all fossils from the Doushantuo assemblage preserve a complex mélange of mineral phases, even where subcellular anatomy appears to be preserved. The findings allow these phases to be distinguished in more controversial fossils, facilitating a critical re-evaluation of the Doushantuo fossil assemblage and its implications as an archive of Ediacaran animal diversity. We find that putative subcellular structures exhibit fabrics consistent with preservation of original morphology. Cells in later developmental stages are not in original configuration and are therefore uninformative concerning gastrulation. Key structures used to identify Doushantuo bilaterians can be dismissed as late diagenetic artefacts. Therefore, when diagenetic mineralization is considered, there is no convincing evidence for bilaterians in the Doushantuo assemblage. PMID:22319125

  10. Under Cover at Pre-Angiosperm Times: A Cloaked Phasmatodean Insect from the Early Cretaceous Jehol Biota

    PubMed Central

    Wang, Maomin; Béthoux, Olivier; Bradler, Sven; Jacques, Frédéric M. B.; Cui, Yingying; Ren, Dong

    2014-01-01

    Background Fossil species that can be conclusively identified as stem-relatives of stick- and leaf-insects (Phasmatodea) are extremely rare, especially for the Mesozoic era. This dearth in the paleontological record makes assessments on the origin and age of the group problematic and impedes investigations of evolutionary key aspects, such as wing development, sexual size dimorphism and plant mimicry. Methodology/Principal Findings A new fossil insect species, Cretophasmomima melanogramma Wang, Béthoux and Ren sp. nov., is described on the basis of one female and two male specimens recovered from the Yixian Formation (Early Cretaceous, ca. 126±4 mya; Inner Mongolia, NE China; known as ‘Jehol biota’). The occurrence of a female abdominal operculum and of a characteristic ‘shoulder pad’ in the forewing allows for the interpretation of a true stem-Phasmatodea. In contrast to the situation in extant forms, sexual size dimorphism is only weakly female-biased in this species. The peculiar wing coloration, viz. dark longitudinal veins, suggests that the leaf-shaped plant organ from the contemporaneous ‘gymnosperm’ Membranifolia admirabilis was used as model for crypsis. Conclusions/Significance As early as in the Early Cretaceous, some stem-Phasmatodea achieved effective leaf mimicry, although additional refinements characteristic of recent forms, such as curved fore femora, were still lacking. The diversification of small-sized arboreal insectivore birds and mammals might have triggered the acquisition of such primary defenses. PMID:24646906

  11. 90Sr and 137Cs in soil and biota of fallout areas in southern Nevada and Utah.

    PubMed

    Romney, E M; Lindberg, R G; Kinnear, J E; Wood, R A

    1983-09-01

    Measurements of 90Sr and 137Cs in soil, vegetation and small mammals were made periodically at sites in southern Nevada and Utah that were contaminated by radioactive fallout from nuclear detonations at the Nevada Test Site (NTS) as well as from global sources. Results from a survey in 1980 indicate that both of these fallout-derived radionuclides have remained primarily within the top 5-cm layer of undisturbed soil in these arid land areas. Trace amounts of 90Sr and 137Cs were measured in soil and biota samples. The 90Sr concentrations in jackrabbit and rodent bone samples in 1980 varied within the range of 2-8 pCi/g ash (equivalent to 0.4-1.6 pCi/g wet bone or 5-20 pCi/g Ca). The 137Cs concentrations in muscle-tissue samples were generally less than 1.5 pCi/g ash (less than 0.045 pCi/g wet muscle). Comparisons of data obtained periodically since the early 1950s show that measured concentrations of 90Sr in bone tissues have been highly variable in trace amounts, and that the concentration attenuation appears to be following radioactive decay of this radionuclide. PMID:6885473

  12. Atlantic Origin of the Arctic Biota? Evidence from Phylogenetic and Biogeographical Analysis of the Cheilostome Bryozoan Genus Pseudoflustra

    PubMed Central

    Kuklinski, Piotr; Taylor, Paul D.; Denisenko, Nina V.; Berning, Björn

    2013-01-01

    The intricate geological evolution of the Arctic Ocean is paralleled by complexities in the biogeographical and phylogenetical histories of the Arctic biota, including bryozoans. Here we present revised taxonomic descriptions for all known species of the bryozoan genus Pseudoflustra, and use the present-day distributions and phylogenetic relationships between these species to infer the historical biogeography of the genus. Nine species belonging to the genus Pseudoflustra are recognized in the Arctic and North Atlantic. One new species, previously identified as Ichthyaria aviculata, is described as Pseudoflustra radeki sp. nov. Another species, previously assigned to Smittoidea as S. perrieri, is transferred to Pseudoflustra. Biogeographical analysis of Pseudoflustra reveals that species distributions mostly match current patterns pertaining in the North Atlantic and Arctic Ocean. Distributions were probably shaped by recent geological history as present-day current directions in the Arctic Ocean are believed to have been similar for at least the last 120 000 years. Phylogenetic analysis of Pseudoflustra places the five Arctic-North Atlantic species in a clade crownward of a paraphyletic grouping of North Atlantic species. Given that the Arctic Ocean was fully glaciated until 18 000 years, the most likely explanation for this phylogeographical pattern is that species of Pseudoflustra colonized the Arctic relatively recently from North Atlantic sources. However, a fuller understanding of the origin of Pseudoflustra in the Arctic will require molecular and fossil data, neither of which are currently available. PMID:23536863

  13. Late cretaceous pelagic sediments, volcanic ASH and biotas from near the Louisville hotspot, Pacific Plate, paleolatitude ?42°S

    USGS Publications Warehouse

    Ballance, Peter F.; Barron, John A.; Blome, Charles D.; Bukry, David; Cawood, Peter A.; Chaproniere, George C.H.; Frisch, Robyn; Herzer, Richard H.; Nelson, Campbell S.; Quinterno, Paula; Ryan, Holly F.; Scholl, David W.; Stevenson, Andrew J.; Tappin, David G.; Vallier, Tracy L.

    1989-01-01

    Dredging on the deep inner slope of the Tonga Trench, immediately north of the intersection between the Louisville Ridge hotspot chain and the trench, recovered some Late Cretaceous (Maestrichtian) slightly tuffaceous pelagic sediments. They are inferred to have been scraped off a recently subducted Late Cretaceous guyot of the Louisville chain. In the vicinity of the Louisville hotspot (present location 50°26?S, 139°09?W; Late Cretaceous location ?42°S, longitude unknown) Late Cretaceous rich diatom, radiolarian, silicoflagellate, foraminiferal and coccolith biotas, accumulated on the flanks of the guyot and are described in this paper. Rich sponge faunas are not described. ?Inoceramus prisms are present. Volcanic ash is of within-plate alkalic character. Isotope ratios in bulk carbonate ?18O ? 2.63 to + 0.85, ?13C + 2.98 to 3.83) are normal for Pacific Maestrichtian sediments. The local CCD may have been shallower than the regional CCD, because of high organic productivity. In some samples Late Cretaceous materials have been mixed with Neogene materials. Mixing may have taken place on the flanks of the guyot during transit across the western Pacific, or on the trench slope during or after subduction and offscraping about 0.5 Ma.

  14. Extractable organohalogens (EOX) in sediment and biota collected at an estuarine marsh near a former chloralkali facility

    SciTech Connect

    Kannan, K.; Giesy, J.P. [Michigan State Univ., East Lansing, MI (United States)] [Michigan State Univ., East Lansing, MI (United States); Kawano, Masahide [Ehime Univ., Matsuyama (Japan). Dept. of Environment Conservation] [Ehime Univ., Matsuyama (Japan). Dept. of Environment Conservation; Kashima, Yuji; Matsui, Mitsuaki [Yokohama City Univ. (Japan). Dept. of Hygiene] [Yokohama City Univ. (Japan). Dept. of Hygiene

    1999-04-01

    Extractable, organically bound chlorine (EOCl), which is determined by neutron activation analysis (NAA), has been used as a measure of pollution by chlorinated organics. In this study, the concentrations and distribution of extractable organohalogens (EOX = EOCl + EOBr + EOl) were measured in sediment, blue crab, fishes, birds, and terrapin collected at an estuarine marsh and a nearby creek contaminated by the disposal of wastes from a former chloralkali facility. The concentrations of the organohalogens were in the order of EOCl {much_gt} EOBr > EOl. The sediment EOCl concentration was comparable to those reported for sediments at sites that have been contaminated by the disposal of bleached kraft pulp mill effluents. The concentrations of EOCl measured in the tissues of blue crab, fishes, and birds were higher than any values previously reported. The absolute concentrations of EOCl coupled with its elevated proportions relative to the concentrations of EOBr or EOl in biota suggest that wastes from the chloralkali processes are a potential source of chlorinated organics present in the environment.

  15. Reconnaissance investigation of water quality, bottom sediment, and biota associated with irrigation drainage in and near Stillwater Wildlife Management Area, Churchill County, Nevada, 1986-87

    SciTech Connect

    Hoffman, R.J.; Hallock, R.J.; Rowe, T.G.; Lico, M.S.; Burge, H.L.

    1990-01-01

    An investigation was initiated to determine whether irrigation drainage in and near the Stillwater Wildlife Management Area has caused or has potential to cause harmful effects on human health or fish and wildlife, or may adversely affect the suitability of water for beneficial uses. Samples of surface and groundwater, bottom sediment, and biota were collected from sites upstream and downstream from the Fallon agricultural area in the Carson Desert and were analyzed for potentially toxic trace elements, including selenium. Other analyses included radioactive substances, major dissolved constituents, and nutrients in water, and pesticide residues in bottom sediments and biota. In areas affected by irrigation drainage, concentrations of the following constituents commonly were found to exceed baseline concentrations or federal and state criteria for the protection of aquatic life or the propagation of wildlife: in water, arsenic, boron, dissolved solids, sodium, and un-ionized ammonia; in bottom sediments, arsenic, lithium, mercury, molybdenum, and selenium; and in biota, arsenic, boron, chromium, copper, mercury, selenium, and zinc. In some wetlands, selenium and mercury appear to be biomagnified whereas arsenic is bioaccumulated. Some radioactive substances were substantially higher at the downstream sites compared with upstream background sites, but the significance of this to wildlife is unknown at present. 88 refs., 32 figs., 19 tabs.

  16. Reconnaissance investigation of water quality, bottom sediment, and biota associated with irrigation drainage in and near Humboldt Wildlife Management Area, Churchill and Pershing Counties, Nevada, 1990-91

    USGS Publications Warehouse

    Seiler, R.L.; Ekechukwu, G.A.; Hallock, R.J.

    1993-01-01

    A reconnaissance investigation was begun in 1990 to determine whether the quality of irrigation drainage in and near the Humboldt Wildlife Management Area, Nevada, has caused or has the potential to cause harmful effects on human health, fish, and wildlife or to impair beneficial uses of water. Samples of surface and ground water, bottom sediment, and biota collected from sites upstream and downstream from the Lovelock agricultural area were analyzed for potentially toxic trace elements. Also analyzed were radioactive substances, major dissolved constitu- ents, and nutrients in water, as well as pesticide residues in bottom sediment and biota. In samples from areas affected by irrigation drainage, the following constituents equaled or exceeded baseline concentrations or recommended standards for protection of aquatic life or propagation of wildlife--in water: arsenic, boron, dissolved solids, mercury, molybdenum, selenium, sodium, and un-ionized ammonia; in bottom sediment; arsenic and uranium; and in biota; arsenic, boron, and selenium. Selenium appears to be biomagnified in the Humboldt Sink wetlands. Biological effects observed during the reconnaissance included reduced insect diversity in sites receiving irrigation drainage and acute toxicity of drain water and sediment to test organisms. The current drought and upstream consumption of water for irrigation have reduced water deliveries to the wetlands and caused habitat degradation at Humboldt Wildlife Management Area. During this investigation. Humboldt and Toulon Lakes evaporated to dryness because of the reduced water deliveries.

  17. Responses of freshwater biota to rising salinity levels and implications for saline water management: a review

    Microsoft Academic Search

    Kimberley R. JamesA; Tom RyanB

    All of the plants and animals that make up freshwater aquatic communities are affected by salinity. Many taxa possess morphological, physiological and life-history characteristics that provide some capacity for tolerance, acclimatisation or avoidance. These characteristics impart a level of resilience to freshwater communities. To maintain biodiversity in aquatic systems it is important to manage the rate, timing, pattern, frequency and

  18. Acute and sublethal effects of organotin compounds on aquatic biota: an interpretative literature evaluation

    Microsoft Academic Search

    Lenwood W. Hall; Alfred E. Pinkney; Roy Laughlin

    1985-01-01

    The objectives of this review were to: (1) collect, synthesize, and interpret acute and sublethal organotin toxicity data in both freshwater and estuarine-marine ecosystems; (2) present environmental water column and sediment concentrations of organotin compounds in both freshwater and estuarine-marine systems to facilitate interpretation of toxicity data; and (3) identify deficiencies in available data to recommend areas of future research

  19. A program in global biology. [biota-environment interaction important to life

    NASA Technical Reports Server (NTRS)

    Mooneyhan, D. W.

    1983-01-01

    NASA's Global Biology Research Program and its goals for greater understanding of planetary biological processes are discussed. Consideration is given to assessing major pathways and rates of exchange of elements such as carbon and nitrogen, extrapolating local rates of anaerobic activities, determining exchange rates of ocean nutrients, and developing models for the global cycles of carbon, nitrogen, sulfur, and phosphorus. Satellites and sensors operating today are covered: the Nimbus, NOAA, and Landsat series. Block diagrams of the software and hardware for a typical ground data processing and analysis system are provided. Samples of the surface cover data achieved with the Advanced Very High Resolution Radiometer, the Multispectral Scanner, and the Thematic Mapper are presented, as well as a productive capacity model for coastal wetlands. Finally, attention is given to future goals, their engineering requirements, and the necessary data analysis system.

  20. Measurement of Lake Roosevelt Biota in Relation to Reservoir Operations; 1992 Annual Report.

    SciTech Connect

    Griffith, Janelle R.; McDowell, Amy C.

    1996-01-01

    The purpose of this research project is to collect data to model resident fish requirements for Lake Roosevelt as part of the Bonneville Power Administration (BPA), Bureau of Reclamation (BoR), and U.S. Army Corps of Engineer`s (ACE) System Operation Review. The System Operation Review (SOR) is a tri-agency team functioning to review the use and partitioning of Columbia Basin waters. User groups of the Columbia have been defined as power, irrigation, flood control, anadromous fish, resident fish, wildlife, recreation, water quality, navigation, and cultural resources. Once completed the model will predict biological responses to different reservoir operation strategies. The model being developed for resident fish is based on Montana Department of Fish, Wildlife, and Parks model for resident fish requirements within Hungry Horse and Libby Reservoirs. While the Montana model predicts fish growth based on the impacts of reservoir operation and flow conditions on primary and secondary production levels, the Lake Roosevelt model will also factor in the affects of water retention time on zooplankton production levels and fish entrainment. Major components of the Lake Roosevelt model include: (1) quantification of impacts to zooplankton, benthic invertebrates, and fish caused by reservoir drawdowns and low water retention times; (2) quantification of number, distribution, and use of fish food organisms in the reservoir by season; (3) determination of seasonal growth of fish species as related to reservoir operations, prey abundance and utilization; and (4) quantification of entrainment levels of fish as related to reservoir operations and water retention times. This report contains the results of the resident fish system operation review program for Lake Roosevelt from January through December 1992.

  1. Measurement of Lake Roosevelt Biota in Relation to Reservoir Operations : Final Report 1993.

    SciTech Connect

    Voeller, Amy C.

    1993-01-01

    The purpose of this study was to collect biological data from Lake Roosevelt to be used in the design of a computer model that will predict biological responses to reservoir operations as part of the System Operation Review Program. This study worked in conjunction with Lake Roosevelt Monitoring Project which investigated the effectiveness of two kokanee salmon hatcheries. This report summarized the data collected from Lake Roosevelt from 1993 and includes limnological, reservoir operation, zooplankton, benthic macroinvertebrate, experimental trawling, and net-pen rainbow trout tagging data. Major components of the Lake Roosevelt model include quantification of impacts to zooplankton, benthic macroinvertebrates, and fish caused by reservoir drawdowns and low water retention times.

  2. Measurement of Lake Roosevelt Biota in Relation to Reservoir Operations Appendices; 1991 Annual Report.

    SciTech Connect

    Griffith, Janelle R.; McDowell, Amy C.; Scholz, Allan T.

    1995-08-01

    This report consists of appendices A-F containing the biological data which were collected from Lake Roosevelt, Washington. The data are to be used in the design of a computer model that would predict biological responses of reservoir operations as part of the System Operation Review program. Major components of the model included: Quantification of impacts to phytoplankton, zooplanktons, benthic invertebrates, and fish caused by reservoir drawdowns and low water retention times; quantification of number, distribution, and use of fish food organisms in the reservoir by season; determination of seasonal growth of fish species as related to reservoir operations, prey abundance and utilization; and quantification of entrainment levels of zooplankton and fish as related to reservoir operations and water retention times.

  3. Comparative analysis of marine paleogene sections and biota from West Siberia and the Arctic Region

    NASA Astrophysics Data System (ADS)

    Akhmet'ev, M. A.; Zaporozhets, N. I.; Iakovleva, A. I.; Aleksandrova, G. N.; Beniamovsky, V. N.; Oreshkina, T. V.; Gnibidenko, Z. N.; Dolya, Zh. A.

    2010-12-01

    The analysis of the main biospheric events that took place in West Siberia and the Arctic region during the Early Paleogene revealed the paleogeographic and paleobiogeographic unity of marine sedimentation basins and close biogeographic relations between their separate parts. Most biotic and abiotic events of the first half of the Paleogene in the Arctic region and West Siberia were synchronous, unidirectional, and interrelated. Shelf settings, sedimentation breaks, and microfaunal assemblages characteristic of these basins during the Paleogene are compared. The comparative analysis primarily concerned events of the Paleocene-Eocene thermal maximum (PETM) and beds with Azolla (aquatic fern). The formation of the Eocene Azolla Beds in the Arctic region and West Siberia was asynchronous, although it proceeded in line with a common scenario related to the development of a system of estuarine-type currents in a sea basin partly isolated from the World Ocean.

  4. Application of Non-Human Biota Assessment Methodologies to the Assessment of Potential Impacts from a Nuclear Waste Repository

    SciTech Connect

    Smith, K.L.; Robinson, C.A. [Enviros Consulting Ltd, D5 Culham Science Centre, Abingdon, OX (United Kingdom); Ikonen, A.T.K. [Posiva Oy, Olkiluoto (Finland)

    2007-07-01

    The protection of the environment from the effects of ionising radiation has become increasingly more topical over the last few years as the intentions enshrined in international principles and agreements have become more binding through national and international law. For example, the Directive on impact of certain projects on the environment (EIA Directive 85/337/EEC) [CEC, 1985], amended in 1997 [CEC, 1997], places a mandatory requirement on all EU Member States to conduct environmental impact assessments for a range of project having potential impact on the environment, including radioactive waste disposal. Such assessments must consider humans, fauna and flora, the abiotic environment (soil, water, air), material assets and cultural heritage as well as the interactions between these factors. In Finland, Posiva Oy are responsible for the overall repository programme for spent nuclear fuel and, as such, are conducting the Safety Case Assessment for a proposed geological repository for nuclear waste. Within the European legislation framework, the Finnish regulatory body requires that the repository safety case assessment should include not only human radiological safety, but also an assessment of the potential impact upon populations of non-human biota. Specifically, the Safety Case should demonstrate that there will be: - no decline in the biodiversity of currently living populations; - no significant detriment to populations of fauna and flora; and, - no detrimental effects on individuals of domestic animals and rare plants and animals. At present, there are no internationally agreed criteria that explicitly address protection of the environment from ionising radiation. However, over recent years a number of assessment methodologies have been developed including, at a European level, the Framework for the Assessment of Environmental impact (FASSET) and Environmental Risks from Ionising Contaminants (ERICA). The International Committee on Radiation Protection (ICRP) have also proposed an approach to allow for assessments of potential impacts on non-human species, in its report in 2003. This approach is based on the development and use of a small set of reference animals and plants, with their associated dose models and data sets. Such approaches are broadly applicable to the Posiva Safety Case. However, the specific biota of concern and the current climatic conditions within Finland present an additional challenge to the assessment. The assessment methods most applicable to the Posiva Safety Case have therefore been reviewed in consideration of the regulatory requirements for the assessment and recommendations made on a suitable assessment approach. This has been applied within a test case and adaptations to the overall assessment method have been made to enable both population and individual impacts to be assessed where necessary. The test case has been undertaken to demonstrate the application of the recommended methodology, but also to identify data gaps, uncertainties and other specific issues associated with the application of an assessment method within the regulatory context. (authors)

  5. Temporal and spatial trends in total PCB and PCB congeners in biota in a river-reservoir system

    SciTech Connect

    Horwitz, R.J.; McNair, J.N.; Hermanson, M.H. [Academy of Natural Sciences of Philadelphia, PA (United States). Environmental Research Division

    1995-12-31

    Since 1984, biennial studies of PCBs have been conducted in fishes, crayfish and insects in the Housatonic River, CT., and additional data are available from earlier studies. PCB data quantitated from presumptive Aroclor concentrations overestimated total PCB concentrations ([TPCB]) by about 13%, although the estimates by the 2 methods were very highly correlated. Ages of all fish specimens were determined. Spatial and temporal trends in [TPCB] were analyzed using ANCOVA to adjust for relationships between [TPCB] and age, lipid content, location and sex. Adjusted [TPCB] consistently decreased in the downstream direction. [TPCB] decreased within the years after cessation of direct inputs (around 1978). However, in the 1984--1992 period [TPCB] trends were weak and variable. Concentrations in 1994 were lower than previous years (statistical comparisons showing 1994 to be the lowest year or among a group of years with the lowest concentrations). Between year differences were probably related to temperature, storm flows and other factors affecting availability and accumulation. These variations were greater in riverine sites than in reservoirs. In brown trout, [TPCB] increased rapidly within 1--2 months after stocking. Over longer periods, [TPCB] were more closely related to seasonal cycles in lipid content rather than to time in river. Increases in [TPCB] with age were most evident for long-lived species in reservoirs. Several congeners which are abundant in Aroclors 1254 and 1260 predominated the samples. However, spatial and temporal differences in accumulation of different congeners were evident. Spatial differences in the concentration of some marker congeners reflected enrichment of these congeners from original Aroclor 1254 and 1260 sources, as well as supplemental inputs of Aroclor 1242.

  6. Hydrothermal vent fields and chemosynthetic biota on the world's deepest seafloor spreading centre.

    PubMed

    Connelly, Douglas P; Copley, Jonathan T; Murton, Bramley J; Stansfield, Kate; Tyler, Paul A; German, Christopher R; Van Dover, Cindy L; Amon, Diva; Furlong, Maaten; Grindlay, Nancy; Hayman, Nicholas; Hühnerbach, Veit; Judge, Maria; Le Bas, Tim; McPhail, Stephen; Meier, Alexandra; Nakamura, Ko-Ichi; Nye, Verity; Pebody, Miles; Pedersen, Rolf B; Plouviez, Sophie; Sands, Carla; Searle, Roger C; Stevenson, Peter; Taws, Sarah; Wilcox, Sally

    2012-01-01

    The Mid-Cayman spreading centre is an ultraslow-spreading ridge in the Caribbean Sea. Its extreme depth and geographic isolation from other mid-ocean ridges offer insights into the effects of pressure on hydrothermal venting, and the biogeography of vent fauna. Here we report the discovery of two hydrothermal vent fields on the Mid-Cayman spreading centre. The Von Damm Vent Field is located on the upper slopes of an oceanic core complex at a depth of 2,300?m. High-temperature venting in this off-axis setting suggests that the global incidence of vent fields may be underestimated. At a depth of 4,960?m on the Mid-Cayman spreading centre axis, the Beebe Vent Field emits copper-enriched fluids and a buoyant plume that rises 1,100?m, consistent with >400?°C venting from the world's deepest known hydrothermal system. At both sites, a new morphospecies of alvinocaridid shrimp dominates faunal assemblages, which exhibit similarities to those of Mid-Atlantic vents. PMID:22233630

  7. Development of a method for assessing the toxicity of volatile organic contaminants (VOCs) to soil biota

    SciTech Connect

    Cureton, P.M. [Environment Canada, Ottawa, Ontario (Canada). Evaluation and Interpretation Branch; Lintott, D.; Balch, G.; Goudey, S. [HydroQual Labs. Ltd., Calgary, Alberta (Canada)

    1994-12-31

    A method was developed to assess the toxicity of VOCs to plants and earthworms (survival of Eisenia foetida). The procedures followed were based on Greene et al. Gas samples for head space analyses were removed, at test initiation a termination, through a bulkhead fitting in the lid equipped with septa. Treatment levels were prepared, at low temperature to minimize volatilization, by spiking a soil sample with the compound of interest and then serially diluting it with clean soil. Root elongation tests were conducted on filter paper supported by 70 mesh silica sand spiked with the volatile of interest. Soils were then inundated with water, shaken with heating, and the headspace reanalyzed for the total contaminant concentration in the test system (total equals headspace plus adsorbed). Enclosing the seeds and worms in containers did not appear to have detrimental effects. VOCs tested included benzene, xylene, toluene, ethylbenzene, tetrachloroethylene, and 1,1,2-trichloroethylene. Each test was repeated three times with different batches of soil, seed lots and worms from different colonies. Endpoints derived based on nominal and measured concentrations included: NOEC, LOEC, LC{sub 50} and LC{sub 25} for earthworm mortality and EC{sub 50} and EC{sub 25} for emergence and root elongation.

  8. Measurement of Lake Roosevelt Biota in Relation to Reservoir Operations; 1991 Annual Report.

    SciTech Connect

    Griffith, Janelle R.; McDowell, Amy C.; Scholz, Allan T.

    1995-08-01

    The purpose of this study was to collect biological data from Lake Roosevelt to be used in the design of a computer model that would predict biological responses to reservoir operations as part of the System Operation Review program. Major components of the Lake Roosevelt model included: quantification of impacts to phytoplankton, zooplanktons, benthic invertebrates, and fish caused by reservoir drawdowns and low water retention times; quantification of number, distribution, and use of fish food organisms in the reservoir by season; determination of seasonal growth of fish species as related to reservoir operations, prey abundance and utilization; and quantification of entrainment levels of zooplankton and fish as related to reservoir operations and water retention times. This report summarized the data collected on Lake Roosevelt for 1991 and includes limnological, zooplankton, benthic macroinvertebrate, fishery, and reservoir operation data. Discussions cover reservoir operation affect upon zooplankton, benthic macroinvertebrates, and fish. Reservoir operations brought reservoir elevations to a low of 1,221.7 in April, the result of power operations and a flood control shift from Dworshak Dam, in Idaho, to Grand Coulee Dam. Water retention times were correspondingly low reaching a minimum of 14.7 days on April 27th.

  9. Hydrothermal vent fields and chemosynthetic biota on the world's deepest seafloor spreading centre

    PubMed Central

    Connelly, Douglas P.; Copley, Jonathan T.; Murton, Bramley J.; Stansfield, Kate; Tyler, Paul A.; German, Christopher R.; Van Dover, Cindy L.; Amon, Diva; Furlong, Maaten; Grindlay, Nancy; Hayman, Nicholas; Hühnerbach, Veit; Judge, Maria; Le Bas, Tim; McPhail, Stephen; Meier, Alexandra; Nakamura, Ko-ichi; Nye, Verity; Pebody, Miles; Pedersen, Rolf B.; Plouviez, Sophie; Sands, Carla; Searle, Roger C.; Stevenson, Peter; Taws, Sarah; Wilcox, Sally

    2012-01-01

    The Mid-Cayman spreading centre is an ultraslow-spreading ridge in the Caribbean Sea. Its extreme depth and geographic isolation from other mid-ocean ridges offer insights into the effects of pressure on hydrothermal venting, and the biogeography of vent fauna. Here we report the discovery of two hydrothermal vent fields on the Mid-Cayman spreading centre. The Von Damm Vent Field is located on the upper slopes of an oceanic core complex at a depth of 2,300?m. High-temperature venting in this off-axis setting suggests that the global incidence of vent fields may be underestimated. At a depth of 4,960?m on the Mid-Cayman spreading centre axis, the Beebe Vent Field emits copper-enriched fluids and a buoyant plume that rises 1,100?m, consistent with >400?°C venting from the world's deepest known hydrothermal system. At both sites, a new morphospecies of alvinocaridid shrimp dominates faunal assemblages, which exhibit similarities to those of Mid-Atlantic vents. PMID:22233630

  10. Environmental Impact of the Contact and Sonoma Mercury Mines on Water, Sediment, and Biota in Anna Belcher and Little Sulphur Creek Watersheds, Sonoma County, California

    USGS Publications Warehouse

    Rytuba, James J.; Hothem, Roger L.; May, Jason T.; Kim, Christopher S.; Lawler, David; Goldstein, Daniel

    2009-01-01

    The Contact and Sonoma mercury (Hg) deposits are among the youngest Hg deposits in the Coast Range Hg mineral belt and are located in the western part of the Clear Lake volcanic field in Sonoma County, California. The mine workings and tailings are located in the headwaters of Anna Belcher Creek, which is a tributary to Little Sulphur Creek. The Contact Hg mine produced about 1,000 flasks of Hg, and the Sonoma mine produced considerably less. Waste rock and tailings eroded from the Contact and Sonoma mines have contributed Hg-enriched mine waste material to the headwaters of Anna Belcher Creek. The mines are located on federal land managed by the U.S. Bureau of Land Management (USBLM). The USBLM requested that the U.S. Geological Survey (USGS) measure and characterize Hg and other geochemical constituents in tailings, sediment, water, and biota at the Contact and Sonoma mines and in Anna Belcher and Little Sulphur Creeks. This report is made in response to the USBLM request, the lead agency mandated to conduct a Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) - Removal Site Investigation (RSI). The RSI applies to removal of Hg-contaminated mine waste from the Contact and Sonoma mines as a means of reducing Hg transport to Anna Belcher and Little Sulphur Creeks. This report summarizes data obtained from field sampling of mine tailings, waste rock, sediment, and water at the Contact and Sonoma mines that was initiated on April 20 during a storm event, and on June 19, 2001. Further sampling of water, sediment, and biota in a pond and tributaries that drain from the mine area was completed on April 1, 2003. Our results permit a preliminary assessment of the mining sources of Hg and associated chemical constituents that could elevate levels of monomethyl Hg (MMeHg) in tributaries and biota that are impacted by historic mining.

  11. Reconnaissance investigation of water quality, bottom sediment, and biota associated with irrigation drainage in the Tulare Lake bed area, southern San Joaquin Valley, California, 1986-87

    USGS Publications Warehouse

    Schroeder, R.A.; Palawski, D.U.; Skorupa, J.P.

    1988-01-01

    Concentrations of numerous toxic trace elements and pesticides were measured during 1986 in water, sediment, and biota from three areas near the Tulare Lake Bed, southern San Joaquin Valley, California: Kern National Wildlife Refuge, Pixley National Wildlife Refuge, and Westfarmers evaporation ponds about 5 mi west of Kern National Wildlife Refuge, to determine whether toxic constituents in agricultural-irrigation drainage pose a threat to beneficial uses of water, especially to uses by wildlife. Pesticide residues were found to be low at all three areas. Trace element concentrations were found to be comparatively low at the Kern and Pixley National Wildlife Refuge areas and high at the Westfarmers evaporation ponds. Dissolved selenium concentrations were < 1 micrograms/L (ug/L) in areas on and adjacent to the refuges, but ranged from 110 to 360 ug/L in the saline drainwater impounded in the evaporation ponds. The ratio of mean selenium concentrations in biota from Westfarmers ponds compared to biota from Kesterson National Wildlife Refuge (where adverse effects have been documented) is 5 for waterboatman, 2 for avocet liver, 1 for avocet eggs, and < 1 for widgeongrass. The low concentrations measured at Kern and Pixley National Wildlife Refuges suggest that trace elements and pesticides pose little threat to wildlife there; however, impounded subsurface drainage from agricultural irrigation does pose a threat to wildlife at the nearby Westfarmers ponds. Preliminary results of surveys conducted in 1987 indicated that there are adverse biological effects on shorebirds nesting at the ponds, although interpretation of the magnitude of the effects is premature, pending completion of ongoing studies by the U.S. Fish and Wildlife Service. (Author 's abstract)

  12. Concentrations of persistent organochlorine contaminants in bowhead whale tissues and other biota from northern Alaska: implications for human exposure from a subsistence diet.

    PubMed

    Hoekstra, P F; O'Hara, T M; Backus, S M; Hanns, C; Muir, D C G

    2005-07-01

    Bowhead whale (Balaena mysticetus; n = 5) blubber, liver, muscle, kidney, heart, diaphragm, tongue, and uncooked maktak (bowhead whale epidermis and blubber) were collected during subsistence hunts at Barrow, AK, USA (1997-1999) to measure concentrations of persistent organochlorine contaminants (OCs). The exposure of humans to OCs via bowhead whales and other biota [fish, ringed (Phoca hispida) and bearded seals (Erignathus barbatus), and beluga whale (Delphinapterus leucas)] as part of a subsistence diet was evaluated. Concentrations of OCs in bowhead whale tissues were correlated with lipid content (P < 0.001) and were less than levels in other marine mammals reported herein, reflecting the lower trophic status of this cetacean. The relative proportions of hexachlorobenzene (HCB) and sum (Sigma) concentrations of chlordane components (SigmaCHL), DDT-related compounds (SigmaDDT), and polychlorinated biphenyls (SigmaPCB) were not statistically different among the tissues analyzed (P < 0.05). However, relatively higher proportions of hexachlorocyclohexane isomers (SigmaHCH), particularly beta-HCH, were observed in bowhead whale heart and diaphragm (P < 0.03). Based on Canadian and World Health Organization daily intake guidelines, "safe" human consumption rates of bowhead whale tissue and other marine biota were calculated. The most restrictive limits (mean value) for daily consumption for bowhead and beluga whale were 302 and 78 g for maktak and maktaaq (beluga whale epidermis and blubber), respectively. The tolerable daily intake limits of dioxin-like compounds from the consumption of bowhead whale blubber and liver were calculated to be 199 g (approximately 600 g for maktak) and 2222 g, respectively. A detailed profile of traditional/country foods consumed by subsistence communities of northern Alaska is required to address chronic exposure in more detail. Overall, bowhead whale tissues and other biota from northern Alaska are safe to consume at, or below, the levels calculated. PMID:15910787

  13. Toxaphene in standard solutions and cleaned biota extracts--results of the first QUASIMEME interlaboratory studies. Quality Assurance of Information for Marine Environmental Monitoring in Europe.

    PubMed

    de Boer, J; Oehme, M; Smith, K; Wells, D E

    2000-08-01

    Two interlaboratory studies on individual toxaphene congeners have been organised by the project Quality Assurance of Information for Marine Environmental Monitoring in Europe (QUASIMEME). Fifteen laboratories analysed two standard solutions in the first study and 13 laboratories analysed a standard solution and two cleaned biota extracts in the second study. The coefficients of variation obtained for the standard solutions were 6-21% and for the cleaned extracts 16-39%. Although the results were comparable to those of other studies, further improvement in the level of agreement between the participating laboratories was considered possible. PMID:10819219

  14. Simultaneous determination by APCI-LC/MS/MS of hydroxylated and methoxylated polybrominated diphenyl ethers found in marine biota.

