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1

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

PubMed

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

Bozhkov, Ognyan; Tzvetkova, Christina; Russeva, Elena

2

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).

3

Seamount biota and biogeography  

NASA Astrophysics Data System (ADS)

A review of the literature and unpublished data has identified 1045 species of plants, invertebrates and fishes collected from more than 100 seamounts worldwide at depths of 29 to 3800 m. Cnidarians and decapod crustaceans among invertebrates, and scorpaenids and morids among fishes, were the most widely distributed groups on seamounts, according to published reports. Biota of seamounts is dominated by organisms inhabiting the nearest continental areas, especially at high latitudes. On shallow seamounts (<1000 m) provincial species with distributions limited to the region in which the seamount is located and widespread/cosmopolitan species are nearly equally represented. On deeper seamounts, the widespread/cosmopolitan categories dominate. Seamounts appear to provide "stepping stones" for trans-oceanic dispersal in both the Atlantic and Pacific oceans. Dispersal onto seamounts probably occurs both actively (swimming) and passively )drift of pelagic and planktonic stages). Seamount endemism is estimated maximally at 15.4% among invertebrates and 11.6% among fishes. Population divergence and possibly speciation have occurred on seamounts of varying depths and distances from continental margins.

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

4

40Ar/ 39Ar dating of hydrothermal activity, biota and gold mineralization in the Rhynie hot-spring system, Aberdeenshire, Scotland  

NASA Astrophysics Data System (ADS)

This study presents a new high-precision 40Ar/ 39Ar age for the Devonian hot-spring system at Rhynie. Hydrothermal K-feldspar sampled from two veins that represent feeder conduits and a hydrothermally altered andesite wall rock, date the hydrothermal activity, the fossilised biota, and syn - K-feldspar gold mineralization at 403.9 ± 2.1 Ma (2?). Oxygen isotope data for the parent fluid (-4‰ to 2‰) show that the K-feldspar was precipitated from a dominantly meteoric fluid, which mixed with magmatic fluids from a degassing magma chamber. The 40Ar/ 39Ar age (403.9 ± 2.1 Ma [2?]) when recalculated (407.1 ± 2.2 Ma [2?]) with respect to the astronomically tuned age for Fish Canyon sanidine (28.201 ± 0.023 Ma [1?]), also provides a robust marker for the polygonalis-emsiensis Spore Assemblage Biozone within the Pragian-?earliest Emsian. Furthermore, the age identifies the Devonian pull-apart volcano-sedimentary basins of the British and Irish Caledonides (and their root zones), as specific targets for future gold exploration.

Mark, D. F.; Rice, C. M.; Fallick, A. E.; Trewin, N. H.; Lee, M. R.; Boyce, A.; Lee, J. K. W.

2011-01-01

5

Impacts of Mine Drainage and Other Nonpoint Source Pollutants on Aquatic Biota in the Upper Powell River System, Virginia  

Microsoft Academic Search

The Clinch-Powell River system of Virginia and Tennessee, USA, is among the most biologically diverse ecosystems in the world, and has been identified as a conservation priority of national importance. Other researchers have attributed declines in Powell River freshwater mussel populations to coal mining-related activities. The objectives of this paper are to synthesize the results of several studies aimed at

David J. Soucek; Donald S. Cherry; Carl E. Zipper

2003-01-01

6

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)

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.

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

2011-12-01

7

Proposed Release Guides to Protect Aquatic Biota  

SciTech Connect

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

Marter, W.L.

2001-03-28

8

Radionuclide data bases available for bioaccumulation factors for freshwater biota  

SciTech Connect

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

Blaylock, B.G.

1982-07-01

9

Sediments in ships: Biota as biological contaminants  

Microsoft Academic Search

Global ports are hubs for industrial activities and trade. In consequence, sediments and water in these areas are often contaminated by an array of chemicals. Sediments also harbour both living, active stages and various diapausing or resting stages of biota. International shipping activities move sediments containing these biotic stages around the world, possibly resulting in biological contamination of port areas.

Sarah A. Bailey; Ian C. Duggan; Kanavillil Nandakumar; Hugh J. MacIsaac

2007-01-01

10

Biochar effects on soil biota – A review  

Microsoft Academic Search

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

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

2011-01-01

11

Extrapolation of Biota-sediment Accumulation Factors  

EPA Science Inventory

When assessing risks at sites with contaminated sediments, risk assessors need to estimate residues in fish and other aquatic biota based upon the levels of contaminants in the sediments. Unfortunately, risk assessors are often challenged by data limitations, i.e., i) contaminan...

12

DDT residues in forest biota: Further data  

Microsoft Academic Search

The USDA-USDI Environmental Statement 2 prepared for the proposed 1974 Douglas-fir tussock moth suppression plan, involving DDT, contains a comprehensive review of knowledge on persistence and cycling of DDT in forests. Its conclusions on terrestrial biota (pp. 214-215) project residue levels of DDT and effects expected in many taxa following a single application; however, it notes that, \\

J. B. Dimond; R. B. Owen; A. S. Getchell

1975-01-01

13

Determination of currently used pesticides in biota.  

PubMed

Although pesticides enable control of the quantity and quality of farm products and food, and help to limit diseases in humans transmitted by insects and rodents, they are regarded as among the most dangerous environmental contaminants because of their tendency to bioaccumulate, and their mobility and long-term effects on living organisms. In the past decade, more analytical methods for accurate identification and quantitative determination of traces of pesticides in biota have been developed to improve our understanding of their risk to ecosystems and humans. Because sample preparation is often the rate-determining step in analysis of pesticides in biological samples, this review first discusses extraction and clean-up procedures, after a brief introduction to the classes, and the methods used in the analysis of pesticides in biota. The analytical methods, especially chromatographic techniques and immunoassay-based methods, are reviewed in detail, and their corresponding advantages, limitations, applications, and prospects are also discussed. This review mainly covers reports published since 2008 on methods for analysis of currently used pesticides in biota. PMID:22918537

Andreu, Vicente; Picó, Yolanda

2012-08-24

14

Density dependence, spatial scale and patterning in sessile biota.  

PubMed

Sessile biota can compete with or facilitate each other, and the interaction of facilitation and competition at different spatial scales is key to developing spatial patchiness and patterning. We examined density and scale dependence in a patterned, soft sediment mussel bed. We followed mussel growth and density at two spatial scales separated by four orders of magnitude. In summer, competition was important at both scales. In winter, there was net facilitation at the small scale with no evidence of density dependence at the large scale. The mechanism for facilitation is probably density dependent protection from wave dislodgement. Intraspecific interactions in soft sediment mussel beds thus vary both temporally and spatially. Our data support the idea that pattern formation in ecological systems arises from competition at large scales and facilitation at smaller scales, so far only shown in vegetation systems. The data, and a simple, heuristic model, also suggest that facilitative interactions in sessile biota are mediated by physical stress, and that interactions change in strength and sign along a spatial or temporal gradient of physical stress. PMID:15968539

Gascoigne, Joanna C; Beadman, Helen A; Saurel, Camille; Kaiser, Michel J

2005-09-29

15

11. Chernobyl's radioactive impact on microbial biota.  

PubMed

Of the few microorganisms that have been studied, all underwent rapid changes in the areas heavily contaminated by Chernobyl. Organisms such as tuberculosis bacilli; hepatitis, herpes, and tobacco mosaic viruses; cytomegalovirus; and soil micromycetes and bacteria were activated in various ways. The ultimate long-term consequences for the Chernobyl microbiologic biota may be worse than what we know today. Compared to humans and other mammals, the profound changes that take place among these small live organisms with rapid reproductive turnover do not bode well for the health and survival of other species. PMID:20002053

Yablokov, Alexey V

2009-11-01

16

Coupling between ocean biota and atmospheric aerosols: Dust, dimethylsulphide, or artifact?  

Microsoft Academic Search

Two hypotheses that postulate interactions between ocean biota and aerosols in the atmosphere have generated substantial research into marine systems. The stimulation of phytoplankton photosynthesis by the provision of iron, a micronutrient contained in deposited aeolian dust (the Iron Hypothesis), and the contribution of dimethylsulphide (DMS) produced by marine ecosystems to the atmospheric burden of aerosols (the CLAW Hypothesis) have

Roger A. Cropp; Albert J. Gabric; Grant H. McTainsh; Roger D. Braddock; Neil Tindale

2005-01-01

17

Application of Phase Contrast Microscopy to the Study of Marine Micro- Biota.  

National Technical Information Service (NTIS)

We present the observation of the activity of artemia, one of the popular marine micro-biota species, in free space by the application of Fourier optics imaging technique The Fourier optic imaging system is consisted by a collimated laser beam source, a F...

C. T. Lian J. S. Hwang M. C. Shih

2000-01-01

18

Role of the terrestrial biota in the global COâ cycle  

Microsoft Academic Search

A new analysis of existing literature is presented. Questions are posed for each section of the biota on the magnitude of their organic carbon storage and whether they are sources or sinks of carbon. A critique on the data and assumptions being used in assessments of the global role of the biota in the carbon cycle, are presented. Sections addressed

S. Brown; A. E. Lugo

1981-01-01

19

Exceptionally preserved Late Ordovician biotas from Manitoba, Canada  

Microsoft Academic Search

There are few body fossil biotas known from early Paleozoic accretionary shorelines, and very few examples of Ordovician soft-bodied assemblages. This study documents two recently discovered biotas from separate sedimentary basins in Manitoba, Canada, that provide unique information about tropical shoreline communities shortly before the Late Ordovician extinction event. Each site represents a distinct depositional environment, but they share biotic

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

2007-01-01

20

Exceptionally preserved Late Ordovician biotas from Manitoba, Canada  

NASA Astrophysics Data System (ADS)

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

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

2007-10-01

21

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

PubMed

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

Kryshev, A I; Sazykina, T G

2011-09-15

22

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

PubMed

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

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

23

Implant and Forget Mechanism to Interact with Biota, in Particular Fauna that May Outgrow Available Habitat.  

National Technical Information Service (NTIS)

An 'implant and forget' device for interacting with biota after a pre-established time period. Preferably, the biota are fauna and more particularly fish. In select embodiments, the device comprises packaging enclosing means for timing interaction via ope...

J. A. Evans J. P. Kirk L. E. Miranda

2005-01-01

24

Becoming New Zealanders: Immigration and the Formation of the Biota  

Microsoft Academic Search

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,

M. S. McGlone

25

Growth rate-stoichiometry couplings in diverse biota  

Microsoft Academic Search

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 :

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

26

A Check List of the Biota of Lower Chesapeake Bay.  

National Technical Information Service (NTIS)

The list is a sequel to the 'Check-list of Marine Invertebrates of Virginia' last revised in 1965. The biota of Chesapeake Bay seems generally less known than that of New England and much of our West Coast. The present work attempts to mollify this discre...

M. L. Wass

1972-01-01

27

Assemblage palaeoecology of the Ediacara biota: The unabridged edition?  