    PubMed

    Kato, Yoshihisa; Okada, Syohei; Atobe, Kazutaka; Endo, Tetsuya; Matsubara, Futoshi; Oguma, Takayoshi; Haraguchi, Koichi

    2009-07-15

    A method has been developed for the simultaneous analysis of hydroxylated and methoxylated analogs of tetrabromodiphenyl ethers (OH-tetraBDEs and MeO-tetraBDEs) and of hydroxylated and methoxylated analogs of tetrabromobiphenyl (diOH-tetraBB and diMeO-tetraBB) using high performance liquid chromatography/atmospheric pressure chemical ionization tandem mass spectrometry (APCI-LC/MS/MS) in negative ion mode. Chromatographic separation was performed on a 150 mm ODS column with acetonitrile:water (9:1, v/v) in mobile phase. Multiple reaction monitoring (MRM) was performed using the precursor [M-H]- ion for hydroxylated analogs, and the [M-Br+O]- ion for tetraBDEs and tetraBB, and their methoxylated analogs. The method was validated using cod liver oil samples spiked with nine analytes (100 ng/g) for linearity (r2 > 0.998), recovery (75-95%), repeatability (8-36% RSD), and sensitivity (limits of quantification (LOQ), 0.1-0.25 ng/g lipid for phenolic analytes and 6-80 ng/g lipid for neutral brominated compounds). The APCI-LC/MS/MS was applied to analyze tiger shark and bull shark liver samples, where their concentrations were up to 8 ng/g (lipid weight) for OH-BDEs, whereas they were up to 540 ng/g (lipid weight) for MeO-BDEs. The results were consistent with values determined by electron ionization (EI)-GC/MS. The first detection of 2,2'-dihydroxy-3,3',5,5'-tetrabromobiphenyl (2,2'-diOH-BB80) by this method was in marine sponge from Micronesia. The advantage of the LC/MS/MS method over GC/MS is that it provides rapid and simultaneous determination of OH-BDEs, MeO-BDEs, and their related analogs with a single preparation step and without the involvement of chemical derivatives. Although the method provides the different LOQ ranges between hydroxylated and neutral brominated analogs, future work could apply the method to the full range of PBDE-like contaminants present in the environment and in biota tissues. PMID:19530686

  15. A method for estimating (41)Ar, (85)(,88)Kr and (131m,133)Xe doses to non-human biota.

    PubMed

    Vives I Batlle, J; Jones, S R; Copplestone, D

    2015-06-01

    A method is presented for estimating (41)Ar, (85,88)Kr and (131m,133)Xe dose rates to terrestrial wildlife without having to resort to comparisons with analogue radionuclides. The approach can be used to calculate the dose rates arising from external exposures to given ambient air concentrations of these isotopes. Dose conversion coefficient (DCC) values for a range of representative organisms are calculated, using a Monte Carlo approach to generate absorbed fractions based on representing animals as reference ellipsoid geometries. Plume immersion is the main component of the total DCC. DCC values calculated for a human-sized organism are compared with human dose conversion factors from ICRP Publication 119, demonstrating the consistency of the biota approach with that for humans. An example of application is provided for hypothetical nuclear power plant atmospheric discharges with associated exposures to birds and insects. In this example, the dose rates appear to be dominated by (133)Xe and (88)Kr, respectively. The biota considered would be protected from the effects of noble gas radiation from a population protection perspective. PMID:25863225

  16. Isomer-specific analysis and toxic evaluation of polychlorinated naphthalenes in soil, sediment, and biota collected near the site of a former chlor-alkali plant

    SciTech Connect

    Kannan, K.; Blankenship, A.L.; Giesy, J.P. [Michigan State Univ., East Lansing, MI (United States)] [Michigan State Univ., East Lansing, MI (United States); Imagawa, T. [National Inst. for Resources and Environment, Tsukuba, Ibaraki (Japan)] [National Inst. for Resources and Environment, Tsukuba, Ibaraki (Japan)

    1998-09-01

    Concentrations and composition of polychlorinated naphthalene (PCN) congeners were determined in soil, sediments, blue crab, striped mullet, and boat-tailed grackle collected near a chlor-alkali plant to determine their congener profile, bioaccumulation properties, and toxic potential. Concentrations of total PCNs as high as 23 {micro}g/g, dry wt, were found in sediments collected at the marsh contaminated by disposal of wastes from the chlor-alkali process. The spatial distribution of sediment-PCN concentrations was not related with those observed for polychlorinated biphenyls (PCBs). The PCN congener profile did not resemble those of any technical mixtures. Hepta- and octa-chloronaphthalenes were the most abundant congeners accounting for greater than 50% of the total PCN concentrations in soil and sediments. A characteristic profile of PCNs in samples collected at the chlor-alkali site suggests the formation of chloronaphthalene congeners during chlor-alkali process, as has been suggested for polychlorinated dibenzofurans (PCDFs). Concentrations of total PCNs in biota were 3--5 orders of magnitude less than in sediments. The profile of PCN congeners in biota was predominated by tetra- or penta-chloronaphthalenes, while hepta- and octa-chloronaphthalenes were not detected.

  17. Biota-sediment accumulation factor (BSAF), bioaccumulation factor (BAF), and contaminant levels in prey fish to indicate the extent of PAHs and OCPs contamination in eggs of waterbirds.

    PubMed

    Kwok, C K; Liang, Y; Leung, S Y; Wang, H; Dong, Y H; Young, L; Giesy, J P; Wong, M H

    2013-12-01

    Samples of pond sediment, fish, and shrimp were collected from the Ramsar site at Mai Po marshes, Hong Kong (south China), and samples of pond sediment, fish, and shrimp, as well as eggs of water birds (Chinese Pond Herons (Ardeola bacchus) and Little Egrets (Egretta garzetta)), were collected from two smaller wetland sites at Jiangsu Province (mid-China), between 2004 and 2007. Accumulation levels of polycyclic aromatic hydrocarbons (PAHs) and organochlorine pesticides (OCPs) in the biota were used to calculate biota-sediment accumulation factor (BSAF) and bioaccumulation factor (BAF). For fish and shrimp, BSAFs of OCPs (3.8-56) were greater than those of PAHs (0.12-6.3). BSAFs and BAFs of 11-79 and 4-34, respectively, were registered for OCPs in eggs of the birds and were greater than those for PAHs (0.11-1.5 and 0.02-1.3, respectively). Assuming that fish were the main prey of the birds, greater bioaccumulation of OCPs was detected for both bird species (BAFs?=4.5-34), while accumulation of PAHs was only detected in Little Egret (BAF=1.3). A significant linear relationship (p<0.01) was observed between concentrations of OCPs in bird eggs and in the prey fish. The present study provides a new possibility of using OCP levels detected in prey fish to predict the extent of OCPs contamination in eggs of waterbirds including the endangered species, as a noninvasive method. PMID:23702571

  18. Co-extraction and simultaneous determination of multi-class hydrophobic organic contaminants in marine sediments and biota using GC-EI-MS/MS and LC-ESI-MS/MS.

    PubMed

    Zhang, Hui; Bayen, Stéphane; Kelly, Barry C

    2015-10-01

    A multi-residue analytical method was developed involving co-extraction and simultaneous determination of 89 hydrophobic organic contaminants (HOCs) in marine sediments and biota using gas chromatography-electron ionization-triple quadrupole mass spectrometry (GC-EI-MS/MS) and liquid chromatography-electrospray ionization-triple quadrupole mass spectrometry (LC-ESI-MS/MS). Target analytes include polychlorinated biphenyls (PCBs), pesticides, chlorobenzenes, brominated and chlorinated flame retardants, nitro-aromatic and polycyclic musks, triclosan and methyl triclosan. Spike-recovery experiments showed relative recoveries of analytes were generally between 70% and 130%. Analyses of a sediment standard reference material (SRM 1944) demonstrated recoveries between 80% and 120% for certified concentrations of individual PCBs and pesticides. Method detection limits of individual compounds ranged from 0.1 to 57.1pg/g dw for sediments and 0.1 to 22.8pg/g ww for biota. A field survey of sediments and biota from Singapore's marine environment demonstrated the occurrence of polycyclic and nitro-aromatic musks (galaxolide, tonalide, musk ketone, etc.), halogenated flame retardants (syn- and anti-dechlorane plus (DP), ?, ? and ?-hexabromocyclododecane (HBCD), tetrabromobisphenol A (TBBPA), etc.), as well as triclosan and methyl triclosan. Galaxolide exhibited relatively high concentrations, with highest levels in polychaete worms (161.7±72.5ng/g ww) and clams (546.8±220.3ng/g ww) from mangroves. Triclosan and methyl triclosan levels were highly correlated in sediments (r(2)=0.9752), while syn- and anti-DP were strongly correlated in biota (r(2)=0.9279). anti-DP/syn-DP stereoisomer ratios were typically >1 and ranged between 0.94 and 29.2 in sediments and biota samples. ?-HBCD exhibited the highest concentrations among HBCD isomers in sediments. Conversely, ?-HBCD was the dominant HBCD isomer in biota. PMID:26078122

  19. Concentrations of metals and trace elements in aquatic biota associated with abandoned mine lands in the Whiskeytown National Recreation Area and nearby Clear Creek watershed, Shasta County, northwestern California, 2002-2003

    USGS Publications Warehouse

    Hothem, Roger L.; May, Jason T.; Gibson, Jennifer K.; Brussee, Brianne E.

    2015-01-01

    Compared with other recently evaluated mine-impacted watersheds in northern California, invertebrates, amphibians, and fish from sites within the Upper Clear Creek watershed tended to have significantly lower concentrations of Hg than at most other sites. For other metals and trace elements, Upper Clear Creek sites were only compared with the Deer Creek watershed, Nevada County, California. Copper from both Willow Creek sites (WLCC and WLTH) in the Clear Creek watershed was the only metal with concentrations in biota that were significantly higher than biota from Deer Creek

  20. 3D Seismic and Magnetic characterization of the Borax Lake Hydrothermal System in the Alvord Desert, southeastern Oregon

    Microsoft Academic Search

    S. Hess; J. Bradford; M. Lyle; P. Routh; L. Liberty; P. Donaldson

    2004-01-01

    As part of an interdisciplinary project aiming to study the link between the physical characteristics of hydrothermal systems and biota that occupy those systems, we are conducting a detailed geophysical characterization of an active hydrothermal system. The Borax Lake Hydrothermal System (BLHS), consisting of Borax Lake and the surrounding hot springs. BLHS is located near the center of the Alvord

  1. Ten-year assessment of agricultural management and land-use practices on pesticide loads and risk to aquatic biota of an oxbow lake in the Mississippi Delta, USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The current chapter examined the combined influence of changing row crop production, implementation of agricultural Best Management Practices (BMPs), and enrollment of 112 ha into Conservation Reserve Program (CRP) on pesticide contamination and potential risk to lake aquatic biota in a 914-ha Beasl...

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

    PubMed

    Li, Y F; Macdonald, R W

    2005-04-15

    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 alpha- and beta-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. PMID:15866269

  3. Surface-water-quality assessment of the Yakima River basin in Washington; major-and minor-element data for sediment, water, and aquatic biota, 1987-91

    USGS Publications Warehouse

    Fuhrer, Gregory J.; Fluter, S.L.; McKenzie, S.W.; Rinella, J.F.; Crawford, J.K.; Cain, D.J.; Hornberger, M.I.; Bridges, J.L.; Skach, K.A.

    1994-01-01

    Major- and minor-element concentrations are pre- sented for streambed and suspended sediment, filtered- and unfiltered-water, and aquatic-biota samples collected during 1987-91 from the Yakima River Basin in south-central Washington. The samples were collected as part of the U.S. Geological Survey's National Water-quality Assessment (NAWQA) program which is designed to provide results that are useful in understanding and managing the Nation's water resources. This report includes the sampling approach, field collection and processing techniques, and methods of chemical analysis, as well as a compilation of chemical data, statistical summaries, and quality- control data. These data may be used by scientists and resource managers to describe (1) spatial distribution of selected major and minor elements in sediment, water, and aquatic biota of the Yakima River Basin; (2) temporal variation for element concentrations in filtered water and in suspended sediment at selected sites; (3) suita- bility of surface water for preservation of aquatic life and protection of human health; and (4) major natural and anthropogenic sources of major and minor elements in the Yakima River Basin that affect observed water-quality conditions. Streambed-sediment samples were collected once from 27 sites in the basin during 1987-91. Suspended-sediment and filtered-water samples were collected monthly and during hydrologic events (including snowmelt and winter rainstorms) at seven sites, and filtered-water samples were collected at least once at an additional 37 sites during synoptic samplings. Unfiltered-water samples were collected at seven sites on a quarterly basis during 1987 only. Samples of aquatic plants were collected once in 1989, and aquatic insects, fish, and clams were collected from 34 sites three times during 1989-90.

  4. Application of Biota Dose Assessment Committee Methodology to Assess Radiological Risk to Salmonids in the Hanford Reach of the Columbia River

    SciTech Connect

    Poston, Ted M.; Antonio, Ernest J.; Peterson, Robert E.

    2002-07-22

    Protective guidance for biota in the U.S. Department of Energy's Graded Approach for Evaluating Radiation Doses to Aquatic and Terrestrial Biota is based on population level protection guides of 10 or 1 mGy.d-1, respectively. Several "ecologically significant units" of Pacific salmon are listed under the Endangered Species Act. The Middle Columbia Steelhead unit is endangered and the adult steelhead spawn in the reach. The reach also supports one of the largest spawning populations of fall chinook salmon in the Northwest. The existence of the major spawning areas in the Hanford Reach has focused considerable attention on their ecological health by the U.S. Department of Energy, other federal and state regulatory agencies, and special interest groups. Dose assessments for developing salmonid embryos were performed for the hypothetical exposure to tritium, strontium-90, technetium-99, iodine-129, and uranium isotopes at specific sites on the Hanford Reach. These early life stages are potentially exposed in some areas of the Hanford Reach to radiological contaminants that enter the river via shoreline seeps and upwelling through the river substrate. At the screening level, one site approached the dose guideline of 10 mGy.d-1 established with the RAD-BCG methodology and exceeded a precautionary benchmark of 2.5 mGy.d-1. Special status of listed species affords these populations more consideration when assessing potential impacts of exposure to radionuclides and other contaminants associated with the Hanford Site operations. The evolution of dose benchmarks for aquatic organisms and consideration of precautionary principal and cumulative impacts are discussed in this paper.

  5. Detailed study of selenium and other constituents in water, bottom sediment, soil, alfalfa, and biota associated with irrigation drainage in the Uncompahgre Project area and in the Grand Valley, west-central Colorado, 1991-93

    USGS Publications Warehouse

    Butler, D.L.; Wright, W.G.; Stewart, K.C.; Osmundson, B.C.; Krueger, R.P.; Crabtree, D.W.

    1996-01-01

    In 1985, the U.S. Department of the Interior began a program to study the effects of irrigation drainage in the Western United States. These studies were done to determine whether irrigation drainage was causing problems related to human health, water quality, and fish and wildlife resources. Results of a study in 1991-93 of irrigation drainage associated with the Uncompahgre Project area, located in the lower Gunnison River Basin, and of the Grand Valley, located along the Colorado River, are described in this report. The focus of the report is on the sources, distribution, movement, and fate of selenium in the hydrologic and biological systems and the effects on biota. Generally, other trace- constituent concentrations in water and biota were not elevated or were not at levels of concern. Soils in the Uncompahgre Project area that primarily were derived from Mancos Shale contained the highest concentrations of total and watrer-extractable selenium. Only 5 of 128\\x11alfalfa samples had selenium concentrations that exceeded a recommended dietary limit for livestock. Selenium data for soil and alfalfa indicate that irrigation might be mobilizing and redistributing selenium in the Uncompahgre Project area. Distribution of dissolved selenium in ground water is affected by the aqueous geochemical environment of the shallow ground- water system. Selenium concentrations were as high as 1,300\\x11micrograms per liter in water from shallow wells. The highest concentrations of dissolved selenium were in water from wells completed in alluvium overlying the Mancos Shale of Cretaceous age; selenium concentrations were lower in water from wells completed in Mancos Shale residuum. Selenium in the study area could be mobilized by oxidation of reduced selenium, desorption from aquifer sediments, ion exchange, and dissolution. Infiltration of irrigation water and, perhaps nitrate, provide oxidizing conditions for mobilization of selenium from alluvium and shale residuum and for transport to streams and irrigation drains that are tributary to the Gunnison, Uncompahgre, and Colorado Rivers. Selenium concentrations in about 64\\x11percent of water samples collected from the lower Gunnison River and about 50 percent of samples from the Colorado River near the Colorado-Utah State line exceeded the U.S.\\x11Environmental Protection Agency criterion of 5\\x11micrograms per liter for protection of aquatic life. Almost all selenium concentrations in samples collected during the nonirrigation season from Mancos Shale areas exceeded the aquatic-life criterion. The maximum selenium concentrations in surface-water samples were 600\\x11micrograms per liter in the Uncompahgre Project area and 380\\x11micrograms per liter in the Grand Valley. Irrigation drainage from the Uncompahgre Project and the Grand Valley might account for as much as 75 percent of the selenium load in the Colorado River near the Colorado-Utah State line. The primary source areas of selenium were the eastern side of the Uncompahgre Project and the western one-half of the Grand Valley, where there is extensive irrigation on soils derived from Mancos Shale. The largest mean selenium loads from tributary drainages were 14.0 pounds per day from Loutsenhizer Arroyo in the Uncompahgre Project and 12.8 pounds per day from Reed Wash in the Grand Valley. Positive correlations between selenium loads and dissolved-solids loads could indicate that salinity-control projects designed to decrease dissolved-solids loads also could decrease selenium loads from the irrigated areas. Selenium concentrations in irrigation drainage in the Grand Valley were much higher than concentrations predicted by simple evaporative concentration of irrigation source water. Selenium probably is removed from pond water by chemical and biological processes and incorporated into bottom sediment. The maximum selenium concentration in bottom sediment was 47 micrograms per gram from a pond on the eastern side of the

  6. Soil pollution associated to the El Borracho Pb-Ag mine (Badajoz Province, Spain). Metal transfer to biota: oak-tree and moss.

    NASA Astrophysics Data System (ADS)

    López-Berdonces, Miguel Angel; María Esbrí, José; Fernández-Calderón, Sergio; Naharro, Elena; García-Noguero, Eva Maria; Higueras, Pablo

    2014-05-01

    El Borracho mine was active since Roman times, but with its higher production period on 19th Century. Mine closure occured without restoration works and nowadays the mining area is dedicated to deer hunting activities. In order to evaluate heavy metals distribution on mining tailings and surrounding soils of the studied area, 40 samples of dumps, soils and sediments were taken. Samples from the mine tailings were collected with an Eijkelkamp soil core sampler for undisturbed samples, with a vertical constant spacing of 25 cm. With this procedure, a total of 21 samples were taken in two points at main dump. Samples of Oak-tree leaves and moss were taken to evaluate metal transfer to biota. Analytical determinations have included soil parameters (pH, conductivity, organic matter content), and total metal contents in geological and biological samples by EDXRF. Analytical determinations shows higher metal contents in dumps, especially in surficial samples, 17,700 mg kg-1 and 470 mg kg-1 in average of Pb and Zn respectively, and lower contents in soils, 5,200 mg kg-1 and 300 mg kg-1, and sediments, 3,500 mg kg-1 and 120 mg kg-1. Metal contents in tailings profiles shows higher levels of Pb, Zn and Cu at 3.5 meters depth, a zone with lower grainsize and higher moisture. Differences in efficiency of extraction techniques and metal remobilization inside the dump can be an explanation for this enrichment level. Metal contents in agricultural soils exceeded maximum allowed levels by European Community (300 mg kg-1 for Pb and Zn and 140 mg kg-1 for Cu). Metal contents in biota evidence that Oak-tree bioaccumulates some metals, especially those with higher mobility in acidic conditions like Zn and Sb, with averages Bioaccumulation factor (BAF = plant concentration/soil concentration) of 0.48 and 0.85 respectively. Moss reaches high concentrations of Pb and Zn (3,000 mg kg-1 and 175 mg kg-1 in average respectively). Uptake pattern of Pb and Zn by plants leaves and mosses seems to be similar and can be characterized by logistic curves, with higher affinity of mosses to uptake metals from soils.

  7. Ethoprophos fate on soil-water interface and effects on non-target terrestrial and aquatic biota under Mediterranean crop-based scenarios.

    PubMed

    Leitão, Sara; Moreira-Santos, Matilde; Van den Brink, Paul J; Ribeiro, Rui; José Cerejeira, M; Sousa, José Paulo

    2014-05-01

    The present study aimed to assess the environmental fate of the insecticide and nematicide ethoprophos in the soil-water interface following the pesticide application in simulated maize and potato crops under Mediterranean agricultural conditions, particularly of irrigation. Focus was given to the soil-water transfer pathways (leaching and runoff), to the pesticide transport in soil between pesticide application (crop row) and non-application areas (between crop rows), as well as to toxic effects of the various matrices on terrestrial and aquatic biota. A semi-field methodology mimicking a "worst-case" ethoprophos application (twice the recommended dosage for maize and potato crops: 100% concentration v/v) in agricultural field situations was used, in order to mimic a possible misuse by the farmer under realistic conditions. A rainfall was simulated under a slope of 20° for both crop-based scenarios. Soil and water samples were collected for the analysis of pesticide residues. Ecotoxicity of soil and aquatic samples was assessed by performing lethal and sublethal bioassays with organisms from different trophic levels: the collembolan Folsomia candida, the earthworm Eisenia andrei and the cladoceran Daphnia magna. Although the majority of ethoprophos sorbed to the soil application area, pesticide concentrations were detected in all water matrices illustrating pesticide transfer pathways of water contamination between environmental compartments. Leaching to groundwater proved to be an important transfer pathway of ethoprophos under both crop-based scenarios, as it resulted in high pesticide concentration in leachates from Maize (130µgL(-1)) and Potato (630µgL(-1)) crop scenarios, respectively. Ethoprophos application at the Potato crop scenario caused more toxic effects on terrestrial and aquatic biota than at the Maize scenario at the recommended dosage and lower concentrations. In both crop-based scenarios, ethoprophos moved with the irrigation water flow to the soil between the crop rows where no pesticide was applied, causing toxic effects on terrestrial organisms. The two simulated agricultural crop-based scenarios had the merit to illustrate the importance of transfer pathways of pesticides from soil to groundwater through leaching and from crop rows to the surrounding soil areas in a soil-water interface environment, which is representative for irrigated agricultural crops under Mediterranean conditions. PMID:24562181

  8. Carbonate systems along nutrient and temperature gradients: some sedimentological and geochemical constraints

    Microsoft Academic Search

    Maria Mutti; Pamela Hallock

    2003-01-01

    Research over the past several decades has clearly demonstrated that changes in the ocean environment have had major impacts on carbonate systems. Changes in climate, ocean circulation and seafloor spreading rates have influenced temperature and seawater chemistry, including carbonate saturation state and nutrient availability, and thereby have determined boundary conditions for the biota that form carbonate platforms. In turn, the

  9. Extremely Low Frequency (ELF) communications system ecological monitoring program: Plan and summary of 1982 progress

    Microsoft Academic Search

    J. E. Zapotosky; M. M. Abromavage

    1983-01-01

    The purpose of the Ecological Monitoring Program is to study ecological and\\/or biological characteristics of selected biota in an environment that includes natural stresses and low-level ELF electromagnetic fields. Sixteen general types of organisms from three major ecosystems in the System area are being examined. Study sites were selected in 1982, and will be examined further in 1983. Statistical methods

  10. 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

    USGS Publications Warehouse

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

    2013-01-01

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

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

    PubMed

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

    2015-09-01

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

  12. Reconnaissance investigation of water quality, bottom sediment, and biota associated with irrigation drainage in the Sun River area, west-central Montana, 1986-87

    SciTech Connect

    Knapton, J.R.; Jones, W.E.; Sutphin, J.W.

    1988-01-01

    The area of study included the Sun River Irrigation Project, Freeze-out Lake Game Management Area, and Benton Lake National Wildlife Refuge. Water, bottom sediment, and biota were sampled at selected sites and analyzed for inorganic and organic constituents that could be toxic at large concentrations. Although selenium was of primary concern, other trace elements and selected pesticides were also analyzed. Some water quality problems have been prevalent for many years in the Sun River Irrigation Projects, including the Sun River and Muddy Creek. However, during this study, most sampling sites were free of concentrations of toxic constituents that are in excess of established criteria and standards. There was little change in arsenic, boron, mercury, and selenium concentrations in fish and invertebrates at Sun river sampling sites upstream and downstream from the irrigation project. Presently, the most serious threat within the irrigation project appears to be from nitrate in groundwater. Water from some wells contains nitrate concentration in excess of drinking water standards established for the State of Montana. The largest selenium concentrations in water and bottom sediment were from seeps that surround Benton Lake, with maximum concentrations of 580 mg/L in water and biological samples. Several eared-grebe livers from Freezeout Lake and several coot livers and eggs from Benton Lake had selenium concentrations indicative of contamination. 58 refs., 12 figs., 21 tabs.

  13. Synthesis of thirty years of surface water quality and aquatic biota data in Shenandoah National Park: collaboration between the US Geological Survey and the National Park Service

    USGS Publications Warehouse

    Rice, Karen C.; Jastram, John D.; Wofford, John E.B.; Schaberl, James P.

    2014-01-01

    The eastern United States has been the recipient of acidic atmospheric deposition (hereinafter, “acid rain”) for many decades. Deleterious effects of acid rain on natural resources have been well documented for surface water (e.g., Likens et al. 1996; Stoddard et al. 2001), soils (Bailey et al. 2005), forest health (Long et al. 2009), and habitat suitability for stream biota (Baker et al. 1993). Shenandoah National Park (SNP) is located in northern and central Virginia and consists of a long, narrow strip of land straddling the Blue Ridge Mountains (Figure 1). The park’s elevated topography and location downwind of the Ohio River valley, where many acidic emissions to the atmosphere are generated (NSTC 2005), have made it a target for acid rain. Characterizing the link between air quality and water quality as related to acid rain, contaminants, soil conditions, and forest health is a high priority for research and monitoring in SNP. The US Geological Survey (USGS) and SNP have had a long history of collaboration on documenting acid rain effects on the park’s natural resources, starting in 1985 and continuing to the present (Lynch and Dise 1985; Rice et al. 2001, 2004, 2005, 2007; Deviney et al. 2006, 2012; Jastram et al. 2013).

  14. Identification and quantification of n-octyl esters of alkanoic and hexanedioic acids and phthalates as urban wastewater markers in biota and sediments from estuarine areas.

    PubMed

    Chaler, Roser; Cantón, Lourdes; Vaquero, Menchu; Grimalt, Joan O

    2004-08-13

    A gas chromatographic method for the identification and quantification of n-octyl esters (from n-octyl tetradecanoate to n-octyl hexa-cosanoate including dioctyl hexanedioate) and phthalates [dibutyl phthalate, benzyl butyl phthalate and di(2-ethylhexyl) phthalate] in sediments and biota from estuarine environments is described. Standards used for identification and quantification of some n-octyl esters were synthesized. The method has allowed the analysis of these compounds in polychaeta (Nereis diversicolor), oysters (Crassostea angulata), crabs (Carcinus maenas) and fish (Chelon labrosus, Platichtys flesus and Chondostroma polylepis) that were collected at different locations of the Urdaibai estuary (Bizkaia, Basque Country, Spain). Total phthalates and n-octyl esters ranged between 0.01 and 12 microg g(-1) and 0.05 and 9.4 microg g(-1), respectively, and were predominantly found in polychaeta and fish. Sediments did not contain these compounds in significant amount, only benzyl butyl phthalate, dioctyl hexanedioate and di(2-ethylhexyl) phthalate were found above limit of detection (0.01-0.05 microg g(-1)). PMID:15387189

  15. A hybrid empirical-mechanistic modeling approach for extrapolating biota-sediment accumulation factors and bioaccumulation factors across species, time, and/or ecosystems.

    PubMed

    Burkhard, Lawrence P; Cook, Philip M; Lukasewycz, Marta T

    2006-07-01

    An approach is presented for extrapolating field-measured biota-sediment accumulation factors (BSAFs) and bioaccumulation factors (BAFs) across species, time, and/or ecosystems. This approach, called the hybrid bioaccumulation modeling approach, uses mechanistic bioaccumulation models to extrapolate field-measured bioaccumulation data (i.e., BSAFs and BAFs) to new sets of ecological conditions. The hybrid approach predicts relative differences in bioaccumulation using food web models with two sets of ecological conditions and parameters: One set for the ecosystem where the BSAFs and/or BAFs were measured, and the other set for the ecological conditions and parameters for which the extrapolated BSAFs and/or BAFs are desired. The field-measured BSAF (or BAF) is extrapolated by adjusting the measured BSAF (or BAF) by the predicted relative difference, which is derived from two separate solutions of the food web model. Extrapolations of polychlorinated biphenyl BSAFs and BAFs for lake trout (Salvelinus namaycush) from southern Lake Michigan to Green Bay of Lake Michigan (Green Bay, WI, USA) walleye (Stizostedion vitreum) and brown trout (Salmo trutta), as well as Hudson River largemouth bass (Micropterus salmoides) and yellow perch (Perca flavescens), resulted in generally better agreement between measured and predicted BSAFs and BAFs with the hybrid approach. PMID:16833159

  16. Total Mercury, Methylmercury, and Carbon and Nitrogen Stable Isotope Data for Biota from Selected Streams in Oregon, Wisconsin, and Florida, 2002-04

    USGS Publications Warehouse

    Chasar, Lia C.; Scudder, Barbara C.; Bell, Amanda H.; Wentz, Dennis A.; Brigham, Mark E.

    2008-01-01

    The U.S. Geological Survey National Water-Quality Assessment Program conducted a multidisciplinary study to investigate the bioaccumulation of mercury from 2002 to 2004. Study areas were located in Oregon, Wisconsin, and Florida. Each study area included one urban site, and one or two nonurban sites that had the following attributes: high-percent wetland or low-percent wetland. Periphyton, macroinvertebrates, and forage fish were collected twice per year (during 2003 and 2004) to capture seasonality. Top predators, specifically largemouth bass (Micropterus salmoides), brown trout (Salmo trutta), and cutthroat trout (Oncorhynchus clarkii), were collected once per year (Oregon, Wisconsin, and Florida in 2003; Florida only in 2004). All biota were identified to the lowest possible taxonomic category and were analyzed for mercury and stable carbon and nitrogen isotopes. Periphyton and invertebrates were analyzed for total mercury and methylmercury; fish were analyzed for total mercury only. This report presents (1) methodology and data on mercury, methylmercury, stable isotopes, and (2) other ecologically relevant measurements in biological tissues of periphyton, invertebrates, forage fish, and predator fish.

  17. Analysis of "total toxaphene" and selected single congeners in biota by ion trap HRGC-EI-MS/MS using congener-optimized parent ion dissociations.

    PubMed

    Skopp, Sonja; Oehme, Michael; Chu, Fong Lam; Yeboah, Faustinus; Chan, Hing Man

    2002-06-15

    A method for the quantification of selected toxaphene congeners as well as "total toxaphene" was developed based on electron ionization (EI) tandem (MS/MS) ion trap mass spectrometry (MS) and a combination of fragment ion dissociations. Congeners were separated by high-resolution gas chromatography. Compared to conventional EI low-resolution MS, a 5-20-fold gain in sensitivity could be obtained for octa- or nonachlorinated compounds such as toxaphene #26 and #62 (according to Parlar nomenclature), allowing for their detection in the low picogram range in biota. In addition, response factors for important congeners such as #26, #32, #40/41, #42, #44, #50, and #62 deviated not more than a factor of 2, which is much less as compared to negative ion chemical ionization. This reduces the risk for systematic errors when determining total toxaphene on the basis of a limited number of reference compounds or the technical mixture. Furthermore, chlordanes and polychlorinated biphenyls did not interfere when applying the proposed MS/MS technique. The applicability of the method was tested by determining both total toxaphene and levels of selected congeners in six Arctic wildlife samples collected from Nunavut, Canada, as well as by repetitive analyses of the SRM 1588 certified reference material. PMID:12099471

  18. An integrated, multiscale approach to predicting the response of lotic biota to climate change in the Apalachicola, Chattahoochee, and Flint Basin

    NASA Astrophysics Data System (ADS)

    Peterson, J.; Freeman, M. C.

    2010-12-01

    Climate change, land development, and water use are among the foremost problems faced by aquatic resource managers. Identifying and quantifying their effects on aquatic communities is crucial for evaluating potential stream conservation strategies. In the Apalachicola, Chattahoochee, and Flint (ACF) river basins, increasing demand for water from the steady growth of the Atlanta Metropolitan Area and increased agricultural irrigation in the Coastal Plain has the potential to alter streamflows throughout the basin. Climate change is expected to have a broad-scale influence on the quantity and the seasonality of streamflows, exacerbating the effects of water use and land development. We developed a multiscale approach to predict the effects of flow and temperature alteration on the persistence of fish and mussel communities in the ACF basin. The modeling approach integrates climate, geology, geomorphology, hydrology, and landscape characterizations within the basin. Existing data sets have been used to allow regionalization of results to other watersheds while minimizing additional data collection. Climate, hydraulic, and ecological models were linked to predict persistence of fish and mussel species under future scenarios of flow alteration, land-use effects, and climate change. We intend this as an adaptive framework, within which model components will be iteratively improved with better understanding of mechanisms linking climate, land use, hydrology, and aquatic biota, to provide useful guidance to natural resource managers.

  19. Establishment of sentinel sampling sites to monitor changes in water and sediment quality and biota related to visitor use at Lake Powell, Arizona and Utah, 2004-2006

    USGS Publications Warehouse

    Hart, Robert J.; Taylor, Howard E.; Anderson, G.M.

    2012-01-01

    Twenty sentinel sampling sites were established and sampled during 2004–06 at Lake Powell, Arizona and Utah, by the U.S. Geological Survey and the National Park Service—Glen Canyon National Recreation Area. The sentinel sampling sites provide sampling locations on Lake Powell, the Nation’s second largest reservoir that can be visited and sampled repeatedly over time to monitor changes in water and sediment quality and also biota. The sites were established in response to an Environmental Impact Statement that addressed the use of personal watercraft on Lake Powell. The use of personal watercraft can potentially introduce hydrocarbons and other contaminants and are of concern to the health of visitors and aquatic habitats of these environments. Data from this initial sampling period (2004–06) include (1) discrete measurements of water temperature, specific conductance, pH, and water clarity; (2) major ions, nutrients, and organic carbon; (3) trace elements including rare earths; (4) organic compounds including oil and grease, total petroleum hydrocarbons, and volatile organic compounds; (5) polycyclic aromatic hydrocarbons in lakebed sediments; and (6) continuous depth profile measurements of water temperature, specific conductance, pH, dissolved oxygen, and turbidity. Also, the National Park Service-Glen Canyon National Recreation Area collected bacteria samples during this initial sampling period.

  20. Compilation of 1988 annual reports of the Navy ELF (extremely low frequency) Communications System Ecological Monitoring Program. Volume 2. Annual progress report No. 7, January-December 1988

    SciTech Connect

    Not Available

    1989-08-01

    This is the seventh compilation of annual reports for the Navy's ELF Communications System Ecological Monitoring Program. The reports document the progress of eight studies performed during 1988 at the Wisconsin and Michigan Transmitting Facilities. The purpose of the monitoring is to determine whether electromagnetic fields produced by the ELF Communications System will affect resident biota or their ecological relationships.

  1. Extremely low frequency (ELF) communications system ecological monitoring program: plan and summary of 1982 progress. Summary report for 1982

    Microsoft Academic Search

    J. E. Zapotosky; M. M. Abromavage

    1983-01-01

    The purpose of the Ecological Monitoring Program is to study ecological and\\/or biological characteristics of selected biota in an environment that includes natural stresses and low-level ELF electromagnetic fields. Sixteen general types of organisms from three major ecosystems in the System area are being examined. Study sites were selected in 1982, and will be examined further in 1983. Statistical methods

  2. Trends in marine biological invasions at local and regional scales: the Northeast Pacific Ocean as a model system

    Microsoft Academic Search

    Marjorie J. Wonham; James T. Carlton

    2005-01-01

    Introduced species are an increasing agent of global change. Biogeographic comparisons of introduced biotas at regional and global scales can clarify trends in source regions, invasion pathways, sink regions, and survey effort. We identify the Northeast Pacific Ocean (NEP; northern California to British Columbia) as a model system for analyzing patterns of marine invasion success in cool temperate waters. We

  3. Ecological Status of the St. Louis River System, as Informed by Spatially Comprehensive Surveys and Comparison to Coastal Wetlands Elsewhere

    EPA Science Inventory

    Extensive data on biota and the physical/chemical environment were collected across the lower St. Louis River in 2004-2007 as part of multiple studies undertaken by EPA. The 2005-2007 work provides a spatially highly-resolved assessment of conditions across the system, while the ...

  4. Applications of biological tools or biomarkers in aquatic biota: A case study of the Tamar estuary, South West England.

    PubMed

    Dallas, Lorna J; Jha, Awadhesh N

    2015-06-30

    Biological systems are the ultimate recipients of pollutant-induced damage. Consequently, our traditional reliance on analytical tools is not enough to assess ecosystem health. Biological responses or biomarkers are therefore also considered to be important tools for environmental hazard and risk assessments. Due to historical mining, other anthropogenic activities, and its conservational importance (e.g. NATURA sites, SACs), the Tamar estuary in South West England is an ideal environment in which to examine applications of such biological tools. This review presents a thorough and critical evaluation of the different biological tools used in the Tamar estuary thus far, while also discussing future perspectives for biomarker studies from a global perspective. In particular, we focus on the challenges which hinder applications of biological tools from being more readily incorporated into regulatory frameworks, with the aim of enabling both policymakers and primary stakeholders to maximise the environmental relevance and regulatory usefulness of such tools. PMID:25817310

  5. How much is enough? Minimal responses of water quality and stream biota to partial retrofit stormwater management in a suburban neighborhood.

    PubMed

    Roy, Allison H; Rhea, Lee K; Mayer, Audrey L; Shuster, William D; Beaulieu, Jake J; Hopton, Matthew E; Morrison, Matthew A; St Amand, Ann

    2014-01-01

    Decentralized stormwater management approaches (e.g., biofiltration swales, pervious pavement, green roofs, rain gardens) that capture, detain, infiltrate, and filter runoff are now commonly used to minimize the impacts of stormwater runoff from impervious surfaces on aquatic ecosystems. However, there is little research on the effectiveness of retrofit, parcel-scale stormwater management practices for improving downstream aquatic ecosystem health. A reverse auction was used to encourage homeowners to mitigate stormwater on their property within the suburban, 1.8 km(2) Shepherd Creek catchment in Cincinnati, Ohio (USA). In 2007-2008, 165 rain barrels and 81 rain gardens were installed on 30% of the properties in four experimental (treatment) subcatchments, and two additional subcatchments were maintained as controls. At the base of the subcatchments, we sampled monthly baseflow water quality, and seasonal (5×/year) physical habitat, periphyton assemblages, and macroinvertebrate assemblages in the streams for the three years before and after treatment implementation. Given the minor reductions in directly connected impervious area from the rain barrel installations (11.6% to 10.4% in the most impaired subcatchment) and high total impervious levels (13.1% to 19.9% in experimental subcatchments), we expected minor or no responses of water quality and biota to stormwater management. There were trends of increased conductivity, iron, and sulfate for control sites, but no such contemporaneous trends for experimental sites. The minor effects of treatment on streamflow volume and water quality did not translate into changes in biotic health, and the few periphyton and macroinvertebrate responses could be explained by factors not associated with the treatment (e.g., vegetation clearing, drought conditions). Improvement of overall stream health is unlikely without additional treatment of major impervious surfaces (including roads, apartment buildings, and parking lots). Further research is needed to define the minimum effect threshold and restoration trajectories for retrofitting catchments to improve the health of stream ecosystems. PMID:24465468

  6. Biota--sediment accumulation factors for polychlorinated biphenyls, dibenzo-p-dioxins, and dibenzofurans in southern Lake Michigan lake trout (Salvelinus namaycush).

    PubMed

    Burkhard, Lawrence P; Cook, Philip M; Lukasewycz, Marta T

    2004-10-15

    A set of high-quality, age-specific biota-sediment accumulation factors (BSAFs) for polychlorinated biphenyls (PCBs), dibenzo-p-dioxins (PCDDs), and dibenzofurans (PCDFs) have been determined from concentrations measured with high-resolution gas chromatography/high-resolution mass spectrometry, by use of the 13C isotopic dilution technique, in lake trout and surficial (0-2 cm) sediment samples from southern Lake Michigan. BSAFs ranged from <0.1 to 18 for PCBs and from <0.001 to 0.32 for PCDDs and PCDFs detected in the fish. PCBs with zero or one chlorine in an ortho position had smaller BSAFs than other PCBs. PCDDs and PCDFs with chlorines at the 2,3,7,8-positions had larger BSAFs than most other PCDDs and PCDFs. The fidelity of the relative bioaccumulation potential data between independent lake trout samples, within and among age classes, suggests that differences in slight rates of net metabolism in the food chain are important and contribute to the apparent differences in BSAFs, not only for PCDDs and PCDFs but also possibly for some PCBs. A complicating factor for non-ortho- and mono-ortho-PCBs is the uncertain contribution of enhanced affinity for black carbon (and possibly volatility) acting in concert with metabolism to reduce measured BSAFs for lake trout. On the basis of the association between chemicals with apparent slight rates of metabolism and measured dioxin-like toxicity, several PCDFs with similar measured BSAFs but unknown toxicity may be candidates for toxicity testing. PMID:15543729

  7. Are standard tests sensitive enough to evaluate effects of human pharmaceuticals in aquatic biota? Facing changes in research approaches when performing risk assessment of drugs.

    PubMed

    Aguirre-Martínez, G V; Owuor, M A; Garrido-Pérez, C; Salamanca, M J; Del Valls, T A; Martín-Díaz, M L

    2015-02-01

    Nowadays, the presence of pharmaceutical products in aquatic environments is not only common, but is also of significant concern regarding the adverse effect they may produce to aquatic biota. In order to determine the adverse effects of caffeine (CAF), ibuprofen (IBU), carbamazepine (CBZ) and novobiocin (NOV), at environmental occurring concentrations, standardized endpoints applied in current guidelines were evaluated in four organisms including bioluminescence response in Vibrio fischeri, growth inhibition in Isochrysis galbana (marine water) and Pseudokirchneriella subcapitata (fresh water) and fertilization and embryo-larval development in Paracentrotus lividus. To reach this aim bioassays were implemented by exposing organisms to water spiked with drugs dissolved in DMSO (0.001% v/v). Risk characterization was performed, calculating the environmental impact of drugs by calculating environmental concentration and predicted no effect concentration ratio (MEC/PNEC). Results indicate that acute toxicity was found above environmental concentrations in the order of mg L(-1) for bacteria bioluminescence, microalgae growth inhibition and sea urchin fertilization. However, teratogenicity was observed on sea urchin after exposure to environmental concentrations of drugs at 0.00001 mg L(-1); at this concentration CBZ and IBU were found to reduce significantly the embryo-larval development compared to controls (p<0.01). The risk calculated for selected drugs suggested they are harmless for aquatic environment except when applying the embryo-larval development endpoint. Endpoints applied in this study showed the necessity of using more sensitive responses, when assessing risk of pharmaceuticals in aquatic environments, since endpoints applied in current guidelines may not be suitable. PMID:25000509

  8. How Much Is Enough? Minimal Responses of Water Quality and Stream Biota to Partial Retrofit Stormwater Management in a Suburban Neighborhood

    PubMed Central

    Roy, Allison H.; Rhea, Lee K.; Mayer, Audrey L.; Shuster, William D.; Beaulieu, Jake J.; Hopton, Matthew E.; Morrison, Matthew A.; St. Amand, Ann

    2014-01-01

    Decentralized stormwater management approaches (e.g., biofiltration swales, pervious pavement, green roofs, rain gardens) that capture, detain, infiltrate, and filter runoff are now commonly used to minimize the impacts of stormwater runoff from impervious surfaces on aquatic ecosystems. However, there is little research on the effectiveness of retrofit, parcel-scale stormwater management practices for improving downstream aquatic ecosystem health. A reverse auction was used to encourage homeowners to mitigate stormwater on their property within the suburban, 1.8 km2 Shepherd Creek catchment in Cincinnati, Ohio (USA). In 2007–2008, 165 rain barrels and 81 rain gardens were installed on 30% of the properties in four experimental (treatment) subcatchments, and two additional subcatchments were maintained as controls. At the base of the subcatchments, we sampled monthly baseflow water quality, and seasonal (5×/year) physical habitat, periphyton assemblages, and macroinvertebrate assemblages in the streams for the three years before and after treatment implementation. Given the minor reductions in directly connected impervious area from the rain barrel installations (11.6% to 10.4% in the most impaired subcatchment) and high total impervious levels (13.1% to 19.9% in experimental subcatchments), we expected minor or no responses of water quality and biota to stormwater management. There were trends of increased conductivity, iron, and sulfate for control sites, but no such contemporaneous trends for experimental sites. The minor effects of treatment on streamflow volume and water quality did not translate into changes in biotic health, and the few periphyton and macroinvertebrate responses could be explained by factors not associated with the treatment (e.g., vegetation clearing, drought conditions). Improvement of overall stream health is unlikely without additional treatment of major impervious surfaces (including roads, apartment buildings, and parking lots). Further research is needed to define the minimum effect threshold and restoration trajectories for retrofitting catchments to improve the health of stream ecosystems. PMID:24465468

  9. Mercury at the Oat Hill Extension Mine and James Creek, Napa County, California: Tailings, Sediment, Water, and Biota, 2003-2004

    USGS Publications Warehouse

    Slowey, Aaron J.; Rytuba, James J.; Hothem, Roger L.; May, Jason T.

    2007-01-01

    Executive Summary The Oat Hill Extension (OHE) Mine is one of several mercury mines located in the James Creek/Pope Creek watershed that produced mercury from the 1870's until 1944 (U.S. Bureau of Mines, 1965). The OHE Mine developed veins and mineralized fault zones hosted in sandstone that extended eastward from the Oat Hill Mine. Waste material from the Oat Hill Mine was reprocessed at the OHE Mine using gravity separation methods to obtain cinnabar concentrates that were processed in a retort. The U.S. Bureau of Land Management requested that the U.S. Geological Survey measure and characterize mercury and other chemical constituents that are potentially relevant to ecological impairment of biota in tailings, sediment, and water at the OHE Mine and in the tributaries of James Creek that drain the mine area (termed Drainage A and B) (Figs. 1 and 2). This report summarizes such data obtained from sampling of tailings and sediments at the OHE on October 17, 2003; water, sediment, and biota from James Creek on May 20, 2004; and biota on October 29, 2004. These data are interpreted to provide a preliminary assessment of the potential ecological impact of the mine on the James Creek watershed. The mine tailings are unusual in that they have not been roasted and contain relatively high concentrations of mercury (400 to 1200 ppm) compared to unroasted waste rock at other mines. These tailings have contaminated a tributary to James Creek with mercury primarily by erosion, on the basis of higher concentration of mercury (780 ng/L) measured in unfiltered (total mercury, HgT) spring water flowing from the OHE to James Creek compared to 5 to 14 ng/L HgT measured in James Creek itself. Tailing piles (presumably from past Oat Hill mine dumping) near the USBLM property boundary and upstream of the main OHE mine drainage channel (Drainage A; Fig. 2) also likely emit mercury, on the basis of their mercury composition (930 to 1200 ppm). The OHE spring water is likely an appreciable source of sulfate and carbonate to James Creek, because the spring water was enriched in sulfate (130 mg/L) and carbonate (430 mg/L as CaCO3) compared to James Creek water (70 to 100 mg/L SO42- and 110 to 170 mg/L as CaCO3) at the time of sampling. Concentrations of mercury in active channel sediment from James Creek are variable and potentially high, on the basis of chemical analysis (2.5 to 17 _g/g-wet sediment) and easily visible cinnabar grains in panned concentrates. Average (geometric mean) organic mercury (presumably monomethyl mercury (MMHg); ?2.3.3) concentrations in several invertebrate taxa collected from the James Creek watershed locations were higher than invertebrates taken from a Northern California location lacking a known point source of mercury. The mean proportion of MMHg to total mercury in James Creek predatory insect samples was 40 percent (1 standard deviation = 30 percent); only 40 percent of all insect samples had a MMHg/HgT proportion greater than 0.5. The low proportions of MMHg measured in invertebrates in James Creek and the presence of cinnabar in the creek suggest that some invertebrates may have anomolously high Hg concentrations as a result of the injestion or adhesion of extremely fine-grained cinnabar particles. Interpretation of HgT in frogs and fish as an indicator of mercury reactivity, biouptake, or trophic transfer is limited, pending MMHg measuremens, by the possibility of these whole-body samples having contained cinnabar particles at the time of analysis. To minimize this limitation, the gastrointestinal tracts and external surfaces of all amphibians, where cinnabar most likely resides, were carefully flushed to remove any visible particles. However, extremely fine-grained, invisible, adhesive cinnabar particles likely exist in the amphibians' habitats. HgT in foothill yellow-legged frogs collected from the James Creek study area, ranging from 0.1 to 0.6 ug/g Hg, was on average twice that of an extensive

  10. Deposit and mobility of cadmium in a marsh-cove ecosystem and the relation to cadmium concentration in biota.

    PubMed Central

    Kneip, T J; Hazen, R E

    1979-01-01

    The study reported here presents the results of an investigation of a marsh-cove ecosystem heavily contaminated by cadmium. The most contaminated aquatic sediments were dredged in 1972-73, but the resuspension of the sediments and recycle of water from the dredge spoil resulted in reestablishment of a large contaminated sediment bed with concentrations very similar to those observed before dredging. The stability of the sediment concentrations and shallow depth of the cadmium in the sediments indicate that the deposit is relatively stable in agreement with the expectations based on the water chemistry of the system. Uptake does occur in both marsh and aquatic plants and all species of animals tested. Significantly elevated concentrations are observed compared to noncontaminated areas; however, edible portions of most fish do not appear to present a hazard. Crabs appear to present the most likely source of a hazard to humans. This potential hazard is still under investigation. The dredging removed about 5.5 MT of cadmium, about one-fourth of that originally estimated to be present, but twice that amount is found to be in the cove sediments 3 to 4 years after dredging. No appreciable improvement in the ecosystem has been made, and more careful consideration should be given to the need for decontamination and the method of removal of contaminated aquatic sediments in any future case. PMID:488050

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

    PubMed

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

    2005-03-29

    The increasing anthropogenic pressure on natural environments results in impacts that affect tropical forest areas and their biodiversity. Adverse impacts on terrestrial and oceanic environments often compound in the intertidal area, where mangrove forest ecosystems thrive. In tropical coastal areas of many developing countries where people depend on wood and other mangrove forest products and services, forest degradation leads to socioeconomic problems. At the same time, increasing freshwater needs in these areas are expected to cause additional problems. On the basis of remote sensing and ground truthing complemented by colonial archival material from the Dutch East India Company (1602-1800), we report that changes to the historic system of inland freshwater management have increased dramatically in recent times. Hydrological changes, such as interbasin transfers, have resulted in a qualitative ecological and socioeconomic degradation in three coastal lagoons in southern Sri Lanka. Variations in river hydrology have caused changes in the areas suitable as mangrove habitat and, thus, have resulted in an altered distribution. However, increases in mangrove area can mask the degradation of the site in terms of floristic composition, significance of the species, and biodiversity (this effect is termed "cryptic ecological degradation"). It is important that such changes be carefully monitored to ensure biological and socioeconomic sustainability. PMID:15797030

  12. Simulation of CO? leakages during injection and storage in sub-seabed geological formations: metal mobilization and biota effects.

    PubMed

    Rodríguez-Romero, Araceli; Basallote, M Dolores; De Orte, Manoela R; DelValls, T Ángel; Riba, Inmaculada; Blasco, Julián

    2014-07-01

    To assess the potential effects on metal mobilization due to leakages of CO2 during its injection and storage in marine systems, an experimental set-up was devised and operated, using the polychaete Hediste diversicolor as the model organism. The objective was to study the effects of such leakage in the expected scenarios of pH values between 8.0 and 6.0. Polychaetes were exposed for 10 days to seawater with sediment samples collected in two different coastal areas, one with relatively uncontaminated sediment as reference (RSP) and the other with known contaminated sediment (ML), under pre-determined pH conditions. Survival and metal accumulation (Al, Fe, Mn, Cu, Zn, As and Hg) in the whole body of H. diversicolor were employed as endpoints. Mortality was significant at the lowest pH level in the sediment with highest metal concentrations. In general, metal concentrations in tissues of individuals exposed to the contaminated sediment were influenced by pH. These results indicate that ocean acidification due to CO2 leakages would provoke increased metal mobilization, causing adverse side effects in sediment toxicity. PMID:24721118

  13. The role of the uplift of the Qinghai-Tibetan Plateau for the evolution of Tibetan biotas.

    PubMed

    Favre, Adrien; Päckert, Martin; Pauls, Steffen U; Jähnig, Sonja C; Uhl, Dieter; Michalak, Ingo; Muellner-Riehl, Alexandra N

    2015-02-01

    Biodiversity is unevenly distributed on Earth and hotspots of biodiversity are often associated with areas that have undergone orogenic activity during recent geological history (i.e. tens of millions of years). Understanding the underlying processes that have driven the accumulation of species in some areas and not in others may help guide prioritization in conservation and may facilitate forecasts on ecosystem services under future climate conditions. Consequently, the study of the origin and evolution of biodiversity in mountain systems has motivated growing scientific interest. Despite an increasing number of studies, the origin and evolution of diversity hotspots associated with the Qinghai-Tibetan Plateau (QTP) remains poorly understood. We review literature related to the diversification of organisms linked to the uplift of the QTP. To promote hypothesis-based research, we provide a geological and palaeoclimatic scenario for the region of the QTP and argue that further studies would benefit from providing a complete set of complementary analyses (molecular dating, biogeographic, and diversification rates analyses) to test for a link between organismic diversification and past geological and climatic changes in this region. In general, we found that the contribution of biological interchange between the QTP and other hotspots of biodiversity has not been sufficiently studied to date. Finally, we suggest that the biological consequences of the uplift of the QTP would be best understood using a meta-analysis approach, encompassing studies on a variety of organisms (plants and animals) from diverse habitats (forests, meadows, rivers), and thermal belts (montane, subalpine, alpine, nival). Since the species diversity in the QTP region is better documented for some organismic groups than for others, we suggest that baseline taxonomic work should be promoted. PMID:24784793

  14. Areas Susceptible to Irrigation-Induced Selenium Contamination of Water and Biota in the Western United States

    USGS Publications Warehouse

    Seiler, Ralph L.; Skorupa, Joseph P.; Peltz, Lorri A.

    1999-01-01

    The U.S. Department of the Interior (DOI) studied contamination induced by irrigation drainage in 26 areas of the Western United States during 1986-95. Comprehensive compilation, synthesis, and evaluation of the data resulting from these studies were initiated by DOI in 1992. Soils and ground water in irrigated areas of the West can contain high concentrations of selenium because of (1) residual selenium from the soil's parent rock beneath irrigated land; (2) selenium derived from rocks in mountains upland from irrigated land by erosion and transport along local drainages, and (3) selenium brought into the area in surface water imported for irrigation. Application of irrigation water to seleniferous soils can dissolve and mobilize selenium and create hydraulic gradients that cause the discharge of seleniferous ground water into irrigation drains. Given a source of selenium, the magnitude of selenium contamination in drainage-affected aquatic ecosystems is strongly related to the aridity of the area and the presence of terminal lakes and ponds. Marine sedimentary rocks and deposits of Late Cretaceous or Tertiary age are generally seleniferous in the Western United States. Depending on their origin and history, some Tertiary continental sedimentary deposits also are seleniferous. Irrigation of areas associated with these rocks and deposits can result in concentrations of selenium in water that exceed criteria for the protection of freshwater aquatic life. Geologic and climatic data for the Western United States were evaluated and incorporated into a geographic information system (GIS) to produce a map identifying areas susceptible to irrigation-induced selenium contamination. Land is considered susceptible where a geologic source of selenium is in or near the area and where the evaporation rate is more than 2.5 times the precipitation rate. In the Western United States, about 160,000 square miles of land, which includes about 4,100 square miles (2.6 million acres) of land irrigated for agriculture, has been identified as being susceptible. Biological data were used to evaluate the reliability of the map. In 12 of DOl's 26 study areas, concentrations of selenium measured in bird eggs were elevated sufficiently to significantly reduce hatchability of the eggs. The GIS map identifies 9 of those 12 areas. Deformed bird embryos having classic symptoms of selenium toxicosis were found in four of the study areas, and the map identifies all four as susceptible to irrigation-induced selenium contamination.

  15. Non-effect of water hardness on the accumulation and toxicity of copper in a freshwater macrophyte (Ceratophyllum demersum): how useful are hardness-modified copper guidelines for protecting freshwater biota?

    PubMed

    Markich, Scott J; King, Angus R; Wilson, Scott P

    2006-12-01

    Several nations have adopted hardness-modified copper (Cu) guidelines for protecting freshwater biota. However, there is a lack of good quality data and mechanistic understanding on the effects of true water hardness (calcium (Ca) and magnesium (Mg)) on the bioavailability and toxicity of Cu to freshwater biota, particularly macrophytes. This study determined the effect of true water hardness (35, 90 and 335 mg CaCO(3)/l, added as Ca and Mg chloride in a 1:1 mole ratio) on the cell surface binding affinity (log K), accumulation and toxicity (96 h growth (biomass and stem length) and photosynthetic pigment inhibition) of Cu in the free-floating submerged macrophyte, Ceratophyllum demersum, in a synthetic freshwater with constant alkalinity (16 mg CaCO(3)/l) and pH (7.0). There were no significant (P>0.05) differences in the cell surface binding affinity, accumulation or toxicity of Cu in C. demersum with a 10-fold increase in water hardness from 35 to 335 mg CaCO(3)/l. The mean 96 h EC(50) values (and 95% confidence intervals) for biomass, the most sensitive endpoint, were 8.4 (7.6-9.2), 8.9 (8.0-9.8) and 9.9 (9.1-10.7) microg/l Cu for 35, 90 and 335 mg CaCO(3)/l, respectively. Speciation calculations indicated only very small (1-6%) differences in the percentage distribution (i.e. bioavailability) of Cu over the hardness range. These collective results indicate no apparent competition between Cu and Ca/Mg for binding sites on the cell surface. Given that the mechanism of Cu uptake (via Cu-specific and Na-linked transporters) is fundamentally different to that of Cd, Ni, Pb and Zn (via Ca transporters), for which other hardness-dependent algorithms have been developed, it is doubtful whether a hardness-modified Cu guideline value will be sufficiently protective of sensitive freshwater biota, such as C. demersum, particularly in medium-hard fresh surface waters with low levels of dissolved organic carbon. The biotic ligand model offers a more flexible and mechanistic approach for deriving site-specific Cu (metal) guidelines for protecting freshwater biota. PMID:16735056

  16. 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

    USGS Publications Warehouse

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

    1999-01-01

    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.

  17. Surface-water-quality assessment of the Yakima River basin in Washington; spatial and temporal distribution of trace elements in water, sediment, and aquatic biota, 1987-91; with a section on geology

    USGS Publications Warehouse

    Fuhrer, Gregory J.; Cain, Daniel J.; McKenzie, Stuart W.; Rinella, Joseph F.; Crawford, J. Kent; Skach, Kenneth A.; Hornberger, Michelle I.; Gannett, Marshall W.

    1999-01-01

    The report describes the distribution of trace elements in sediment, water, and aquatic biota in the Yakima River basin, Washington. Trace elements were determined from streambed sediment, suspended sediment, filtered and unfiltered water samples, aquatic insects, clams, fish livers, and fish fillets between 1987 and 1991. The distribution of trace elements in these media was related to local geology and anthropogenic sources. Additionally, annual and instantaneous loads were estimated for trace elements associated with suspended sediment and trace elements in filtered water samples. Trace elements also were screened against U.S. Environmental Protection Agency guidelines established for the protection of human health and aquatic life.

  18. Detailed study of irrigation drainage in and near wildlife management areas, west-central Nevada, 1987-90; Part B, Effect on biota in Stillwater and Fernley Wildlife Management Areas and other nearby wetlands

    USGS Publications Warehouse

    Hallock, Robert J., (Edited By); Hallock, Linda L.

    1993-01-01

    A water-quality reconnaissance study during 1986-87 found high concentrations of several potentially toxic elements in water, bottom sediment, and biota in and near Stillwater Wildlife Management Area (WMA). This study prompted the U.S. Department of the Interior to initiate a more detailed study to determine the hydrogeochemical processes that control water quality in the Stillwater WMA, and other nearby wetlands, and the resulting effects on biota, especially migratory birds. Present wetland size is about 10% of historical size; the dissolved- solids load in the water in these now-isolated wetlands has increased only moderately, but the dissolved-solids concentration has increased more than seven-fold. Wetland vegetation has diminished and species composition in flow water has shifted to predominant salt-tolerant species in many areas. Decreased vegetative cover for nesting is implicated in declining waterfowl production. Decreases in numbers or virtual absence of several wildlife species are attributed to degraded water quality. Results of toxicity tests indicate that water in some drains and wetland areas is acutely toxic to some fish and invertebrates. Toxicity is attributed to the combined presence of arsenic, boron, lithium, and molybdenum. Biological pathways are involved in the transport of mercury and selenium from agricultural drains to wetlands. Hatch success of both artificially incubated and field-reared duck eggs was greater than/= 90 percent; no teratogenesis was observed. Mercury in muscle tissue of waterfowl harvested from Carson Lake in October 1987 exceeded the human health criterion six-fold.

  19. Activity measurements of a suite of radionuclides (241Am, 239,240Pu, 238Pu, 238U, 234U, 235U, 232Th, 230Th, 228Th, 228Ra, 137Cs, 210Pb, 90Sr and 40K) in biota reference material (Ocean Shellfish): CCRI(II)-S3

    NASA Astrophysics Data System (ADS)

    Nour, S.; Karam, L. R.; Inn, K. G. W.

    2012-01-01

    In 2005, the CCRI decided that a comparison undertaken from 2002 to 2008 by the NIST (under the auspices of the Inter-America Metrology System [SIM]) in the development of a new biota (Ocean Shellfish) standard reference material (SRM) was sufficiently well constructed that it could be converted into a supplementary comparison under CCRI(II), with comparison identifier CCRI(II)-S3. This would enable the comparison to be used to support calibration and measurement capability (CMC) claims for radionuclide measurements in reference materials (specifically, animal-based organic materials). Previous comparisons of radionuclides have been of single or multiple nuclides in non-complex matrices and results of such could not be extended to support capabilities to measure the same nuclides in reference materials. The results of this comparison have been used to determine the certified reference value of the SRM. The key comparison working group (KCWG) of the CCRI(II) has approved this approach as a mechanism to link all the results to certified 'reference values' in lieu of the key comparison reference value (KCRV) of these specified radionuclides in this type of matrix (shellfish) so as to support CMCs of similar materials submitted by the present participants. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  20. Soil food web properties explain ecosystem services across European land use systems.

    PubMed

    de Vries, Franciska T; Thébault, Elisa; Liiri, Mira; Birkhofer, Klaus; Tsiafouli, Maria A; Bjørnlund, Lisa; Bracht Jørgensen, Helene; Brady, Mark Vincent; Christensen, Søren; de Ruiter, Peter C; d'Hertefeldt, Tina; Frouz, Jan; Hedlund, Katarina; Hemerik, Lia; Hol, W H Gera; Hotes, Stefan; Mortimer, Simon R; Setälä, Heikki; Sgardelis, Stefanos P; Uteseny, Karoline; van der Putten, Wim H; Wolters, Volkmar; Bardgett, Richard D

    2013-08-27

    Intensive land use reduces the diversity and abundance of many soil biota, with consequences for the processes that they govern and the ecosystem services that these processes underpin. Relationships between soil biota and ecosystem processes have mostly been found in laboratory experiments and rarely are found in the field. Here, we quantified, across four countries of contrasting climatic and soil conditions in Europe, how differences in soil food web composition resulting from land use systems (intensive wheat rotation, extensive rotation, and permanent grassland) influence the functioning of soils and the ecosystem services that they deliver. Intensive wheat rotation consistently reduced the biomass of all components of the soil food web across all countries. Soil food web properties strongly and consistently predicted processes of C and N cycling across land use systems and geographic locations, and they were a better predictor of these processes than land use. Processes of carbon loss increased with soil food web properties that correlated with soil C content, such as earthworm biomass and fungal/bacterial energy channel ratio, and were greatest in permanent grassland. In contrast, processes of N cycling were explained by soil food web properties independent of land use, such as arbuscular mycorrhizal fungi and bacterial channel biomass. Our quantification of the contribution of soil organisms to processes of C and N cycling across land use systems and geographic locations shows that soil biota need to be included in C and N cycling models and highlights the need to map and conserve soil biodiversity across the world. PMID:23940339

  1. The contribution of flocculated material to shrimp ( Litopenaeus vannamei) nutrition in a high-intensity, zero-exchange system

    Microsoft Academic Search

    Michele A Burford; Peter J Thompson; Robins P McIntosh; Robert H Bauman; Doug C Pearson

    2004-01-01

    High-intensity, zero-exchange shrimp ponds contain a high density of flocculated particles, rich in bacteria and phytoplankton, compared with flow-through systems. The flocculated particles provide a potential food source for shrimp. Short-term tank experiments were conducted to determine the retention of nitrogen (N) from natural biota, dominated by flocculated particles, in white shrimp (Litopenaeus vannamei) at a high-intensity, zero-exchange shrimp farm

  2. Patch and reach-scale dynamics of a macrophyte-invertebrate system in a New Zealand lowland stream

    Microsoft Academic Search

    Kevin J. Collier; Paul D. Champion; Glenys F. Croker

    1999-01-01

    Abundant growths of macrophytes are a common feature of streams in open lowland areas of New Zealand during summer, but the\\u000a values of these to aquatic biota are poorly understood. We studied the temporal dynamics of, and associations amongst, elements\\u000a of a macrophyte-invertebrate system to provide an improved information base for lowland stream management. The biomass of\\u000a macrophytes increased significantly

  3. Detailed study of irrigation drainage in and near wildlife management areas, west-central Nevada, 1987-90; Part C, Summary of irrigation-drainage effects on water quality, bottom sediment, and biota

    USGS Publications Warehouse

    Hoffman, Ray J.

    1993-01-01

    This report presents a summary of the detailed scientific study of Stillwater Wildlife Management Area and other nearby wetlands in west-central Nevada during 1987-90. The work was funded by the National Irrigation Water Quality Program of the U.S. Department of the Interior with the overall objectives of determining (1) the extent, magnitude, and effects of selected water-quality constituents associated with irrigation drainage on fish, wildlife, and human health, and (2) the sources and exposure pathways that cause contamination where adverse effects are documented. Much of the information in this report was summarized from two previously published interpretive reports that were completed to fulfill study objectives. Where applicable, data for the study area from other published sources also were utilized. The results of these studies indicate that the aquatic biota in natural wetlands of the Carson Desert are adversely affected by hydrological and geochemical sources and processes in the Newlands Irrigation Project area. Reactions between water and naturally occurring minerals in the shallow alluvial aquifer increase concentrations of potentially toxic constituents in ground water that eventually enters the wetlands. Once in the wetlands, these constituents are furhter concentrated by evaporation and transpiration. Water from some agricultural drains that enter Stillwater WMA was acutely toxic to aquatic organisms. The drains in the agricultural areas, which eventually discharge to the wetlands, were also implicated as sites of uptake of selenium and mercury by aquatic organisms.

  4. Reconnaissance investigation of water quality, bottom sediment, and biota associated with irrigation drainage in the Sacramento National Wildlife Refuge Complex, California, 1988-89. Water resources investigation

    SciTech Connect

    Dileanis, P.D.; Sorenson, S.K.; Schwarzbach, S.E.; Maurer, T.C.

    1992-01-01

    The report describes results of a reconnaissance field investigation of the quality of irrigation drainwater and the effects of its use on five federally managed wildlife refuges in the Sacramento Valley, California. The investigation was designed to determine the magnitude and extent of any water-quality problems that could threaten wildlife and human health. Samples of water, sediment, and biological tissue were collected on or near the refuges and analyzed for selected chemical constituents. The results of the chemical analyses were compared to various standards and criteria, baseline data, and toxicological studies. These comparisons are discussed in the context of the geological, hydrological, and biological systems in the study area.

  5. Evaluation of spatial correlation between nutrient exchange rates and benthic biota in a reef-flat ecosystem by GIS-assisted flow-tracking

    Microsoft Academic Search

    Toshihiro Miyajima; Yoshiyuki Tanaka; Isao Koike; Hiroya Yamano; Hajime Kayanne

    2007-01-01

    A Geographic Information System (GIS)-aided flow-tracking technique was adopted to investigate nutrient exchange rates between\\u000a specific benthic communities and overlying seawater in a fringing reef of Ishigaki Island, subtropical Northwestern Pacific.\\u000a Net exchange rates of NO3\\u000a ?, NO2\\u000a ?, NH4\\u000a +, PO4\\u000a 3?, Total-N and Total-P were estimated from concentration changes along the drogue trajectories, each of which was tracked

  6. Biological indicators for monitoring water quality of MTF canals system

    NASA Technical Reports Server (NTRS)

    Sethi, S. L.

    1975-01-01

    Biological models, diversity indexes, were developed to predict environmental effects of NASA's Mississippi test facility (MTF) chemical operations on canal systems in the area. To predict the effects on local streams, a physical model of unpolluted streams was established. The model is fed by artesian well water free of background levels of pollutants. The species diversity and biota composition of unpolluted MTF stream was determined; resulting information will be used to form baseline data for future comparisons. Biological modeling was accomplished by adding controlled quantities or kinds of chemical pollutants and evaluating the effects of these chemicals on the biological life of the stream.

  7. Reconnaissance investigation of water quality, bottom sediment, and biota associated with irrigation drainage in Bowdoin National Wildlife Refuge and adjacent areas of the Milk River basin, northeastern Montana, 1986-87

    USGS Publications Warehouse

    Lambing, J.H.; Jones, W.E.; Sutphin, J.W.

    1988-01-01

    Concentrations of trace elements, radiochemicals, and pesticides in the Bowdoin National Wildlife Refuge lakes generally were not substantially larger than those in the water supplied from Dodson South Canal or in irrigation drainage. Concentrations of arsenic (47 micrograms/L), uranium (43 microg/L), and vanadium (51 microg/L) in Dry Lake Unit, and boron (1,000 microg/L) in Lake Bowdoin were notably larger than at other sites. Zinc concentrations in an irrigation drain (56 microg/L) and two shallow domestic wells (40 and 47 microg/L) were elevated relative to other sites. Concentrations of gross alpha radiation (64 picocuries/L) and gross beta radiation (71 picocuries/L) were elevated in Dry Lake Unit. Pesticides concentrations at all sites were 0.08 microg/L or less. Water use guidelines concentrations for boron, cadmium, uranium, zinc, and gross alpha radiation were slightly exceeded at several sites. In general, trace-constituent concentrations measured in the water do not indicate any potential toxicity problems in Bowdoin National Wildlife Refuge; however, highwater conditions in 1986 probably caused dilution of dissolved constituents compared to recent dry years. Trace element concentrations in bottom sediments of the refuge lakes were generally similar to background concentrations in the soils. The only exception was Dry Lake Unit, which had concentrations of chromium (99 micrograms/g), copper (37 microg/g), nickel (37 microg/g), vanadium (160 microg/g), and zinc (120 microg/g) that were about double the mean background concentrations. The maximum selenium concentration in bottom sediment was 0.6 microg/g. Pesticide concentrations in bottom sediments were less than analytical detection limits at all sites. With few exceptions, concentrations of trace elements and pesticides in biota generally were less than values known to produce harmful effects on growth or reproduction. (Lantz-PTT)

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

    PubMed

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

    2015-02-01

    Analyses of how organisms are likely to respond to a changing climate have focused largely on the direct effects of warming temperatures, though changes in other variables may also be important, particularly the amount and timing of precipitation. Here, we develop a network of eight growth-increment width chronologies for freshwater mussel species in the Pacific Northwest, United States and integrate them with tree-ring data to evaluate how terrestrial and aquatic indicators respond to hydroclimatic variability, including river discharge and precipitation. Annual discharge averaged across water years (October 1-September 30) was highly synchronous among river systems and imparted a coherent pattern among mussel chronologies. The leading principal component of the five longest mussel chronologies (1982-2003; PC1(mussel)) accounted for 47% of the dataset variability and negatively correlated with the leading principal component of river discharge (PC1(discharge); r = -0.88; P < 0.0001). PC1(mussel) and PC1(discharge) were closely linked to regional wintertime precipitation patterns across the Pacific Northwest, the season in which the vast majority of annual precipitation arrives. Mussel growth was also indirectly related to tree radial growth, though the nature of the relationships varied across the landscape. Negative correlations occurred in forests where tree growth tends to be limited by drought while positive correlations occurred in forests where tree growth tends to be limited by deep or lingering snowpack. Overall, this diverse assemblage of chronologies illustrates the importance of winter precipitation to terrestrial and freshwater ecosystems and suggests that a complexity of climate responses must be considered when estimating the biological impacts of climate variability and change. PMID:25258169

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

    USGS Publications Warehouse

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

    2015-01-01

    Analyses of how organisms are likely to respond to a changing climate have focused largely on the direct effects of warming temperatures, though changes in other variables may also be important, particularly the amount and timing of precipitation. Here, we develop a network of eight growth-increment width chronologies for freshwater mussel species in the Pacific Northwest, United States and integrate them with tree-ring data to evaluate how terrestrial and aquatic indicators respond to hydroclimatic variability, including river discharge and precipitation. Annual discharge averaged across water years (October 1–September 30) was highly synchronous among river systems and imparted a coherent pattern among mussel chronologies. The leading principal component of the five longest mussel chronologies (1982–2003; PC1mussel) accounted for 47% of the dataset variability and negatively correlated with the leading principal component of river discharge (PC1discharge; r = ?0.88; P < 0.0001). PC1mussel and PC1discharge were closely linked to regional wintertime precipitation patterns across the Pacific Northwest, the season in which the vast majority of annual precipitation arrives. Mussel growth was also indirectly related to tree radial growth, though the nature of the relationships varied across the landscape. Negative correlations occurred in forests where tree growth tends to be limited by drought while positive correlations occurred in forests where tree growth tends to be limited by deep or lingering snowpack. Overall, this diverse assemblage of chronologies illustrates the importance of winter precipitation to terrestrial and freshwater ecosystems and suggests that a complexity of climate responses must be considered when estimating the biological impacts of climate variability and change.

  10. Detailed study of water quality, bottom sediment, and biota associated with irrigation drainage in the Klamath Basin, California and Oregon, 1990-92

    USGS Publications Warehouse

    Dileanis, P.D.; Schwarzbach, S.E.; Bennett, Jewel

    1996-01-01

    The effect of irrigation drainage on the water quality and wildlife of the Klamath Basin in California and Oregon was evaluated during 1990-92 as part of the National Irrigation Water Quality Program of the U.S. Department of the Interior. The study focused on land serviced by the Bureau of Reclamation Klamath Project, which supplies irrigation water to agricultural land in the Klamath Basin and the Lost River Basin. The Tule Lake and Lower Klamath National Wildlife Refuges, managed by the U.S. Fish and Wildlife Service, are in the study area. These refuges provide critical resting and breeding habitat for waterfowl on the Pacific flyway and are dependent on irrigation drainwater from upstream agriculture for most of their water supply. Water-quality characteristics throughout the study area were typical of highly eutrophic systems during the summer months of 1991 and 1992. Dissolved-oxygen concentrations and pH tended to fluctuate each day in response to diurnal patterns of photosynthesis, and frequently exceeded criteria for protection of aquatic organisms. Nitrogen and phosphorus concentrations were generally at or above threshold levels characteristic of eutrophic lakes and streams. At most sites the bulk of dissolved nitrogen was organically bound. Elevated ammonia concentrations were common in the study area, especially down- stream of drain inputs. High pH of water increased the toxicity of ammonia, and concentrations exceeded criteria at sites upstream and downstream of irrigated land. Concentrations of ammonia in samples from small drains on the Tule Lake refuge leaseland were higher than those measured in the larger, integrating drains at primary monitoring sites. The mean ammonia concentration in leaseland drains [1.21 milligrams per liter (mg/L)] was significantly higher than the mean concentration in canals delivering water to the leaseland fields (0.065 mg/L) and higher than concentrations reported to be lethal to Daphnia magna (median lethal concentration of 0.66 mg/L). Dissolved- oxygen concentrations also were lower, and Daphnia survivability measured during in situ bioassays was correspondingly lower in the leaseland drains than in water delivery canals. In static laboratory bioassays, water samples collected at the primary monitoring sites caused toxicity in up to 78 percent of Lemna minor tests, in up to 49 percent of Xenopus laevis tests, in 17 percent and 8 percent of Hyalella azteca and Pimephales promelas tests, respectively, and 0 percent in Daphnia magna tests. In situ exposure at the sites caused mortality in more than 83 percent of Pimephales tests and in more than 41 percent of Daphnia and Hyalella tests. Much of the observed toxicity appears to have been caused by low dissolved oxygen, high pH, and ammonia. Although water in the study area was toxic to a variety of organisms, no statistically significant differences in the degree of toxicity between sites were observed above or below irrigated agricultural land in any of the bioassays. Pesticides were frequently detected in water samples collected at the monitoring sites during the 1991 and 1992 irrigation seasons. Among the most frequently detected compounds were the herbicides simazine, metribuzin, EPTC, and metolachlor and the insecticide terbufos. All the insecticides detected were at concentrations substantially below acute toxicity values reported for aquatic organisms. The herbicide acrolein has been used extensively in the basin to manage aquatic plant growth in irrigation canals and drains. The concentration of acrolein was monitored in a canal near Tule Lake after an application in order to evaluate the potential for the pesticide to be transported to refuge waters. Although acrolein concentrations were toxic to fish in the channels adjacent to Tule Lake, very little of the canal water entered the refuge during the monitoring period. Organochlorine pesticide concentrations in 25 surficial sediment samples collected in 1990 were below bas

  11. Development of an innovative and "green" stir bar sorptive extraction-thermal desorption-gas chromatography-tandem mass spectrometry method for quantification of polycyclic aromatic hydrocarbons in marine biota.