Microsoft Academic Search

Fossils of the Ediacara biota offer our earliest insight into diverse macroscopic life on this planet. In particular, given the diversity and range of exquisite soft-bodied preservation, the potential for unraveling aspects of the paleobiology and paleoecology is great. Clearly, however, there can be a taphonomic overprint that dictates how complete the assemblage is. New diversity data (including richness and

Mary L. Droser; James G. Gehling; Sören R. Jensen

2006-01-01

28

Direct Application of Biota-sediment Accumulation Factors  

EPA Science Inventory

Biota-sediment bioaccumulation factors (BSAFs) relate chemical residues in fish to chemical concentrations in contaminated sediments. BSAFs used by EPAs Office of Water in developing water quality criteria and by EPAs Superfund program in performing risk assessments for sites wi...

29

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

Microsoft Academic Search

The radiological assessment of non-human biota is now accepted by a number of international bodies. In this connection the scientific basis to assess and evaluate biota internal and external radiation exposure is required. This paper presents the comparison of freshwater biota (hydrophyte species) exposure due to discharged anthropogenic radionuclides with that due to natural background radiation. The radionuclides from Ignalina

T. Nedveckaite; V. Filistovic; D. Marciulioniene; D. Kiponas; V. Remeikis; N. A. Beresford

2007-01-01

30

[Analysis of cell arrangements in Biota orientalis using Fourier transformation].  

PubMed

Fourier transform image-processing technology is applied for determining the cross section cell arrangement of early-wood in Biota orientalis. In this method, the disc-convoluted dot map from each cell radius with 10 pixels is transformed by Fourier transform, generating the angle distribution function in the power spectral pattern. The maximum value is the arrangement of the cell. The results of Fourier transform image-processing technology indicated that the arrangements of the cell of Biota orientalis are 15 degrees in oblique direction, respectively. This method provides a new basis for the digitized identification of the wood, and also the new theoretical research direction for the digitized identification and examination of the wood species. PMID:20038030

Duo, Hua-Qiong; Wang, Xi-Ming

2009-10-01

31

Community structure and composition of the Cambrian Chengjiang biota  

Microsoft Academic Search

Based on previously published species data (228 species in over 18 phyla) and field sampling (114 species and 18406 individuals)\\u000a in the Chengjiang-Haikou-Anning area, we analyzed quantitatively the paleocommunity composition and structure of the Cambrian\\u000a Chengjiang biota (Cambrian Series 2, eastern Yunnan, China). Arthropods dominate the community both in species diversity (species:\\u000a 37%) and in abundance (individuals: 51.8%). Priapulids (individuals:

FangChen Zhao; MaoYan Zhu; ShiXue Hu

2010-01-01

32

Human colonic biota studied by ribosomal DNA sequence analysis  

Microsoft Academic Search

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

KENNETH H. WILSON; R. B. Blitchington

1996-01-01

33

Burgess Shale-Type Biotas Were not Entirely Burrowed Away  

Microsoft Academic Search

Burgess Shale?type biotas occur globally in the Cambrian record and offer unparalleled insight into the Cambrian explosion, the initial Phanerozoic radiation of the Metazoa. Deposits bearing exceptionally preserved soft-bodied fossils are unusually common in Cambrian strata; more than 40 are now known. The well-documented decline of soft-bodied preservation following the Middle Cambrian represents the closure of a taphonomic window that

Robert Gaines; M. L. Droser; P. J. Orr; D. Garson; E. U. Hammarlund; C. Qi; Donald Canfield

2012-01-01

34

Evolution of the Mesozoic oceanic biota: Response to abiotic factors  

Microsoft Academic Search

An analysis of the biota evolution during the Mesozoic in response to abiotic factors shows that the most important among\\u000a them are the climate, sea-level position, dynamics and structure of the water column, its chemistry, volcanism, tectonics\\u000a (horizontal and vertical movements of lithospheric blocks), and collision of the earth with astronomical bodies (impact events).\\u000a Stable conditions and a variety of

M. S. Barash

2008-01-01

35

Harvester ant nests, soil biota and soil chemistry  

Microsoft Academic Search

Many ant species accumulate organic debris in the vicinity of their nests. These organic materials should provide a rich resource\\u000a base for the soil biota. We examined the effect of harvester ant nests (Pogonomyrmex barbatus) on the soil community and soil chemistry. Ant nest soils supported 30-fold higher densities of microarthropods and 5-fold\\u000a higher densities of protozoa than surrounding, control

Diane Wagner; Mark J. F. Brown; Deborah M. Gordon

1997-01-01

36

Conversion ratios for the foodstuffs and biota environmental surveillance program  

SciTech Connect

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

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

1998-09-01

37

Soil Biota Reduce Allelopathic Effects of the Invasive Eupatorium adenophorum  

PubMed Central

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

Zhu, Xunzhi; Zhang, Jintun; Ma, Keping

2011-01-01

38

The Lightning-Biota Climatic Feedback  

NASA Astrophysics Data System (ADS)

We portray and investigate a negative climatic feedback which involves an increase in deposition of lightning produced nitrogen compounds (LNOx) into global ecosystems as a response to a global temperature rise. This increases primary production which reduces atmospheric CO2, and consequently global temperature in return. There are large uncertainties in numerous processes and parameters involved in this feedback and therefore in its importance. This feedback is investigated over the range of uncertainties using a conceptual dynamical model. The feedback exhibits a damped oscillator behavior throughout most of the parameter space examined, yet can sustain stable oscillations at high values of leading parameters. We test the role that this feedback might play in counteracting anthropogenic induced warming as may result from emission of CO_2. This feedback tends to reduce the rate of accumulation of atmospheric CO_2. However, this tendency (feedback gain) decreases with higher CO_2 levels in the atmosphere and smaller sequestering capacity of the vegetation. Overall, this study suggests that this feedback is of mild strength in the climate system, but raises the intriguing possibility that it should be considered in long term climate simulations. Further work in investigating this climatic feedback in a more complicated models is required.

Shepon, A.; Gildor, H.

2006-12-01

39

The utility of stream habitat and biota for identifying potential conflicting forest land uses: Montane riparian areas  

Microsoft Academic Search

Rinne, J.N., 1990. The utility of stream habitat and biota for identifying potential conflicting forest land uses: Montane riparian areas. For. Ecol. Manage., 33\\/34: 363-383. Investigations since 1960 on the effects of land-management practices on riparian-stream systems often have produced contradictory results. Inconsistencies have occurred, in part, because of efforts that have not been totally comprehensive and, in part, because

John N. Rinne

1990-01-01

40

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

PubMed

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

Muscatello, J R; Janz, D M

2008-11-25

41

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

PubMed

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

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

2009-08-15

42

Ediacara Biota: Ancestors of Modern Life or Evolutionary Dead End?  

NSDL National Science Digital Library

Ediacara Biota are the first convincing fossils of Precambrian animals that were found in the Ediacara Hills of Australia. The unusual fossils, originally interpreted as jellyfish, strange worms, and frond-like corals, gave scientists their first look at the animals that populated the Precambrian seas. In Canada, Ediacaran fossils are found in the Northwest Territories, Yukon, British Columbia, and Newfoundland. The Mackenzie Mountains, NWT, has the thickest continuous section of rock (2.5 kilometers) containing Ediacaran fossils in the world. This site provides information on the fossils and features a location map with active links and a link to information on Ediacaran fossils found in Namibia.

43

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

SciTech Connect

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

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

44

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...

45

The importance of the biodiversity of soil biota in arid ecosystems  

Microsoft Academic Search

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

Walter G. Whitford

1996-01-01

46

A New Exceptionally Preserved Biota from the Lower Silurian of Wisconsin, U.S.A  

Microsoft Academic Search

A new biota including lightly sclerotized and soft-bodied organisms occurs in finely laminated argillaceous dolomites of late Llandoverian age in Waukesha County, Wisconsin. This discovery fills a gap between well known Cambrian and Devonian Konservat Lagerstatten. The biota is dominated by arthropods. A dalmanitid is the most numerous of 13 genera of trilobites; the crustaceans include phyllocarids and ostracods; the

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

1985-01-01

47

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

Microsoft Academic Search

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

A. I. Kryshev; T. G. Sazykina

48

Prevailing Negative Soil Biota Effect and No Evidence for Local Adaptation in a Widespread Eurasian Grass  

PubMed Central

Background Soil biota effects are increasingly accepted as an important driver of the abundance and distribution of plants. While biogeographical studies on alien invasive plant species have indicated coevolution with soil biota in their native distribution range, it is unknown whether adaptation to soil biota varies among populations within the native distribution range. The question of local adaptation between plants and their soil biota has important implications for conservation of biodiversity and may justify the use of seed material from local provenances in restoration campaigns. Methodology/Principal Findings We studied soil biota effects in ten populations of the steppe grass Stipa capillata from two distinct regions, Europe and Asia. We tested for local adaptation at two different scales, both within (ca. 10–80 km) and between (ca. 3300 km) regions, using a reciprocal inoculation experiment in the greenhouse for nine months. Generally, negative soil biota effects were consistent. However, we did not find evidence for local adaptation: both within and between regions, growth of plants in their ‘home soil’ was not significantly larger relative to that in soil from other, more distant, populations. Conclusions/Significance Our study suggests that negative soil biota effects can prevail in different parts of a plant species' range. Absence of local adaptation points to the possibility of similar rhizosphere biota composition across populations and regions, sufficient gene flow to prevent coevolution, selection in favor of plasticity, or functional redundancy among different soil biota. From the point of view of plant - soil biota interactions, our findings indicate that the current practice of using seeds exclusively from local provenances in ecosystem restoration campaigns may not be justified.

Wagner, Viktoria; Antunes, Pedro M.; Ristow, Michael; Lechner, Ute; Hensen, Isabell

2011-01-01

49

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

PubMed

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

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

2010-01-27

50

The global carbon cycle change: Le Chatelier principle in the response of biota to changing CO 2 concentration in the atmosphere  

Microsoft Academic Search

Summary  The long-term existence of natural biota in the environment means that such a system is stable with respect to external disturbances.\\u000a This system must follow the Le Chatelier principle which is based on the processes that compensate the disturbing effects.\\u000a The use of the Le Chatelier principle makes it possible to choose between contradictory observational data. Available observational\\u000a data on

V. G. Gorshkov; S. G. Sherman; K. Ya. Kondratyev

1990-01-01

51

Response of Confined Aquatic Biota to Mine Depressurization Water in Beaver Creek Reservoir.  

National Technical Information Service (NTIS)

The response of selected species of aquatic biota to saline mine depressurization water after average dilution in the Beaver Creek Reservoir was investigated. Test organisms included periphyton, native fish species, and native invertebrates. Studies exami...

T. Jantzie L. R. Noton N. R. Chymko

1980-01-01

52

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...