    PubMed

    Lacroix, C; Le Cuff, N; Receveur, J; Moraga, D; Auffret, M; Guyomarch, J

    2014-07-01

    There is a growing awareness of the need to reduce the negative impact of chemical analyses on the environment and to develop new eco-friendly and sustainable analytical methods without compromising performance. In this study, we developed a "green" analytical method enabling the accurate and simultaneous routine analysis of 21 polycyclic aromatic hydrocarbons (PAHs) in reduced quantities (100mg and 1g wet weight (WW)) of marine biota samples (fish muscle, mussel and oyster tissues) using alkaline digestion combined with stir bar sorptive extraction-thermal desorption-gas chromatography-tandem mass spectrometry (SBSE-GC-MS/MS). The innovative method provides good selectivity and specificity for most compounds. In 1gWW samples, limits of quantification (LOQs) ranged from 1 to 10?g/kgWW in fish muscle and from 0.5 to 10?g/kgWW in mussel tissue. The method enables most analytes to be quantified below the restrictive limits established by the European Commission (2 and 10?g/kgWW in fish muscle and bivalve mollusc, respectively). Higher LOQs were obtained in 100mgWW samples ranging from 1 to 50?g/kgWW. Recovery and linearity were assessed for all analytes. The results were satisfactory for most compounds with recoveries ranging from 94% to 117% in 1gWW mussel samples at spike concentration of 10ng/gWW with standard deviation not exceeding 12%. However, results confirmed that the SBSE efficiency is affected by the complexity of biological matrices, especially for high molecular weight compounds in lipid-rich mussel tissue. Because of the matrix effects, matrix-matched calibrations were carried out. Validation was performed using the standard reference material 1974c with recovery ranging from 71% to 119% except for naphthalene, anthracene and benzo(e)pyrene that were therefore not validated. Overall, the developed method meets analytical validation criteria for most compounds. Thanks to the combination of alkaline digestion and SBSE, which greatly simplifies sample treatment and limits solvent use to ethanol, the developed method followed most green analytical chemistry principles. PMID:24857036

  12. NMITA: Neogene Marine Biota of Tropical America

    NSDL National Science Digital Library

    Hosted by the Department of Geoscience, University of Iowa, and funded by the National Science Foundation, NMITA is an online biotic database "containing images and data for taxa used in analyses of Tropical American biodiversity over the past 25 million years." The Website offers Taxonomic Lists (with links to images and data for individual taxa), Morphologic Characters (currently for Zooxanthellate Corals and Elasmobranchs and Teleosteans), Identification Keys (currently for Zooxanthellate Corals), Occurrences in the Dominican Republic, and Instructional Aids. Images and data are provided for the following individual taxa: Bivalves, Gastropods, Bryozoans, Azooxanthellate Corals, Zooxanthellate Corals, Benthic Forams, Ostracodes, and Elasmobranchs and Teleosteans. Although Panama data will eventually be included, the site currently highlights data from the Dominican Republic.

  13. Biota and biological parameters as environmental indicators

    USGS Publications Warehouse

    Greeson, Phillip E., (Edited By)

    1981-01-01

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

  14. Toxaphene in Great Lakes biota and air

    NASA Astrophysics Data System (ADS)

    Glassmeyer, Susan Theresa

    1998-11-01

    Toxaphene is a complex mixture of at least 600 hexa- through decachlorinated bornanes and bornenes, which was used as an insecticide in the United States from the 1950's until 1982, when it was banned. Toxaphene is ubiquitous in the environment, probably because of its atmospheric transport away from areas of use. Toxaphene's complex nature makes accurate quantitation difficult. I have developed a computer program to automate quantitation, thus decreasing the time required for analysis while maintaining precise quantitation. I have shown that toxaphene in lake trout (Salvelinus namaycush) and rainbow smelt (Osmerus mordax) taken from Lake Superior have not decreased as they have in the four other Great Lakes from the time of the ban though 1992. This result could be due to three possibilities: ( a) There had been a food chain perturbation that made the 1982 concentrations unusually low. (b) The physical properties of Lake Superior make the loss rate significantly lower than the other Great Lakes. (c) There are current sources of toxaphene entering the Lake Superior basin. I analyzed an extended time series of lake trout from Lake Superior and from northern Lake Michigan to test the first two hypotheses. The concentrations of toxaphene have been constant in trout from Lake Superior since the late 1970's, so hypothesis a can be negated. The northern Lake Michigan samples did not decline as greatly as the southern basin samples, so hypothesis b can not be disproved. To determine the atmospheric deposition of toxaphene to Lake Superior, I analyzed air samples collected every twelve days for sixteen months at Eagle Harbor, Michigan. The concentrations of toxaphene in these samples are similar to those found in recent studies of air collected at Traverse City, MI., but significantly lower than samples taken at a land based site in southern Ontario in 1988 and 1989. This difference in concentration may (or may not) be due to differences in sampling times or locations or in quantitation protocols. These finding imply that Lake Superior is not receiving a unique atmospheric burden, but, because I have not explored terrestrial inputs, I cannot fully nullify hypothesis c.

  15. Ecological Linkages between aboveground and belowground biota

    Microsoft Academic Search

    David A. Wardle; Richard D. Bardgett; John N. Klironomos; H. Setälä; Wim H. van der Putten; Diana H. Wall

    2004-01-01

    All terrestrial ecosystems consist of aboveground and belowground components that interact to influence community- and ecosystem-level processes and properties. Here we show how these components are closely interlinked at the community level, reinforced by a greater degree of specificity between plants and soil organisms than has been previously supposed. As such, aboveground and belowground communities can be powerful mutual drivers,

  16. Diversity and distribution of Victoria Land biota

    Microsoft Academic Search

    Byron J. Adams; Richard D. Bardgett; Edward Ayres; Diana H. Wall; Jackie Aislabie; Stuart Bamforth; Roberto Bargagli; Craig Cary; Paolo Cavacini; Laurie Connell; Peter Convey; Jack W. Fell; Francesco Frati; Ian D. Hogg; Kevin K. Newsham; Anthony O’Donnell; Nicholas Russell; Rodney D. Seppelt; Mark I. Stevens

    2006-01-01

    Understanding the relationship between soil biodiversity and ecosystem functioning is critical to predicting and monitoring the effects of ecosystem changes on important soil processes. However, most of Earth's soils are too biologically diverse to identify each species present and determine their functional role in food webs. The soil ecosystems of Victoria Land (VL) Antarctica are functionally and biotically simple, and

  17. Detailed study of selenium and selected constituents in water, bottom sediment, soil, and biota associated with irrigation drainage in the San Juan River area, New Mexico, 1991-95

    USGS Publications Warehouse

    Thomas, Carole L.; Wilson, R.M.; Lusk, J.D.; Bristol, R.S.; Shineman, A.R.

    1998-01-01

    In response to increasing concern about the quality of irrigation drainage and its potential effects on fish, wildlife, and human health, the U.S. Department of the Interior began the National Irrigation Water Quality Program (NIWQP) to investigate these concerns at irrigation projects sponsored by the Department. The San Juan River in northwestern New Mexico was one of the areas designated for study. Study teams composed of scientists from the U.S. Geological Survey, the U.S. Fish and Wildlife Service, the Bureau of Reclamation, and the Bureau of Indian Affairs collected water, bottom-sediment, soil, and biological samples at 61 sites in the San Juan River area during 1993-94. Supplemental data collection conducted during 1991-95 by the Bureau of Indian Affairs and its contractor extended the time period and sampling sites available for analysis. Analytical chemistry performed on samples indicated that most potentially toxic elements other than selenium generally were not high enough to be of concern to fish, wildlife, and human health. Element concentrations in some water, bottom-sediment, soil, and biological samples exceeded applicable standards and criteria suggested by researchers in current literature. Selenium concentrations in water samples from 28 sites in the study area exceeded the 2-microgram-per-liter wildlife-habitat standard. Vanadium concentrations in water exceeded the 100-microgram-per-liter standard for livestock-drinking water at one site. In biota, selenium and aluminum concentrations regularly equaled or exceeded avian dietary threshold concentrations. In bottom sediment and soil, element concentrations above the upper limit of the baseline range for western soils were: selenium, 24 exceedances; lead, 2 exceedances; molybdenum, 2 exceedances; strontium, 4 exceedances; and zinc, 4 exceedances. Concentrations of total selenium in bottom-sediment and soil samples were significantly greater for Cretaceous than for non-Cretaceous soil types in the study area and were generally similar for habitats within and outside irrigation-affected areas. Mean and median total-selenium concentrations in samples from areas with Cretaceous soil types were 4.6 and 2.2 micrograms per gram, respectively. Mean and median total-selenium concentrations in samples from areas with non-Cretaceous soil types were 0.6 and 0.15 microgram per gram, respectively. Samples from the study area had low concentrations of organic constituents. Organochlorine pesticides and polychlorinated biphenyls were detected in a few biological samples at low concentrations. Polycyclic aromatic hydrocarbon (PAH) compounds were not detected in whole-water samples collected using conventional water-sampling techniques. In tests involving the use of semipermeable-membrane devices to supplement conventional water assays for PAH's, low concentrations of PAH's were found at several locations in the Hammond Irrigation Supply Canal, but were not detected in the Hammond ponds at the downstream reach of the Hammond irrigation service area. PAH compounds do not appear to reach the San Juan River through the Hammond Canal. Data indicate that water samples from irrigation-drainage-affected habitats had increased mean selenium concentrations compared with samples from irrigation-delivery habitat. The mean selenium concentration in water was greatest at seeps and tributaries draining irrigated land (17 micrograms per liter); less in irrigation drains and in ponds on irrigated land (6 micrograms per liter); and least in backwater, the San Juan River, and irrigation-supply water (0.5 - 0.6 microgram per liter). Statistical tests imply that irrigation significantly increases selenium concentrations in water samples when a Department of the Interior irrigation project is developed on selenium-rich sediments. Water samples from sites with Cretaceous soils had signi

  18. Bioavailability of heavy metals in terrestrial and aquatic systems: A quantitative approach

    SciTech Connect

    Plette, A.C.C.; Nederlof, M.M.; Temminmghoff, E.J.M.; Riemsduk, W.H. van

    1999-09-01

    Speciation and bioavailability are the keywords in the relation between the total metal content of the system and the resulting effects for biota. The metal ion binding to the biotic surface is pH dependent, as is metal ion binding to soils. The binding of metal ion to the biotic surface of an organism when present in soil can decrease with increasing pH, whereas the binding behavior of the biotic surface as such will always increase with increasing pH. The metal toxicity for plants often increases with increasing pH for water culture experiments, in which the opposite effect is observed for plants growing in soils. These seemingly contradictive observations can be explained by considering the interaction between an organism and metal ions present in soil to be the result of competition for that metal ion by all components (including the organism) present in the system. This concept is illustrated on the basis of model calculations concerning cadmium binding to a bacterium present in a clay and a sandy soil as influenced by pH and calcium concentration. In addition, the concept is applied for calculating the impact of algal bloom on the copper speciation in an aquatic system. The concept might be a valuable tool in predicting quantitatively the metal ion sorption to biota present in a complex system and to predict the relative change in availability due to environmental changes.

  19. Field information management systems for DNA barcoding.

    PubMed

    Deck, John; Gross, Joyce; Stones-Havas, Steven; Davies, Neil; Shapley, Rebecca; Meyer, Christopher

    2012-01-01

    Information capture pertaining to the "what?", "where?", and "when?" of biodiversity data is critical to maintain data integrity, interoperability, and utility. Moreover, DNA barcoding and other biodiversity studies must adhere to agreed upon data standards in order to effectively contextualize the biota encountered. A field information management system (FIMS) is presented that locks down metadata associated with collecting events, specimens, and tissues. Emphasis is placed on ease of use and flexibility of operation. Standardized templates for data entry are validated through a flexible, project-oriented validation process that assures adherence to data standards and thus data quality. Furthermore, we provide export functionality to existing cloud-based solutions, including Google Fusion Tables and Flickr to allow sharing of these data elements across research collaboration teams and other potential data harvesters via API services. PMID:22684960

  20. Integrated Taxonomic Information System

    NSDL National Science Digital Library

    Six US federal agencies have worked together to develop an efficient system for naming and classifying all of nature's living organisms. As the basic currency of scientific research, management, and education, ITIS is "a database of the current names and classifications of all biota." The website is organized into three main sections: About ITIS (general overview), Data Access (how to query the ITIS database), and TRED (the taxonomic experts behind the ITIS database). The core of the site is the Data Access section, which describes how to locate, access, and download scientific names and other information for a taxon. The ITIS database may be queried by full or partial Scientific Name, Vernacular (Common) Name, or TSN (Taxonomic Serial Number). Typical returns are Scientific Name, Vernacular (Common) Name, TSN, Author, Taxonomic Rank, and Synonym Name or TSN; note that the review process is still underway, and information is constantly added. In addition to the database, users are instructed on how to submit data to the ITIS database or match a list of taxa to the ITIS Database. A final, useful feature is the Taxonomic Workbench (free for downloading), "a windows-based software tool for entry of taxonomic information into ITIS' relational database format." Information on how to participate in this extraordinary and ambitious effort is provided at the site.

  1. Microbial community responses to anthropogenically induced environmental change: towards a systems approach.

    PubMed

    Bissett, Andrew; Brown, Mark V; Siciliano, Steven D; Thrall, Peter H

    2013-05-01

    The soil environment is essential to many ecosystem services which are primarily mediated by microbial communities. Soil physical and chemical conditions are altered on local and global scales by anthropogenic activity and which threatens the provision of many soil services. Despite the importance of soil biota for ecosystem function, we have limited ability to predict and manage soil microbial community responses to change. To better understand causal relationships between microbial community structure and ecological function, we argue for a systems approach to prediction and management of microbial response to environmental change. This necessitates moving beyond concepts of resilience, resistance and redundancy that assume single optimum stable states, to ones that better reflect the dynamic and interactive nature of microbial systems. We consider the response of three soil groups (ammonia oxidisers, denitrifiers, symbionts) to anthropogenic perturbation to motivate our discussion. We also present a network re-analysis of a saltmarsh microbial community which illustrates how such approaches can reveal ecologically important connections between functional groups. More generally, we suggest the need for integrative studies which consider how environmental variables moderate interactions between functional groups, how this moderation affects biogeochemical processes and how these feedbacks ultimately drive ecosystem services provided by soil biota. PMID:23679012

  2. PRMS-IV, the precipitation-runoff modeling system, version 4

    USGS Publications Warehouse

    Markstrom, Steven L.; Regan, Robert S.; Hay, Lauren E.; Viger, Roland J.; Webb, Richard M.; Payn, Robert A.; LaFontaine, Jacob H.

    2015-01-01

    Computer models that simulate the hydrologic cycle at a watershed scale facilitate assessment of variability in climate, biota, geology, and human activities on water availability and flow. This report describes an updated version of the Precipitation-Runoff Modeling System. The Precipitation-Runoff Modeling System is a deterministic, distributed-parameter, physical-process-based modeling system developed to evaluate the response of various combinations of climate and land use on streamflow and general watershed hydrology. Several new model components were developed, and all existing components were updated, to enhance performance and supportability. This report describes the history, application, concepts, organization, and mathematical formulation of the Precipitation-Runoff Modeling System and its model components. This updated version provides improvements in (1) system flexibility for integrated science, (2) verification of conservation of water during simulation, (3) methods for spatial distribution of climate boundary conditions, and (4) methods for simulation of soil-water flow and storage.

  3. System

    NASA Astrophysics Data System (ADS)

    Diao, Jiang; Fan, Guozheng; Liu, Xuan; Xie, Bing

    2014-10-01

    Molecular dynamics simulations were carried out to investigate the anionic structures of the molten CaO-SiO2-P2O5 system. The results show that the average first nearest-neighbor distances for Si-O and P-O pairs are 1.61 and 1.53 Å, respectively. As expected, above 98 pct P and 95 pct Si show fourfold coordination and form tetrahedral structures. Due to the high basicity, nonbridging oxygen occupies a predominant position in Si and P tetrahedron. Based on the oxygen number of different types, the structures of both Si and P tetrahedron were classified as Q 0, Q 1, Q 2, Q 3, and Q 4, where the superscript referred to the number of bridging oxygen atoms. With the substitution of P2O5 for SiO2, Q 0 decreased and other type of Q i units increased. For Si tetrahedron, Q 2 and Q 3 show most notable change, for P tetrahedron, Q 1and Q 2 show the most notable change. The change of Q i units for Si tetrahedron is larger than that for P tetrahedron. The concentration of free oxygen decreases remarkably with the increase of P2O5 content. The Si-O-P linkage is energetically more favorable than Si-O-Si and P-O-P linkages. P ion has a tendency to promote the polymerization of phosphosilicate melts.

  4. Biogeochemistry of mercury in a river-reservoir system: impact of an inactive chloralkali plant on the Holston River-Cherokee Reservoir, Virginia and Tennessee

    SciTech Connect

    Hildebrand, S. G.; Lindberg, S. E.; Turner, R. R.; Huckabee, J. W.; Strand, R. H.; Lund, J. R.; Andren, A. W.

    1980-08-01

    Elevated mercury concentrations in fish species from the North Fork of the Holston River were observed in the early 1970's. The source of the mercury was a chloralkali plant which had ceased operation in 1972. Mercury continues to be released to the river from two large (approx. 40-ha) waste disposal ponds at the plant site. This report presents results of a study of the emission of mercury to the environment from the abandoned waste ponds and of the distribution of mercury in water, sediment, and biota of the Holston River-Cherokee Reservoir System in Virginia and eastern Tennessee.

  5. Global analysis of river systems: from Earth system controls to Anthropocene syndromes.

    PubMed

    Meybeck, Michel

    2003-12-29

    Continental aquatic systems from rivers to the coastal zone are considered within two perspectives: (i) as a major link between the atmosphere, pedosphere, biosphere and oceans within the Earth system with its Holocene dynamics, and (ii) as water and aquatic biota resources progressively used and transformed by humans. Human pressures have now reached a state where the continental aquatic systems can no longer be considered as being controlled by only Earth system processes, thus defining a new era, the Anthropocene. Riverine changes, now observed at the global scale, are described through a first set of syndromes (flood regulation, fragmentation, sediment imbalance, neo-arheism, salinization, chemical contamination, acidification, eutrophication and microbial contamination) with their related causes and symptoms. These syndromes have direct influences on water uses, either positive or negative. They also modify some Earth system key functions such as sediment, water, nutrient and carbon balances, greenhouse gas emissions and aquatic biodiversity. Evolution of river syndromes over the past 2000 years is complex: it depends upon the stages of regional human development and on natural conditions, as illustrated here for the chemical contamination syndrome. River damming, eutrophication and generalized decrease of river flow due to irrigation are some of the other global features of river changes. Future management of river systems should also consider these long-term impacts on the Earth system. PMID:14728790

  6. Effects of the Operation of Kerr and Hungry Horse Dams on the Kokanee Fishery in the Flathead River System, 1979-1985 Final Research Report.

    SciTech Connect

    Clancy, Patrick

    1986-05-01

    This study was undertaken to assess the effects of the operation of Hungry Horse Dam on the kokanee fishery in the Flathead River system. Studies concerning operation of the dam on the Flathead River aquatic biota began in 1979 and continued to 1982 under Bureau of Reclamation funding. These studies resulted in flow recommendations for the aquatic biota in the main stem Flathead River, below the influence of Hungry Horse Dam on the South Fork. Studies concerned specifically with kokanee salmon have continued under Bonneville Power Administration funding since 1982. This completion report covers the entire study period (September 1979 to June 1985). Major results of this study were: (1) development and refinement of methods to assess hydropower impacts on spawning and incubation success of kokanee; (2) development of a model to predict kokanee year class strength from Flathead River flows; and (3) implementation of flows favorable for successful kokanee reproduction. A monitoring program has been developed which will assess the recovery of the kokanee population as it proceeds, and to recommend management strategies to maintain management goals for the kokanee fishery in the river system.

  7. 43 CFR 37.11 - Nomination, evaluation, and designation of significant caves.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...the following features, characteristics, or values. (1) Biota. The cave provides seasonal or yearlong habitat for organisms...hydrologic system or contains water that is important to humans, biota, or development of cave resources. (5)...

  8. 36 CFR 290.3 - Nomination, evaluation, and designation of significant caves.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...the following features, characteristics, or values. (1) Biota. The cave provides seasonal or yearlong habitat for organisms...hydrologic system or contains water which is important to humans, biota, or development of cave resources. (5)...

  9. 36 CFR 290.3 - Nomination, evaluation, and designation of significant caves.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...the following features, characteristics, or values. (1) Biota. The cave provides seasonal or yearlong habitat for organisms...hydrologic system or contains water which is important to humans, biota, or development of cave resources. (5)...

  10. 36 CFR 290.3 - Nomination, evaluation, and designation of significant caves.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...the following features, characteristics, or values. (1) Biota. The cave provides seasonal or yearlong habitat for organisms...hydrologic system or contains water which is important to humans, biota, or development of cave resources. (5)...

  11. 43 CFR 37.11 - Nomination, evaluation, and designation of significant caves.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...the following features, characteristics, or values. (1) Biota. The cave provides seasonal or yearlong habitat for organisms...hydrologic system or contains water that is important to humans, biota, or development of cave resources. (5)...

  12. 43 CFR 37.11 - Nomination, evaluation, and designation of significant caves.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...the following features, characteristics, or values. (1) Biota. The cave provides seasonal or yearlong habitat for organisms...hydrologic system or contains water that is important to humans, biota, or development of cave resources. (5)...

  13. Managing soil microbial communities in grain production systems through cropping practices

    NASA Astrophysics Data System (ADS)

    Gupta, Vadakattu

    2013-04-01

    Cropping practices can significantly influence the composition and activity of soil microbial communities with consequences to plant growth and production. Plant type can affect functional capacity of different groups of biota in the soil surrounding their roots, rhizosphere, influencing plant nutrition, beneficial symbioses, pests and diseases and overall plant health and crop production. The interaction between different players in the rhizosphere is due to the plethora of carbon and nutritional compounds, root-specific chemical signals and growth regulators that originate from the plant and are modulated by the physico-chemical properties of soils. A number of plant and environmental factors and management practices can influence the quantity and quality of rhizodeposition and in turn affect the composition of rhizosphere biota communities, microbe-fauna interactions and biological processes. Some of the examples of rhizosphere interactions that are currently considered important are: proliferation of plant and variety specific genera or groups of microbiota, induction of genes involved in symbiosis and virulence, promoter activity in biocontrol agents and genes correlated with root adhesion and border cell quality and quantity. The observation of variety-based differences in rhizodeposition and associated changes in rhizosphere microbial diversity and function suggests the possibility for the development of varieties with specific root-microbe interactions targeted for soil type and environment i.e. designer rhizospheres. Spatial location of microorganisms in the heterogeneous field soil matrix can have significant impacts on biological processes. Therefore, for rhizosphere research to be effective in variable seasonal climate and soil conditions, it must be evaluated in the field and within a farming systems context. With the current focus on security of food to feed the growing global populations through sustainable agricultural production systems there is a need to develop innovative cropping systems that are both economically and environmentally sustainable.

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

    PubMed Central

    2014-01-01

    Background The formation of the East African Rift System has decisively influenced the distribution and evolution of tropical Africa’s biota by altering climate conditions, by creating basins for large long-lived lakes, and by affecting the catchment and drainage directions of river systems. However, it remains unclear how rifting affected the biogeographical patterns of freshwater biota through time on a continental scale, which is further complicated by the scarcity of molecular data from 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. PMID:24597925

  15. [Prospects of systemic radioecology in solving innovative tasks of nuclear power engineering].

    PubMed

    Spiridonov, S I

    2014-01-01

    A need of systemic radioecological studies in the strategy developed by the atomic industry in Russia in the XXI century has been justified. The priorities in the radioecology of nuclear power engineering of natural safety associated with the development of the radiation-migration equivalence concept, comparative evaluation of innovative nuclear technologies and forecasting methods of various emergencies have been identified. Also described is an algorithm for the integrated solution of these tasks that includes elaboration of methodological approaches, methods and software allowing dose burdens to humans and biota to be estimated. The rationale of using radioecological risks for the analysis of uncertainties in the environmental contamination impacts,at different stages of the existing and innovative nuclear fuel cycles is shown. PMID:25775830

  16. Summary of information on synthetic organic compounds and trace elements in tissue of aquatic biota, Clark Fork-Pend Oreille and Spokane River basins, Montana, Idaho, and Washington, 1974-96

    USGS Publications Warehouse

    Maret, Terry R.; Dutton, DeAnn M.

    1999-01-01

    As part of the Northern Rockies Intermontane Basins study of the National Water-Quality Assessment Program, data collected between 1974 and 1996 were compiled to describe contaminants in tissue of riverine species. Tissue-contaminant data from 11 monitoring programs and studies representing 28 sites in the study area were summarized. Tissue-contaminant data for most streams generally were lacking. Many studies have focused on and around mining-affected areas on the Clark Fork and Coeur d'Alene Rivers and their major tributaries. DDT and PCBs and their metabolites and congeners were the synthetic organic contaminants most commonly detected in fish tissue. Fish collected from the Spokane River in Washington contained elevated concentrations of PCB arochlors, some of which exceeded guidelines for the protection of human health and predatory wildlife. Tissue samples of fish from the Flathead River watershed contained higher-than-expected concentrations of PCBs, which might have resulted from atmospheric transport. Trace element concentrations in fish and macroinvertebrates collected in and around mining areas were elevated compared with background concentrations. Some cadmium, copper, lead, and mercury concentrations in fish tissue were elevated compared with results from other studies, and some exceeded guidelines. Macroinvertebrates from the Coeur d'Alene River contained higher concentrations of cadmium, lead, and zinc than did macroinvertebrates from other river systems in mining-affected areas. A few sportfish fillet samples, most from the Spokane River in Washington, were collected to assess human health risk. Concentrations of PCBs in these fillets exceeded screening values for the protection of human health. At present, there is no coordinated, long-term fish tissue monitoring program for rivers in the study area, even though contaminants are present in fish at levels considered a threat to human health. Development of a coordinated, centralized national data base for contaminants in fish tissue is needed. The National Water-Quality Assessment Program can provide a framework for other agencies to evaluate tissue contaminants in the Northern Rockies Intermontane Basins study area. As of 1996, there are no fish consumption advisories or fishing restrictions as a result of elevated contaminants on any rivers within the study area.

  17. Soil Biota and Litter Decay in High Arctic Ecosystems

    Microsoft Academic Search

    G. González; F. Rivera; O. Makarova; W. A. Gould

    2006-01-01

    Frost heave action contributes to the formation of non-sorted circles in the High Arctic. Non-sorted circles tend to heave more than the surrounding tundra due to deeper thaw and the formation of ice lenses. Thus, the geomorphology, soils and vegetation on the centers of the patterned-ground feature (non-sorted circles) as compared to the surrounding soils (inter-circles) can be different. We

  18. Methylmercury in biota downstream of Arivaca lake, Arizona, USA.

    PubMed

    Marr, Carrie L H; Robertson, Kathy; Reynolds, Kevin D

    2014-04-01

    Concentrations of total mercury (Hg) and methylmercury (MeHg) were determined in water, sediment, periphyton, spiders, and amphibians from the streams and desert marsh downstream from Arivaca Lake, Arizona, to better understand their distribution and bioaccumulation. Mean concentrations of MeHg in water ranged from 0.09 to 0.93 ng/L, and mean concentrations of total Hg in sediment ranged from 10.4 to 126 ?g/kg. Hg and MeHg in water and sediments downstream from Arivaca Lake were low enough that they did not exceed human health or ecological thresholds. Hg and MeHg between sites ranged from 0.11 to 1.90 ?g/g Hg and 0.01 to 0.3 ?g/g MeHg in periphyton, from 0.09 to 0.25 ?g/g Hg and 0.04 to 0.10 ?g/g MeHg in spiders, and from 0.15 to 0.38 ?g/g Hg and 0.14 to 0.35 ?g/g MeHg in adult bullfrogs. No Hg toxicity data exist for periphyton or spiders, but MeHg concentrations in tadpoles (0.04 ± 0.005 ?g/g) were lower than those known to cause sublethal effects and subchronic mortality. The mean total Hg concentration in adult bullfrogs in the present study was 0.24 ?g/g, which is slightly lower than the mean (0.37 ?g/g) from an Hg-contaminated wetland in California. MeHg bioaccumulated at each successive trophic level, and MeHg bioconcentration factors from the Arivaca watershed were similar to those for periphyton but greater than amphibians in other studies. Local resource managers can use these data to determine if water should be released from Arivaca Lake to recharge the aquifer downstream or to decrease Hg methylation in the reservoir. PMID:24468966

  19. Diversification of rocky-shore biotas through geologic time

    Microsoft Academic Search

    Markes E. Johnson; B. Gudveig Baarli

    1999-01-01

    Changes in biodiversity of rocky-shore ecosystems from the early Precambrian (3,500 Ma) to the last interglacial epoch (125 Ka) are summarized on the basis of the fossil record associated with geological unconformities that reflect coastal paleotopography. This analysis is derived from data reported in 130 published papers culled and updated from previous bibliographic reviews. Minimum total diversity of fossil and

  20. Assemblage palaeoecology of the Ediacara biota: The unabridged edition?

    E-print Network

    Lyubomirsky, Ilya

    understanding of Ediacaran ecosystems is a full description and interpretation of the many problematica; Neoproterozoic; Flinders; Taphonomy; Paleoecology 1. Introduction Ediacaran strata contain the earliest diverse in siliciclastic sediments, were placed in modern animal phyla. Radially symmet- rical and sea pen like forms have

  1. Heavy metal concentrations in Louisiana waterways, sediments, and biota

    SciTech Connect

    Bundy, K.J.; Berzins, D. [Tulane Univ., New Orleans, LA (United States). Biomedical Engineering Dept.

    1994-12-31

    In this investigation polarographic methods (along with GFAAS and ICP) have been used to study the distribution of lead and chromium in Bayou Trepagnier and Devil`s Swamp. Both laboratory and field research have been conducted. Separation and extraction methodology appropriate for analysis of the contaminants at these sites have been developed. Particular attention has been paid to extraction methods for chromium which do not lead to valence state conversion. The availability of such techniques is essential to take full advantage of polarography, a method capable of performing speciation analysis. The results indicate that there is a very inhomogeneous distribution of heavy metals in these environments. In Devil`s Swamp, for example, separation and analysis of aqueous and variously sized particulate moieties in the water and sediment compartments were conducted to determine the partition of lead between them. The results showed that the average lead content was 14.7 ppb and 19.8 ppm, respectively, in these compartments. Apparently bull frogs in Devil`s Swamp can bioaccumulate lead (compared to the measured water level), since the muscle concentration was found to be about 0.6 ppm. This phenomenon is being investigated in a Xenopus frog laboratory model of heavy metal uptake. The basic methodology validated in this study should be fairly generally applicable to assays of other heavy metals.

  2. Interactions between soil biota and the effects on geomorphological features

    NASA Astrophysics Data System (ADS)

    Zaitlin, Beryl; Hayashi, Masaki

    2012-07-01

    The interaction of animals with abiotic features of their environment has long been known to cause alterations to geomorphic features, and these interactions may cause feedback loops that further alter geomorphic features and animal communities. This paper samples the literature on selected burrowing animals in western North America, and discusses the interactions of animals with abiotic features of the environment and with each other, and the resulting impacts on geomorphic features and each other. As expected, burrowing characteristics of animals influence geomorphological processes. For example, pocket gophers and certain ground squirrels that burrow horizontal tunnels on sloping grounds seem to have significant impacts on horizontal movement of soils, whereas prairie dogs and harvester ants have more impact on vertical movement of soils. Burrowing animals, in general, increase the patchiness of the environment, which creates localized patch habitat for other plants and animals, thereby increasing biodiversity at the landscape scale. Burrowing animals influence and are influenced by microbes: sylvatic plague wiped out large populations of prairie dogs, earthworms cause major changes in soil microflora, pocket gophers and harvester ants cause changes in mycorrhizal communities, which in turn impact plant communities.

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

    Microsoft Academic Search

    Karsten Reise; Elisabeth Herre; Manfred Sturm

    2008-01-01

    Where, since the 1980s, patchy and variable green algal mats are prevailing, distinct belts of an amphipod (Corophium volutator) and seagrass (Zostera spp.) had dominated in the 1930s. The zonation between tide marks has been mapped in a sheltered sedimentary bay in the Wadden\\u000a Sea near the island of Sylt (coastal eastern North Sea). Maps on vegetation from 1924 and

  4. COLUMBIA RIVER BASIN CONTAMINANT AQUATIC BIOTA AND SEDIMENT DATA

    EPA Science Inventory

    Numerous studies have been done to determine the levels of chemical contaminants in fish and sediment in the Columbia River Basin. These studies were done because of concern that releases of toxic Chemicals into the Columbia River Basin may be impacting health and the environment...

  5. Mercury accumulation in biota of Thunder Creek, Saskatchewan

    SciTech Connect

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

    1980-12-01

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

  6. Solar-driven chemical energy source for a Martian biota

    NASA Technical Reports Server (NTRS)

    Clark, B. C.

    1979-01-01

    Microorganisms deep in the Martian soil could derive energy indirectly from the sun via chemical reactions involving atmospheric photolysis products of the solar ultraviolet flux. The Viking discovery of a chemically uniform regolith which, though poor in organics, is rich in sulfur-containing compounds suggests reaction sequences in which sulfur is recycled through reduced and oxidized states by biologically catalyzed reactions with photochemically-produced atmospheric constituents. One candidate reaction, reduction of soil sulfate minerals by molecular hydrogen, is already exploited on earth by bacteria of the ubiquitous and tenacious Desulfovibrio genus.

  7. The Caspian Lake: History, biota, structure, and function

    Microsoft Academic Search

    H. J. Dumont

    1998-01-01

    The elongate, endorheic Caspian Lake has a north-south orientation and its main freshwater inflow, the Volga River, enters at the shallow north end. Two deep basins occupy its central and southern regions. These facts lead to horizontal differences in temperature, salinity, and ecology. Nutrient levels and primary production are low. Historically, lake level has fluctuated by -6 m, but on

  8. Cryptic northern refugia and the origins of the modern biota

    Microsoft Academic Search

    John R. Stewart; Adrian M. Lister

    2001-01-01

    Viewed from a geological perspective, present-day animal and plant communities in many parts of the world have a remarkably short history. The environmental revolution at the end of the Pleistocene, a mere 10?000 years ago, triggered major shifts in the ranges of species and hence composition of communities. Present-day communities in the boreal and temperate zones assembled at this time

  9. LINKING STORMFLOW HYDROLOGY AND BIOTA IN SUBURBAN STREAMS

    EPA Science Inventory

    Suburban land development has been found to alter the hydrology of landscapes, changing streamflow transient behavior, which may contribute to the typical negative impacts of development on aquatic ecosystems. The linkages between residential development, hydrologic response, and...

  10. SUSPENDED AND DISSOLVED SOLIDS EFFECTS ON FRESHWATER BIOTA: A REVIEW

    EPA Science Inventory

    It is widely recognized that suspended and dissolved solids in lakes, rivers, streams, and reservoirs affect water quality. In this report the research needs appropriate to setting freshwater quality criteria or standards for suspended solids (not including bedload) and dissolved...

  11. Timing the diversification of the Amazonian biota: butterfly divergences

    E-print Network

    Garzón-Orduña, Ivonne

    geological events in the Neotropics, such as the uplift of the Andes, the formation of a large lacustrine that is consistent and comparable across taxa. Our results show that 72% of speciation events leading time: one that emphasizes Neogene (23­2.6 Ma) vicariance events as a result of major rearrange- ments

  12. A lamprey from the Cretaceous Jehol biota of China

    Microsoft Academic Search

    Mee-Mann Chang; Jiangyong Zhang; Desui Miao

    2006-01-01

    Widespread nowadays in freshwater and coastal seas of the cold and temporal zones, lampreys are a jawless vertebrate group that has been in existence for more than 300 million years but left a meagre fossil record. Only two fossil lamprey species, namely Mayomyzon pieckoensis and Hardistiella montanensis, have been recognized with certainty from North American Carboniferous marine deposits. Here we

  13. A lamprey from the Cretaceous Jehol biota of China.

    PubMed

    Chang, Mee-mann; Zhang, Jiangyong; Miao, Desui

    2006-06-22

    Widespread nowadays in freshwater and coastal seas of the cold and temporal zones, lampreys are a jawless vertebrate group that has been in existence for more than 300 million years but left a meagre fossil record. Only two fossil lamprey species, namely Mayomyzon pieckoensis and Hardistiella montanensis, have been recognized with certainty from North American Carboniferous marine deposits. Here we report a freshwater lamprey from the Early Cretaceous epoch (about 125 million years ago) of Inner Mongolia, China. The new taxon, Mesomyzon mengae, has a long snout, a well-developed sucking oral disk, a relatively long branchial apparatus showing branchial basket, seven gill pouches, gill arches and impressions of gill filaments, about 80 myomeres and several other characters that are previously unknown or ambiguous. Our finding not only indicates Mesomyzon's closer relationship to extant lampreys but also reveals the group's invasion into a freshwater environment no later than the Early Cretaceous. The new material furthers our understanding of ancient lampreys, bridges the gap between the Carboniferous ones and their recent relatives, and adds to our knowledge of the evolutionary history of lampreys. PMID:16791193

  14. Nickel63 in Marine and Terrestrial Biota, Soil, and Sediment

    Microsoft Academic Search

    Thomas M. Beasley; Edward E. Held

    1969-01-01

    A previously unreported radionuclide, nickel-63 (half-life, 92 years), produced in the testing of nuclear devices, was measured in biological and environmental samples from areas of the Pacific Ocean and the eastern seaboard of the United States. The concentrations of nickel-63 are low (maximum of 163 disintegrations per minute per gram of dry weight), but this radionuclide may be a useful

  15. EFFECTS OF CONTAMINATED SEDIMENTS ON MARINE BENTHIC BIOTA AND COMMUNITIES

    EPA Science Inventory

    Our understanding of the effects of contaminants on benthic organisms lags well behind that for water column species because of the way in which sediments mediate bioavailability and because test protocols using infaunal organism are still in the developmental stage. lthough quan...

  16. Biodiversity and ecosystem functioning: the emergence of a

    E-print Network

    Minnesota, University of

    's biota is not a passive epiphenomenon of Earth's physical conditions and geochemical pro- cesses. Through the collective metabolic and growth activities of its trillions of organisms, Earth's biota1 moves hundreds the functional2 signi®cance of Earth's biota to ecosystem or Earth-system functioning is well established

  17. Evolution of centralized nervous systems: two schools of evolutionary thought.

    PubMed

    Northcutt, R Glenn

    2012-06-26

    Understanding the evolution of centralized nervous systems requires an understanding of metazoan phylogenetic interrelationships, their fossil record, the variation in their cephalic neural characters, and the development of these characters. Each of these topics involves comparative approaches, and both cladistic and phenetic methodologies have been applied. Our understanding of metazoan phylogeny has increased greatly with the cladistic analysis of molecular data, and relaxed molecular clocks generally date the origin of bilaterians at 600-700 Mya (during the Ediacaran). Although the taxonomic affinities of the Ediacaran biota remain uncertain, a conservative interpretation suggests that a number of these taxa form clades that are closely related, if not stem clades of bilaterian crown clades. Analysis of brain-body complexity among extant bilaterians indicates that diffuse nerve nets and possibly, ganglionated cephalic neural systems existed in Ediacaran organisms. An outgroup analysis of cephalic neural characters among extant metazoans also indicates that the last common bilaterian ancestor possessed a diffuse nerve plexus and that brains evolved independently at least four times. In contrast, the hypothesis of a tripartite brain, based primarily on phenetic analysis of developmental genetic data, indicates that the brain arose in the last common bilaterian ancestor. Hopefully, this debate will be resolved by cladistic analysis of the genomes of additional taxa and an increased understanding of character identity genetic networks. PMID:22723354

  18. Absorption Capacities as a Basis of Stability for Closed Ecological Systems

    NASA Astrophysics Data System (ADS)

    Rygalov, V.; Pechurkin, N.; Wheeler, R.; Fowler, P.

    Growing plants in highly closed ecological systems (CES) will ultimately require conservation and recycling of plant essential elements to reduce system costs. One method for rapid recycling of elements would be incineration of residual, inedible biomass. The paper attempts to analyze the impact of biomass incineration for mineral recycling in a CES. Depending on system constraints, each CES will have its own range of steady-state operation, and this range becomes narrower as recycling rates increase. The paper presents a metric for CES stability, with the numerical estimates linked to carbon cycling rates. Along w th retrieving somei plant-essential elements, incineration of waste biomass would also release carbon dioxide, water, and other volatile compounds, depending on flue gas handling. Toxic products such as SO2 could damage or disrupt CES stability at high recycling rates. If such toxic species are not neutralized, the system tolerance would then be proportional to CES buffering or absorption capacity, and would be a non-linear function of the tolerance of the biota. We developed formulas to evaluate absorption capacities required for a stable CES by assessing different rates of material turnover. Numerical estimates of system stabilities in relation to carbon cycling rates were calculated for several examples of CES, including the Earth's Biosphere, the BIOS-3 project in Krasnoyarsk, Russia, and the Biosphere-2 project in Tucson, Arizona, USA.

  19. Autonomous video camera system for monitoring impacts to benthic habitats from demersal fishing gear, including longlines

    NASA Astrophysics Data System (ADS)

    Kilpatrick, Robert; Ewing, Graeme; Lamb, Tim; Welsford, Dirk; Constable, Andrew

    2011-04-01

    Studies of the interactions of demersal fishing gear with the benthic environment are needed in order to manage conservation of benthic habitats. There has been limited direct assessment of these interactions through deployment of cameras on commercial fishing gear especially on demersal longlines. A compact, autonomous deep-sea video system was designed and constructed by the Australian Antarctic Division (AAD) for deployment on commercial fishing gear to observe interactions with benthos in the Southern Ocean finfish fisheries (targeting toothfish, Dissostichus spp). The Benthic Impacts Camera System (BICS) is capable of withstanding depths to 2500 m, has been successfully fitted to both longline and demersal trawl fishing gear, and is suitable for routine deployment by non-experts such as fisheries observers or crew. The system is entirely autonomous, robust, compact, easy to operate, and has minimal effect on the performance of the fishing gear it is attached to. To date, the system has successfully captured footage that demonstrates the interactions between demersal fishing gear and the benthos during routine commercial operations. It provides the first footage demonstrating the nature of the interaction between demersal longlines and benthic habitats in the Southern Ocean, as well as showing potential as a tool for rapidly assessing habitat types and presence of mobile biota such as krill ( Euphausia superba).

  20. Increased Use of No-till Cropping Systems Improves Stream Ecosystem Quality

    NASA Astrophysics Data System (ADS)

    Yates, A. G.; Bailey, R. C.; Schwindt, J. A.

    2005-05-01

    Release of sediments to streams from tilled lands has been a significant stressor to streams in agro-ecosystems for decades and has been shown to impact aquatic biota in a variety of ways. To limit soil erosion from cultivated lands, conservation tillage techniques, including the use of no-till systems, have been developed and widely adopted throughout the region. However, there haves been no tests of the effects of no-till systems on stream quality at a watershed scale. We measured habitat and water quality and sampled the benthic macroinvertebrate (BMI) and fish communities in 32 small (100-1400 ha) subwatersheds along a gradient of the proportion of land under no-till cropping systems to determine relationships between the use of no-till and stream quality. Our results demonstrate that with increasing proportions of no-till, habitat scores improve, the quantities of sediment and sediment associated stressors in the water decline, the BMI community exhibits reduced dominance by Oligocheata and Sphaeriidae, as well as improved Family Biotic Index (FBI) scores, and fish species richness increases. We concluded that increased use of no-till cropping systems by farmers does contribute to improved quality of streams in agro-ecosystems.

  1. Pesticides in the hydrologic system - What do we know and what's next?

    USGS Publications Warehouse

    Gilliom, R.J.

    2001-01-01

    Even though the occurrence and behaviour of pesticides in the environment have been studied for decades, water-quality managers and the public still demand more complete and consistent information, and there are many unanswered questions for environmental scientists. In many respects, the greatest potential for unintended adverse effects of pesticides is through contamination of the hydrologic system, which supports aquatic life and related food chains and is used for recreation, drinking water, and many other purposes. The movement of water is one of the primary mechanisms by which pesticides are transported from targeted application areas to other parts of the environment; thus, there is potential for movement into and through all components of the hydrologic system. Extensive reviews of existing information on pesticides in the hydrologic system, including the atmosphere (Majewski and Capel, 1995), ground water (Barbash and Resek, 1996), surface water (Larson et al., 1997), and fluvial sediments and aquatic biota (Nowell et al., 1999), uncovered volumes of useful information, but also noted critical information gaps. For example: (a) relatively few pesticides have been thoroughly studied, particularly transformation products; (b) most data have been collected for small-scale site and field studies in agricultural areas; (c) urban areas have received little attention for monitoring or research; (d) the geographic and temporal distributions of data collection have been highly uneven; and (e) comparing and synthesizing results from most studies is difficult because of inconsistent approaches to data collection and chemical analysis.

  2. Assessing land-use impacts on biodiversity using an expert systems tool

    USGS Publications Warehouse

    Crist, P.J.; Kohley, T.W.; Oakleaf, J.

    2000-01-01

    Habitat alteration, in the form of land-use development, is a leading cause of biodiversity loss in the U.S. and elsewhere. Although statutes in the U.S. may require consideration of biodiversity in local land-use planning and regulation, local governments lack the data, resources, and expertise to routinely consider biotic impacts that result from permitted land uses. We hypothesized that decision support systems could aid solution of this problem. We developed a pilot biodiversity expert systems tool (BEST) to test that hypothesis and learn what additional scientific and technological advancements are required for broad implementation of such a system. BEST uses data from the U.S. Geological Survey's Gap Analysis Program (GAP) and other data in a desktop GIS environment. The system provides predictions of conflict between proposed land uses and biotic elements and is intended for use at the start of the development review process. Key challenges were the development of categorization systems that relate named land-use types to ecological impacts, and relate sensitivities of biota to ecological impact levels. Although the advent of GAP and sophisticated desktop GIS make such a system feasible for broad implementation, considerable ongoing research is required to make the results of such a system scientifically sound, informative, and reliable for the regulatory process. We define a role for local government involvement in biodiversity impact assessment, the need for a biodiversity decision support system, the development of a prototype system, and scientific needs for broad implementation of a robust and reliable system.

  3. Environmental impacts of cooling system on Abou Qir Bay.

    PubMed

    Mohamed, Manal A; Abd-Elaty, Magda M; El-Shall, Wafaa I; Ramadan, Abou Bakr; Tawfik, Mohamed S

    2005-01-01

    This study was conducted to evaluate the impacts of cooling water on cooling system of Abou Qir Power Plant and on the receiving Abou Qir Bay. Abou Qir Power Plant is a conventional steam electric power plant located in Alexandria Governorate, Egypt. Water and biota samples were collected monthly from cooling water and Abou Qir Bay over a year. Heavy metals, radionuclide, anions and total hydrocarbons were analyzed in the samples using Instrumental Neutron Activation Analysis (INAA), Gamma-ray Spectrometry (GS), Ion Selective Electrodes (ISE) and Gas Chromatography (GC). The results revealed that the characteristics of inlet cooling water had a tendency to be corrosive to the cooling system. The outlet cooling water complied with Environmental Law 4/1994 in all measured parameters except phosphate, ammonia and total petroleum hydrocarbons. On the other hand, samples from all sites had the lowest annual total count of algae in winter and highest count during summer. There are -ve correlations between algae and heavy metals, hydrocarbons, and radioactivity. Algae correlated highly significantly (p<0.01) with Pb, Cu, Ni, total petroleum hydrocarbons, dissolved petroleum hydrocarbon and uranium. Anabaena Sp. (blue green algae) and Euglina Sp.(flagellate) had highly significant (p<0.01) -ve correlation with heavy metals and natural radioactivity. The accumulation percentage of heavy metals by algae ranged from 22% to 37%, and the highest percent was for uranium and the lowest was for chromium. It is recommended to optimize the addition of polyphosphate inhibitor at inlet cooling water to inhibit corrosion in the cooling system and to avoid increase of Anabaena Sp. in the outlet, and to avoid enhancing algae growth that has a great tendency to accumulate heavy metals, and good housekeeping to avoid oil spills containing hydrocarbons from the power plant to sea water. PMID:17187744

  4. Effects of placer mining on hydrologic systems in Alaska; status of knowledge

    USGS Publications Warehouse

    Madison, R.J.

    1981-01-01

    The report briefly summarizes the current state of knowledge regarding placer mining in Alaska. A review of literature indicates that nearly all of the significant information on the effects of placer mining on the hydrologic system in Alaska is referenced in available reports. The addition of sediment, as well as other indirect changes this generates, appears to be the primary impact of placer mining on Alaskan streams. Other potential water-quality effects that should be considered are: increases in organic loading in the stream system; increases in minor element content; potential for acid drainage; and impacts on fish and other aquatic biota. Existing information is adequate to define parameters that may be affected by placer mining but inadequate to quantify changes resulting from an individual mining operation or to allow the prediction of the magnitude or duration of the impact. Additional studies that would improve the knowledge of the effects of placer mining include: short-term assessments, using available photographic information and existing hydrologic records, to document historical changes and active placer mining features; short-term studies using emperical sediment-transport formulas to estimate the effects of placer mine activities; and river quality assessments of selected basins affected by placer mining. (USGS)

  5. Microbial ecology of terrestrial Antarctica: Are microbial systems at risk from human activities?

    SciTech Connect

    White, G.J.

    1996-08-01

    Many of the ecological systems found in continental Antarctica are comprised entirely of microbial species. Concerns have arisen that these microbial systems might be at risk either directly through the actions of humans or indirectly through increased competition from introduced species. Although protection of native biota is covered by the Protocol on Environmental Protection to the Antarctic Treaty, strict measures for preventing the introduction on non-native species or for protecting microbial habitats may be impractical. This report summarizes the research conducted to date on microbial ecosystems in continental Antarctica and discusses the need for protecting these ecosystems. The focus is on communities inhabiting soil and rock surfaces in non-coastal areas of continental Antarctica. Although current polices regarding waste management and other operations in Antarctic research stations serve to reduce the introduction on non- native microbial species, importation cannot be eliminated entirely. Increased awareness of microbial habitats by field personnel and protection of certain unique habitats from physical destruction by humans may be necessary. At present, small-scale impacts from human activities are occurring in certain areas both in terms of introduced species and destruction of habitat. On a large scale, however, it is questionable whether the introduction of non-native microbial species to terrestrial Antarctica merits concern.

  6. Soil moisture's underestimated role in climate change impact modelling in low-energy systems.

    PubMed

    le Roux, Peter Christiaan; Aalto, Juha; Luoto, Miska

    2013-10-01

    Shifts in precipitation regimes are an inherent component of climate change, but in low-energy systems are often assumed to be less important than changes in temperature. Because soil moisture is the hydrological variable most proximally linked to plant performance during the growing season in arctic-alpine habitats, it may offer the most useful perspective on the influence of changes in precipitation on vegetation. Here we quantify the influence of soil moisture for multiple vegetation properties at fine spatial scales, to determine the potential importance of soil moisture under changing climatic conditions. A fine-scale data set, comprising vascular species cover and field-quantified ecologically relevant environmental parameters, was analysed to determine the influence of soil moisture relative to other key abiotic predictors. Soil moisture was strongly related to community composition, species richness and the occurrence patterns of individual species, having a similar or greater influence than soil temperature, pH and solar radiation. Soil moisture varied considerably over short distances, and this fine-scale heterogeneity may contribute to offsetting the ecological impacts of changes in precipitation for species not limited to extreme soil moisture conditions. In conclusion, soil moisture is a key driver of vegetation properties, both at the species and community level, even in this low-energy system. Soil moisture conditions represent an important mechanism through which changing climatic conditions impact vegetation, and advancing our predictive capability will therefore require a better understanding of how soil moisture mediates the effects of climate change on biota. PMID:23749628

  7. System requirements. [Space systems

    SciTech Connect

    Austin, R.E.

    1982-06-01

    Requirements of future space systems, including large space systems, that operate beyond the space shuttle are discussed. Typical functions required of propulsion systems in this operational regime include payload placement, retrieval, observation, servicing, space debris control and support to large space systems. These functional requirements are discussed in conjunction with two classes of propulsion systems: (1) primary or orbit transfer vehicle (OTV) and (2) secondary or systems that generally operate within or relatively near an operational base orbit. Three propulsion system types are described in relation to these requirements: cryogenic OTV, teleoperator maneuvering system and a solar electric OTV.

  8. HAZARD ASSESSMENT OF METALS AND METAL COMPOUNDS IN TERRESTRIAL SYSTEMS

    EPA Science Inventory

    Metal accumulation in soil can result in adverse effects on soil biota, and may concentrate metals in food chains to levels detrimental to humans and wildlife. A SETAC Pellston Workshop entitled " Hazard Identification Approach For Metals And Inorganic Metal Substances" examined...

  9. The role of sediments in the chemistry of aquatic systems; proceedings of the sediment chemistry workshop

    USGS Publications Warehouse

    Bradford, Wesley L., (Edited By); Horowitz, A.J.

    1988-01-01

    A workshop on sediment chemistry was held at the U.S. Geological Survey National Headquarters in Reston, Virginia, February 8-12, 1982, to discuss the state of the science and possible future directions for research and operational programs in the Water Resources Division of the U.S. Geological Survey. Technical papers presented broad overviews of current conceptual models for and research on the interactions between sediments, water, and biota with respect to the occurrence, distribution, movement, and fate of metals and organic substances in aquatic systems. Five separate disciplines within the overall theme were discussed: physical and chemical partitioning of inorganic constituents; analysis association, and effects of organic constituents; bioavailability of sediment-bound metals; concepts and methods regarding physical properties of sediments; and simulation of transport-related properties. The discussions of the participants regarding needs and possible future directions are summarized. The papers and discussions should help guide individual investigators and policy/program managers alike for the next several years.

  10. The origin of life near deep-sea hydrothermal systems during the Cambrian explosion: data from the Kyzyl Tashtyg sulphide deposit (Central Asia)

    NASA Astrophysics Data System (ADS)

    Simonov, Vladimir; Terleev, Alexander; Safonova, Inna; Kotlyarov, Alexey; Stupakov, Sergey; Tokarev, Dmitry

    2015-04-01

    On Earth the solar radiation and the hydrothermal circulation both affect life evolution. Recent extensive studies of the World Ocean have shown that the biodiversity of Earth is linked with hydrothermal activity on the oceanic floor. These deep-sea ecosystems use chemical energy, not solar radiation. In the last quarter of the XX century, a new type of hydrothermal systems, so-called black smokers, was discovered in mid-oceanic ridges. As black smokers form sulfide ores and are surrounded by abundant bio-oases or symbioses, identification of their analogues in ancient orogenic belts is necessary for studying life origin and evolution. Of special importance are problems of life associated with deep-sea hydrothermal systems acted at the Precambrian-Cambrian boundary - the time of Cambrian explosion (Maruyama et al., 2013). During that explosion life significantly evolved and diversified due to dramatic changes of Earth's environment. Consequently, the early Cambrian - late Precambrian Kyzyl Tashtyg sulphide deposit of East Tuva in the Central Asian Orogenic Belt is of special interest. This deposit was formed on the bottom of ancient back-arc deep-sea basin as a result of black smoker hydrothermal activity and is hosted by volcanogenic-sedimentary rocks altered by the high temperature solutions. The altered Kyzyl Tashtyg basalts have an amygdules (filled by albite, epidote and carbonates), contain brown-green microfossils, often attached to their walls. The microfossils are thin tubes 5 to 25 microns in diameter and 500 microns long. This tubes are empty and have straight, curved or branching shape. Chemically, the tube material is close to epidote. In consideration of microscopic dimensions, simple morphology and similarity with modern tubular microorganisms, the studied tube-shaped microfossils can be related to cyanobacteria. Almost the same fossils, associated with oceanic basalt complexes, were described earlier (Furnes et al., 2007; Mcloughlin et al., 2007). Our studies of fluid inclusions in minerals of amygdules showed that basalts, which contain microfossils, were altered by hydrothermal solutions heated up to 120-180 C and compositionally close to the sea water. The Kyzyl Tashtyg sedimentary complexes include hydrothermal quartz-hematite constructions. Ferriferous-siliceous rocks from these structures contain different types of ancient biota: monocyatea, cyanobacteria, cribricyatea and sponge spicules. Thus, our study of early Cambrian - late Precambrian volcanogenic-sedimentary rocks determine different types of ancient biota, which natural occurrence was connected with deep-sea hydrothermal ore-forming black smoker systems of the Kyzyl Tashtyg sulphide deposit. Some part of these hydrothermal solutions were suppliers of energy and nutritive elements for microfossils in closed spaces of amygdules in altered basalts, where cyanobacteria evolved without light and depend on chemosynthesis only. Presence of fossils in the ferriferous-siliceous rocks, formed on the bottom of the ancient deep-sea basin, was connected with biota growth during formation of quartz-hematite constructions as a result of hydrothermal system activity.

  11. Distribution of biologic, anthropogenic, and volcanic constituents as a proxy for sediment transport in the San Francisco Bay Coastal System

    USGS Publications Warehouse

    McGann, Mary; Erikson, Li H.; Wan, Elmira; Powell, Charles, II; Maddocks, Rosalie F.

    2013-01-01

    Although conventional sediment parameters (mean grain size, sorting, and skewness) and provenance have typically been used to infer sediment transport pathways, most freshwater, brackish, and marine environments are also characterized by abundant sediment constituents of biological, and possibly anthropogenic and volcanic, origin that can provide additional insight into local sedimentary processes. The biota will be spatially distributed according to its response to environmental parameters such as water temperature, salinity, dissolved oxygen, organic carbon content, grain size, and intensity of currents and tidal flow, whereas the presence of anthropogenic and volcanic constituents will reflect proximity to source areas and whether they are fluvially- or aerially-transported. Because each of these constituents have a unique environmental signature, they are a more precise proxy for that source area than the conventional sedimentary process indicators. This San Francisco Bay Coastal System study demonstrates that by applying a multi-proxy approach, the primary sites of sediment transport can be identified. Many of these sites are far from where the constituents originated, showing that sediment transport is widespread in the region. Although not often used, identifying and interpreting the distribution of naturally-occurring and allochthonous biologic, anthropogenic, and volcanic sediment constituents is a powerful tool to aid in the investigation of sediment transport pathways in other coastal systems.

  12. Assessing waterbird habitat use in coastal evaporative systems using stable isotopes (? 13C, ? 15N and ?D) as environmental tracers

    NASA Astrophysics Data System (ADS)

    Ramírez, Francisco; Abdennadher, Aida; Sanpera, Carola; Jover, Lluís; Wassenaar, Leonard I.; Hobson, Keith A.

    2011-04-01

    Isotopic patterns of biota across salinity gradients in man-made evaporative systems could assist in determining the use of these habitats by animals. Here we report ? 13C, ? 15N and ?D measurements of a euryhaline fish, the Mediterranean toothcarp ( Aphanius fasciatus), inhabiting a range of salinities in the Thyna saltworks near Sfax (Tunisia). The contribution of these salinity niches to egg formation of two typically piscivorous bird species breeding in the area and feeding within saltworks, Little Tern ( Sternula albifrons) and Little Egret ( Egretta garzetta), was inferred trough a triple-isotope (? 13C, ? 15N and ?D) Bayesian mixing model. Isotopic trends for fish ? 15N and ?D across the salinity gradient followed the equations: ? 15N = e (1.1 + 47.68/Salinity) and ?D = -175.74 + Salinity + Salinity 2; whereas fish ? 13C increased as salinity rose (? 13C = -10.83 + 0.02·Salinity), after a sudden drop in fish isotopic values for salinities >60 (Practical Salinity Scale) (average fish ? 13C for salinities <60 = -5.92‰). Both bird species fed largely on low hypersalinity ponds (salinity = 43; average contribution = 37% and 22% for Little Egrets and Little Terns, respectively), although the use of intermediate hypersalinities (salinities 63 and 70) by Little Terns also occurred (16% and 21%, respectively). Isotopic patterns across salinity gradients allow the use of isotopic measurements to inform studies of habitat occupancy within evaporative systems and provide further insights into how wildlife communities interact with them.

  13. Coniform stromatolites from geothermal systems, North Island, New Zealand

    USGS Publications Warehouse

    Jones, B.; Renaut, R.W.; Rosen, Michael R.; Ansdell, K.M.

    2002-01-01

    Coniform stromatolites are found in several sites in the Tokaanu and Whakarewarewa geothermal areas of North Island, New Zealand. At Tokaanu, silicification of these stromatolites is taking place in Kirihoro, a shallow hot springfed pool. At Whakarewarewa, subfossil silicified coniform stromatolites are found on the floor of "Waikite Pool" on the discharge apron below Waikite Geyser, and in an old sinter succession at Te Anarata. The microbes in the coniform stromatolites from Tokaanu, Waikite Pool, and Te Anarata have been well preserved through rapid silicification. Nevertheless, subtle differences in the silicification style induced morphological variations that commonly mask or alter morphological features needed for identification of the microbes in terms of extant taxa. The coniform stromatolites in the New Zealand hotspring pools are distinctive because (1) they are formed of upward tapering (i.e., conical) columns, (2) neighboring columns commonly are linked by vertical sheets or bridges, (3) internally, they are formed of alternating high- and low-porosity laminae that have a conical vertical profile, and (4) Phormidium form more than 90% of the biota. As such, they are comparable to modern coniform mats and stromatolites found in the geothermal systems of Yellowstone National Park and ice-covered lakes in Antarctica. Formation of the coniform stromatolites is restricted to pools that are characterized by low current energy and a microflora that is dominated by Phormidium. These delicate and intricate stromatolites could not form in areas characterized by fast flowing water or a diverse microflora. Thus, it appears that the distribution of these distinctive stromatolites is controlled by biological constraints that are superimposed on environmental needs.

  14. Body Systems

    NSDL National Science Digital Library

    2011-11-02

    What are the parts and functions of the different systems in the body? Circulatory System Watch the Circulatory System and the Heart video. Complete one of the Circulatory System quizzes. Excretory System Label the parts of the excretory system. Respiratory System Quiz Complete respiratory system quiz to review parts. Skeletal System Label each part of the skeletal system. Vocabulary Review Change the settings to only include body system terms and play Hangman to review new vocabulary. ...

  15. Library System Library System

    E-print Network

    Cinabro, David

    Library System #12;Library System 5150 Anthony Wayne Drive David Adamany Undergraduate Library that for the current fiscal year, we've been given an additional $600,000 for our library materials budget. We're very subscriptions. The Wayne State University Libraries are deeply committed to providing our faculty and students

  16. Interacting Effects of Discharge and Channel Morphology on Transport of Semibuoyant Fish Eggs in Large, Altered River Systems

    PubMed Central

    Worthington, Thomas A.; Brewer, Shannon K.; Farless, Nicole; Grabowski, Timothy B.; Gregory, Mark S.

    2014-01-01

    Habitat fragmentation and flow regulation are significant factors related to the decline and extinction of freshwater biota. Pelagic-broadcast spawning cyprinids require moving water and some length of unfragmented stream to complete their life cycle. However, it is unknown how discharge and habitat features interact at multiple spatial scales to alter the transport of semi-buoyant fish eggs. Our objective was to assess the relationship between downstream drift of semi-buoyant egg surrogates (gellan beads) and discharge and habitat complexity. We quantified transport time of a known quantity of beads using 2–3 sampling devices at each of seven locations on the North Canadian and Canadian rivers. Transport time was assessed based on median capture time (time at which 50% of beads were captured) and sampling period (time period when 2.5% and 97.5% of beads were captured). Habitat complexity was assessed by calculating width?depth ratios at each site, and several habitat metrics determined using analyses of aerial photographs. Median time of egg capture was negatively correlated to site discharge. The temporal extent of the sampling period at each site was negatively correlated to both site discharge and habitat-patch dispersion. Our results highlight the role of discharge in driving transport times, but also indicate that higher dispersion of habitat patches relates to increased retention of beads within the river. These results could be used to target restoration activities or prioritize water use to create and maintain habitat complexity within large, fragmented river systems. PMID:24802361

  17. Evaluation of ecologically relevant bioassays for a lotic system impacted by a coal-mine effluent, using Isonychia.

    PubMed

    Kennedy, A J; Cherry, D S; Currie, R J

    2004-07-01

    Many studies investigating the ecotoxicological impacts of industrial effluents on fresh-water biota utilize standardized test species such as the daphnids, Ceriodaphnia dubia, Daphnia magna, and the fathead minnow, Pimephales promelas. Such species may not be the most predictive or ecologically relevant gauges of the responses of instream benthic macroinvertebrates to certain stressors, such as total dissolved solids. An indigenous species approach should be adopted, using a sensitive benthic collector-filterer following development of practical laboratory bioassays. In the Leading Creek Watershed (southeast Ohio), an aggregated approximately 99% reduction in mean mayfly abundance for all impacted sites was observed below a coal-mine effluent with mean specific conductivity (SC) of 8,109 (7,750-8,750) microS cm(-1). The mayfly, Isonychia, was exposed for 7-days to a simulation of this effluent, in lotic microcosms. Based on lowest observable adverse effect concentrations, Isonychia survival was a more sensitive endpoint to SC (1,562 microS cm(-1)) than were 7-day C. dubia survival and fecundity (3,730 microS cm(-1)). Isonychia molting, a potentially more sensitive endpoint, was also examined. Using traditional test species to assess discharges to surface water alone may not adequately protect benthic macroinvertebrate assemblages in systems impaired by discharges high in SC. PMID:15195819

  18. Interacting effects of discharge and channel morphology on transport of semibuoyant fish eggs in large, altered river systems

    USGS Publications Warehouse

    Worthington, Thomas A.; Brewer, Shannon K.; Farless, Nicole; Grabowski, Timothy B.; Gregory, Mark S.

    2014-01-01

    Habitat fragmentation and flow regulation are significant factors related to the decline and extinction of freshwater biota. Pelagic-broadcast spawning cyprinids require moving water and some length of unfragmented stream to complete their life cycle. However, it is unknown how discharge and habitat features interact at multiple spatial scales to alter the transport of semi-buoyant fish eggs. Our objective was to assess the relationship between downstream drift of semi-buoyant egg surrogates (gellan beads) and discharge and habitat complexity. We quantified transport time of a known quantity of beads using 2–3 sampling devices at each of seven locations on the North Canadian and Canadian rivers. Transport time was assessed based on median capture time (time at which 50% of beads were captured) and sampling period (time period when 2.5% and 97.5% of beads were captured). Habitat complexity was assessed by calculating width:depth ratios at each site, and several habitat metrics determined using analyses of aerial photographs. Median time of egg capture was negatively correlated to site discharge. The temporal extent of the sampling period at each site was negatively correlated to both site discharge and habitat-patch dispersion. Our results highlight the role of discharge in driving transport times, but also indicate that higher dispersion of habitat patches relates to increased retention of beads within the river. These results could be used to target restoration activities or prioritize water use to create and maintain habitat complexity within large, fragmented river systems.

  19. Transport and accumulation of cesium-137 and mercury in the Clinch River and Watts Bar Reservoir system. Environmental Restoration Program

    SciTech Connect

    Olsen, C.R.; Larsen, I.L.; Lowry, P.D.; Moriones, C.R.; Ford, C.J.; Dearstone, K.C.; Turner, R.R.; Kimmel, B.L.; Brandt, C.C.

    1992-06-01

    Operations and waste disposal activities at the Oak Ridge Y-12 Plant, the Oak Ridge National Laboratory (ORNL), and the Oak Ridge K-25 Site (formerly the Oak Ridge Gaseous Diffusion Plant) on the US Department of Energy (DOE) Oak Ridge Reservation (ORR) have introduced a variety of airborne, liquid, and solid wastes into the surrounding environment. Some of these wastes may affect off-site areas by entering local streams, which ultimately drain into the Clinch and Tennessee river system. Previously reported concentrations of radionuclides, metals and organic compounds in water, sediment, and biota of the Clinch River and Watts Bar Reservoir suggest the presence of a variety of contaminants of possible concern to the protection of human health and the environment. The work reported here represents part of the initial scoping phase for the Clinch River RCRA Facility Investigation. In this work, the distribution of {sup 137}Cs is used to identify contaminant accumulation patterns and potential problem, or ``hot-spot,`` areas with regard to environmental hazard or human health. Radiocesium was chosen for this scoping effort because (1) its history of release into the Clinch River is reasonably well documented, (2) it is easy and inexpensive to measure by gamma spectrometry, and (3) it is rapidly sorbed to particulate matter and thus serves as a cost-effective tracer for identifying the transport and accumulation patterns of many other particle-reactive contaminants, such as mercury (Hg), lead (Pb), and plutonium (Pu), and polychlorinated biphenyls (PCBs).

  20. Transport and accumulation of cesium-137 and mercury in the Clinch River and Watts Bar Reservoir system

    SciTech Connect

    Olsen, C.R.; Larsen, I.L.; Lowry, P.D.; Moriones, C.R.; Ford, C.J.; Dearstone, K.C.; Turner, R.R.; Kimmel, B.L.; Brandt, C.C.

    1992-06-01

    Operations and waste disposal activities at the Oak Ridge Y-12 Plant, the Oak Ridge National Laboratory (ORNL), and the Oak Ridge K-25 Site (formerly the Oak Ridge Gaseous Diffusion Plant) on the US Department of Energy (DOE) Oak Ridge Reservation (ORR) have introduced a variety of airborne, liquid, and solid wastes into the surrounding environment. Some of these wastes may affect off-site areas by entering local streams, which ultimately drain into the Clinch and Tennessee river system. Previously reported concentrations of radionuclides, metals and organic compounds in water, sediment, and biota of the Clinch River and Watts Bar Reservoir suggest the presence of a variety of contaminants of possible concern to the protection of human health and the environment. The work reported here represents part of the initial scoping phase for the Clinch River RCRA Facility Investigation. In this work, the distribution of {sup 137}Cs is used to identify contaminant accumulation patterns and potential problem, or hot-spot,'' areas with regard to environmental hazard or human health. Radiocesium was chosen for this scoping effort because (1) its history of release into the Clinch River is reasonably well documented, (2) it is easy and inexpensive to measure by gamma spectrometry, and (3) it is rapidly sorbed to particulate matter and thus serves as a cost-effective tracer for identifying the transport and accumulation patterns of many other particle-reactive contaminants, such as mercury (Hg), lead (Pb), and plutonium (Pu), and polychlorinated biphenyls (PCBs).

  1. Immune System

    MedlinePLUS

    ... could put us out of commission. What the Immune System Does The immune (pronounced: ih- myoon ) system, which ... Continue Things That Can Go Wrong With the Immune System Disorders of the immune system can be broken ...

  2. Endocrine System

    MedlinePLUS

    ... is called the endocrine system . What Is the Endocrine System? Although we rarely think about the endocrine system, ... stores of energy. Back Continue What Does the Endocrine System Do? Once a hormone is secreted, it travels ...

  3. Distributed Systems Multiagent Systems

    E-print Network

    Polani, Daniel

    ; no \\big brother" #15; distributedness 5 #12; Why RoboCup? \\Conventional" Scienti#12;c Approach: #15 { solution of problems in a team { against adversarial conditions { planning, learning and adaptation #15; no \\Big Brother"! #15; prototype for multiagent systems 11 #12; Scenario server agent team 2 agent team 1

  4. Operating Systems.

    ERIC Educational Resources Information Center

    Denning, Peter J.; Brown, Robert L.

    1984-01-01

    A computer operating system spans multiple layers of complexity, from commands entered at a keyboard to the details of electronic switching. In addition, the system is organized as a hierarchy of abstractions. Various parts of such a system and system dynamics (using the Unix operating system as an example) are described. (JN)

  5. Aerospace Systems

    NSDL National Science Digital Library

    This pdf contains a syllabus for a course on aerospace systems as part of the Aerospace Technology Program. This course covers an introduction to expendable and reusable Space Launch Vehicle (SLV) systems including hydraulic, pneumatic, electrical, propulsion, mechanical, HVAC (heating, ventilation and air conditioning), and ECLSS (Environmental Control and Life Support Systems). How systems interact with computer and data acquisition systems is also covered.

  6. Immune System

    MedlinePLUS

    ... JavaScript on. Read more information on enabling JavaScript. Immune System Top Banner Content Area Skip Content Marketing Share ... and growth to maintain optimal health. Understanding the Immune System Overview of the Immune System Features of an ...

  7. Water and the Earth System in the Anthropocene: Evolution of Socio-Hydrology

    NASA Astrophysics Data System (ADS)

    Sivapalan, M.; Bloeschl, G.

    2014-12-01

    Over the past century, hydrological science has evolved through distinct eras as judged by ideas, information sources, technological advances and societal influences: Empirical Era which was data based with little theory, Systems Era that focused on input-output relationships, Process Era with a focus on processes, and the Geosciences Era where hydrology was considered an Earth System science. We argue that as the human footprint on earth becomes increasingly dominant, we are moving into a Co-evolution Era. Co-evolution implies that the components of the Earth system are intimately intertwined at many time scales - fast scales of immediate feedbacks that translate into slow scale interdependencies and trends. These involve feedbacks between the atmosphere, biota, soils and landforms, mediated by water flow and transport processes. The human factor is becoming a key component of this coupled system. While there is a long tradition of considering effects of water on humans, and vice versa, the new thrust on socio-hydrology has a number of defining characteristics that sets it apart from traditional approaches: - Capturing feedbacks of human-natural water system in a dynamic way (slow and fast processes) to go beyond prescribing human factors as mere boundary conditions. These feedbacks will be essential to understand how the system may evolve in the future into new, perhaps previously unobserved, states. - Quantifying system dynamics in a generalizable way. So far, water resources assessment has been context dependent, tied to local conditions. While for immediate decision making this is undoubtedly essential, for more scientific inquiry, a more uniform knowledge base is indispensable. - Not necessarily predictive. The coupled human-nature system is inherently non-linear, which may prohibit predictability in the traditional sense. The socio-hydrologic approach may still be predictive in a statistical sense and, perhaps even more importantly, it may yet reveal possible futures not predicted by traditional forecasts, yet essential for long-term decision making. Guided by these overarching arguments, and a review of recent progress, we will present a structured overview of socio-hydrology, framing the theoretical, observational and methodological challenges that lie ahead and ways to address them.