53

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

Microsoft Academic Search

BackgroundSoil biota may trigger strong physiological responses in plants and consequently induce distinct phenotypes. Plant phenotype, in turn, has a strong impact on herbivore performance. Here, we tested the hypothesis that aboveground herbivores are able to adapt to plant phenotypes induced by soil biota.Methodology and Principal FindingsWe bred spider mites for 15 generations on snap beans with three different belowground

Dries Bonte; Annelies de Roissart; Martijn L. Vandegehuchte; Daniel J. Ballhorn; Thomas van Leeuwen; Eduardo de La Peña; Corrie S. Moreau

2010-01-01

54

Palaeoecology of the Early Cambrian Sinsk biota from the Siberian Platform  

Microsoft Academic Search

The Sinsk biota (Early Cambrian, Botoman Stage, Siberian Platform) inhabited an open-marine basin within the photic zone, but in oxygen-depleted bottom waters. Its rapid burial in a fine-grained sediment under anoxic conditions led to the formation of one of the earliest Cambrian Lagerstätte. All the organisms of the biota were adapted to a life under dysaerobic conditions. It seems possible

Andrey Yu. Ivantsov; Andrey Yu. Zhuravlev; Anton V. Leguta; Valentin A. Krassilov; Lyudmila M. Melnikova; Galina T. Ushatinskaya

2005-01-01

55

Effects of soil biota from different ranges on Robinia invasion: acquiring mutualists and escaping pathogens.  

PubMed

The net effects of soil biota on exotic invaders can be variable, in part, because net effects are produced by many interacting mutualists and antagonists. Here we compared mutualistic and antagonistic biota in soils collected in the native, expanded, and invasive range of the black locust tree, Robinia pseudoacacia. Robinia formed nodules in all soils with a broad phylogenetic range of N-fixing bacteria, and leaf N did not differ among the different sources of soil. This suggests that the global expansion of Robinia was not limited by the lack of appropriate mutualistic N-fixers. Arbuscular mycorrhizal fungi (AMF) from the native range stimulated stronger positive feedbacks than AMF from the expanded or invasive ranges, a biogeographic difference not described previously for invasive plants. Pythium taxa collected from soil in the native range were not more pathogenic than those from other ranges; however, feedbacks produced by the total soil biota were more negative from soils from the native range than from the other ranges, overriding the effects of AMF. This suggests that escape from other pathogens in the soil or the net negative effects of the whole soil community may contribute to superior performance in invaded regions. Our results suggest that important regional evolutionary relationships may occur among plants and soil biota, and that net effects of soil biota may affect invasion, but in ways that are not easily explained by studying isolated components of the soil biota. PMID:21661564

Callaway, Ragan M; Bedmar, Eulogio J; Reinhart, Kurt O; Silvan, Cinta Gómez; Klironomos, John

2011-05-01

56

Linking stormflow hydrology and biota in suburban streams  

NASA Astrophysics Data System (ADS)

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.

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

2005-12-01

57

Temporal trends of Hg in Arctic biota, an update.  

PubMed

A statistically robust method was applied to 83 time-series of mercury in Arctic biota from marine, freshwater and terrestrial ecosystems with the purpose of generating a 'meta-analysis' of temporal trend data collected over the past two to three decades, mostly under the auspices of the Arctic Monitoring and Assessment Program (AMAP). Sampling locations ranged from Alaska in the west to northern Scandinavia in the east. Information from recently published temporal trend studies was tabulated to supplement the results of the statistical analyses. No generally consistent trend was evident across tissues and species from the circumpolar Arctic during the last 30years or so. However, there was a clear west-to-east gradient in the occurrence of recent increasing Hg trends, with larger numbers and a higher proportion of biotic datasets in the Canadian and Greenland region of the Arctic showing significant increases than in the North Atlantic Arctic. Most of the increasing datasets were for marine species, especially marine mammals. A total of 16 (19%) out of the 83 time-series could be classified as "adequate", where adequate is defined as the number of actual monitoring years in a time-series being equal to or greater than the number of years of sampling required to detect a 5% annual change in Hg concentrations, with a significance level of P<0.05 and 80% statistical power. At the time of the previous AMAP Assessment, only 10% of the Hg time-series were deemed adequate. If an additional 5years of data were to be added to the current set of time-series, it is predicted that 53% of time-series would become adequate. PMID:21684574

Rigét, Frank; Braune, Birgit; Bignert, Anders; Wilson, Simon; Aars, Jon; Born, Erik; Dam, Maria; Dietz, Rune; Evans, Marlene; Evans, Thomas; Gamberg, Mary; Gantner, Nikolaus; Green, Norman; Gunnlaugsdóttir, Helga; Kannan, Kurunthachalam; Letcher, Robert; Muir, Derek; Roach, Pat; Sonne, Christian; Stern, Gary; Wiig, Oystein

2011-08-15

58

The Land Cover Cascade: Cause-Effect Couples Between Watersheds and Stream Biota  

NASA Astrophysics Data System (ADS)

A cascade may be defined as the propagation of a stimulus through a series of interdependent cause - effect relationships that generate an ultimate response. The cascade concept has been applied to biotic systems ranging in scope from molecules to ecosystems. The approach has been useful in organizing complex, multivariate, biotic relationships, and in identifying mechanisms associated with the transformation of stimuli in biotic systems. We propose the Land Cover Cascade (LCC) to summarize the translation of anthropogenic disturbance through physical ecosystem elements to ultimate influences on stream biota. Much is known about how individual or groups of stream elements respond to disturbance, but how element responses are coupled, and how these couples translate disturbance implications, are largely unknown. To quantify the LCC, we estimated land-cover and physical ecosystem elements in streams influenced by agricultural land-uses. Path analysis identified cascades that organized direct and indirect effects of elements on biotic responses, and assessed the predictive ability of each cascade. Cascade models of 3-4 links explained 50-94 percent of variation observed in thirteen fish and macroinvertebrate assemblage responses. This approach moves us beyond traditional bivariate relationships, and brings us closer to identifying the mechanisms and pathways involved in ecosystem responses to disturbance.

Burcher, C.; Benfield, E. F.; Valett, H. M.

2005-05-01

59

Improvements and application of a modified gas chromatography atomic fluorescence spectroscopy method for routine determination of methylmercury in biota samples.  

PubMed

Improvements to the application of a combined solid-phase microextraction followed by gas chromatography coupled to pyrolysis and atomic fluorescence spectrometry method (SPME-GC-AFS) for methylmercury (MeHg) determination in biota samples are presented. Our new method includes improvements in the methodology of determination and the quantification technique. A shaker instead of a stirrer was used, in order to reduce the possibility of sample contamination and to simplify cleaning procedures. Then, optimal rotation frequency and shaking time were settled at 800rpm and 10min, respectively. Moreover, the GC-AFS system was equipped with a valve and an argon heater to eliminate the effect of the decrease in analytical signal caused by the moisture released from SPME fiber. For its determination, MeHg was first extracted from biota samples with a 25% KOH solution (3h) and then it was quantified by two methods, a conventional double standard addition method (AC) and a modified matrix-matched calibration (MQ) which is two times faster than the AC method. Both procedures were successfully tested with certified reference materials, and applied for the first time to the determination of MeHg in muscle samples of goosander (Mergus merganser) and liver samples of white-tailed eagle (Haliaeetus albicilla) with values ranging from 1.19 to 3.84mg/kg dry weight (dw), and from 0.69 to 6.23mgkg(-1) dw, respectively. PMID:24054647

Gorecki, Jerzy; Díez, Sergi; Macherzynski, Mariusz; Kalisinska, El?bieta; Golas, Janusz

2013-06-28

60

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

Microsoft Academic Search

Concentrations of selenium (Se) in bottom material ranged from 0·6 to 5·0 lg g~1, and from 0·5 to 18·3 l gg ~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

Jaqueline GarcmH; Kirke A. King; Anthony L. Velasco; Evgueni Shumilin; Miguel A. MoraA; Edward P. Glenn

2001-01-01

61

Biota participating in wastewater treatment in a horizontal flow constructed wetland.  

PubMed

During the period 1996-1997, three constructed wetlands with sub-surface horizontal flow were investigated. All systems are designed to treat municipal sewage from small villages (150, 200 and 300 PE). The survey included microscopical identification of organisms in both wastewater and filtration substrate. The organisms were used as an indication of oxygen conditions (aerobic, anoxic and anaerobic) in the particular microenvironment. Saprobiological terms characterizing different levels of saprobity were employed to characterize inflowing wastewater, filtration bed and outflowing water. The occurrence of organisms was correlated with BOD5 values in particular profiles. It has been found that the biocenosis in the inflowing wastewater differs from those found in the filtration bed and water outflowing from the vegetated beds. The organisms were grouped into those living under anaerobic and anoxic conditions and those living under aerobic conditions. More than 70 species of bacteria, amoebae, ciliates, rotifers, colorless flagellates, cyanobacteria and algae were found and the most important 45 species were figured in a plate together with saprobiological information for each species. Biota of the inflowing water is usually restricted to bacteria, ciliata and colorless flagellata while the organisms found in outflowing water as well as in periphyton growing on outflow structures indicate 2-3 levels better quality. PMID:11804097

Vymazal, J; Sládedek, V; Stach, J

2001-01-01

62

[Fungal biota in manned space environment and impact on human health].  

PubMed

It is important to promote microbiological research essential for long-term manned space activities under microgravity and in a completely closed environment in space craft in relation to long-duration space expeditions on the International Space Station (ISS) or to the moon and Mars in the future. Environmental monitoring data from the space shuttle, the Mir, and the ISS have already shown that microorganisms isolated from air and on inner surfaces of space craft were generally carried by crew members. The Japanese Experiment Module (JEM) "KIBO" was attached to the ISS and started its operation from 2008. It is an invaluable opportunity to begin the survey of the transition of microbiota, particularly fungal biota, in JEM from "brand-new" to "well-used" condition at various periods. Therefore, we are preparing the on-board analyzing systems for microbiota in air and on inner surfaces of ISS/JEM and normal microbiota of the astronauts themselves. In this paper, we introduce the current status and future plans on fungal research on ISS/JEM to protect flight crew members and flight hardware from potentially hazardous microorganisms from the environmental and biomedical aspects of Japan Aerospace Exploration Agency (JAXA). PMID:21358138

Makimura, Koichi; Satoh, Kazuo; Sugita, Takashi; Yamazaki, Takashi

2011-01-01

63

Ecospace utilization, paleoenvironmental trends, and the evolution of early nonmarine biotas  

NASA Astrophysics Data System (ADS)

Paleozoic nonmarine trace fossils evidence paleoenvironmental trends that are linked directly to progressive ecospace utilization (spatial and functional). These trends resulted in a considerable increase of ichnodiversity throughout the Paleozoic. Colonization of nonmarine settings began as early as the Late Ordovician, as recorded by the presence of terrestrial burrow systems associated with ancient soils. In the other cases, the presence of "nonmarine" trace fossils in Cambrian and Ordovician sedimentary rocks was the result of temporary colonization by marginal marine organisms and does not reflect establishment of true fresh-water faunas. Devonian trace fossils have been reported from alluvial and alluvial-lacustrine transitional environments. Surface arthropod trackways are dominant in marginal lake settings, representing the development of true nonmarine biotas. The presence of vertical burrows in fluvial deposits records the establishment of deep suspension-feeding infaunal organisms. Trace fossils from the Carboniferous reflect migration farther into the lakes. Ichnofossils have been reported from shallow and deep lake deposits and from alluvial and alluvial-lacustrine transitional environments. Lake assemblages are dominated by surface grazing trails. The Permian was characterized by the establishment of a deep deposit-feeding infauna, commonly recorded by the Scovenia ichnofacies represented by backfilled meniscate burrows.