  8. Bioaccumulation of organochlorine pesticides in aquatic system—an overview

    Microsoft Academic Search

    A. K. Chopra; Mukesh Kumar Sharma; Shikha Chamoli

    2011-01-01

    In recent years, various environmental issues have aroused a concern on the pollution of pesticides in rivers and in their\\u000a various intercompartments. Multiple residues of pesticides discharged from industries or as a result of extensive use of agrochemicals\\u000a in agriculture have been monitored. These pesticide residues contaminate the river ecosystem and its intercompartments such\\u000a as sediments, and aquatic biota, and

  9. Systems Thinking (and Systems Doing).

    ERIC Educational Resources Information Center

    Brethower, Dale M.; Dams, Peter-Cornelius

    1999-01-01

    Introduces human performance technology (HPT) by answering the following questions related to: what systems does; practical issues and questions to which systems thinking is relevant; research questions and answers with respect to systems thinking; how HPT practitioners can do systems thinking; systems thinking tools; what is and is not known…

  10. The dispersal and storage of sediment-associated metals in an arid river system: the Leichhardt River, Mount Isa, Queensland, Australia.

    PubMed

    Taylor, Mark Patrick; Hudson-Edwards, Karen A

    2008-03-01

    This paper details the distribution of Cu, Pb and Zn in aquatic systems draining Mount Isa Ag-Cu-Pb-Zn Mine in arid northern Queensland, Australia. Sediment-metal concentrations in the <2mm grain-size fraction adjacent to and downstream of the mine significantly exceed background concentrations (Cu, 159; Pb, 36; Zn, 86 ppm) as well as Australian government sediment quality low trigger guidelines (Cu, 65; Pb, 50; Zn, 200 ppm). Overbank sediments are more contaminated than channel sediments with mean values of Cu, 480; Pb, 540; Zn, 750 ppm. Mean concentrations in cut riverbank samples from the <2mm fraction were Cu, 195; Pb, 724; Zn, 807 ppm. Corresponding <180 microm samples returned concentrations of Cu, 321; Pb, 995; Zn, 1110 ppm. Delivery of contaminants during wet seasons from Mount Isa Mine and historically contaminated riverbanks remains an ongoing issue. The ease of dust entrainment in arid zones means that sediments enriched in toxic concentrations of metals may be widely dispersed and ultimately ingested and absorbed by biota. PMID:17611008

  11. Projected Evolution of California's San Francisco Bay-Delta-River System in a Century of Climate Change

    PubMed Central

    Cloern, James E.; Knowles, Noah; Brown, Larry R.; Cayan, Daniel; Dettinger, Michael D.; Morgan, Tara L.; Schoellhamer, David H.; Stacey, Mark T.; van der Wegen, Mick; Wagner, R. Wayne; Jassby, Alan D.

    2011-01-01

    Background Accumulating evidence shows that the planet is warming as a response to human emissions of greenhouse gases. Strategies of adaptation to climate change will require quantitative projections of how altered regional patterns of temperature, precipitation and sea level could cascade to provoke local impacts such as modified water supplies, increasing risks of coastal flooding, and growing challenges to sustainability of native species. Methodology/Principal Findings We linked a series of models to investigate responses of California's San Francisco Estuary-Watershed (SFEW) system to two contrasting scenarios of climate change. Model outputs for scenarios of fast and moderate warming are presented as 2010–2099 projections of nine indicators of changing climate, hydrology and habitat quality. Trends of these indicators measure rates of: increasing air and water temperatures, salinity and sea level; decreasing precipitation, runoff, snowmelt contribution to runoff, and suspended sediment concentrations; and increasing frequency of extreme environmental conditions such as water temperatures and sea level beyond the ranges of historical observations. Conclusions/Significance Most of these environmental indicators change substantially over the 21st century, and many would present challenges to natural and managed systems. Adaptations to these changes will require flexible planning to cope with growing risks to humans and the challenges of meeting demands for fresh water and sustaining native biota. Programs of ecosystem rehabilitation and biodiversity conservation in coastal landscapes will be most likely to meet their objectives if they are designed from considerations that include: (1) an integrated perspective that river-estuary systems are influenced by effects of climate change operating on both watersheds and oceans; (2) varying sensitivity among environmental indicators to the uncertainty of future climates; (3) inevitability of biological community changes as responses to cumulative effects of climate change and other drivers of habitat transformations; and (4) anticipation and adaptation to the growing probability of ecosystem regime shifts. PMID:21957451

  12. Microfluidic Systems Integrated Microfluidic Systems**

    E-print Network

    Ismagilov, Rustem F.

    Microfluidic Systems Integrated Microfluidic Systems** Rustem F. Ismagilov* Keywords: analytical methods · enzymes · microfluidics · microreactors · protein structures Microfluidic systems use networks of channels thinner than a human hair to manipulate nanoliter volumes of re- agents. The goal of microfluidics

  13. LEVELS OF SYNTHETIC MUSK COMPOUNDS IN MUNICIPAL WASTEWATER FOR ESTIMATION OF BIOTA EXPOSURE IN RECEIVING WATERS

    EPA Science Inventory

    To be presented is an overview of the chemistry, the monitoring methodology, and the statistical evaluation of concentrations obtained from the analysis of a suite of compounds (e.g., Galaxolide®, musk xylene, and amino musk xylene) in an aquatic ecological site. ...

  14. Coelacanths from the Middle Triassic Luoping Biota, Yunnan, South China, with the earliest evidence of

    E-print Network

    Benton, Michael

    of coelacanths is patchy, with very few taxa known from the Triassic of Asia. We report here two new genera ocean conditions in the aftermath of the end-Permian mass extinction. Key words: Actinistia erected the name coelacanth ("hollow spine") on the basis of an incomplete specimen from the Permian

  15. Identification of long-chain perfluorinated acids in biota from the Canadian Arctic.

    PubMed

    Martin, Jonathan W; Smithwick, Marla M; Braune, Birgit M; Hoekstra, Paul F; Muir, Derek C G; Mabury, Scott A

    2004-01-15

    Recently it was discovered that humans and animals from various urban and remote global locations contained a novel class of persistent fluorinated contaminants, the most pervasive of which was perfluorooctane sulfonate (PFOS). Lower concentrations of perfluorooctanoate, perfluorohexane sulfonate, and heptadecafluorooctane sulfonamide have also been detected in various samples. Although longer perfluoroalkyl carboxylates (PFCAs) are used in industry and have been detected in fish following a spill of aqueous film forming foam, no studies have been conducted to examine the widespread occurrence of long-chain PFCAs (e.g., CF3(CF2)xCOO-, where x > 6). To provide a preliminary assessment of fluorinated contaminants, including PFCAs, in the Canadian Arctic, polar bears, ringed seals, arctic fox, mink, common loons, northern fulmars, black guillemots, and fish were collected at various locations in the circumpolar region. PFOS was the major contaminant detected in most samples and in polar bear liver was the most prominent organohalogen (mean PFOS = 3.1 microg/g wet weight) compared to individual polychlorinated biphenyl congeners, chlordane, or hexachlorocyclohexane-related chemicals in fat. Using two independent mass spectral techniques, it was confirmed that all samples also contained ng/g concentrations of a homologous series of PFCAs, ranging in length from 9 to 15 carbons. Sum concentrations of PFCAs (sum(PFCAs)) were lower than total PFOS equivalents (sum(PFOS)) in all samples except for mink. In mink, perfluorononanoate (PFNA) concentrations exceeded PFOS concentrations, indicating that PFNA and other PFCAs should be considered in future risk assessments. Mammals feeding at higher trophic levels had greater concentrations of PFOS and PFCAs than mammals feeding at lower trophic positions. In general, odd-length PFCAs exceeded the concentration of even-length PFCAs, and concentrations decreased with increasing chain length in mammals. PFOS and PFCA concentrations were much lower for animals living in the Canadian Arctic than for the same species living in mid-latitude regions of the United States. Future studies should continue to monitor all fluorinated contaminants and examine the absolute and relative toxicities for this novel suite of PFCAs. PMID:14750710

  16. Soil Biology & Biochemistry 38 (2006) 30033018 Diversity and distribution of Victoria Land biota

    E-print Network

    Wall, Diana

    2006-01-01

    d Landcare Research, Private Bag 3127, Hamilton, New Zealand e Department of Ecology, Evolution and Evolution, Massey University, Private Bag 11-222, Palmerston North, New Zealand Received 15 November 2005 and monitoring the effects of ecosystem changes on important soil processes. However, most of Earth's soils

  17. Photographic monitoring of benthic biota at Stetson Bank, Gulf of Mexico

    E-print Network

    Bernhardt, Sarah Praeger

    2000-01-01

    FIGURE Page Map of study site and photostation locations at Stetson Bank, Gulf of Mexico. . Stetson Bank two year temperature record at 21. 5 m. . 12 SCUBA diver using T-framer and Nikonos V camera to photograph repetitive photostations at Stetson.... EVALUATION OF IMAGE ANALYSIS TECHNIQUES Analysis of photographs from marine environments based on photogrammetric methods (American Society of Photogrammetry, 1952) was initially used to assess the number of individuals of different species present in each...

  18. Aromatic Hydrocarbons in Biota from the Detroit River and Western Lake Erie

    Microsoft Academic Search

    Chris D. Metcalfel; Tracy L. Metcalfe; Geoffrey Riddle; G. Douglas Haffner

    1997-01-01

    Polynuclear aromatic hydrocarbons (PAHs) and PCBs in zebra mussels were elevated to concentrations greater than 5,000 ng\\/g lipid and 15,000 ng\\/g lipid, respectively, at the Ambassador Bridge in the Detroit River and concentrations gradually declined at downstream locations, which included three stations in the western basin of Lake Erie (Middle Sister Island, East Sister Island, Pelee Island). PCB concentrations in

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

    Microsoft Academic Search

    J. R. Muscatello; D. M. Janz

    2009-01-01

    Uranium mining and milling operations have the potential to release trace elements such as arsenic, molybdenum, nickel, selenium and uranium and ions (e.g., sulfate, ammonium) into the receiving aquatic ecosystem. The major implication of elevated environmental selenium is its propensity to accumulate in the aquatic food chain, potentially impairing fish reproduction. The objective of this study was to investigate the

  20. COMPARATIVE LIMNOLOGY AND BIOTA OF MINE SPOILS PONDS IN COLORADO (JOURNAL VERSION)

    EPA Science Inventory

    Physico-chemical and biotic parameters were investigated from June 1977 to May 1978 in coal strip-mine ponds in Colorado which differed in age and in the proportion of drainage derived from the mine. There were no discernible effects of mine drainage on temperature, dissolved oxy...

  1. Uncertainties associated with estimates of radium accumulation in lake sediments and biota

    SciTech Connect

    Brenkert, A.L.; Gardner, R.H.; Bartell, S.M.; Hoffman, F.O.

    1987-01-01

    A dynamic model of radium transfers between water, sediments and fish-flesh was developed to compare lakes that differ in their biological and physical characteristics. Results indicate that factors associated with differences in biological productivity between lakes can result in significant differences in the predictions and uncertainties of radium in various aquatic components. 5 refs., 2 figs., 2 tabs.

  2. Organochlorine Pesticides and Polychlorinated Biphenyls (PCBs) in Sediments and Biota from Four US Arctic Lakes

    Microsoft Academic Search

    S. M. Allen-Gil; C. P. Gubala; R. Wilson; D. H. Landers; T. L. Wade; J. L. Sericano; L. R. Curtis

    1997-01-01

    .   Organochlorine (OC) concentrations in surface sediment, snails (Lymnea sp.), and two freshwater fish species (grayling, Thymallus arcticus; and lake trout, Salvelinus namaycush) from four lakes in the US Arctic were determined. In surface sediment, chlorinated benzenes (including hexachlorobenzene,\\u000a HCB), and p,p?-DDT were the primary analytes detected (max?=?0.7 ng\\/g dry wt), while individual polychlorinated biphenyl (PCB) congeners\\u000a were always below

  3. Organochlorine pesticides and polychlorinated biphenyls (PCBs) in sediments and biota from four US Arctic lakes.

    PubMed

    Allen-Gil, S M; Gubala, C P; Wilson, R; Landers, D H; Wade, T L; Sericano, J L; Curtis, L R

    1997-11-01

    Organochlorine (OC) concentrations in surface sediment, snails (Lymnea sp.), and two freshwater fish species (grayling, Thymallus arcticus; and lake trout, Salvelinus namaycush) from four lakes in the US Arctic were determined. In surface sediment, chlorinated benzenes (including hexachlorobenzene, HCB), and p,p'-DDT were the primary analytes detected (max = 0.7 ng/g dry wt), while individual polychlorinated biphenyl (PCB) congeners were always below 0.1 ng/g. A wider range of compounds and higher concentrations were found in lake trout, the top predatory fish species in the same lakes. The concentration ranges for hexachlorocyclohexanes (HCHs), chlordane-related compounds (CHLORs), DDTs, and PCBs in lake trout and grayling were similar to those reported for other arctic freshwater fish (1-100 ng/g wet wt), but one to two orders of magnitude lower than Great Lakes salmonids. Nitrogen isotope analysis confirmed that differences in OC concentrations between grayling and lake trout are explained partly by differences in food web position. PMID:9419256

  4. Lake Michigan: Man's effects on native fish stocks and other biota

    USGS Publications Warehouse

    Wells, LaRue; McLain, Alberton L.

    1973-01-01

    Exploitation was largely responsible for the changes in Lake Michigan fish stocks before the invasion of the smelt, and probably before the invasion of the sea lamprey. The lamprey and alewife, however, have exerted a greater impact than the fishery on native fish populations in recent decades. Accelerated eutrophication and other pollution, although important, have not equalled the other factors in causing changes in native fish populations.

  5. Mercury Distribution in the Biota of a Great Lakes Estuary: Old Woman Creek, Ohio

    Microsoft Academic Search

    Donna R. Francis; David J. Jude; James A. Barres

    1998-01-01

    A study of mercury contamination in a wetland ecosystem was undertaken to assess degree of contamination in various compartments of the food web, and determine the most important routes for mercury to enter fish species. Old Woman Creek is a freshwater estuary on the southern shore of Lake Erie and has been recognized as an important nursery area for fish.

  6. Polybrominated diphenylethers in sediments and biota downstream of potential sources in the UK

    Microsoft Academic Search

    C. R Allchin; R. J Law; S Morris

    1999-01-01

    In a pilot survey, samples of sediment and fish tissue have been collected in the vicinity and downstream of suspected sources of brominated flame retardant compounds. These have been analysed for polybrominated diphenylethers (PBDEs) by means of gas chromatography with electron-capture detection (GC–ECD), with the identity of residues in some samples being confirmed by coupled gas chromatography–mass spectrometry. The concentrations

  7. Biogeochemistry of the Stable Isotopes of Hydrogen and Carbon in Salt Marsh Biota 1

    PubMed Central

    Smith, Bruce N.; Epstein, Samuel

    1970-01-01

    Deuterium to hydrogen ratios of 14 plant species from a salt marsh and lagoon were 55‰ depleted in deuterium relative to the environmental water. Carbon tetrachloride-extractable material from these plants was another 92‰ depleted in deuterium. This gave a fractionation factor from water to CCl4 extract of 1.147. This over-all fractionation was remarkably constant for all species analyzed. Plants also discriminate against 13C, particularly in the lipid fraction. Data suggest that different mechanisms for carbon fixation result in different fractionations of the carbon isotopes. Herbivore tissues reflected the isotopic ratios of plants ingested. Apparently different metabolic processes are responsible for the different degrees of fractionation observed for hydrogen and carbon isotopes. PMID:16657539

  8. Forest harvest impacts on water quality and aquatic biota on the Boreal Plain: introduction to

    E-print Network

    Long, Bernard

    and the water column mixed or weakly thermally strati- fied. Chlorophyll a, cyanobacteria (Aphanizomenon­Anabaena-LR) et les densités de cyanobactéries (Aphanisomenon-Anabaena) ont crû après la récolte, particulièrement

  9. SURVEY, ECOLOGY, AND SYSTEMATICS OF THE UPPER POTOMAC ESTUARY BIOTA: AUFWUCHS MICROFAUNA PHASE III

    E-print Network

    District of Columbia, University of the

    were seeded with the filamentous blue-green alga, Anabaena. To all aquaria was added a mixture these zooplankters could remove the Anabaena.) The experimental side received activated sludge from Blue Plains

  10. Distribution of perfluorinated compounds in water, sediment, biota and floating plants in Baiyangdian Lake, China.

    PubMed

    Shi, Yali; Pan, Yuanyuan; Wang, Jieming; Cai, Yaqi

    2012-02-01

    The distribution of perfluorinated compounds (PFCs) in Baiyangdian Lake, China, was determined in this study. Perfluorooctanoic acid (PFOA) was the dominant PFC in lake water (1.70-73.5 ng L(-1), median 9.72 ng L(-1)), while perfluorooctane sulfonate (PFOS) was the dominant PFC in sediments (0.06-0.64 ng g(-1) dry wt, median 0.19 ng g(-1) dry wt) and in aquatic animals (0.57-13.7 ng g(-1) wet wt, median 2.56 ng g(-1) wet wt). Significant differences in PFC levels were observed among various aquatic animals. We also determined, for the first time, the PFC levels in floating plants, including Ceratophyllum demersum L., Hydrocharis dubia (Bl.) Backer and Salvinia natans (L.), and we found that PFOA and PFNA were the dominant PFCs in these plants. Furthermore, floating plants were observed to have different composition profiles compared to aquatic animals. Geographical differences in PFC levels were also observed, with higher PFC levels in samples from the north part of Baiyangdian Lake than those in the south. The differences in human and industrial activities in different parts of the lake and the discharged wastewater from the Fuhe River may be the major contributors for these geographical differences. PMID:22200049

  11. Biota of the 300-FF-1 operable unit. [Westinghouse Hanford Company

    SciTech Connect

    Rickard, W.H. Jr.; Fitzner, R.E.; Brandt, C.A.

    1990-10-01

    This report summarizes Task 5a-2 of the Phase I Remedial Investigation -- Operable Unit Characterization of the 300-FF-1 Operable Unit on the Hanford Site, near Richland, Washington. The ultimate goal of Phase I is to determine the nature and extent of the threat to public health and the environment from releases of hazardous substances from the operable unit. The purpose of Task 5a-2 was to determine what species inhabit the 300-FF-1 Operable Unit and how they use the unit. The focus is on those species listed as endangered or threatened, those that are economically important, or those that constitute significant components of the human food chain. 39 refs., 5 figs., 5 tabs.

  12. Late Palaeozoic global changes affecting high-latitude environments and biotas: An introduction

    Microsoft Academic Search

    G. R. Shi; J. B. Waterhouse

    The Late Palaeozoic Ice Age (LPIA), spanning approximately from ~320 Ma (Serpukhovian, late Mississippian) to 290 Ma (mid-Sakmarian, Early Permian), represents the vegetated Earth’s largest and most long-lasting regime of severe and multiple glaciations, involving processes and patterns probably comparable to those of the Last Ice Age. Accompanying the LPIA occurred a number of broadly synchronous global environmental and biotic

  13. Paleoenvironmental analysis of a middle Wisconsinan biota site, southwestern Virginia, U.S.A.

    NASA Astrophysics Data System (ADS)

    Whittecar, G. Richard; Wynn, Thomas C.; Bartlett, Charles S.

    2007-07-01

    The Ratcliff Site in southwestern Virginia lies in a small second-order stream valley filled with approximately 3.5 m of organic-rich deposits that contain bones of mammoth, mastodon, deer (or antelope), logs, and plant macrofossils. Radiocarbon analyses indicate the age of the organic-rich sediment ranges from > 44,000 to 29,100 14C yr BP, a time period with no fossil remains reported in this region of the Appalachians. Analyses of field observations, textural data, organic carbon content, and plant macrofossils indicate that the organic-rich sediments contain interbedded standing-water and debris-flow deposits. Up to 6 m of oxidized debris-flow sediments bury the organic-rich sediments. The presence of Rubus parviflorus (Thimble Berry) throughout the deposit indicates the site had a boreal environment from > 44,000 to 29,100 14C yr BP. Plant macrofossil evidence indicates the uplands had stands of spruce/jack-pine forests while the valley contained ponds and associated wetlands. Three debris flows occurred at the site between approximately 38,000 and 29,000 14C yr BP, suggesting a recurrence interval for major storms of approximately 3000 yr, even though the apparent stability of the boreal environment implies a climate not conducive to catastrophic rainstorms. This conflicting combination of features suggests that during the middle Wisconsinan this area experienced generally cool climates, dominated by polar air masses, but was punctuated by relatively brief warm periods marked by incursions of tropical air masses.

  14. The role of biota in retention of fine sediment in deltas

    Microsoft Academic Search

    R. C. Littlewood; S. Dayley; K. Frederick; C. Paola

    2010-01-01

    The fate of Louisiana coastal wetlands is an urgent scientific question and management challenge as well as a key focus of NCED research. This work addresses the effect of wetland vegetation (macrophyton and periphyton) on the proportion of fine material retained by a vegetated delta. Simple geometric considerations suggest that viable delta land area is roughly proportional to this retention

  15. The role of biota in retention of fine sediment in deltas

    NASA Astrophysics Data System (ADS)

    Littlewood, R. C.; Dayley, S.; Frederick, K.; Paola, C.

    2010-12-01

    The fate of Louisiana coastal wetlands is an urgent scientific question and management challenge as well as a key focus of NCED research. This work addresses the effect of wetland vegetation (macrophyton and periphyton) on the proportion of fine material retained by a vegetated delta. Simple geometric considerations suggest that viable delta land area is roughly proportional to this retention fraction; therefore, understanding controls on transport and deposition will be critical for effective management and restoration of Mississippi Delta wetlands. The experimental methodology developed involves a variety of physical models of sediment-laden flow through and over macrophytes and periphyton. Since fines in deltas and estuaries generally exist in a flocculated state, the experiments use kaolinite that is chemically flocculated to approximate observations of diffuse, low-density sediment aggregates in such settings. Results positively relating biomass to sediment trapping agree with field observations suggesting that trapping of fines by marsh vegetation may play a major role in delta morphodynamics.

  16. Photographic monitoring of benthic biota at Stetson Bank, Gulf of Mexico 

    E-print Network

    Bernhardt, Sarah Praeger

    2000-01-01

    at the 2 m² level. Overall the photostations were dominated by Millepora alcicornis (30 %), various poriferans (30 %), and exposed substrate (30 %). No overall temporal changes occurred at Stetson Bank during the period of the study. Two color segmentation...

  17. The Jehol Biota (Lower Cretaceous, China): new discoveries and future prospects.

    PubMed

    Barrett, Paul M; Hilton, Jason M

    2006-03-01

    Continuing work on the paleontology and sedimentology of the Jehol Group (Lower Cretaceous, China) is yielding numerous new insights into the evolution of many Mesozoic plant and animal clades. Nevertheless, many questions remain unanswered regarding Jehol paleoenvironments, paleobiology and paleobiogeography. All of this information will be crucial in providing a detailed reconstruction of this extinct ecosystem. PMID:21395985

  18. Selenium Levels in Biota from Irrigation Drainwater Impoundments in the San Joaquin Valley, California

    Microsoft Academic Search

    Douglas A. Barnum; David S. Gilmer

    1988-01-01

    Waterfowl, fish, invertebrates, and plants were collected from impoundments used for evaporating subsurface irrigation drainwater in Kings and Kern counties, California. Specimens were analyzed for trace elements with emphasis on selenium. Dry weight concentrations of total selenium ranged from 2.5 to 17 ?g\\/g in wigeongrass, Ruppia maritima; 7.6 to 30 ?g\\/g in water boatmen, Corixidae; 12 to 40 ?\\/g in

  19. On the eve of animal radiation: phylogeny, ecology and evolution of the Ediacara biota.

    PubMed

    Xiao, Shuhai; Laflamme, Marc

    2009-01-01

    Ediacara fossils document an important evolutionary episode just before the Cambrian explosion and hold critical information about the early evolution of macroscopic and complex multicellular life. They also represent an enduring controversy in paleontology. How are the Ediacara fossils related to living animals? How did they live? Do they share any evolutionary patterns with other life forms? Recent developments indicate that Ediacara fossils epitomize a phylogenetically diverse biosphere, probably including animals, protists, algae, fungi and others. Their simple ecology is dominated by epibenthic osmotrophs, deposit feeders and grazers, but few if any predators. Their evolution started with an early morphospace expansion followed by taxonomic diversification within confined morphospace, and concluded by extinction of many taxa at the Ediacaran-Cambrian boundary. PMID:18952316

  20. The biota of Antarctic pack ice in the Weddell sea and Antarctic Peninsula regions

    Microsoft Academic Search

    David L. Garrison; Kurt R. Buck

    1989-01-01

    Pack ice surrounding Antarctica supports rich and varied populations of microbial organisms. As part of the Antarctic Marine Ecosystem Research in the Ice Edge Zone (AMERIEZ) studies, we have examined this community during the late spring, autumn, and winter. Although organisms are found throughout the ice, the richest concentrations often occur in the surface layer. The ice flora consists of

  1. Secondary successions of biota in oil-polluted peat soil upon different biological remediation methods

    NASA Astrophysics Data System (ADS)

    Melekhina, E. N.; Markarova, M. Yu.; Shchemelinina, T. N.; Anchugova, E. M.; Kanev, V. A.

    2015-06-01

    The effects of different bioremediation methods on restoration of the oil-polluted peat soil (Histosol) in the northernmost taiga subzone of European Russia was studied. The population dynamics of microorganisms belonging to different trophic groups (hydrocarbon-oxidizing, ammonifying, nitrifying, and oligonitrophilic) were analyzed together with data on the soil enzyme (catalase and dehydrogenase) activities, population densities of soil microfauna groups, their structures, and states of phytocenoses during a sevenyear-long succession. The remediation with biopreparations Roder composed of oil-oxidizing microorganisms-Roder with Rhodococcus rubber and R. erythropolis and Universal with Rhodotorula glutinis and Rhodococcus sp.-was more efficient than the agrochemical and technical remediation. It was concluded that the biopreparations activate microbiological oil destruction, thereby accelerating restoration succession of phytocenosis and zoocenosis. The succession of dominant microfauna groups was observed: the dipteran larvae and Mesostigmata mites predominant at the early stages were replaced by collembolans at later stages. The pioneer oribatid mite species were Tectocepheus velatus, Oppiella nova, Liochthonius sellnicki, Oribatula tibialis, and Eupelops sp.

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

    Microsoft Academic Search

    G. M. DeGraeve; R. L. Overcast; H. L. Bergman

    1980-01-01

    The acute and embryo-larval toxicity of the Laramie Energy Technology Center's Hanna-3 underground coal gasification (UCG) condenser water and its constituents were studied in continuous-flow bioassays. The 96-hr LC50 dilution values for untreated Hanna-3 UCG condenser water were 0.1% for rainbow trout, 0.11% for fathead minnows and the 48-hr LC50 dilution forDaphnia pulicaria was 0.18%. Separate 96-hr acute tests with

  3. Organosulfur Compounds: Molecular and Isotopic Evolution from Biota to Oil and Gas

    NASA Astrophysics Data System (ADS)

    Amrani, Alon

    2014-05-01

    Organosulfur compounds (OSCs) play important roles in the formation, preservation, and thermal degradation of sedimentary organic matter and the associated petroleum generation. Improved analytical techniques for S isotope analysis have recently enhanced our understanding of the mechanisms for OSC formation and maturation and their associated S isotope distributions. The close interaction of OSCs with inorganic S species throughout their formation and maturation affects their 34S/32S isotopic ratio (δ34S), forming specific signatures for distinct sources and processes. Ultimately, thermal maturation homogenizes the δ34S values of different fractions and individual compounds. Reservoir processes such as thermochemical sulfate reduction (TSR) introduce exogenous and isotopically distinct S into hydrocarbons and can significantly change the δ34S of petroleum or kerogen. Specific OSCs react at different rates and thus can be used to evaluate the extent of processes such as TSR. This article reviews factors that affect the 34S/32S isotopic distribution of OSCs along pathways of formation, diagenesis, and thermal alteration.

  4. Environmental Exposure of Aquatic and Terrestrial Biota to Triclosan and Triclocarban.

    PubMed

    Chalew, Talia E; Halden, Rolf U

    2009-01-01

    The synthetic biocides triclosan (5-chloro-2-(2,4-dichlorophenoxy)phenol) and triclocarban (3,4,4'-trichlorocarbanilide) are routinely added to a wide array of antimicrobial personal care products and consumer articles. Both compounds can persist in the environment and exhibit toxicity toward a number of biological receptors. Recent reports of toxicological effects in wildlife, human cell cultures, and laboratory animals have heightened the interest in the occurrence of these biocide and related toxic effects. The present study aimed to summarize published environmental concentrations of biocides and contrast them with toxicity threshold values of susceptible organisms. Environmental occurrences and toxicity threshold values span more than six orders of magnitude in concentration. The highest biocide levels, measured in the mid parts-per-million range, were determined to occur in aquatic sediments and in municipal biosolids destined for land application. Crustacea and algae were identified as the most sensitive species, susceptible to adverse effects from biocide exposures in the parts-per-trillion range. An overlap of environmental concentrations and toxicity threshold values was noted for these more sensitive organisms, suggesting potential adverse ecological effects in aquatic environments. Affirmative evidence for this is lacking, however, since studies examining environmental occurrences of biocides vis-à-vis the health and diversity of aquatic species have not yet been conducted. PMID:20046971

  5. Environmental Exposure of Aquatic and Terrestrial Biota to Triclosan and Triclocarban

    PubMed Central

    Chalew, Talia E.; Halden, Rolf U.

    2009-01-01

    The synthetic biocides triclosan (5-chloro-2-(2,4-dichlorophenoxy)phenol) and triclocarban (3,4,4'-trichlorocarbanilide) are routinely added to a wide array of antimicrobial personal care products and consumer articles. Both compounds can persist in the environment and exhibit toxicity toward a number of biological receptors. Recent reports of toxicological effects in wildlife, human cell cultures, and laboratory animals have heightened the interest in the occurrence of these biocide and related toxic effects. The present study aimed to summarize published environmental concentrations of biocides and contrast them with toxicity threshold values of susceptible organisms. Environmental occurrences and toxicity threshold values span more than six orders of magnitude in concentration. The highest biocide levels, measured in the mid parts-per-million range, were determined to occur in aquatic sediments and in municipal biosolids destined for land application. Crustacea and algae were identified as the most sensitive species, susceptible to adverse effects from biocide exposures in the parts-per-trillion range. An overlap of environmental concentrations and toxicity threshold values was noted for these more sensitive organisms, suggesting potential adverse ecological effects in aquatic environments. Affirmative evidence for this is lacking, however, since studies examining environmental occurrences of biocides vis-à-vis the health and diversity of aquatic species have not yet been conducted. PMID:20046971

  6. Cadmium and polychlorinated biphenyls: Different distribution pattern in North Sea Benthic biota

    NASA Astrophysics Data System (ADS)

    Everaarts, J. M.; Otter, E.; Fischer, C. V.

    Whole-body concentrations of cadmium in the shrimp Crangon allmanni and the starfish Asterias rubens were significantly higher in specimens collected from areas north and northeast of the Dogger Bank than in other areas of the North Sea studied. In the brown shrimp Crangon crangon, whose distribution is restricted to the estuarine and coastal zone, the cadmium concentration was found to be significantly lower than in C. allmanni and did not vary with sampling site. The cadmium concentrations in shrimp increased from the estuarine area (including the Dutch Wadden Sea) to the coastal zone and Southern Bight of the North Sea and again to the open central North Sea (Dogger Bank). Concentrations of the total of 50 polychlorinated biphenyl congeners ( ?50-CB) were higher in Crangon crangon and Asterias rubens occurring in the coastal zone of the Southern Bight than in specimens of the central and northern part of the Dutch continental shelf. The ?50-CB concentration in the shrimp Crangon allmanni was considerably lower than in the closely related species C. crangon. Thus, cadmium and PCBs showed different distribution patterns in North Sea benthic invertebrates: highest concentrations of ?50-CB were restricted to estuarine and coastal areas and highest concentrations of cadmium were found in the open sea (central North Sea, north of the Dogger Bank).

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

    SciTech Connect

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

    2010-06-09

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

  8. The natural history of Enewetak Atoll: Volume 1, The ecosystem: Environments, biotas, and processes

    SciTech Connect

    Devaney, D.M.; Reese, E.S.; Burch, B.L.; Helfrich, P. (eds.)

    1987-01-01

    The two volumes of The Natural History of Enewetak Atoll summarize research done at the Mid-Pacific Research Laboratory from 1954 to 1984 under the auspices of the Department of Energy. The history of the laboratory and the reasons for its support by the United States Department of Energy are described in Chapter 1 of Volume 1. Volume 1 provides a synthesis of the research carried out under the subject headings of the respective chapters. Certain of the chapters, e.g., those on geology, subtidal and intertidal environments and ecology, and those on reef processes and trophic relationships, summarize a great diversity of research carried out by many scientists for many years. In contrast, the chapters on meteorology and oceanography summarize research carried out under one integrated program involving fewer scientists working over a shorter period. Individual chapters are processed separately for the data base.

  9. Effects of Antarctic sea ice biota on seeding as studied in aquarium experiments

    Microsoft Academic Search

    Harri Kuosa; Bosse Norrman; Kai Kivi; Frederico Brandini

    1992-01-01

    The potential seeding impact of sea ice microbial communities was studied during late austral winter early spring 1988 in the Weddell Sea, Antarctica. Experiments were performed in seawater aquariums with natural seawater and seawater enriched with crushed ice. Algal, protozoan and bacterial cell numbers were followed, as well as nutrients and DOC levels. The results showed a potential seeding effect

  10. Contribution to the lichen biota of Slovenia XII. Some lichens from Logarska dolina.

    PubMed

    Bilovitz, Peter Othmar; Arup, Ulf; Mayrhofer, Helmut

    2010-11-01

    A list of 94 species is presented including Bacidia subacerina and Lopadium disciforme as new for Slovenia and Bilimbia accedens, Lecanora leptyrodes, Megalaria grossa, Mycobilimbia epixanthoides, Rinodina efflorescens, and Sclerophora peronella as new for the alpine phytogeographical region of Slovenia. PMID:22319012

  11. Yeast biota associated to naturally fermented table olives from different Italian cultivars.

    PubMed

    Tofalo, Rosanna; Perpetuini, Giorgia; Schirone, Maria; Suzzi, Giovanna; Corsetti, Aldo

    2013-02-15

    The yeast communities associated with the fermentation of six different cultivars of Italian table olives were studied. Molecular identification of a total of 117 isolates was achieved by a combination of PCR-RFLP of the 5.8S ITS rRNA region and sequencing of the D1/D2 domain of the 26S rRNA gene. In addition, the isolates were differentiated by RAPD-PCR. The yeast population was also monitored by a culture-independent method based on PCR-DGGE analysis. This combined strategy resulted to be a powerful and reliable tool to investigate table olives yeast ecology and revealed that Saccharomyces cerevisiae was present in all the processed olives. Moreover, strains were characterized on the basis of different properties of technological interest. In particular, ?-glucosidase, catalase, pectinolytic, xylanolytic, esterase and lipase activities were investigated and the ability to grow up in presence of different salt concentration (5-7.5-10-14-20% w/v) was evaluated. The majority of strains showed catalase activity and none of them expressed pectinolytic, xylanolytic, esterase or lipase activities. Six strains belonging to Pichia galeiformis and six strains of Wicheramomyces anomalus showed ?-glucosidase activity. Only 10 S. cerevisiae strains were able to grow in presence of 14% NaCl. The obtained results offer valuable information on yeast population biodiversity and dynamics in naturally fermented Italian table olives and show the potential use of some yeast strains, besides lactic acid bacteria, as a part of mixed starter cultures for table olive fermentation. PMID:23334098

  12. Influence of trophic status on PCB distribution in lake sediments and biota

    Microsoft Academic Search

    O. Berglund; P. Larsson; G. Ewald; L. Okla

    2001-01-01

    We investigated the relationship between trophic status and polychlorinated biphenyl (PCB) distribution in 19 Swedish lakes. We analyzed PCB in water, phytoplankton, zooplankton, fish and sediment during two sampling periods, in spring and summer. The mass of ?PCB in the lake sediments was positively related to lake trophy, i.e. more PCBs were accumulated and buried in the sediment of eutrophic

  13. Analysis of Engineered Nanomaterials in Complex Matricies (Environment and Biota): General Considerations and Conceptual Case Studies

    EPA Science Inventory

    Advances in the study of the environmental fate, transport, and ecotoxicological effects of engineered nanomaterials (ENMs) have been hampered by a lack of adequate techniques for the detection and quantification of ENMs at environmentally relevant concentrations in complex media...

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

    E-print Network

    Bonaccorso, Elisa; Guayasamin, Juan Manuel

    2013-06-26

    of the genus, and an analysis in BEAST was used to estimate a time framework for its diversification. A sister relationship between the Pantepui and Andes+Cordillera de la Costa was significantly more likely than topologies indicating other hypothesis...