Buatois, Luis Alberto; Mángano, María Gabriela

1993-07-01

64

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

NASA Astrophysics Data System (ADS)

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.

Robinson, Chris; Ortlepp, Johannes

2010-05-01

65

Dissolved oxygen decline in ice-covered rivers of northern Alberta and its effects on aquatic biota  

Microsoft Academic Search

To determine whether existing dissolved oxygen (DO) regulationswere adequate to protect riverine biota, the Northern River Basins Studyrequired a research and assessment program to establish the effect ofpulp mill and municipal sewage discharges on under-ice DO concentrationsand aquatic biota in the Athabasca, Wapiti and Smoky rivers of northernAlberta, Canada. Analysis of monitoring data collected over >30 yearsshowed that pulp mill

Patricia A. Chambers; Scott Brown; Joseph M. Culp; Richard B. Lowell; Alain Pietroniro

2000-01-01

66

Speciation analysis of antimony in marine biota by HPLC(UV)-HG-AFS: Extraction procedures and stability of antimony species  

Microsoft Academic Search

Speciation analysis of antimony in marine biota is not well documented, and no specific extraction procedure of antimony species from algae and mollusk samples can be found in the literature. This work presents a suitable methodology for the speciation of antimony in marine biota (algae and mollusk samples). The extraction efficiency of total antimony and the stability of Sb(III), Sb(V)

Ida De Gregori; Waldo Quiroz; Hugo Pinochet; Florence Pannier; Martine Potin-Gautier

2007-01-01

67

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

PubMed Central

Background Soil biota may trigger strong physiological responses in plants and consequently induce distinct phenotypes. Plant phenotype, in turn, has a strong impact on herbivore performance. Here, we tested the hypothesis that aboveground herbivores are able to adapt to plant phenotypes induced by soil biota. Methodology and Principal Findings We bred spider mites for 15 generations on snap beans with three different belowground biotic interactions: (i) no biota (to serve as control), (ii) arbuscular mycorrhizal fungi and (ii) root-feeding nematodes. Subsequently, we conducted a reciprocal selection experiment using these spider mites, which had been kept on the differently treated plants. Belowground treatments induced changes in plant biomass, nutrient composition and water content. No direct chemical defence through cyanogenesis was detected in any of the plant groups. Growth rates of spider mites were higher on the ecotypes on which they were bred for 15 generations, although the statistical significance disappeared for mites from the nematode treatment when corrected for all multiple comparisons. Conclusion/Significance These results demonstrate that belowground biota may indeed impose selection on the aboveground insect herbivores mediated by the host plant. The observed adaptation was driven by variable quantitative changes of the different separately studied life history traits (i.e. fecundity, longevity, sex-ratio, time to maturity).

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

2010-01-01

68

Review of impacts on soil biota caused by copper residues from fungicide application  

Microsoft Academic Search

Unlike most other agricultural chemicals, a significant weight of evidence exists that copper based fungicides have a long-term impact on a wide range of soil biota. Effects can occur at relatively low Cu concentrations and influence a number of soil processes including microbial activity, earthworm activity and bioturbation. In most soils, copper residues are likely to remain indefinitely, and will

Lukas Van-Zwieten; Graham Merrington; Melissa Van-Zwieten

69

Effects of Pollution on Biota of the Pigeon River, North Carolina and Tennessee.  

National Technical Information Service (NTIS)

Wastes from the Champion Paper Company and the city of Canton, North Carolina, polluted the Pigeon River and adversely affected the biota of the river in the states of North Carolina and Tennessee. This pollution: Reduced the growth of both the desirable ...

L. E. Keup R. K. Stewart

1966-01-01

70

Effects of land use on water quality and aquatic biota of three North Carolina Piedmont streams  

Microsoft Academic Search

Three streams in the Piedmont ecoregion of North Carolina were studied to evaluate the effect of land use (forested, agricultural, urban) on water quality and aquatic biota. In comparison with the forested stream, there were few changes in water quality at the agricultural and urban streams. Suspended-sediment yield was greatest for the urban catchment and least at the forested catchment.

David R. Lenat; J. Kent Crawford

1994-01-01

71

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

PubMed

The radiological assessment of non-human biota is now accepted by a number of international bodies. In this connection the scientific basis to assess and evaluate biota internal and external radiation exposure is required. This paper presents the comparison of freshwater biota (hydrophyte species) exposure due to discharged anthropogenic radionuclides with that due to natural background radiation. The radionuclides from Ignalina Nuclear Power Plant (Lithuania) are discharged into cooling pond - Druksiai Lake. Submerged hydrophytes were selected as biota exposure indicators because they represent the largest biomass in this lake and have comparatively high radionuclide activity concentrations. The detailed methodology evaluation of the submerged hydrophyte dose rate is presented. The ionizing radiation exposure dose rates to submerged hydrophyte roots and above sediment parts due to the major radionuclides ((54)Mn, (60)Co, (137)Cs, (90)Sr) discharged into the INPP cooling pond - Druksiai Lake were 0.044 microGyh(-1) and 0.004 microGyh(-1), respectively. The internal exposure dose rate due to natural background alpha-emitters ((210)Po,(238)U, (226)Ra) was estimated to be 1.24 microGyh(-1), as compared with that of anthropogenic alpha-emitter (240)Pu - 0.04 microGyh(-1), whereas the external exposure was 0.069 microGyh(-1). The presented data deeper the knowledge about the concentration of radionuclides and submerged hydrophytes' exposure dose rates in European freshwater ecosystems. PMID:17544183

Nedveckaite, T; Filistovic, V; Marciulioniene, D; Kiponas, D; Remeikis, V; Beresford, N A

2007-06-01

72

Absorbed dose rate conversion coefficients for reference terrestrial biota for external photon and internal exposures  

Microsoft Academic Search

The paper describes dosimetric models that allow the estimation of average radiation exposures to terrestrial biota due to environmental sources in the soil as well as internal uniform distributions of radionuclides. Simple three-dimensional phantoms for 13 faunal reference organisms are specified. The calculation of absorbed dose per unit source strength for these targets is based on photon and electron transport

V. Taranenko; G. Pröhl; J. M. Gómez-Ros

2004-01-01

73

A practical method for assessment of dose conversion coefficients for aquatic biota  

Microsoft Academic Search

Radiological impact assessment for flora and fauna requires adequate dosimetric data. Due to the variability of habitats, shapes, and masses of the non-human biota, assessment of doses is a challenging task. External and internal dose conversion coefficients for photons and electrons have been systematically calculated by Monte Carlo methods for spherical and ellipsoidal shapes in water medium. An interpolation method

A. Ulanovsky; G. Pröhl

2006-01-01

74

A new, Middle Cambrian, Burgess Shale-type biota, Bolaspidella Zone, Chancellor Basin, southeastern British Columbia  

Microsoft Academic Search

A newly discovered Burgess Shale-type (BST) biota occurs in southeastern British Columbia on Haiduk and Tangle peaks. The fossiliferous rocks of the informally named Vermilion sub-unit and Duchesnay unit occur in the Bolaspidella Zone, one trilobite biozone younger than the Burgess Shale Formation. The younger rocks abut the Eldon Escarpment in a stratigraphic and depositional relationship that mirrors that of

Kimberley J. Johnston; Paul A. Johnston; Wayne G. Powell

2009-01-01

75

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

Microsoft Academic Search

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

Martin Brasier; Duncan McIlroy

76

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

Microsoft Academic Search

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

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

1970-01-01

77

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...

78

Responses of selected aquatic biota to discharges from Colbert Steam Plant, Tennessee River, 1978 and 1979  

SciTech Connect

Results of studies of hydrothermodynamics, water quality, nonfisheries and fisheries biology, supplemented by water chemistry, phytoplankton, periphyton, zooplankton, and benthic macroinvertebrate collections are presented and evaluated. The objective was to examine the effects of thermal discharges from the Colbert Steam Electric Plant, situated in northwest Alabama on Pickwick Reservoir of the Tennessee River, on the aquatic biota of the Tennessee River. (ACR)

Dycus, D.L.; Harned, R.D.; Laborde, S.M.; Miller, J.L.; Price, J.H.; Wade, D.C.

1981-06-01

79

Bioaccumulation of PCBs in aquatic biota from a tidal freshwater marsh ecosystem.  

PubMed

Water, sediments, and aquatic biota were sampled in a tidal river-marsh on the Potomac River near Washington, DC (USA) to assess baseline concentrations of polychlorinated biphenyls (PCBs) and bioaccumulation in finish species. The mean sediment total-PCB concentration in the wetland was 50 ng/g dry weight, and mean concentrations in biota ranged from 150 ng/g to 450 ng/g wet weight. The highest PCB concentrations were observed in channel catfish. The median biota-sediment accumulation factor (BSAF) estimated in all finfish species for total-PCBs was 2.9. However, some of the individual and co-eluting PCB congeners had median BSAFs that were substantially greater (e.g., congener numbers 42, 74, 182/187/128, and 171) or lower (e.g., congener numbers 18/15, 45, 185, and 208) than the total-PCB average. Apparent bioaccumulation factors (biota/water PCB concentration ratios) for PCB congeners showed a parabolic relation with n-octanol/water partition coefficients, confirming some previous investigations. There was no clear trend between apparent bioaccumulation factors and trophic level. Organic-carbon-normalized sediment distribution constants (sediment/water PCB concentration ratios) were linearly related to the apparent bioaccumulation factors for all the finfish species investigated. PMID:11994779

Crimmins, B S; Brown, P Doelling; Kelso, D P; Foster, G D

2002-05-01

80

Degradation of Laurentian Great Lakes Biota--Causes and Effects Through 1970  

Microsoft Academic Search

Pollutants from direct and indirect human activities have resulted in alterations of Great Lakes biota, and many of these alterations have had negative economic impacts. Lake Erie, with the least volume of water, and with the largest human population on surrounding land, suffered the most dramatic changes, particularly as a consequence of phosphorus and mercury pollution. Accelerated eutrophication altered the

ROBERT A SWEENEY

1982-01-01

81

Radiological Benchmarks for Effects on Aquatic Biota at the Oak Ridge Reservation  

Microsoft Academic Search

Radiological benchmarks for aquatic biota were developed for use at the U.S. Department of Energy's Oak Ridge Reservation as screening values to determine the spatial extent of potential ecological effects and to identify the need for additional site-specific investigation. The Point Source Dose Distribution approach was used to calculate water and sediment activities for selected radionuclides that result in a

Daniel S. Jones

2000-01-01

82

Acidification in the Adirondacks: defining the biota in trophic levels of 30 chemically diverse acid-impacted lakes.  

PubMed

The Adirondack Mountains in New York State have a varied surficial geology and chemically diverse surface waters that are among the most impacted by acid deposition in the U.S. No single Adirondack investigation has been comprehensive in defining the effects of acidification on species diversity, from bacteria through fish, essential for understanding the full impact of acidification on biota. Baseline midsummer chemistry and community composition are presented for a group of chemically diverse Adirondack lakes. Species richness of all trophic levels except bacteria is significantly correlated with lake acid-base chemistry. The loss of taxa observed per unit pH was similar: bacterial genera (2.50), bacterial classes (1.43), phytoplankton (3.97), rotifers (3.56), crustaceans (1.75), macrophytes (3.96), and fish (3.72). Specific pH criteria were applied to the communities to define and identify acid-tolerant (pH<5.0), acid-resistant (pH 5.0-5.6), and acid-sensitive (pH>5.6) species which could serve as indicators. Acid-tolerant and acid-sensitive categories are at end-points along the pH scale, significantly different at P<0.05; the acid-resistant category is the range of pH between these end-points, where community changes continually occur as the ecosystem moves in one direction or another. The biota acid tolerance classification (batc) system described herein provides a clear distinction between the taxonomic groups identified in these subcategories and can be used to evaluate the impact of acid deposition on different trophic levels of biological communities. PMID:20614900

Nierzwicki-Bauer, Sandra A; Boylen, Charles W; Eichler, Lawrence W; Harrison, James P; Sutherland, James W; Shaw, William; Daniels, Robert A; Charles, Donald F; Acker, Frank W; Sullivan, Timothy J; Momen, Bahram; Bukaveckas, Paul

2010-08-01

83

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

PubMed

A dose per unit concentration database has been generated for application to ecosystem assessments within the FASSET framework. Organisms are represented by ellipsoids of appropriate dimensions, and the proportion of radiation absorbed within the organisms is calculated using a numerical method implemented in a series of spreadsheet-based programs. Energy-dependent absorbed fraction functions have been derived for calculating the total dose per unit concentration of radionuclides present in biota or in the media they inhabit. All radionuclides and reference organism dimensions defined within FASSET for marine and freshwater ecosystems are included. The methodology has been validated against more complex dosimetric models and compared with human dosimetry based on ICRP 72. Ecosystem assessments for aquatic biota within the FASSET framework can now be performed simply, once radionuclide concentrations in target organisms are known, either directly or indirectly by deduction from radionuclide concentrations in the surrounding medium. PMID:15700696

Vives i Batlle, J; Jones, S R; Gómez-Ros, J M

2004-12-01

84

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

PubMed

In recent years there has been growing international interest in the assessment of doses and risks from ionising contaminants to biota. In this study the ERICA Tool, developed within the EC 6th Framework Programme, was applied to estimate incremental dose rates to biota in freshwater ecosystems in Finland mainly resulting from exposure to the Chernobyl-derived radionuclides (137)Cs, (134)Cs and (90)Sr. Data sets consisting of measured activity concentrations in fish, aquatic plants, lake water and sediment for three selected lakes located in a region with high (137)Cs deposition were applied in the assessment. The dose rates to most species studied were clearly below the screening level of 10 microGy h(-1), indicating no significant impact of the Chernobyl fallout on these species. However, the possibility of higher dose rates to certain species living on or in the bottom sediment cannot be excluded based on this assessment. PMID:19828217

Vetikko, Virve; Saxén, Ritva

2009-10-13

85

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

PubMed

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

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

2012-06-14

86

Climate Warming and Disease Risks for Terrestrial and Marine Biota  

Microsoft Academic Search

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,

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

2002-01-01

87

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

Microsoft Academic Search

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

Patrick De Deckker

1983-01-01

88

Trace elements in soil and biota in confined disposal facilities for dredged material  

USGS Publications Warehouse

We studied the relation of trace element concentrations in soil to those in house mice (Mus musculus), common reed (Phragmites australis) and ladybugs (Coccinella septempunctata) at five disposal facilities for dredged material. The sites had a wide range of soil trace element concentrations, acid soils and a depauperate fauna. They were very poor wildlife habitat because they were dominated by the common reed. Bioassay earthworms exposed to surface soils from three of the five sites died, whereas those exposed to four of five soils collected a meter deep survived, presumably because the deeper, unoxidized soil, was not as acid. Concentrations of Ni and Cr in the biota from each of the sites did not seem to be related to the concentrations of the same elements in soil. Although Pb, Zn and Cu concentrations in biota were correlated with those in soil, the range of concentrations in the biota was quite small compared to that in soil. The concentrations of Pb detected in mice were about as high as the concentrations previously reported in control mice from other studies. Mice from the most contaminated site (530 ppm Pb in soil) contained only slightly more Pb (8 ppm dry wt) than did mice (2-6 ppm dry wt) from sites containing much less Pb (22-92 ppm in soil). Despite the acid soil conditions, very little Cd was incorporated into food chains. Rather, Cd was leaching from the surface soil. We concluded that even the relatively high concentrations of trace elements in the acid dredged material studied did not cause high, concentrations of trace elements in the biota.

Beyer, W.N.; Miller, G.; Simmers, J.W.

1990-01-01

89

Distribution of biota in a stream polluted by acid mine-drainage  

Microsoft Academic Search

Acidic water draining from coal mines has severly restricted the diversity of biota inhabiting Roaring Creek, eastern West Virginia. Polluted reaches of the stream (median pH values ranging from 2.8 to 3.8) were inhabited by 3 to 12 genera of bottom-dwelling invertebrates and 10 to 19 species of periphytic algae. Invertebrates tolerant of the pollution included Sialis sp., chironomus plumosus

1971-01-01

90

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

Microsoft Academic Search

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

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

1987-01-01

91

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

Microsoft Academic Search

Global environmental changes are expected to impact the abundance of plants and animals aboveground, but comparably little\\u000a is known about the responses of belowground organisms. Using meta-analysis, we synthesized results from over 75 manipulative\\u000a experiments in order to test for patterns in the effects of elevated CO2, warming, and altered precipitation on the abundance of soil biota related to taxonomy,

Joseph C. BlankinshipPascal; Pascal A. Niklaus; Bruce A. Hungate

2011-01-01

92

How Ant Nests Increase Soil Biota Richness and Abundance: A Field Experiment  

Microsoft Academic Search

Although many studies have shown that ant nests tend to increase soil nutrient concentrations, only a few have examined ant\\u000a impact on soil biota. To date, no one has examined the mechanism behind this complex ‘ant effect.’ In this study, we employed\\u000a a 2 × 2 complete factorial design (water × food) in the field to mimic the effects of harvester ant nests (Messor

April M. Boulton; Keith D. Amberman

2006-01-01

93

How ant nests increase soil biota richness and abundance: a field experiment  

Microsoft Academic Search

Although many studies have shown that ant nests tend to increase soil nutrient concentrations, only a few have examined ant\\u000a impact on soil biota. To date, no one has examined the mechanism behind this complex ‘ant effect.’ In this study, we employed\\u000a a 2 × 2 complete factorial design (water × food) in the field to mimic the effects of

April M. Boulton; Keith D. Amberman

94

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

Microsoft Academic Search

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

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

2001-01-01

95

Silica-secreting biota and mass extinctions: survival patterns and processes  

Microsoft Academic Search

High survival and at least regional blooms of siliceous marine groups, with coeval retreat of calcareous organisms, is known from the Frasnian–Famennian (radiolarians, silicisponges) and end-Cretaceous (diatoms, radiolarians) mass extinctions. A strictly actualistic approach to the palaeoecology of silica-secreting biota is of limited significance, especially for silica-enriched and oligotrophic Palaeozoic epeiric seas and, in particular, during biotic turnovers. Adaptation among

Grzegorz Racki

1999-01-01

96

DISTRIBUTION OF BIOTA IN A STREAM POLLUTED BY ACID MINE-DRAINAGE1  

Microsoft Academic Search

Acidic water draining from coal mines has severely restricted the diversity of biota inhabiting Roaring Creek, eastern West Virginia. Polluted reaches of the stream (median pH values ranging from 2.8 to 3.8) were inhabited by 3 to 12 genera of bottom-dwelli ng invertebrates and 10 to 19 species of periphytic algae. Invertebrates tolerant of the pollution included Sialis sp., Chironomus

RICHARD W. WARNER

1971-01-01

97

Natural and synthetic endocrine disrupting compounds (EDCs) in water, sediment and biota of a coastal lagoon  

Microsoft Academic Search

We report a survey on the occurrence and distribution of natural (17?-estradiol, E2; estrone, E1) and synthetic (nonylphenol, NP; nonylphenol monoethoxylate carboxylate, NP1EC; bisphenol-A, BPA; benzophenone, BP; mestranol, MES; 17?-ethinylestradiol, EE2; diethylstilbestrol, DES) endocrine disrupting compounds (EDCs) in water, sediment and biota (Mediterranean mussel, Mytilus galloprovincialis) in the Venice lagoon, a highly urbanized coastal water ecosystem that receives both industrial

Giulio Pojana; Alessio Gomiero; Niels Jonkers; Antonio Marcomini

2007-01-01

98

Chlorobenzenes, chlorinated pesticides, coplanar chlorobiphenyls and other organochlorine compounds in Greenland biota.  

PubMed

This paper summarises the levels and composition of chlorobenzenes, chlorinated pesticides, coplanar polychlorinated biphenyls (PCBs) and the chlorinated compounds octachlorostyrene (OCS), hexachlorocyclobutadiene (HCBD) and pentachloro-anisole (PCA) in biota from the terrestrial, freshwater and marine environment of Greenland. The data were obtained during the second phase of the Arctic Monitoring and Assessment Programme (AMAP). Of the chlorobenzenes, hexachlorobenzene was the main constituent detected in almost all samples. The chlorobenzenes accumulate in the marine food web in a similar manner to the better-studied persistent organic pollutants, with maximum concentrations in beluga, minke whale and narwhal. However, concentrations in ringed seals and kittiwakes were lower than in marine fish, contradicting biomagnification. Of the organochlorine pesticides, the drin pesticides (aldrin, endrin, dieldrin) and heptachlor had increasing concentrations along the food chain, whilst biomagnification was less pronounced for endosulfan, methoxychlor and mirex. Endosulfan and methoxychlor are pesticides still in use and considered less persistent than other organochlorine pesticides. Their occurrence in Arctic biota is of particular concern, also given the high acute toxicity of endosulfan to fish. Chlorobenzene and pesticide concentrations tended to be lower in the Greenland samples than in the same animals from the Canadian Arctic, whilst their concentrations were similar to samples from Svalbard and Iceland. However, temporal trends might overlap the geographical differences. Coplanar chlorobiphenyls (CBs) were found in all samples analysed, with the maximum concentrations found in marine mammals such as beluga and narwhal. Biota from the terrestrial environment appeared to be less contaminated. The main contributor on a TEQ basis was CB126. OCS, HCBD and PCA were detected in biota from Greenland, although at very low concentrations. OCS seems to have the widest occurrence and the highest potential for biomagnification of the three compounds analysed. PMID:15325147

Vorkamp, Katrin; Riget, Frank; Glasius, Marianne; Pécseli, Maria; Lebeuf, Michel; Muir, Derek

2004-09-20

99

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

Microsoft Academic Search

The accumulation patterns of ten metals in tissues of plant, Eichornia crassipes, and fishes, Hydrocynus forskahlii and Oreochromis mossambicus, were modeled with simple fuzzy classification (SFC) to assess toxic effects of anthropogenic activities on the coastal biota.\\u000a The plant sample was separated into root, stem, and leaves and the fishes into bones, internal tissues, and muscles. They\\u000a were analyzed for

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

100

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

SciTech Connect

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

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

1981-12-01

101

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

PubMed Central

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

Bonaccorso, Elisa; Guayasamin, Juan M.