  15. Interactive effects of plant species diversity and elevated CO2 on soil biota and nutrient cycling.

    PubMed

    Niklaus, P A; Alphei, J; Kampichler, C; Kandeler, E; Körner, C; Tscherko, D; Wohlfender, M

    2007-12-01

    Terrestrial ecosystems consist of mutually dependent producer and decomposer subsystems, but not much is known on how their interactions are modified by plant diversity and elevated atmospheric CO2 concentrations. Factorially manipulating grassland plant species diversity and atmospheric CO2 concentrations for five years, we tested whether high diversity or elevated CO2 sustain larger or more active soil communities, affect soil aggregation, water dynamics, or nutrient cycling, and whether plant diversity and elevated CO2 interact. Nitrogen (N) and phosphorus (P) pools, symbiotic N2 fixation, plant litter quality, soil moisture, soil physical structure, soil nematode, collembola and acari communities, soil microbial biomass and microflora community structure (phospholipid fatty acid [PLFA] profiles), soil enzyme activities, and rates of C fluxes to soils were measured. No increases in soil C fluxes or the biomass, number, or activity of soil organisms were detected at high plant diversity; soil H2O and aggregation remained unaltered. Elevated CO2 affected the ecosystem primarily by improving plant and soil water status by reducing leaf conductance, whereas changes in C cycling appeared to be of subordinate importance. Slowed-down soil drying cycles resulted in lower soil aggregation under elevated CO2. Collembola benefited from extra soil moisture under elevated CO2, whereas other faunal groups did not respond. Diversity effects and interactions with elevated CO2 may have been absent because soil responses were mainly driven by community-level processes such as rates of organic C input and water use; these drivers were not changed by plant diversity manipulations, possibly because our species diversity gradient did not extend below five species and because functional type composition remained unaltered. Our findings demonstrate that global change can affect soil aggregation, and we advocate that soil aggregation should be considered as a dynamic property that may respond to environmental changes and feed back on other ecosystem functions. PMID:18229849

  16. Age-related changes in salivary antibodies to commensal oral and gut biota.

    PubMed

    Percival, R S; Marsh, P D; Challacombe, S J

    1997-02-01

    The prevalence of mucosally derived infections appears to increase with age, suggesting dysfunction at the mucosal surfaces. The present investigation was undertaken to examine any age-related changes in secretion rates and concentrations of secretory antibodies in whole and parotid saliva in a healthy adult population. A total of 116 subjects were subdivided into the following age groups: 20-39 years, 40-59 years, 60-79 years and 80 years and over. Specific immunoglobulin A (IgA), IgG and IgM antibodies in whole and parotid saliva to Streptococcus mutans (serotype c), Actinomyces viscosus NCTC 10951, and Escherichia coli NCTC 10418 were quantified by enzyme-linked immunosorbent assay. IgA antibodies to all three organisms examined increased with age in both whole and parotid saliva, whereas IgG antibody levels to S. mutans in whole saliva were significantly decreased with age. IgG antibodies to E. coli in parotid saliva were reduced in older age groups. IgM antibody levels to S. mutans were reduced with age in both secretions, whereas IgM antibodies to A. viscosus were greatest in the oldest age groups. No significant changes with age were observed in salivary IgM antibody levels to E. coli. No significant reduction in the secretion rates of IgA antibodies were observed in parotid or whole saliva, whereas IgG and IgM antibody secretion rates to all three microorganisms were reduced in most age groups in both whole and parotid saliva. The results of this investigation have demonstrated age-related changes with salivary antibodies, but, whereas salivary IgG and IgM antibodies showed decreases, salivary IgA levels generally increased with age. This suggests that the ability to form IgA antibody responses is not impaired with increased age, and that secretion rates and functional properties of antibodies may be as important as concentrations in protection against mucosal infective diseases. PMID:9151645

  17. Influence of Fatty Alcohols and Acids on the Clarity and Biota of Impounded Reservoirs 

    E-print Network

    Davis, W. B.; Reynolds, T. D.

    1969-01-01

    H, hardness, alkalinity, turbidity, surface clarity, oxygen diffusion, diurnal oxygen, chlorophyll, bacterial counts, some unicellular algae, some filamentous algae, waterweeds (Anacharis) and fish (Gambusia affins and Fundalus notatus). Field and laboratory...

  18. Community palaeoecology of the early Cambrian Maotianshan Shale biota: Ecological dominance of priapulid worms

    E-print Network

    Dornbos, Stephen Q.

    of priapulid worms Stephen Q. Dornbos a,, Jun-Yuan Chen b a Department of Geosciences, University of Wisconsin that the three most abundant genera comprise 43.2% of all specimens: the tubiform priapulid worm Paraselkirkia (16.0%), the diminutive priapulid worm Sicyophorus (14.3%), and the brachiopod Heliomedusa (12

  19. Scales of climatic variability and time averaging in Pleistocene biotas: implications for ecology and evolution

    Microsoft Academic Search

    Kaustuv Roy; James W. Valentine; David Jablonski; Susan M. Kidwell

    1996-01-01

    Biotic responses to Pleistocene climatic fluctuations have traditionally been analyzed in the context of glacial-interglacial cycles on the scale of 10000–100 000 years. However, emerging evidence indicates that short-term, high-amplitude, climatic ‘flickers’, close to the limits of the resolving power of the fossil record, occurred within the glacial and interglacial substages. Because species shift geographically in response to the climate

  20. MUSKEGON, MICHIGAN INDUSTRIAL-MUNICIPAL WASTEWATER STORAGE LAGOONS: BIOTA AND ENVIRONMENT

    EPA Science Inventory

    A limnological investigation was carried out on two 344 hectare (850 acre) industrial-municipal wastewater storage lagoons from August 1973 until August 1975. Besides monitoring physical and chemical parameters during the period of the initial filling, the biological community wa...

  1. Changes in atmospheric CO2 - Influence of the marine biota at high latitude

    NASA Technical Reports Server (NTRS)

    Knox, F.; Mcelroy, M. B.

    1984-01-01

    Approximately half of the nitrogen and phosphorus entering deep waters of the contemporary ocean are transported from the surface in inorganic form as preformed nutrients. A simple model for ocean chemistry is presented and shown to account for the present level of atmospheric CO2. Fluctuations in preformed nutrients, modulated by changes in insolation and circulation at high latitudes, can result in significant variations in CO2. It is suggested that these changes may account for the apparent control on climate exercised by secular variations in the orbital parameters of the earth.

  2. Accumulation of polychlorinated terphenyls in aquatic biota of an estuarine creek.

    PubMed

    Gallagher, K; Hale, R C; Greaves, J; Bush, E O; Stilwell, D A

    1993-12-01

    Aroclor 5432, a mixture of polychlorinated terphenyls (PCT), was detected in several biological compartments including saltmarsh cordgrass (Spartina alterniflora), American oysters (Crassostrea virginica), red-jointed fiddler crabs (Uca minax), wharf crabs (Sesarma reticulatum), and mummichogs (Fundulus heteroclitus) collected from Tabbs Creek. This tidal creek is located in the southern Chesapeake Bay region and contains sediments with high concentrations of PCT. Samples were collected at four sites, ranging from a suspected outfall near the head of the creek, to its mouth, approximately 2.5 river kilometers downstream. Species from several phyla were selected in order to examine PCT accumulation in physiologically and ecologically different organisms. PCT concentrations in sediment, saltmarsh cordgrass, native oysters, and fiddler crabs decreased with distance downstream. Residues in transplanted oysters and mummichogs showed a more variable trend with distance downstream. The organism with the highest mean concentration (18,300 micrograms/kg dry wt) was the native oyster, a benthic filter feeder. PMID:7507821

  3. Revising the fundamentals of ecological knowledge: the biota–environment interaction

    Microsoft Academic Search

    Victor G. Gorshkov; Anastassia M. Makarieva; Vadim V. Gorshkov

    2004-01-01

    The foundations of ecological science were laid down at those times when the problem of a possible loss of local and global environmental sustainability was not as acute as it has become today. To make sure that the proposed scientific solutions to this problem are responsible, it is useful to revise the existing frameworks of environmental thought. In this paper,

  4. The Bering Land Bridge: a moisture barrier to the dispersal of steppe-tundra biota?

    NASA Astrophysics Data System (ADS)

    Elias, Scott A.; Crocker, Barnaby

    2008-12-01

    The Bering Land Bridge (BLB) connected the two principal arctic biological refugia, Western and Eastern Beringia, during intervals of lowered sea level in the Pleistocene. Fossil evidence from lowland BLB organic deposits dating to the Last Glaciation indicates that this broad region was dominated by shrub tundra vegetation, and had a mesic climate. The dominant ecosystem in Western Beringia and the interior regions of Eastern Beringia was steppe-tundra, with herbaceous plant communities and arid climate. Although Western and Eastern Beringia shared many species in common during the Late Pleistocene, there were a number of species that were restricted to only one side of the BLB. Among the vertebrate fauna, the woolly rhinoceros was found only to the west of the BLB, North American camels, bonnet-horned musk-oxen and some horse species were found only to the east of the land bridge. These were all steppe-tundra inhabitants, adapted to grazing. The same phenomenon can be seen in the insect faunas of the Western and Eastern Beringia. The steppe-tundra beetle fauna of Western Beringia was dominated by weevils of the genus Stephanocleonus, a group that was virtually absent from Eastern Beringia. The dry-adapted weevils, Lepidophorus lineaticollis and Vitavitus thulius were important members of steppe-tundra communities in Eastern Beringia, but were either absent or rare in Western Beringia. The leaf beetles Chrysolina arctica, C. brunnicornis bermani, and Galeruca interrupta circumdata were typical members of the Pleistocene steppe-tundra communities of Western Beringia, but absent from Eastern Beringia. On the other hand, some steppe tundra-adapted leaf beetles managed to occupy both sides of the BLB, such as Phaedon armoraciae. Much of the BLB remains unstudied, but on biogeographic grounds, it appears that there was some kind of biological filter that blocked the movements of some steppe-tundra plants and animals across the BLB.

  5. Impact of gold mining associated with mercury contamination in soil, biota sediments and tailings in Kenya.

    PubMed

    Odumo, Benjamin Okang'; Carbonell, Gregoria; Angeyo, Hudson Kalambuka; Patel, Jayanti Purshottam; Torrijos, Manuel; Rodríguez Martín, José Antonio

    2014-11-01

    This work considered the environmental impact of artisanal mining gold activity in the Migori-Transmara area (Kenya). From artisanal gold mining, mercury is released to the environment, thus contributing to degradation of soil and water bodies. High mercury contents have been quantified in soil (140 ?g kg(-1)), sediment (430 ?g kg(-1)) and tailings (8,900 ?g kg(-1)), as expected. The results reveal that the mechanism for transporting mercury to the terrestrial ecosystem is associated with wet and dry depositions. Lichens and mosses, used as bioindicators of pollution, are related to the proximity to mining areas. The further the distance from mining areas, the lower the mercury levels. This study also provides risk maps to evaluate potential negative repercussions. We conclude that the Migori-Transmara region can be considered a strongly polluted area with high mercury contents. The technology used to extract gold throughout amalgamation processes causes a high degree of mercury pollution around this gold mining area. Thus, alternative gold extraction methods should be considered to reduce mercury levels that can be released to the environment. PMID:24943890

  6. Paleoenvironmental analysis of a middle Wisconsinan biota site, southwestern Virginia, U.S.A

    Microsoft Academic Search

    G. Richard Whittecar; Thomas C. Wynn; Charles S. Bartlett

    2007-01-01

    The Ratcliff Site in southwestern Virginia lies in a small second-order stream valley filled with approximately 3.5 m of organic-rich deposits that contain bones of mammoth, mastodon, deer (or antelope), logs, and plant macrofossils. Radiocarbon analyses indicate the age of the organic-rich sediment ranges from >44,000 to 29,100 14C yr BP, a time period with no fossil remains reported in this region

  7. Prediction of the response of pond biota to animal waste fertilization. Technical completion report

    Microsoft Academic Search

    J. H. Peverly; E. C. Moran

    1983-01-01

    This study examined the production and water quality response of non-flowing ponds fertilized with anaerobically digested dairy manure at three fertilization rates: 5,500, 16,400, and 36,900 kg ha -1 yr -1 (wet weight). Primary productivity, the concentration of solids and fish yield (Micropterus salmoides and Notemigonus crysoleucas) were monitored in addition to N and P concentrations and fluxes. Primary productivity

  8. Contribution to the lichen biota of Slovenia XII. Some lichens from Logarska dolina

    PubMed Central

    Bilovitz, Peter Othmar; Arup, Ulf; Mayrhofer, Helmut

    2011-01-01

    A list of 94 species is presented including Bacidia subacerina and Lopadium disciforme as new for Slovenia and Bilimbia accedens, Lecanora leptyrodes, Megalaria grossa, Mycobilimbia epixanthoides, Rinodina efflorescens, and Sclerophora peronella as new for the alpine phytogeographical region of Slovenia. PMID:22319012

  9. Possible impacts of climate change on wetlands and its biota in the Brazilian Amazon.

    PubMed

    Barros, D F; Albernaz, A L M

    2014-11-01

    Wetlands cover approximately 6% of the Earth's surface. They are frequently found at the interface between terrestrial and aquatic ecosystems and are strongly dependent on the water cycle. For this reason, wetlands are extremely vulnerable to the effects of climate change. Mangroves and floodplain ecosystems are some of the most important environments for the Amazonian population, as a source of proteins and income, and are thus the types of wetlands chosen for this review. Some of the main consequences that can be predicted from climate change for wetlands are modifications in hydrological regimes, which can cause intense droughts or inundations. A possible reduction in rainfall can cause a decrease of the areas of mangroves and floodplains, with a consequent decline in their species numbers. Conversely, an increase in rainfall would probably cause the substitution of plant species, which would not be able to survive under new conditions for a long period. An elevation in water temperature on the floodplains would cause an increase in frequency and duration of hypoxic or anoxic episodes, which might further lead to a reduction in growth rates or the reproductive success of many species. In mangroves, an increase in water temperature would influence the sea level, causing losses of these environments through coastal erosion processes. Therefore, climate change will likely cause the loss of, or reduction in, Amazonian wetlands and will challenge the adaptability of species, composition and distribution, which will probably have consequences for the human population that depend on them. PMID:25627590

  10. Impacts on water quality and biota from natural acid rock drainage in Colorado's Lake Creek watershed

    USGS Publications Warehouse

    Bird, D.A.; Sares, Matthew A.; Policky, Greg A.; Schmidt, Travis S.; Church, Stanley E.

    2006-01-01

    Colorado's Lake Creek watershed hosts natural acid rock drainage that significantly impacts surface water, streambed sediment, and aquatic life. The source of the ARD is a group of iron-rich springs that emerge from intensely hydrothermally altered, unexploited, low-grade porphyry copper mineralization in the Grizzly Peak Caldera. Source water chemistry includes pH of 2.5 and dissolved metal concentrations of up to 277 mg/L aluminum, 498 mg/L iron, and 10 mg/L copper. From the hydrothermally altered area downstream for 27 kilometers to Twin Lakes Reservoir, metal concentrations in streambed sediment are elevated and the watershed experiences locally severe adverse impacts to aquatic life due to the acidic, metal-laden water. The water and sediment quality of Twin Lakes Reservoir is sufficiently improved that the reservoir supports a trout fishery, and remnants of upstream ARD are negligible.

  11. Polybrominated diphenyl ethers and organochlorine compounds in biota from the marine environment of East Greenland.

    PubMed

    Vorkamp, Katrin; Christensen, Jan H; Riget, Frank

    2004-09-20

    Ten black guillemot eggs, 19 ringed seals, 20 shorthorn sculpins and 20 Arctic chars were collected around Ittoqqortoormiit (Scoresbysund, Central East Greenland) in summer 2001 and analysed for 11 brominated diphenyl ether congeners (BDEs) and organochlorine compounds. Congeners BDE85 and BDE183 were not detected in any sample. SigmaBDE was highest in black guillemot eggs, with a median value of 80 ng/g lipid weight. This was approximately three times higher than that found for black guillemot eggs from West Greenland, thus supporting the spatial trend observed for organochlorines in Greenland. The median SigmaBDE concentration in ringed seal blubber was 36 ng/g lipid weight. This was clearly higher than SigmaBDE concentrations in ringed seal from the Canadian Arctic, but slightly lower than those found in ringed seals from Svalbard collected in 1981 and approximately 10 times lower than levels in seals from the Baltic Sea. Adult ringed seals had significantly higher SigmaBDE concentrations than animals less than 5 years old. Shorthorn sculpin liver and Arctic char muscle had similar concentrations of SigmaBDE, both with a median value of 7-10 ng/g lipid weight. The levels in shorthorn sculpin were similar to those reported from a previous study in Southwest Greenland. SigmaBDE levels correlated with PCB, DDT and chlordane-concentrations in the same samples, indicating similar mechanisms of uptake, bioaccumulation and biomagnification. The summed chlorobiphenyl concentrations in the same samples exceeded the SigmaBDE concentrations by a factor of approximately 15-30. The BDE congener patterns in black guillemot eggs and ringed seals were investigated using compound ratios and multivariate data analysis. The intraspecies variance was relatively small for black guillemot eggs and larger for ringed seals. Ringed seals had higher relative levels of the lower BDE congeners, e.g. BDE28 and BDE47 than black guillemots. The reasons for these different accumulation patterns are largely unknown and may reflect species-related differences in pollutant exposure, bioavailablity and metabolism. PMID:15325146

  12. Footprints of large theropod dinosaurs and implications on the age of Triassic biotas from Southern Brazil

    NASA Astrophysics Data System (ADS)

    da Silva, Rafael Costa; Barboni, Ronaldo; Dutra, Tânia; Godoy, Michel Marques; Binotto, Raquel Barros

    2012-11-01

    Dinosaur footprints found in an outcrop of the Caturrita Formation (Rio Grande do Sul State, Southern Brazil), associated with a diverse and well preserved record of fauna and flora, reopen the debate about its exclusive Triassic age. The studied footprints were identified as Eubrontes isp. and are interpreted as having been produced by large theropod dinosaurs. The morphological characteristics and dimensions of the footprints are more derived than those commonly found in the Carnian-Norian, and are more consistent with those found during the Rhaetian-Jurassic. The trackmaker does not correspond to any type of dinosaur yet known from Triassic rocks of Brazil. Recent studies with the paleofloristic content of this unit also support a more advanced Rhaetian or even Jurassic age for this unit.

  13. Mercury uptake patterns of biota in a seasonally anoxic northern California Reservoir

    Microsoft Academic Search

    D. G. Slotton; J. E. Reuter; C. R. Goldman

    1995-01-01

    Biotic uptake of mercury (Hg) in Davis Creek Reservoir, California increased dramatically in conjunction with the entrainment of anoxic hypolimnetic water into the mixed layer. This indicated a seasonal pulse increase of bioavailable Hg associated with thermal destratification. The effect was more pronounced in juvenile bass (70–200% seasonal increases in muscle Hg concentration), as compared to adults (15–25% increases), and

  14. Woody Debris: Linking Stream Morphology and Aquatic Biota in Southeastern Coastal Plain Streams, USA

    NASA Astrophysics Data System (ADS)

    Thom, T. A.; Herod, J. J.

    2005-05-01

    In-stream habitat including woody debris is widely recognized as an important aspect of aquatic health. Relationships between woody debris and the distribution and life history of aquatic species are increasingly documented in the literature. In southeastern coastal plain streams, woody debris may have a greater influence on stream form and function than in other regions due to highly mobile shifting sand substrates. In an effort to document baseline stream conditions, natural variability within biological communities, and to also link chemical, physical and biological parameters within the Gulf Coastal Plain physiographic region, aquatic surveys have been conducted on Eglin Air Force Base, Florida over the past four years. We developed quantitative indicators of habitat health and protocols for measuring habitat condition at various geographic scales. Physical variables included stream channel characteristics, habitat connectivity, riparian cover and in-stream habitat including woody debris. Biological data (fishes and aquatic insects) were compared with in-stream habitat data for 56 sites. Significant relationships between species and in-stream habitat presence/absence and abundance were detected. Associations between woody debris and bed morphology were also significant. These preliminary data suggest that woody debris is an important factor shaping biological communities and stream geomorphic features in sand-bottom coastal plain streams.

  15. Diverse Nonmarine Biota from the Whidbey Formation (Sangamonian) at Point Wilson, Washington

    NASA Astrophysics Data System (ADS)

    Karrow, Paul F.; Ceska, Adolph; Hebda, Richard J.; Miller, Barry B.; Seymour, Kevin L.; Smith, Alison J.

    1995-11-01

    Previously undescribed plant and animal fossils from the Whidbey Formation represent two environments. An upper sand unit contains predominantly terrestrial molluscs (4 taxa), insects, and a vole (cf. Phenacomys), whereas a lower clay unit contains ostracodes (9 taxa), freshwater molluscs (6 taxa), insects (9 taxa), freshwater plant seeds (6 taxa), and fish (cf. Gasterosteus : stickleback). These taxa are compatible with interglacial climatic conditions on a coastal plain environment. The inferred freshwater and terrestrial environments of the Whidbey Formation imply local tectonic subsidence of the regional since the last interglaciation.

  16. Pesticides at The Ebro River Delta: Occurrence and Toxicity in Water and Biota

    Microsoft Academic Search

    Marianne Köck-Schulmeyer; Miren de Alda; Elena Martínez; Marinella Farré; Asunción Navarro; Antoni Ginebreda; Damià Barceló

    \\u000a Pesticide use has increased worldwide to protect the food supply of the swelling global population. Although it is undisputed\\u000a that pesticides are essential in modern agriculture, there is a growing concern about environmental contamination from agrochemicals.\\u000a For example, application of pesticides in the Ebro River delta (NE, Spain) during the rice-growing season is suspected to\\u000a be one of the major

  17. Allelopathic effect of new introduced biofuel crops on the soil biota: A comparative study

    NASA Astrophysics Data System (ADS)

    Hed?nec, Petr; Frouz, Jan; Ustak, Sergej; Novotny, David

    2015-04-01

    Biofuel crops as an alternative to fossil fuels are a component of the energy mix in many countries. Many of them are introduced plants, so they pose a serious threat of biological invasions. Production of allelopathic compounds can increase invasion success by limiting co-occurring species in the invaded environment (novel weapons hypothesis). In this study, we focused on plant chemistry and production of allelopathic compounds by biofuel crops (hybrid sorrel Rumex tianschanicus x Rumex patientia and miscanthus Miscanthus sinensis) in comparison with invasive knotweed (Fallopia sachalinensis) and cultural meadow species. First, we tested the impact of leachates isolated from hybrid sorrel, miscanthus, knotweed and cultural meadow species compared to deionized water, used as a control, on seed germination of mustard (Sinapis arvensis) and wheat (Triticum aestivum) cultivated on sand and soil. Secondly, we studied the effect of leachates on the growth of soil fungal pathogens Fusarium culmorum, Rhizoctonia solani, Sclerotinia solani and Cochliobolus sativus. Finally, we tested the effect of litter of hybrid sorrel, miscanthus, knotweed and cultural meadow litter mixed with soil on population growth of Enchytraeus crypticus and Folsomia candida. Miscanthus and knotweed litter had a higher C:N ratio than the control meadow and hybrid sorrel litter. Miscanthus and hybrid sorrel litter had a higher content of phenols than knotweed and cultural meadow litter. Leachates from hybrid sorrel, miscanthus and knotweed biomass significantly decreased seed germination of wheat and mustard in both substrates. Soil fungal pathogens grew less vigorously on agar enriched by leachates from both biofuel crops than on agar enriched by knotweed and leachates. Litter from hybrid sorrel, miscanthus and knotweed significantly altered (both ways) the population growth of the soil mesofauna.

  18. Polycyclic and nitro musks in the environment: A comparison between Canadian and European aquatic biota

    Microsoft Academic Search

    Robert Gatermann; Jocelyne Hellou; Heinrich Hühnerfuss; Gerhard Rimkus; Vladimir Zitko

    1999-01-01

    Nitro and polycyclic musks were determined for the first time in Canadian aquatic fauna such as lobster, winter flounder, American eel, lake trout, clams and mussels. Samples from densely populated areas, Halifax and the industrialized Miramachi estuary, showed relatively high concentrations of musk ketone (4-acetyl-1-tert-butyl-3,5-dimethyl-2,6-dinitrobenzene, MK; maximum levels: mussels 2,200 ng\\/g lipid; winter flounder muscle 2,700 ng\\/g lipid; clams 17,700

  19. Synthetic musk residues in biota and water from Tama River and Tokyo Bay (Japan)

    Microsoft Academic Search

    Tatsunori Yamagishi; Tomoyuki Miyazaki; Shozo Horii; Kazuyuki Akiyama

    1983-01-01

    Musk xylene and musk ketone (synthetic musks) were detected in 100% and 80%, respectively of 74 samples, [freshwater fish (three species), marine shellfish (four species), river water, and wastewater (three sewage treatment plants)] collected from several sampling stations along the Tama River, a dam, and Tokyo Bay, during July and October, 1980 and 1981. The average concentrations of musk xylene

  20. Effects of a Low-Head Dam and Water Abstraction on Migratory Tropical Stream Biota

    Microsoft Academic Search

    Jonathan P. Benstead; James G. March; Catherine M. Pringle; Frederick N. Scatena

    1999-01-01

    Migration of large-bodied ''macroconsumers'' (e.g., fishes, shrimps, and snails) is an important functional linkage between many tropical rivers and their estuaries. Increasingly, this linkage is being severed by dams and water abstraction. The ecological impacts of these activities are poorly understood and are largely being ignored by dam operators. We investigated the direct effects of a water intake and low-head

  1. Seasonality of the soil biota of grazed and ungrazed hill grasslands

    Microsoft Academic Search

    R. D. Bardgett; D. K. Leemans; R. Cook; P. J. Hobbs

    1997-01-01

    Temporal and spatial measurements of soil microbial biomass, activity and community structure and nematode abundance were made in grazed and ungrazed Agrostis-Festuca and Nardus dominated hill grasslands, with brown earth and podzolic soils, respectively. Microbial biomass and activity were significantly higher in podzolic soils with Nardus dominated vegetation, than in brown earth soils with Agrostis-Festuca vegetation. Phospholipid fatty acid analysis

  2. Provision of watering points in the Australian arid zone: a review of effects on biota

    Microsoft Academic Search

    Craig D. James; Jill Landsberg; Stephen R. Morton

    1999-01-01

    In this paper we review the effects of the provision of artificial sources of water on native flora and fauna in arid and semi-arid zones, with emphasis on Australia but drawing on information from other countries where possible. The effects of artificial sources of water are profound and are a rarely-cited aspect of change in arid and semi-arid zone rangelands.

  3. Spatial differences and temporal trends of organochlorine compounds in biota from the northwestern hemisphere

    Microsoft Academic Search

    Östen Andersson; Carl-Eric Linder; Mats Olsson; Lars Reutergårdh; Ulla-Britt Uvemo; Ulla Wideqvistt

    1988-01-01

    Tissues of animal species from various trophic levels in the northwestern hemisphere were collected and analyzed for the presence of polychlorinated camphenes (PCC,e.g. toxaphene), DDT and its metabolites DDD and DDE (sDDT) and polychlorinated biphenyls (PCB) to elucidate differences in geographical distribution, biomagnification and temporal trends. Many of the samples were also analyzed for the presence of chlordane. The previously

  4. Changes in atmospheric CO2 - Influence of the marine biota at high latitude

    Microsoft Academic Search

    Fanny Knox; M. B. McElroy

    1984-01-01

    Approximately half of the nitrogen and phosphorus entering deep waters of the contemporary ocean are transported from the surface in inorganic form as preformed nutrients. A simple model for ocean chemistry is presented and shown to account for the present level of atmospheric CO2. Fluctuations in preformed nutrients, modulated by changes in insolation and circulation at high latitudes, can result

  5. PARSING THE ALLOCHTHONOUS FROM THE AUTOCHTHONOUS FUNGAL BIOTA IN THE POULTRY INTESTINE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Examination of intestinal microbial communities is complicated by the presence of both autochthonous (natively colonizing) and allochthonous (transient) taxa. To examine community dynamics in poultry ceca an experiment was performed in which day-old turkeys were housed in isolators on raised wire f...

  6. Bioinvasion in a Brazilian Bay: Filling Gaps in the Knowledge of Southwestern Atlantic Biota

    Microsoft Academic Search

    Barbara L. Ignacio; Luciana M. Julio; Andrea O. R. Junqueira; Maria A. G. Ferreira-Silva

    2010-01-01

    BackgroundBiological invasions are a major cause of global species change. Nevertheless, knowledge about the distribution and ecology of introduced species is regionally biased, and many gaps in knowledge exist for most developing countries.Methodology\\/Principal FindingsTo study the zoobenthos on the hard substratum of the Ilha Grande Bay, a survey was conducted on both natural and artificial substrata at three depths and

  7. How old is the Hawaiian biota? Geology and phylogeny suggest recent divergence.

    PubMed Central

    Price, Jonathan P; Clague, David A

    2002-01-01

    This study quantifies long-term landscape changes in the Hawaiian archipelago relating to dispersal, speciation and extinction. Accounting for volcano growth, subsidence and erosion, we modelled the elevations of islands at time intervals of 0.5 Myr for the last 32 Myr; we also assessed the variation in the spacing of volcanoes during this period. The size, spacing and total number of volcanic islands have varied greatly over time, with the current landscape of large, closely spaced islands preceded by a period with smaller, more distantly spaced islands. Considering associated changes in rates of dispersal and speciation, much of the present species pool is probably the result of recent colonization from outside the archipelago and divergence within contemporary islands, with limited dispersal from older islands. This view is in accordance with abundant phylogenetic studies of Hawaiian organisms that estimate the timing of colonization and divergence within the archipelago. Twelve out of 15 multi-species lineages have diverged within the lifetime of the current high islands (last 5 Myr). Three of these, and an additional seven (mostly single-species) lineages, have colonized the archipelago within this period. The timing of colonization of other lineages remains uncertain. PMID:12495485

  8. Effects of reservoir drawdown and refill on mercury levels in fish and other biota

    SciTech Connect

    Jagoe, C.H.; Salice, C.; Yabnochko, G.; Grasman, B.T.; Youngblood, T. [Savannah River Ecology Lab., Aiken, SC (United States)

    1995-12-31

    Mercury bioavailability from contaminated sediments is controlled by methylation, related to bacterial activity and degradable organic material. These variables may be affected by large changes in water level and chemistry in a reservoir. At Par Pond, a 1,200 ha impoundment on the USDOE Savannah River Site, South Carolina, potential failure of an earthen dam prompted lowering the reservoir by 3 meters over a two month period in 1991, decreasing water volume about 70%. The reservoir was refilled over a two month period in 1995. Largemouth bass (Micropterus salmoides) were sampled at quarterly intervals before, during and after the drawdown. Length and weight were determined, and liver and muscle analyzed for total Hg. Hg was also measured in top level predators (alligators), forage fish, macrophytes and invertebrates. From Fall 1991 Winter 1994--5, Hg ranged from 0.05 to 2.0 ug/g wet mass in bass muscle, and was strongly related to fish size, based on about 400 fish. Condition factor rose soon after drawdown, then declined as forage populations collapsed. Using fish size as covariate, bass muscle Hg was greater in spring 1992 than all other sampling dates. However, after 3 years of drawdown, there was no overall trend in bass Hg. Forage species differed in Hg, with highest concentrations in brook silversides (0.13 {micro}g Hg/g wet mass in 2 g fish). Alligators contained up to 20 {micro}g Hg/g dry mass in liver. Refill caused inundation of terrestrial plants on exposed sediments, and microbial action associated with the decay of these may enhance Hg methylation. Experiments with caged fish are underway to measure uptake rates.

  9. An atypical intra-platform environment and biota from the Silurian of Gotland, MIKAEL CALNER1

    E-print Network

    Calner, Mikael

    and graptoloid graptolites, conodonts, eurypterids, and the brachiopod Lingula. An unusually good collection, Sweden, where graptolites are fairly common in the most distal platform marls but practically absent in strata of the platform interior. In this paper we provide a documentation and discussion of an atypical

  10. Bioinvasion in a Brazilian Bay: Filling Gaps in the Knowledge of Southwestern Atlantic Biota

    PubMed Central

    Ignacio, Barbara L.; Julio, Luciana M.; Junqueira, Andrea O. R.; Ferreira-Silva, Maria A. G.

    2010-01-01

    Background Biological invasions are a major cause of global species change. Nevertheless, knowledge about the distribution and ecology of introduced species is regionally biased, and many gaps in knowledge exist for most developing countries. Methodology/Principal Findings To study the zoobenthos on the hard substratum of the Ilha Grande Bay, a survey was conducted on both natural and artificial substrata at three depths and seven sites. The species recorded were classified as native, cryptogenic or introduced. Multivariate analyses were conducted to assess the prevalence of introduced species in these communities and to compare the distribution of species on natural and artificial substrata of this bay to identify possible discrepancies in habitat use. Of the 61 species, 25 were cryptogenic, 10 were introduced and 26 were native. Similar numbers of introduced species were found on both natural and artificial substrata, though the community composition was significantly different between them. We also compared the species composition of the Ilha Grande Bay survey to other inventories taken around the world. The highest similarities were found between the Ilha Grande Bay inventory and the Atlantic coastal region (Tampa Bay, USA and the Gulf of Mexico), American Samoa and Pearl Harbor (USA) inventories. Conclusions/Significance This study presents the first published comprehensive list of hard substratum sessile marine invertebrate species in a Brazilian bay. The high percentage of cryptogenic species reveals gaps in both zoological records and information on introduced species for the Brazilian coast. The introduced species successfully colonized different sites in the Ilha Grande Bay, including both natural and artificial substrata. In addition, we find that artificial structures may not be good surrogates for natural rocky shores and may represent an ecological threat. Comparisons with other inventories suggest a history of broad-scale invasion, though more evidence is needed to support this conclusion. PMID:20927375

  11. A Biota Associated with Matuyama-Age Sediments in West-Central Illinois

    NASA Astrophysics Data System (ADS)

    Miller, Barry B.; Graham, Russell W.; Morgan, Alan V.; Miller, Norton G.; McCoy, William D.; Palmer, Donald F.; Smith, Alison J.; Pilny, J. J.

    1994-05-01

    A fossil assemblage containing molluscs, mammals, insects, ostracodes, and plants has been recovered from a silt-filled depression near Lima, in west-central Illinois. The reversed remanent magnetic signature of the sediments and the temporal ranges of two mammals, Microtus paroperarius and Lasiopodomys deceitensis, constrain the age of the assemblage to between 730,000 and 830,000 yr B.P. The extent of isoleucine epimerization in the molluscan shell is consistent with this age interpretation. The fauna includes at least 43 taxa of beetles from 11 families, 35 nominal species of molluscs, and two genera of ostracodes. The mammals include two shrews, three rodents, and a rabbit. The plant macrofossils (no pollen recovered) include 25 species of seed plants and four kinds of terrestrial or wetland mosses. Most of the plant species identified still occur in the upper Midwest, although a few of the taxa are found mainly to the north of the site. The fauna is characterized by an almost total absence of true aquatic taxa. The association of both boreal and thermophilous faunal and floral elements suggest that summer temperatures were not greatly different from present ones, but cooler, moist areas must have been available to support the boreal elements. Local conditions were probably similar to those now found in northeastern Iowa, where rains blocks, fissures, and joints in carbonate bedrock serve as traps for debris accumulations, provide shade, and are kept cool and moist during the hot summer months by cold-air drainage and groundwater seepage. Summer mean temperature in these microhabitats was probably between 18 and 20°C, similar to temperatures that now occur near the northern hardwood spruce-fir transition in the eastern United States.

  12. Late Pleistocene woodlands in the Bolson de Mapimi: A refugium for the Chihuahuan Desert Biota?

    NASA Astrophysics Data System (ADS)

    Van Devender, Thomas R.; Burgess, Tony L.

    1985-11-01

    Packrat middens radiocarbon dated at 12,280 ± 345 and 12,700 ± 165 yr B.P. record expansions of junipers and papershell pinyon ( Pinus remota) into the desert lowlands of Durango and Coahuila, Mexico (26° N). Extralocal trees and shrubs presently occur 24-580 km in nearly all directions including more subtropical areas to the northeast and southeast. An equable Late Wisconsin climate marked by mild winters with increased precipitation and by cool summers with reduced summer monsoons is proposed. The extensive playas of the Bolson de Mapimi probably held water at that time. The Bolson de Mapimi was not a geographical refugium unaffected by glacial climates, although many Chihuahuan Desert plants and animals probably remain in situ as members of equable woodlands. Equable climates, low extinction rates, and repeated, rapid glacial/interglacial climatic fluctuations may have been important in the evolution and accumulation of species at lower latitudes.

  13. Acetic Acid Bacterial Biota of the Pink Sugar Cane Mealybug, Saccharococcus sacchari, and Its Environs

    PubMed Central

    Ashbolt, Nicholas J.; Inkerman, Peter A.