2013-01-01

102

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

Microsoft Academic Search

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

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

2000-01-01

103

Evidence for the transfer of polychlorinated biphenyls, polychlorinated dibenzo- p-dioxins, and polychlorinated dibenzofurans from soil into biota  

Microsoft Academic Search

The concentrations of six indicator and co-planar polychlorinated biphenyls (PCBs), 17 polychlorinated dibenzo-p-dioxins, and polychlorinated dibenzofurans (PCDD\\/Fs) were determined in soil and associated biota samples collected from a polluted and wasted farmland in southern China. The sum of six indicator PCBs (Nos 28, 52, 101, 138, 153 and 180) concentrations in biota samples were proportional to the total amount of

Xingru Zhao; Minghui Zheng; Bing Zhang; Qinghua Zhang; Wenbin Liu

2006-01-01

104

The Cretaceous Tetori biota in Japan and its evolutionary significance for terrestrial ecosystems in Asia  

USGS Publications Warehouse

Cretaceous nonmarine deposits are widely distributed on the Asian continent and include various kinds of zoo- and phyto-assemblages. The Tetori Group is one of the most important Mesozoic terrestrial deposits in East Asia, and for this reason its geology, stratigraphy, and biota have been studied intensively by our group for more than a decade. We present the main results herein. We confirm that formations as lithostratigraphic units are the best geological correlation tools for the Tetori Group and the best tools for a geological mapping of the group. Although subgroups have previously been used for correlation, proper designation and evaluation of subgroups is required if they are to be used effectively, and we show that previous geological correlation of the Tetori Group has been confused by inappropriate definition of these subgroups. We located fossil localities including reported zoo- and phyto-assemblages in the framework of formations correlated by our stratigraphy. The occurrence of zoo-assemblages was probably controlled by environments (i.e., most are in situ), but phyto-assemblages were mostly transported and rapidly buried by high-energy river systems. Although two distinct dinosaur faunas and four floras have been named for the zoo- and phyto-assemblages in the Tetori Group, in reality there is only one Tetori Dinosaur Fauna and one Tetori Flora, as proved by careful correlation. Two types of zoo-assemblages co-occur in the Tetori Group: vertebrate species whose ancestors flourished in the Jurassic (as found in China), and their descendants from the Late Cretaceous. As the latter modern type of assemblage is more abundant than the former, changeable environments at the continental margin probably accelerated evolution of more modern species. We can employ nonmarine molluscan species as geological correlation tools in some cases, i.e., when their taxon ranges are well-confirmed by independent evidence. However, because freshwater molluscan species and terrestrial vertebrate species had many opportunities to move to optimum habitat as environments changed through time on the Cretaceous Asian continent, their correlation potential is uncertain. Many nonmarine molluscan species from the Japanese and Chinese Cretaceous had their stratigraphic occurrences controlled by changing environments. ?? 2005 Elsevier Ltd. All rights reserved.

Matsukawa, M.; Ito, M.; Nishida, N.; Koarai, K.; Lockley, M. G.; Nichols, D. J.

2006-01-01

105

Climate Warming and Disease Risks for Terrestrial and Marine Biota  

NASA Astrophysics Data System (ADS)

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.

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

2002-06-01

106

Climate warming and disease risks for terrestrial and marine biota  

USGS Publications Warehouse

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.

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

2002-01-01

107

Acidification and Deoxygenation during Hyperthermal Events: Evidence from Seafloor Biota  

NASA Astrophysics Data System (ADS)

The Paleocene-Eocene Thermal Maximum and other early Eocene hyperthermals were short-lived (104-105 years) episodes of very warm climate, linked to emission of isotopically depleted carbon into the ocean-atmosphere system (~55-50 Ma). During these episodes there was severe dissolution of carbonate on the seafloor, and there is evidence of low oxygen conditions at least in parts of the world’s oceans. Benthic foraminifera suffered severe extinction during the most severe hyperthermal, the PETM. On Walvis Ridge (SE Atlantic), benthic foraminiferal assemblages were studied along a depth transect (1500-3600 m) across the PETM, Eocene Thermal Maximum 2 (ETM-2 or Elmo, ~ 1.8 myr after the PETM) and Eocene Thermal Maximum 3 (ETM-3 or X-event, ~ 3.1 myr after the PETM). During hyperthermals, benthic assemblages at all sites are characterized by low-diversity and dominance of relatively small and thin-walled specimens, and indicate a lower supply of food to the seafloor, possibly because of decreased open-ocean productivity during periods of warming. The severe dissolution associated with the PETM allowed no preservation of carbonate tests along the depth transect, but the dissolution interval reflected less time at the shallower sites. Benthic assemblages from above the dissolution interval indicate that Oxygen Minimum Zones expanded downwards over the shallower sites in the earlier and later stages of the main Carbon Isotope Excursion (CIE) associated with the PETM. Benthic foraminifera were present throughout the CIE associated with ETM-2 at the deepest site, but absent to very rare in a few samples from the shallowest site. Assemblages show a similar to, but less extreme pattern than that during the PETM, with development of low-oxygen conditions during the earliest and latest stages of the event. There is no evidence in the benthic assemblages from ETM-3 that OMZs expanded to the depth transect. It is not yet clear whether the combination of ocean acidification and deoxygenation caused the global extinction of deep-sea benthic foraminifera during the PETM, or whether warming itself and/or its effect on oceanic productivity were major factors. Benthic foraminiferal preservation and diversity across the PETM, Walvis Ridge Site 1263 (paleodepth 1500m).

Thomas, E.; Zachos, J. C.; Roehl, U.

2010-12-01

108

Polybrominated diphenyl ethers (PBDEs) in aquatic biota from the lower reach of the Yangtze River, East China.  

PubMed

Sixteen species of aquatic biota from the lower reach of the Yangtze River including fishes, crabs and shrimps were collected and analyzed for 13 polybrominated diphenyl ethers (PBDEs) congeners. All the PBDEs congeners except BDE-17 were detectable in the samples indicating that the aquatic biota from the lower reach of the Yangtze River are widely exposed to these pollutants. The Sigma(12)PBDEs ranged from 3.52 to 603.69 ng/g lipid (0.032-62.69 ng/g wet wt), with a mean of 44.04 ng/g lipid (2.69 ng/g wet wt). The PBDEs levels in the Yangtze River aquatic biota were low to average compared to PBDEs levels in aquatic biota around the world. The predominant congeners were BDE-47, BDE-28, BDE-154, BDE-100 and BDE-153. The proportion of BDE-28 seemed to be relatively high which was different from the result in other studies around the world but consistent with the results in China. The congener pattern of the sample was similar to the pattern in the sediment from the Yangtze River which implies that sediment may be an important PBDEs source for aquatic biota in the lower reach of the Yangtze River. Although the PBDEs levels in aquatic biota this area is comparable to or even lower than that in other areas in China, such as the Pearl River Delta and the Laizhou Bay, the increasing textiles, chemical and electronic industry may bring more and more PBDEs contamination to the Yangtze River Delta. The fact that PBDEs were detectable in all the biota samples from the lower reach of the Yangtze River should be an alarm for increasing risk in the Yangtze River Delta, East China. PMID:19261320

Gao, Zishen; Xu, Jie; Xian, Qiming; Feng, Jianfang; Chen, Xiaohui; Yu, Hongxia

2009-03-03

109

Threatened biotas: \\  

Microsoft Academic Search

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

Norman Myers

1988-01-01

110

Soil Biota  

NSDL National Science Digital Library

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

Mccarville, Katherine

111

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

PubMed

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

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

112

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

NASA Astrophysics Data System (ADS)

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

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

2011-06-01

113

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

SciTech Connect

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

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

1984-08-01

114

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

PubMed

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

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

2010-07-01

115

Spatial patterns of mercury in biota of Adirondack, New York lakes.  

PubMed

We studied the spatial distribution patterns of mercury (Hg) in lake water, littoral sediments, zooplankton, crayfish, fish, and common loons in 44 lakes of the Adirondacks of New York State, USA, a region that has been characterized as a "biological Hg hotspot". Our study confirmed this pattern, finding that a substantial fraction of the lakes studied had fish and loon samples exceeding established criteria for human and wildlife health. Factors accounting for the spatial variability of Hg in lake water and biota were lake chemistry (pH, acid neutralizing capacity (ANC), percent carbon in sediments), biology (taxa presence, trophic status) and landscape characteristics (land cover class, lake elevation). Hg concentrations in zooplankton, fish and common loons were negatively associated with the lake water acid-base status (pH, ANC). Bioaccumulation factors (BAF) for methyl Hg (MeHg) increased from crayfish (mean log(10) BAF = 5.7), to zooplankton (5.9), to prey fish (6.2), to larger fish (6.3), to common loons (7.2). MeHg BAF values in zooplankton, crayfish, and fish (yellow perch equivalent) all increased with increasing lake elevation. Our findings support the hypothesis that bioaccumulation of MeHg at the base of the food chain is an important controller of Hg concentrations in taxa at higher trophic levels. The characteristics of Adirondack lake-watersheds (sensitivity to acidic deposition; significant forest and wetland land cover; and low nutrient inputs) contribute to elevated Hg concentrations in aquatic biota. PMID:21691858

Yu, Xue; Driscoll, Charles T; Montesdeoca, Mario; Evers, David; Duron, Melissa; Williams, Kate; Schoch, Nina; Kamman, Neil C

2011-06-21

116

Testing endocrine disruption in biota samples: a method to remove interfering lipids and natural hormones.  

PubMed

A cleanup method was developed to remove coextracted lipids and natural hormones from biota samples in order to test the endocrine-disrupting (ED) capacity of their extracts in in vitro bioassays. Unspiked and spiked fish tissues were cleaned with a combination of dialysis, gel permeation chromatography (GPC), and normal-phase liquid chromatography (NP-HPLC). The spiking mixture consisted of a broad range of environmental pollutants (endocrine disruptors and genotoxic compounds). Chemical recoveries of each test compound, and thyroid-hormone-like and (anti)androgenic activities of the cleaned extracts were investigated. Despite the chemical and toxicological complexity of the spiking mixture and the sequential sample treatment, chemical analysis revealed acceptable recoveries on average: 89 ± 8% after each cleanup step separately and 75 ± 3% after the whole extraction and cleanup procedure in the extracts. In addition, recovered activities in the bioassays were in good agreement with the spiking levels. The developed cleanup method proved to be capable of lipid and natural hormone removal from fish extracts, enabling the measurement of selected endocrine-hormone-like activities in T(4)*-TTR and AR-CALUX bioassays. The method can be used as a sample preparation method of biota samples for toxicity profiling and effect-directed analysis (EDA). PMID:20883034

Simon, Eszter; Lamoree, Marja H; Hamers, Timo; Weiss, Jana M; Balaam, Jan; de Boer, Jacob; Leonards, Pim E G

2010-11-01

117

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

PubMed

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

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

2006-09-22

118

Role of the terrestrial biota in the global CO/sub 2/ cycle  

SciTech Connect

A new analysis of existing literature is presented. Questions are posed for each section of the biota on the magnitude of their organic carbon storage and whether they are sources or sinks of carbon. A critique on the data and assumptions being used in assessments of the global role of the biota in the carbon cycle, are presented. Sections addressed are: tropical forests, temperate forests, boreal forests, tundra, peatlands and other wetlands and grasslands. Because it appears that undisturbed terrestrial ecosystems are not in balance with the atmosphere, the widely held assumption that mature forests are in steady state and play no role in the global carbon cycle is invalid. The absence of a steady state relative to atmospheric carbon is more significant in moist, tropical regions, where abundant rainfall magnifies the fraction of carbon loss via hydrologic fluxes, where the turnover of biomass is faster due to better growth conditions, and where periodic natural perturbations set back succession to younger states. Global carbon models should test non-steady state scenarios in order to better characterize the carbon budget of the earth and to aid in the final formulation of answers to the questions about the role of plants in the global carbon balance. 4 tables.

Brown, S. (Univ. of Illinois, Urbana); Lugo, A.E.

1981-09-01

119

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

PubMed Central

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

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

1995-01-01

120

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

SciTech Connect

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

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

2008-01-01

121

An Integrated Case Study for Evaluating the Impacts of an Oil Refinery Effluent on Aquatic Biota in the Delaware River: Advanced Chemical Fingerprinting of PAHs  

Microsoft Academic Search

More than one thousand samples were collected and analyzed to evaluate the potential impact of Motiva's oil refinery effluent on the receiving water, sediment, and biota of the Delaware River. The data collected from these samples were used with advanced chemical fingerprinting of polycyclic aromatic hydrocarbons (PAHs) in Motiva's oil refinery effluent to differentiate Motiva-related PAHs in sediment and biota

Allen D. Uhler; Stephen Emsbo-Mattingly; Bo Liu; Lenwood W. Hall Jr; Dennis T. Burton

2005-01-01

122

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

PubMed

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

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

2011-06-08

123

Identification of Martian biota using their radioresistance ability and specific isotopic composition  

NASA Astrophysics Data System (ADS)

Because of a thin atmosphere and weak magnetic field, Martian surface is a subject to high levels of ionizing radiation. On the other hand, variations in Martian obliquity produce the global climate oscillations (with the main period ~120000 years) of the great magnitude. Martian biota would accumulate large radiation dosage during the periods of cold climate, when it would be in the dormant state and would rebuild its population during the periods of warm climate. Therefore, all types of hypothetical Martian microorganisms living in subsurface layers of soil have to posses very high radiation tolerance. In our experiments, we find that "ordinary" bacteria (Escherichia coli and two species of Bacillus ) can develop radioresistance ability after a number of cycles of exposure to the high (almost lethal) radiation dosages, followed by recovery of the bacterial population. We show that natural cycles of this kind could take place only on Mars. On the other hand, high radiation tolerance is hardly necessary for the survival in any natural environment on Earth. A few number of terrestrial microorganisms (radioresistant bacteria) posses this peculiar ability (Deinococus radiodurance , Rubrobacter radiotolerance, Rubrobacter xylanophilus ). The radiation background on Earth, including vicinity of natural nuclear reactor Oklo is many orders of magnitude lower than the lethal dose for these microorganisms. We show that such radioresistance can be "trained" only in the Martian conditions. Therefore, we propose that Earth has been infected several times by the Martian biota on Martian meteorites. We propose that high radioresistance could be a strong sign of the Martian origin for potential microorganisms acquired in the sample return missions. Another way to identify "Martian" microorganisms and exclude contamination in returned samples involves analysis of the radionuclides abundance (being produced by the high energy cosmic rays in the Martian soil). We show that these radionuclides (3H, 14C, 32Si,41Ca) should have higher concentration in the hypothetical Martian microorganisms comparing to any terrestrial analogues. We propose a set of measurements of such "isotopic imprints" with accelerator mass spectrometry. We also show that unusually high ratios of stable isotopes 15N/14N and D/H in the Martian atmosphere can be used for identification of Martian microorganisms because those ratios would be incorporated into the Martian biota.

Pavlov, A. K.; Kalinin, V.; Konstantinov, A.; Shelegedin, V.; Pavlov, A. A.

2003-04-01

124

Was Earth Ever Infected by Martian Biota? Clues from Radioresistant Bacteria  

NASA Astrophysics Data System (ADS)

Here we propose that the radioresistance (tolerance to ionizing radiation) observed in several terrestrial bacteria has a martian origin. Multiple inconsistencies with the current view of radioresistance as an accidental side effect of tolerance to desiccation are discussed. Experiments carried out 25 years ago were reproduced to demonstrate that "ordinary" bacteria can develop high radioresistance ability after multiple cycles of exposure to high radiation dosages followed by cycles of recovery of the bacterial population. We argue that "natural" cycles of this kind could have taken place only on the martian surface, and we hypothesize that Mars microorganisms could have developed radioresistance in just several million years' time and, subsequently, have undergone transfer to Earth by way of martian meteorites. Our mechanism implies multiple and frequent exchanges of biota between Mars and Earth.

Pavlov, Anatoly K.; Kalinin, Vitaly L.; Konstantinov, Alexei N.; Shelegedin, Vladimir N.; Pavlov, Alexander A.

2006-12-01

125

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

PubMed

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

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

2010-03-01

126

Cellulolytic microbes in the Yanbaru, a subtropical rainforest with an endemic biota on Okinawa Island, Japan.  

PubMed

Cellulolytic microbes in the soil of the Yanbaru, a subtropical forest with an endemic biota, on Okinawa Island, were isolated and characterized in a search for novel microbial strains with biotechnological potential. Soil samples of the Yanbaru were suspended in sterilized water, inoculated on mineral salt agar overlaid with a filter paper as carbon source, and cultivated aerobically at 30 °C. After 2 weeks of cultivation, emerging colonies were isolated and subjected to phylogenetic and enzyme analyses. The phylogenetic analyses revealed bacterial and fungal isolates belonging to nine and three genera respectively. All isolates possessed cellulase activity, and several strains showed strong activity comparable to Trichoderma cellulase. Many isolates also exhibited xylanase activity. PMID:22738957

Fujii, Katsuhiko; Oosugi, Ayaka; Sekiuchi, Shiori

2012-05-07

127

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

SciTech Connect

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

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

2000-05-01

128

Signature of the end-Cretaceous mass extinction in the modern biota.  

PubMed

The long-term effects of mass extinctions on spatial and evolutionary dynamics have been poorly studied. Here we show that the evolutionary consequences of the end-Cretaceous [Cretaceous/Paleogene (K/Pg)] mass extinction persist in present-day biogeography. The geologic ages of genera of living marine bivalves show a significant break from a smooth exponential distribution, corresponding to the K/Pg boundary. The break reflects a permanent increase in origination rates, intermediate between the Mesozoic rate and the post-extinction recovery pulse. This global rate shift is most clearly seen today in tropical bioprovinces and weakens toward the poles. Coupled with the modern geographic distributions of taxa originating before and after the K/Pg boundary, this spatial pattern indicates that tropical origination rates after the K/Pg event have left a permanent mark on the taxonomic and biogeographic structure of the modern biota, despite the complex Cenozoic history of marine environments. PMID:19197060

Krug, Andrew Z; Jablonski, David; Valentine, James W

2009-02-01

129

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

PubMed Central

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.

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

2011-01-01

130

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

NASA Astrophysics Data System (ADS)

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

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

2007-05-01

131

Lead (Pb) in Biota and Perceptions of Pb Exposure at a Recently Designated Superfund Beach Site in New Jersey  

Microsoft Academic Search

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

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

2012-01-01

132

Short and medium-chain chlorinated paraffins in biota from the European Arctic — differences in homologue group patterns  

Microsoft Academic Search

Congener and homologue group patterns of chlorinated paraffins (CPs) in biota can be influenced by different processes, but these are not well studied yet. Short- (SCCPs) and medium-chain chlorinated paraffins (MCCPs) were quantified in liver from Arctic char and seabirds (little auk and kittiwake) collected at Bear Island (European Arctic) as well as in cod from Iceland and Norway. CP

Margot Reth; Anita Ciric; Guttorm N. Christensen; Eldbjørg S. Heimstad; Michael Oehme

2006-01-01

133

Longitudinal changes in biota along four New Zealand streams: Declines and improvements in stream health related to land use  

Microsoft Academic Search

We studied four streams in southern New Zealand in 2002 to document downstream changes in water quality, habitat, and stream biota in relation to land use. Two streams were in catchments that had increasing intensity of agricultural development downstream from relatively pristine headwaters. A third stream had the most intense land use in the headwaters and a riparian corridor of

Dev K. Niyogi; Mark Koren; Chris J. Arbuckle; Colin R. Townsend

2007-01-01

134

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

Microsoft Academic Search

This review summarizes and synthesizes the significant amount of data which was generated on mercury (Hg) and persistent organic pollutants (POPs) in Canadian Arctic marine biota since the first Canadian Arctic Contaminants Assessment Report (CACAR) was published in 1997. This recent body of work has led to a better understanding of the current levels and spatial and temporal trends of

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

2005-01-01

135

Evaluation of the use of landsca e classifications for the prediction of freshwater biota: synt ! esis and recommendations  

Microsoft Academic Search

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. Classifications based on landscape spatial scales are used or are being evaluated for use in several countries for aquatic

JEROEN GERRITSEN; K. JACKS; R. JAN

136

Distribution patterns of polychlorinated biphenyl congeners in water, sediment and biota from Midway Atoll (North Pacific Ocean)  

Microsoft Academic Search

To increase our understanding of critical pathways of polychlorinated biphenyl (PCB) transfer from abiotic media into marine organisms, this study quantified 20 PCB congeners in surface water, sediment and tissues of marine biota (macrophytes, snails, urchins, bivalves, sea cucumbers, fishes) taken from Midway Atoll. PCBs 138, 153, 170, 180 and 187 were the most abundant congeners in all samples analysed.

Bruce Hope; Susan Scatolini; Eric Titus; Jeff Cotter

1997-01-01

137

Effects of global climate change on freshwater biota: A review with special emphasis on the Italian situation  

Microsoft Academic Search

There is much evidence that climate is rapidly changing at a global scale, especially regarding mean annual temperatures, precipitations and evaporation. The consequences of this rapid environmental change on freshwater biota are still not clear, but undoubtedly they could be severe. Among the main effects of climate change, we can individuate the enhancement of water temperatures, particularly important for poikilothermic

S. Fenoglio; T. Bo; M. Cucco; L. Mercalli; G. Malacarne

2010-01-01

138

Responses of Selected Aquatic Biota to Thermal Discharges from Cumberland Steam-Electric Plant: Barkley Reservoir, Tennessee, 1978 and 1979.  