    1990-01-01

    Saccharococcus sacchari is the primary colonizer of the developing “sterile” tissue between the leaf sheath and stem of sugar cane. The honeydew secreted by the mealybugs is acidic (about pH 3) and supports an atypical epiphytic microbiota dominated by acetobacter-like bacteria and acidophilic yeast species. However, Erwinia and Leuconostoc species predominate within the leaf sheath pocket region when the mealybugs die out. The unidentified acetobacters were readily isolated from S. sacchari throughout its life cycle and from other genera of mealybugs on sugar cane and various other plants, both above and below ground. No other insect present on sugar cane was a significant vector of acetic acid bacteria. The major factors restricting microbial diversity within the environs of mealybugs were considered to be yeast activity along with bacterial production of acetic acid, ketogluconic acids, and gamma-pyrones, in association with their lowering of pH. The microbial products may aid in suppressing the attack by the parasitic mold Aspergillus parasiticus on mealybugs but could act as attractants for the predatory fruit fly Cacoxenus perspicax. PMID:16348144

  14. The Transport of Chemicals and Biota into Coastal Rivers and Marine Ecosystems

    E-print Network

    Ng, Charlene Marie

    2012-01-01

    ocean-derived particles and sediments from coastal erosion) and degradationfrom the ocean or coastal erosion. In situ degradation ofoceans depend on rates of transport and export of river-borne materials from channels versus rates of in-channel processing: degradation,

  15. Bacterial-biota dynamics of eight bryophyte species from different ecosystems

    PubMed Central

    Koua, Faisal Hammad Mekky; Kimbara, Kazuhide; Tani, Akio

    2014-01-01

    Despite the importance of bryophyte-associated microorganisms in various ecological aspects including their crucial roles in the soil-enrichment of organic mass and N2 fixation, nonetheless, little is known about the microbial diversity of the bryophyte phyllospheres (epi-/endophytes). To get insights into bacterial community structures and their dynamics on the bryophyte habitats in different ecosystems and their potential biological roles, we utilized the 16S rRNA gene PCR-DGGE and subsequent phylogenetic analyses to investigate the bacterial community of eight bryophyte species collected from three distinct ecosystems from western Japan. Forty-two bacterial species belonging to ?-proteobacteria and Firmicutes with 71.4% and 28.6%, respectively, were identified among 90 DGGE gel band population. These DGGE-bands were assigned to 13 different genera with obvious predomination the genus Clostridium with 21.4% from the total bacterial community. These analyses provide new insights into bryophyte-associated bacteria and their relations to the ecosystems. PMID:25737654

  16. Organic Pollutants in Coastal Waters, Sediments, and Biota: A Relevant Driver for Ecosystems During the Anthropocene?

    Microsoft Academic Search

    Jordi Dachs; Laurence Méjanelle

    2010-01-01

    The total number of synthetic organic chemicals introduced to the environment by humans has never been quantified, but it\\u000a is not lower than thousands. A fraction of these chemicals have toxic effects to coastal organisms and presumably affect ecosystems\\u000a structure and function. During the last decades, some of the processes affecting the transport, degradation, and fate of a\\u000a limited number

  17. The Transport of Chemicals and Biota into Coastal Rivers and Marine Ecosystems

    E-print Network

    Ng, Charlene Marie

    2012-01-01

    from the ocean or coastal erosion. In situ degradation ofand sediments from coastal erosion) and degradation of theerosion has left the current estuary shallow with a greatly decreased tidal prism, consisting mainly of sand bars and coastal

  18. Snow crystal imaging using scanning electron microscopy: III. Glacier ice, snow and biota

    Microsoft Academic Search

    A. RANGO; W. P. WERGIN; E. F. ERBE; E. G. JOSBERGER

    2000-01-01

    Low-temperature scanning electron microscopy (SEM) was used to observe metamorphosed snow, glacial firn, and glacial ice obtained from South Cascade Glacier in Washington State, USA. Biotic samples consisting of algae (Chlamydomonas nivalis) and ice worms (a species of oligochaetes) were also collected and imaged. In the field, the snow and biological samples were mounted on copper plates, cooled in liquid

  19. Soil stabilization by a prokaryotic desert crust - Implications for Precambrian land biota

    NASA Technical Reports Server (NTRS)

    Campbell, S. E.

    1979-01-01

    The ecology of the cyanophyte-dominated stromatolitic mat forming the ground cover over desert areas of Utah and Colorado is investigated and implications for the formation of mature Precambrian soils are discussed. The activation of the growth of the two species of filamentous cyanophyte identified and the mobility of their multiple trichromes upon wetting are observed, accompanied by the production and deposition of a sheath capable of accreting and stabilizing sand and clay particles. The formation of calcium carbonate precipitates upon the repeated wetting and drying of desert crust is noted, and it is suggested that the desert crust community may appear in fossil calcrete deposits as lithified microscopic tubes and cellular remains of algal trichromes. The invasion of dry land by both marine and freshwater algae on the model of the desert crust is proposed to be responsible for the accumulation, stabilization and biogenic modification of mature Precambrian soils.

  20. Using Bayesian networks to assess the vulnerability of Hawaiian terrestrial biota to climate change

    NASA Astrophysics Data System (ADS)

    Fortini, L.; Jacobi, J.; Price, J.; Vorsino, A.; Paxton, E.; Amidon, F.; 'Ohukani'ohi'a Gon, S., III; Koob, G.; Brink, K.; Burgett, J.; Miller, S.

    2012-12-01

    As the effects of climate change on individual species become increasingly apparent, there is a clear need for effective adaptation planning to prevent an increase in species extinctions worldwide. Given the limited understanding of species responses to climate change, vulnerability assessments and species distribution models (SDMs) have been two common tools used to jump-start climate change adaptation efforts. However, although these two approaches generally serve the same purpose of understanding species future responses to climate change, they have rarely mixed. In collaboration with research and management partners from federal, state and non-profit organizations, we are conducting a climate change vulnerability assessment for hundreds of plant and forest bird species of the Main Hawaiian Islands. This assessment is the first to comprehensively consider the potential threats of climate change to a significant portion of Hawaii's fauna and flora (over one thousand species considered) and thus fills a critical gap defined by natural resource scientists and managers in the region. We have devised a flexible approach that effectively integrates species distribution models into a vulnerability assessment framework that can be easily updated with improved models and data. This tailors our assessment approach to the Pacific Island reality of often limited and fragmented information on species and large future climate uncertainties, This vulnerability assessment is based on a Bayesian network-based approach that integrates multiple landscape (e.g., topographic diversity, dispersal barriers), species trait (e.g., generation length, fecundity) and expert-knowledge based information (e.g., capacity to colonize restored habitat) relevant to long-term persistence of species under climate change. Our presentation will highlight some of the results from our assessment but will mainly focus on the utility of the flexible approach we have developed and its potential application in other settings.

  1. Temporal trends of mercury in marine biota of west and northwest Greenland.

    PubMed

    Rigét, Frank; Dietz, Rune; Born, Erik W; Sonne, Christian; Hobson, Keith A

    2007-01-01

    Temporal trends in mercury concentrations ([Hg]) during the last two to three decades were determined in liver of shorthorn sculpin, ringed seal and Atlantic walrus from northwest Greenland (NWG, 77 degrees N) and in liver of shorthorn sculpin and ringed seal from central west Greenland (CWG, 69 degrees N) during the last decade. Stable-nitrogen (delta(15)N) and carbon (delta(13)C) isotope values were determined in muscle of ringed seals to provide insight into potential trophic level changes through time. Log-linear regressions on annual median [Hg] did not reveal any temporal trend in shorthorn sculpin from CWG and NWG and walrus from NWG. In ringed seals from NWG, an increase in [Hg] of 7.8% per year was observed. When based on delta(15)N-adjusted [Hg] this rate increased to 8.5% but was still non-significant. In ringed seal from CWG no trend was found in [Hg] during the period 1994-2004. However, during the last part of the period (1999-2004) the [Hg] increased significantly. Including tissue delta(15)N values as a covariate had a marked effect on these results. The annual changes in delta(15)N-adjusted [Hg] was estimated to -5.0% for the whole period and 2.2% during the last 5 years compared to -1.3% and 12.4%, respectively, for the non-adjusted [Hg]. PMID:17049950

  2. Availability of Biota-sediment Accumulation Factor Data Set and PCB Residue Effects Database

    EPA Science Inventory

    At contaminated sites, EPA?s Superfund program must decide how best to protect public health and the environment. This research was undertaken to better inform decision making and reduce uncertainties related to risk assessments at Superfund sites. A residue-effects database (PCB...

  3. GROUP REPORT: PHYSIOLOGICAL AND ECOLOGICAL EFFECTS OF ACIDIFICATION ON AQUATIC BIOTA

    EPA Science Inventory

    Acidification affects all components of biological communities in lakes and streams: microbes, algae, macrophytes, invertebrates, fish, amphibians, and other vertebrates that rely on aquatic ecosystems for habitat or food. echanisms of effect are both direct (toxic responses to c...

  4. GSFLOW - Coupled Ground-Water and Surface-Water Flow Model Based on the Integration of the Precipitation-Runoff Modeling System (PRMS) and the Modular Ground-Water Flow Model (MODFLOW-2005)

    USGS Publications Warehouse

    Markstrom, Steven L.; Niswonger, Richard G.; Regan, R. Steven; Prudic, David E.; Barlow, Paul M.

    2008-01-01

    The need to assess the effects of variability in climate, biota, geology, and human activities on water availability and flow requires the development of models that couple two or more components of the hydrologic cycle. An integrated hydrologic model called GSFLOW (Ground-water and Surface-water FLOW) was developed to simulate coupled ground-water and surface-water resources. The new model is based on the integration of the U.S. Geological Survey Precipitation-Runoff Modeling System (PRMS) and the U.S. Geological Survey Modular Ground-Water Flow Model (MODFLOW). Additional model components were developed, and existing components were modified, to facilitate integration of the models. Methods were developed to route flow among the PRMS Hydrologic Response Units (HRUs) and between the HRUs and the MODFLOW finite-difference cells. This report describes the organization, concepts, design, and mathematical formulation of all GSFLOW model components. An important aspect of the integrated model design is its ability to conserve water mass and to provide comprehensive water budgets for a location of interest. This report includes descriptions of how water budgets are calculated for the integrated model and for individual model components. GSFLOW provides a robust modeling system for simulating flow through the hydrologic cycle, while allowing for future enhancements to incorporate other simulation techniques.

  5. Impacts and environmental catastrophes: A study of the effects of impact events on the climate system

    NASA Technical Reports Server (NTRS)

    Pierazzo, E.

    2005-01-01

    The goal of this work is to investigate the perturbation of the climate system due to large impact events. Impacts are among the most important mechanisms for the evolution, distribution, and destruction of life in the universe. However, the possible climatic effects of an impact were not seriously considered until 1980, when Louis and Walter Alvarez suggested that the profound end-Cretaceous extinction might have been caused by the impact of an asteroid or comet about 10 km in diameter. Since then, the climatic change associated with the end-Cretaceous impact has become one of the most interesting and still unresolved questions in linking the well-known Chicxulub impact event and the end- Cretaceous mass extinction. While the end-Cretaceous impact offers the best-documented case of an impact affecting the Earth's climate and biota, even smaller (and more frequent in time) impacts could introduce significant perturbations of the climate comparable, if not larger, to the largest known volcanic perturbations. We propose to study the mechanical and thermal state of the atmosphere following an impact event. This will be done by using both one-dimensional and three-dimensional climate models. When necessary, modifications of the state-of-the-art general circulation models will b e carried out. We want to use the end-Cretaceous impact event as a case study. This allows us to take advantage of the extensive modeling of this impact event that has already been carried out through a previous Exobiology grant. Furthermore, a large experimental dataset, that can be used to constrain and test our models, is associated with the end-Cretaceous mass extinction (one of the largest of the Phanerozoic) and impact event.

  6. Fluid Management System (FMS) fluid systems overview

    NASA Technical Reports Server (NTRS)

    Baird, R. S.

    1990-01-01

    Viewgraphs on fluid management system (FMS) fluid systems overview are presented. Topics addressed include: fluid management system description including system requirements (integrated nitrogen system, integrated water system, and integrated waste gas system) and physical description; and fluid management system evolution.

  7. Systems thinking

    Microsoft Academic Search

    Derek Cabrera; Laura Colosi; Claire Lobdell

    2008-01-01

    Evaluation is one of many fields where “systems thinking” is popular and is said to hold great promise. However, there is disagreement about what constitutes systems thinking. Its meaning is ambiguous, and systems scholars have made diverse and divergent attempts to describe it. Alternative origins include: von Bertalanffy, Aristotle, Lao Tsu or multiple aperiodic “waves.” Some scholars describe it as

  8. Solar System

    NSDL National Science Digital Library

    Ms. Wright

    2009-10-09

    An introduction to to the solar system. How to distinguish between the different planets. Activities to play while getting to know the solar system. Cosmic Cookies Solar System Scavenger Hunt Edible Earth Strawkets and Control Strawkets and Thrust Strawkets and Weight ...

  9. Linked Systems.

    ERIC Educational Resources Information Center

    Association of Research Libraries, Washington, DC.

    Three papers are compiled here for research library directors: (1) "Background: Open Systems Interconnection," in which David F. Bishop provides fundamental background information to explain the concept of the emerging technology of linked systems and open systems interconnection--i.e., an agreed upon standard set of conventions or rules that,…

  10. Energy Systems

    NSDL National Science Digital Library

    Office of Educational Partnerships,

    Posters are provided for several different energy conversion systems. Students are provided with cards that give the name and a description of each of the components in an energy system. They match these with the figures on the diagram. Since the groups look at different systems, they also describe their results to the class to share their knowledge.

  11. Geochemical Flows of Heavy Metals in Aquatic Systems of the Volga River Delta

    NASA Astrophysics Data System (ADS)

    Lychagin, Mikhail; Tkachenko, Anna; Kasimov, Nikolay

    2014-05-01

    The paper presents the results of the long-term environmental-geochemical studies of aquatic systems of the Volga River mouth area. It occupies a special place among the world's largest river deltas. The strong interest of researchers from different fields of science in the problems of the Volga River delta is associated with the high rate of periodic fluctuations of the Caspian Sea level, and also many factors of the technogenic geochemical impact on the aquatic systems. They range from the local impact of pollution sources in the delta to the regional impact of pollution sources located upstream. Aquatic systems of the Volga delta are highly diverse in morphology, hydrodynamic regime, lithology, sediments, and biota. This diversity determines the considerable spatial and temporal variability of the conditions of migration of heavy metals (HM) and other chemical elements. The study showed that the present contamination of the aquatic systems is manifested mainly in excess of heavy metals (Cu, Pb, Cd) in suspended matter over the global background values, most notably, in the flood period. In general the content of HM in the water and sediments during the last decades remains low; pollution of the bottom sediments is largely insignificant and of local character. We have identified the significant role of the water plants due to migration and accumulation of heavy metals in the shallow near-shore zones. Higher aquatic plants may serve as biogeochemical indicators of aquatic systems pollution. The metal content in macrophytes varies substantially depending on the ecological and morphological characteristics of species, as well as on conditions of their habitat. The difference between the minimal and maximal HM content may reach two to three orders of magnitude. Thickets of hornweed (Ceratophyllum demersum) and of other macrophytes in the mouths of the watercourses at the near-shore mouth area play the role of the biofilters precipitating a significant part of the river suspended matter. We have determined a number of complex geochemical barrier zones in the Volga mouth area where the bulk of metals brought with the water flow are deposited. The first one formed in the stream mouths at the deltaic sea edge. Due to the combined effect of the hydrodynamic, sorption, oxygen, and biogeochemical barriers, the deposition of suspended matter that carries HM takes place there. As a result, Zn, Mn, Ni, and Co accumulate in the bottom sediments of the mouths of the watercourses. The maximal HM concentrations in some samples exceed the average value by three and more times. The finest fractions of suspended matter migrate via delta to the near-shore mouth area where the further geochemical barrier zones are formed.

  12. Dust in the Earth system: the biogeochemical linking of land, air and sea.

    PubMed

    Ridgwell, Andy J

    2002-12-15

    Understanding the response of the Earth's climate system to anthropogenic perturbation has been a pressing priority for society since the late 1980s. However, recent years have seen a major paradigm shift in how such an understanding can be reached. Climate change demands analysis within an integrated 'Earth-system' framework, taken to encompass the suite of interacting physical, chemical, biological and human processes that, in transporting and transforming materials and energy, jointly determine the conditions for life on the whole planet. This is a highly complex system, characterized by multiple nonlinear responses and thresholds, with linkages often between apparently disparate components. The interconnected nature of the Earth system is wonderfully illustrated by the diverse roles played by atmospheric transport of mineral 'dust', particularly in its capacity as a key pathway for the delivery of nutrients essential to plant growth, not only on land, but perhaps more importantly, in the ocean. Dust therefore biogeochemically links land, air and sea. This paper reviews the biogeochemical role of mineral dust in the Earth system and its interaction with climate, and, in particular, the potential importance of both past and possible future changes in aeolian delivery of the micro-nutrient iron to the ocean. For instance, if, in the future, there was to be a widespread stabilization of soils for the purpose of carbon sequestration on land, a reduction in aeolian iron supply to the open ocean would occur. The resultant weakening of the oceanic carbon sink could potentially offset much of the carbon sequestered on land. In contrast, during glacial times, enhanced dust supply to the ocean could have 'fertilized' the biota and driven atmospheric CO(2) lower. Dust might even play an active role in driving climatic change; since changes in dust supply may affect climate, and changes in climate, in turn, influence dust, a 'feedback loop' is formed. Possible feedback mechanisms are identified, recognition of whose operation could be crucial to our understanding of major climatic transitions over the past few million years. PMID:12626273

  13. Geophysical Characterization of the Borax Lake Hydrothermal System in the Alvord Desert, Southeastern Oregon.

    NASA Astrophysics Data System (ADS)

    Hess, S.; Paul, C.; Bradford, J.; Lyle, M.; Clement, W.; Liberty, L.; Myers, R.; Donaldson, P.

    2003-12-01

    We are conducting a detailed geophysical characterization of an active hydrothermal system as part of an interdisciplinary project aiming to study the link between the physical characteristics of hydrothermal systems and biota that occupy those systems. The Borax Lake Hydrothermal System (BLHS), consisting of Borax Lake and the surrounding hot springs, is located near the center of the Alvord Basin in southeastern Oregon. As a result of Basin and Range extension, the Alvord Basin is a north-south trending graben bounded by the Steens Mountains to the west and the Trout Creek Mountains to the east. We are using several geophysical techniques to generate both basin-wide and high-resolution local characterizations of the Alvord Basin and the BLHS. To date we have completed two scales of seismic reflection surveys: an east-west trending basin scale survey and a shallow (~10 - 300 m depth) 3D survey of the BLHS. The basin scale seismic survey consists of 11 km of 2D, 60 fold CMP data acquired with a 200 lb accelerated weight drop. We acquired the 3D survey of the BLHS using a 7.62x39 mm SKS rifle and 240 channel recording system. The 3D patch covers ~ 90,000 sq. m with a maximum inline offset aperture of 225 m, crossline aperture of 75 m, and 360 degree azimuthal coverage. Additionally, we have completed a regional total-field magnetic survey for a large portion of the Alvord Basin and a 3D transient electromagnetic (TEM) survey of the BLHS. The 3D TEM survey covers the central portion of the 3D seismic survey. Initial results from the regional magnetic and seismic surveys indicate a mid-basin basement high. The basement high appears to correlate with the northeast trending BLHS. Additionally, the cross-basin seismic profile clearly shows that recent deformation has primarily been along an eastward dipping normal fault that bounds the basement high to the east. This suggests that both spatial and temporal characteristics of deformation control hydrothermal activity within the BLHS.

  14. Systems Thinking 2: Thermodynamic Systems

    NSDL National Science Digital Library

    Linda Vanasupa

    This video explains thermodynamic systems, open and closed systems, and the four key properties of a system. This video is part of the Sustainability Learning Suites, made possible in part by a grant from the National Science Foundation. See 'Learn more about this resource' for Learning Objectives, Assessment, and Activities.

  15. Antenna Systems Advanced Antenna Systems

    E-print Network

    Fang, Yuguang "Michael"

    EEL4461 EEL5462 Fall 2014 Antenna Systems Advanced Antenna Systems Instructor Dr. Jenshan Lin://lss.at.ufl.edu/) Textbooks Required: Balanis, Antenna Theory - Analysis and Design, 3rd ed. 2005 Prerequisite EEL3472 principles of antenna and to apply them to the design and analysis of antenna systems. Students will learn

  16. Characterization of tropical near-shore fish communities by coastal habitat status on spatially complex island systems

    E-print Network

    Sealey, Kathleen Sullivan

    of species) were markedly different at sites with varying coverage of seagrass and macro-algae and extents biota, which is associated with the seagrass and benthic macro- algae, may contribute to a high expanses of sand, seagrass and algae (Almeda-Villela et al. 2002), which often comprise the largest areas

  17. Operating Systems

    NSDL National Science Digital Library

    Bin Muhammad, Rashid

    Rashid Bin Muhammad at Kent State University presents his page of lectures notes and other instructional materials on operating systems. The site is divided into a number of topics about operating systems: history, structure, process, threads, Solaris-2, CPU / process scheduling, schedule algorithm, interprocess communication, deadlock, important UNIX commands, and references. The site is then followed by links to outside resources to help supplement the material presented here. This is a great resource for computer science instructors teaching students about operating systems.

  18. [Information systems].

    PubMed

    Rodríguez Maniega, José Antonio; Trío Maseda, Reyes

    2005-03-01

    The arrival of victims of the terrorist attacks of 11 March at the hospital put the efficiency of its information systems to the test. To be most efficient, these systems should be simple and directed, above all, to the follow-up of victims and to providing the necessary information to patients and families. A specific and easy to use system is advisable. PMID:15771852

  19. Geothermal systems

    NASA Technical Reports Server (NTRS)

    Mohl, C.

    1978-01-01

    Several tasks of JPL related to geothermal energy are discussed. The major task is the procurement and test and evaluation of a helical screw drive (wellhead unit). A general review of geothermal energy systems is given. The presentation focuses attention on geothermal reservoirs in California, with graphs and charts to support the discussion. Included are discussions on cost analysis, systems maintenance, and a comparison of geothermal and conventional heating and cooling systems.

  20. Systemic Darwinism

    PubMed Central

    Winther, Rasmus Grønfeldt

    2008-01-01

    Darwin's 19th century evolutionary theory of descent with modification through natural selection opened up a multidimensional and integrative conceptual space for biology. We explore three dimensions of this space: explanatory pattern, levels of selection, and degree of difference among units of the same type. Each dimension is defined by a respective pair of poles: law and narrative explanation, organismic and hierarchical selection, and variational and essentialist thinking. As a consequence of conceptual debates in the 20th century biological sciences, the poles of each pair came to be seen as mutually exclusive opposites. A significant amount of 21st century research focuses on systems (e.g., genomic, cellular, organismic, and ecological/global). Systemic Darwinism is emerging in this context. It follows a “compositional paradigm” according to which complex systems and their hierarchical networks of parts are the focus of biological investigation. Through the investigation of systems, Systemic Darwinism promises to reintegrate each dimension of Darwin's original logical space. Moreover, this ideally and potentially unified theory of biological ontology coordinates and integrates a plurality of mathematical biological theories (e.g., self-organization/structure, cladistics/history, and evolutionary genetics/function). Integrative Systemic Darwinism requires communal articulation from a plurality of perspectives. Although it is more general than these, it draws on previous advances in Systems Theory, Systems Biology, and Hierarchy Theory. Systemic Darwinism would greatly further bioengineering research and would provide a significantly deeper and more critical understanding of biological reality. PMID:18697926

  1. Anticipatory systems as linguistic systems

    NASA Astrophysics Data System (ADS)

    Ekdahl, Bertil

    2000-05-01

    The idea of system is well established although not well defined. What makes up a system depends on the observer. Thinking in terms of systems is only a convenient way to conceptualize organizations, natural or artificial, that show coherent properties. Among all properties, which can be ascribed to systems, one property seems to be more outstanding than others, namely that of being anticipatory. In nature, anticipatory properties are found only in living organizations. In this way it can be said to separate non-living systems from living because there is no indication that any natural phenomenon occurring in systems where there is no indication of life is anticipatory. The characteristic of living systems is that they are exposed to the evolution contrary to causal systems that do not undergo changes due to the influence of the environment. Causal systems are related to the past in such a way that subsequent situations can be calculated from knowledge of past situations. In causal systems the past is the cause of the present and there is no reference to the future as a determining agent, contrary to anticipatory systems where expectations are the cause of the present action. Since anticipatory properties are characteristic of living systems, this property, as all other properties in living systems, is a result of the evolution and can be found in plants as well as in animals. Thus, it is not only tied to consciousness but is found at a more basic level, i.e., in the interplay between genotype and phenotype. Anticipation is part of the genetic language in such a way that appropriate actions, for events in the anticipatory systems environment, are inscribed in the genes. Anticipatory behavior, as a result of the interpretation of the genetic language, has been selected by the evolution. In this paper anticipatory systems are regarded as linguistic systems and I argue that as such anticipation cannot be fragmented but must be holistically studied. This has the implication that anticipatory behavior can only partially be described in a computer language and, furthermore, it shows that only a restricted class of anticipatory systems can be transferred to computers.

  2. A critical comparison of different approaches to sediment-quality assessments in the Santos Estuarine System in Brazil.

    PubMed

    Torres, Ronaldo J; Cesar, Augusto; Pastor, Victor A; Pereira, Camilo D S; Choueri, Rodrigo B; Cortez, Fernando S; Morais, Rodofley D; Abessa, Denis M S; do Nascimento, Marcos R L; Morais, Cassia R; Fadini, Pedro S; Casillas, Tomas A Del Valls; Mozeto, Antônio A

    2015-01-01

    This study focuses on the discussion of different lines of evidence (LoEs) applied to a sediment-quality assessment that considered the following: chemical concentrations of metals; polycyclic aromatic hydrocarbons (PAHs) in estuarine waters, sediments, and oysters (native and caged Crassostrea brasiliana); PAHs in semipermeable membrane devices (SPMDs); simultaneously extracted metals-acid volatile sulfides (SEM-AVS); benthic community assessment (the exploratory benthic index and the relative benthic index); chronic toxicity tests with the sea urchin Lytechinus variegatus; and bioaccumulation models. Significantly contaminated sediments from the Santos Estuarine System and the consequent toxicity of tested organisms were measured. Caged oysters presented bioaccumulation rates ?2,500% of total PAH content and 200% of metal content when compared with control organisms from an uncontaminated area. SPMD results presented the same bioaccumulation pattern as caged oysters but at lower concentrations. Benthic communities presented some alterations, and there was a predominance of tolerant species in the inner part of the estuary. According to the SEM-AVS approach, metals should be assumed to be nonbioavailable, but experiments with transplanted C. brasiliana showed metal bioaccumulation, particularly in the cases of chromium, copper, mercury, and zinc. The weight-of-evidence approach was applied to compare and harmonize LoEs commonly used in sediment-quality assessments and to then classify estuary environments according to both their potential for having adverse effects on the biota and their possible ecological risks. All of the results of these approaches (except for SEM-AVS) were found to complement each other. PMID:25398222

  3. Hydrothermal carbonization of biomass residues: mass spectrometric characterization for ecological effects in the soil-plant system.

    PubMed

    Jandl, Gerald; Eckhardt, Kai-Uwe; Bargmann, Inge; Kücke, Martin; Greef, Jörg-Michael; Knicker, Heike; Leinweber, Peter

    2013-01-01

    Hydrochars, technically manufactured by hydrothermal carbonization (HTC) of biomass residues, are recently tested in high numbers for their suitability as feedstock for bioenergy production, the bioproduct industry, and as long-term carbon storage in soil, but ecological effects in the soil-plant system are not sufficiently known. Therefore, we investigated the influence of different biomass residues and process duration on the molecular composition of hydrochars, and how hydrochar addition to soils affected the germination of spring barley ( L.) seeds. Samples from biomass residues and the corresponding hydrochars were analyzed by pyrolysis-field ionization mass spectrometry (Py-FIMS) and gaseous emissions from the germination experiments with different soil-hydrochar mixtures by gas chromatography/mass spectrometry (GC/MS). The molecular-level characterization of various hydrochars by Py-FIMS clearly showed that the kind of biomass residue influenced the chemical composition of the corresponding hydrochars more strongly than the process duration. In addition to various detected possible toxic substances, two independent mass spectrometric methods (Py-FIMS and GC/MS) indicated long C-chain aliphatic compounds which are typically degraded to the C-unit ethylene that can evoke phytotoxic effects in high concentrations. This showed for the first time possible chemical compounds to explain toxic effects of hydrochars on plant growth. It is concluded that the HTC process did not result in a consistent product with defined chemical composition. Furthermore, possible toxic effects urgently need to be investigated for each individual hydrochar to assess effects on the soil organic matter composition and the soil biota before hydrochar applications as an amendment on agricultural soils. PMID:23673755

  4. Disperse Systems

    Microsoft Academic Search

    Makoto Takeo

    1999-01-01

    Interesting applications for disperse systems exist in many areas of modern technology. Weight and cost savings achieved in engineered foams for complex designs and computer-modeled optical pigments for creating astounding effects in coating are but two examples of such diverse applications. In addition to the cost and material reductions already achieved in existing applications, future applications of disperse systems are

  5. Blackboard systems

    Microsoft Academic Search

    I. D. Craig

    1988-01-01

    The blackboard architecture is becoming an increasingly popular basis for the construction of problem-solving systems which operate in domains requiring qualitatively different kinds of knowledge to be applied in order to arrive at a solution to a problem. This paper presents the metaphor on which blackboard systems are based. The metaphor is then given an interpretation which constitutes the blackboard

  6. Multimedia Systems

    NSDL National Science Digital Library

    Ms Laurie Patterson

    CSC 304. Multimedia Systems (3) Prerequisite: CSC 121. Introduction to technologies of the Internet and networked multimedia systems. Issues in web page design; Internet client/server programming; collaborative computing and group work; network publishing; security and encryption; audio and video compression; ethical issues and privacy; e-commerce; and distributed object computing. Open only to students of junior or senior standing.

  7. Organ Systems

    NSDL National Science Digital Library

    W. R. Klemm

    2001-01-01

    This "Organ Systems" module has five units of instruction that focus on the main classes of functions that a body must perform. Rather than just naming organs of the body and what they do, they present a perspective on the body as a coordinated group of systems that must do certain things correctly in order to survive and thrive.

  8. Power system

    DOEpatents

    Hickam, Christopher Dale (Glasford, IL)

    2008-03-18

    A power system includes a prime mover, a transmission, and a fluid coupler having a selectively engageable lockup clutch. The fluid coupler may be drivingly connected between the prime mover and the transmission. Additionally, the power system may include a motor/generator drivingly connected to at least one of the prime mover and the transmission. The power-system may also include power-system controls configured to execute a control method. The control method may include selecting one of a plurality of modes of operation of the power system. Additionally, the control method may include controlling the operating state of the lockup clutch dependent upon the mode of operation selected. The control method may also include controlling the operating state of the motor/generator dependent upon the mode of operation selected.

  9. Systems and Components Fuel Delivery System, Water Delivery System, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Systems and Components - Fuel Delivery System, Water Delivery System, Derrick Crane System, and Crane System Details - Marshall Space Flight Center, F-1 Engine Static Test Stand, On Route 565 between Huntsville and Decatur, Huntsville, Madison County, AL

  10. File Systems File System Overview

    E-print Network

    Hamey, Len

    Pig Cat Cow Dog Goat Owl Ox Hen Ibis Lion Tree After T fig 5.2 Abstract view - properties System file (reposition) Open Close #12;File Creation Find space in the file system Make a new entry in appropriate storage space used by the file Truncate: Empty file Rename: Modify/move directory entry #12;Other

  11. Processing system

    NASA Technical Reports Server (NTRS)

    Hilland, J. E.

    1983-01-01

    To implement the analysis techniques and to provide end-to-end processing, a system was designed with the following capabilities: receive and catalog data from many sources; organize the data on mass storage for rapid access; edit for reasonableness; create new data sets by sorting on parameter, averaging and merging; provide statistical analysis and display tools; and distribute data on demand. Consideration was given to developing a flexible system that could meet immediate workshop needs and respond to future requirements. System architecture and data set details implemented are discussed.

  12. System Toolbox

    NSDL National Science Digital Library

    System Toolbox is designed for system administrators who deal with a variety of platforms. The site covers Windows NT, General Unix, Novell, Linux, Solaris, HP-UX, and the Mac OS. The "toolbox" for each platform offers annotated links to Tools (Disk Management, Anti-Virus, Security, etc.), Articles, and other useful Links. While the information here is hardly comprehensive, the site offers useful, if often basic, resources for administrators. System Toolbox's brand new History section looks promising, with two articles currently posted, "Von Braun's Slide Rule" and "The Godfather of Computing - Charles Babbage." The Comments section allows users to post questions or comments.

  13. Sources and Fates of Dissolved Organic Carbon in Rural and Urban Watersheds in Brazos County, Texas 

    E-print Network

    Cioce, Danielle

    2012-10-19

    quality. Dissolved organic matter is crucial in aquatic systems as it provides an energy source for biota and protects aquatic life from UV light (Williamson and Zagarese 1994; Leenheer and Croue 2003). It is also responsible for the complexation...

  14. The Systems Integration Modeling System

    SciTech Connect

    Danker, W.J.; Williams, J.R. [USDOE Office of Civilian Radioactive Waste Management, Washington, DC (United States)

    1990-10-01

    This paper discusses the systems integration modeling system (SIMS), an analysis tool for the detailed evaluation of the structure and related performance of the Federal Waste Management System (FWMS) and its interface with waste generators. It`s use for evaluations in support of system-level decisions as to FWMS configurations, the allocation, sizing, balancing and integration of functions among elements, and the establishment of system-preferred waste selection and sequencing methods and other operating strategies is presented. SIMS includes major analysis submodels which quantify the detailed characteristics of individual waste items, loaded casks and waste packages, simulate the detailed logistics of handling and processing discrete waste items and packages, and perform detailed cost evaluations.

  15. Tear System

    MedlinePLUS

    ... or tear drainage. Increased Tear Production and Dry Eyes The eye has two sets of structures that ... and cosmetic surgeon who specializes in the eyelids, orbit, and tear drain system. It’s also important that ...

  16. Earth Systems

    NSDL National Science Digital Library

    Houghton Mifflin Science

    This self-contained module on Earth systems includes a range of fun activities that students can perform in the classroom and at home with family members. They impart important concepts such as observation, identification, measurement, and differentiation.

  17. Recommender systems

    NASA Astrophysics Data System (ADS)

    Lü, Linyuan; Medo, Matúš; Yeung, Chi Ho; Zhang, Yi-Cheng; Zhang, Zi-Ke; Zhou, Tao

    2012-10-01

    The ongoing rapid expansion of the Internet greatly increases the necessity of effective recommender systems for filtering the abundant information. Extensive research for recommender systems is conducted by a broad range of communities including social and computer scientists, physicists, and interdisciplinary researchers. Despite substantial theoretical and practical achievements, unification and comparison of different approaches are lacking, which impedes further advances. In this article, we review recent developments in recommender systems and discuss the major challenges. We compare and evaluate available algorithms and examine their roles in the future developments. In addition to algorithms, physical aspects are described to illustrate macroscopic behavior of recommender systems. Potential impacts and future directions are discussed. We emphasize that recommendation has great scientific depth and combines diverse research fields which makes it interesting for physicists as well as interdisciplinary researchers.

  18. Respiratory System

    NSDL National Science Digital Library

    Jim Bidlack

    The purpose, components, and functions of the respiratory system are presented in this learning through disussion and visualizations. Participants learn about the nasal cavity, pharynx, larynx, trachea, bronchi, bronchioles, and alveoli.

  19. Root systems

    NSDL National Science Digital Library

    N/A N/A (U.S. Government; )

    2004-10-30

    One purpose that roots serve is that of anchoring the plant in the ground. Roots also take up water and nutrients for the plant. Plants all have different root system types to fit their individual needs and locations.

  20. Embedded Systems

    NSDL National Science Digital Library

    Leske, Cavin.

    Embedded systems are dedicated computers designed to perform a specific task. They are usually fairly simple devices that are used in areas where powerful, customizable computers are unnecessary; however, they can also be quite complex on occasion. Embedded systems can be found almost anywhere, including automobiles and cellular phones, and their importance is reflected in their near omnipresence.An excellent introduction to embedded systems can be found in the first three pages of this online course material (1). The educational module gives a thorough definition of embedded systems, several examples of where they are used, and a discussion of their common components. For a more detailed explanation of how these devices are used to control various appliances, motors, and other real world products, this site (2) is worth a visit. Sixteen sections comprise the site, and each includes background information and an example experiment. Although certain equipment is required for the experiments, much can be learned simply from reading the introductions. This enlightening essay (3) documents the history and development of embedded systems. Despite being somewhat specific to the author's life, it effectively illustrates the evolution of embedded systems and their incorporation into many facets of everyday life. A paper presented at the 2003 International Cryptology Conference (4) considers the vulnerability of embedded cryptosystems to side channel attacks, which are different from normal security violations because they involve monitoring parts of the hardware system instead of the software. The authors propose the design of private circuits that are resistant to such attacks. The Center for Robotics and Embedded Systems at the University of Southern California is the source of this paper (5) about networked robots. Although it is somewhat dated, the paper provides some valuable insights into how robots can be used in human environments and how they can be controlled and coordinated with wireless communications. An article from Dedicated Systems Magazine (6) highlights the role of embedded systems in NASA's Mars Exploration Rovers, which were launched in June and July 2003. The technologies that enabled the rovers to have powerful, reliable operation are described. The April 2003 issue of ACM Queue (7), the online magazine of the Association for Computing Machinery, is dedicated to embedded systems. Seven articles are included in the issue, dealing with the design and construction process of embedded devices and the hardware/software interface. Lastly, a short paper that was presented at a computer architecture symposium in January 2003 looks ahead to the realization of ubiquitous computing (8). This technology revolution, which has been predicted for many years, promises to make tiny computers embedded in virtually everything, even clothing and walls. The author focuses on the area of intelligent vehicles and wheeled mobile robots.