National Technical Information Service (NTIS)

The extent and degree of exposure of aquatic biota to the thermal plume from Cumberland Steam-Electric Plant (CUF) depends upon several factors, including temperature and volume of water discharged from the plant into the Cumberland River and river flow r...

T. M. Craven D. L. Dycus D. C. Wade

1983-01-01

139

MERCURY CONCENTRATIONS IN SEDIMENT, WATER AND BIOTA COLLECTED FROM NEAR-COASTAL AREAS IMPACTED BY COMMON ESTUARINE STRESSORS  

EPA Science Inventory

Mercury concentrations in non-commercial organisms indigenous to the Gulf of Mexico are not well characterized particularly when compared to potential sources. In response to this need, mercury levels were determined in sediment, water and various biota in reference and non-refer...

140

USE OF THE BIOTIC LIGAND MODEL TO PREDICT METAL TOXICITY TO AQUATIC BIOTA IN AREAS OF DIFFERING GEOLOGY1  

Microsoft Academic Search

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

Kathleen S. Smith

141

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

Microsoft Academic Search

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

C A Robinson; K L Smith; S Norris

2010-01-01

142

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

PubMed

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

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

2012-07-22

143

Organophosphorus flame retardants and plasticizers in marine and fresh water biota and in human milk.  

PubMed

The levels and relative proportions of 11 organophosphorus flame retardants and plasticizers (OPs), some of which are reportedly toxic to aquatic organisms, were investigated in human breast milk and samples of fish and mussels from Swedish lakes and coastal areas in order to assess spatial differences in environmental exposure and spatial and temporal differences in human exposure. Some of the biota samples were collected at locations with known potential sources of OPs, but most were collected in background locations. Tris-2-chloroisopropyl phosphate (TCPP) and triphenyl phosphate (TPP) dominated in the biota with levels ranging from 170 to 770 ng g(-1) for TCPP in perch and between 21 and 180 ng g(-1) for TPP. In milk samples, TCPP (median 45 ng g(-1)) and tributyl phosphate (median 12 ng g(-1)) were the most frequently occurring OPs. Among samples of fish from background locations, the concentrations and profiles of most OPs were quite similar, indicating that their sources were diffuse. However, in fish from sample locations near known sources, there were marked differences in OP concentrations and profiles. Fish from a stream receiving surface water from Arlanda airport displayed high levels of OPs (10 200 ng g(-1)) that are commonly used in aircraft hydraulic fluids. Fish collected at points 1 or 2 km downstream of sewage treatment plants showed significantly higher levels of tris(2-butoxyethyl) phosphate (TBEP), one of the most typically abundant OP in effluents from such plants. In the milk samples obtained from women in different towns no distinct differences were detected in OP concentrations or profiles. However, the levels of TBEP tended to be higher in milk collected 10 years ago than in milk collected more recently. However, human exposure to OPs through eating fish or to breastfeeding babies seems to be of minor importance in relation to other potential sources, such as indoor dust inhalation and ingestion. PMID:20383376

Sundkvist, Anneli Marklund; Olofsson, Ulrika; Haglund, Peter

2010-02-02

144

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

NASA Astrophysics Data System (ADS)

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

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

2013-04-01

145

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

PubMed

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

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

2013-07-17

146

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

PubMed Central

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.

Birkhofer, Klaus; Schoning, Ingo; Alt, Fabian; Herold, Nadine; Klarner, Bernhard; Maraun, Mark; Marhan, Sven; Oelmann, Yvonne; Wubet, Tesfaye; Yurkov, Andrey; Begerow, Dominik; Berner, Doreen; Buscot, Francois; Daniel, Rolf; Diekotter, Tim; Ehnes, Roswitha B.; Erdmann, Georgia; Fischer, Christiane; Foesel, Barbel; Groh, Janine; Gutknecht, Jessica; Kandeler, Ellen; Lang, Christa; Lohaus, Gertrud; Meyer, Annabel; Nacke, Heiko; Nather, Astrid; Overmann, Jorg; 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

147

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

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

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

2003-01-01

148

RESPONSES OF AIRBORNE BIOTA TO MICROWAVE TRANSMISSION FROM SATELLITE POWER SYSTEM (SPS)  

EPA Science Inventory

The goal of this program is to determine whether microwave irradiation adversely alters a wide-range of complex avian behavior modes that are essential to their survival. Effects of microwaves (2.45 GHz) have been studied extensively in mammalian species, e.g., rats, mice, rabbit...

149

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

PubMed

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

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

2012-05-29

150

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

SciTech Connect

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

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

1995-11-01

151

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

PubMed

An extensive programme of experiments on transfer of radionuclides to aquatic species was conducted in the former USSR starting from the early 1950s. Only a few of these studies were made available in the English language literature or taken into account in international reviews of radionuclide behaviour in marine ecosystems. Therefore, an overview of original information on radionuclide transfer to marine biota species available from Russian language literature sources is presented here. The concentration ratio (CR) values for many radionuclides and for marine species such as: (239)Pu, (106)Ru and (95)Zr (crustacean), (54)Mn, (90)Sr, (95)Nb, (106)Ru, (137)Cs (239)Pu, (241)Am and natural U (molluscs), and (54)Mn, (90)Sr, (137)Cs and (144)Ce (fish) are in good agreement with those previously published, whilst for some of them, in particular, for (32)P and (110)Ag (crustaceans), (35)S (molluscs), (32)P, (35)S, (95)Nb, and (106)Ru (macroalgae) and (60)Co and (239,240)Pu (fish) the data presented here suggest that changes in the default CR reference values presented in recent marine reviews may be required. The data presented here are intended to supplement substantially the CR values being collated within the handbook on Wildlife Transfer Coefficients, coordinated under the IAEA EMRAS II programme. PMID:20798950

Fesenko, S; Fesenko, E; Titov, I; Karpenko, E; Sanzharova, N; Fonseca, A Gondin; Brown, J

2010-08-27

152

Two new carnivores from an unusual late Tertiary forest biota in eastern North America.  

PubMed

Late Cenozoic terrestrial fossil records of North America are biased by a predominance of mid-latitude deposits, mostly in the western half of the continent. Consequently, the biological history of eastern North America, including the eastern deciduous forest, remains largely hidden. Unfortunately, vertebrate fossil sites from this vast region are rare, and few pertain to the critically important late Tertiary period, during which intensified global climatic changes took place. Moreover, strong phylogenetic affinities between the flora of eastern North America and eastern Asia clearly demonstrate formerly contiguous connections, but disparity among shared genera (eastern Asia-eastern North America disjunction) implies significant periods of separation since at least the Miocene epoch. Lacustrine sediments deposited within a former sinkhole in the southern Appalachian Mountains provide a rare example of a late Miocene to early Pliocene terrestrial biota from a forested ecosystem. Here we show that the vertebrate remains contained within this deposit represent a unique combination of North American and Eurasian taxa. A new genus and species of the red (lesser) panda (Pristinailurus bristoli), the earliest and most primitive so far known, was recovered. Also among the fauna are a new species of Eurasian badger (Arctomeles dimolodontus) and the largest concentration of fossil tapirs ever recorded. Cladistical analyses of the two new carnivores strongly suggest immigration events that were earlier than and distinct from previous records, and that the close faunal affinities between eastern North America and eastern Asia in the late Tertiary period are consistent with the contemporaneous botanical record. PMID:15457257

Wallace, Steven C; Wang, Xiaoming

2004-09-30

153

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

PubMed

An exercise to compare 10 approaches for the calculation of unweighted whole-body absorbed dose rates was conducted for 74 radionuclides and five of the ICRP's Reference Animals and Plants, or RAPs (duck, frog, flatfish egg, rat and elongated earthworm), selected for this exercise to cover a range of body sizes, dimensions and exposure scenarios. Results were analysed using a non-parametric method requiring no specific hypotheses about the statistical distribution of data. The obtained unweighted absorbed dose rates for internal exposure compare well between the different approaches, with 70% of the results falling within a range of variation of ±20%. The variation is greater for external exposure, although 90% of the estimates are within an order of magnitude of one another. There are some discernible patterns where specific models over- or under-predicted. These are explained based on the methodological differences including number of daughter products included in the calculation of dose rate for a parent nuclide; source-target geometry; databases for discrete energy and yield of radionuclides; rounding errors in integration algorithms; and intrinsic differences in calculation methods. For certain radionuclides, these factors combine to generate systematic variations between approaches. Overall, the technique chosen to interpret the data enabled methodological differences in dosimetry calculations to be quantified and compared, allowing the identification of common issues between different approaches and providing greater assurance on the fundamental dose conversion coefficient approaches used in available models for assessing radiological effects to biota. PMID:21113609

Vives i Batlle, J; Beaugelin-Seiller, K; Beresford, N A; Copplestone, D; Horyna, J; Hosseini, A; Johansen, M; Kamboj, S; Keum, D-K; Kurosawa, N; Newsome, L; Olyslaegers, G; Vandenhove, H; Ryufuku, S; Vives Lynch, S; Wood, M D; Yu, C

2010-11-27

154

Arthropod visual predators in the early pelagic ecosystem: evidence from the Burgess Shale and Chengjiang biotas.  

PubMed

Exceptional fossil specimens with preserved soft parts from the Maotianshan Shale (ca 520 Myr ago) and the Burgess Shale (505 Myr ago) biotas indicate that the worldwide distributed bivalved arthropod Isoxys was probably a non-benthic visual predator. New lines of evidence come from the functional morphology of its powerful prehensile frontal appendages that, combined with large spherical eyes, are thought to have played a key role in the recognition and capture of swimming or epibenthic prey. The swimming and steering of this arthropod was achieved by the beating of multiple setose exopods and a flap-like telson. The appendage morphology of Isoxys indicates possible phylogenetical relationships with the megacheirans, a widespread group of assumed predator arthropods characterized by a pre-oral 'great appendage'. Evidence from functional morphology and taphonomy suggests that Isoxys was able to migrate through the water column and was possibly exploiting hyperbenthic niches for food. Although certainly not unique, the case of Isoxys supports the idea that off-bottom animal interactions such as predation, associated with complex feeding strategies and behaviours (e.g. vertical migration and hunting) were established by the Early Cambrian. It also suggests that a prototype of a pelagic food chain had already started to build-up at least in the lower levels of the water column. PMID:19403536

Vannier, J; García-Bellido, D C; Hu, S-X; Chen, A-L

2009-04-29

155

Arthropod visual predators in the early pelagic ecosystem: evidence from the Burgess Shale and Chengjiang biotas  

PubMed Central

Exceptional fossil specimens with preserved soft parts from the Maotianshan Shale (ca 520?Myr ago) and the Burgess Shale (505?Myr ago) biotas indicate that the worldwide distributed bivalved arthropod Isoxys was probably a non-benthic visual predator. New lines of evidence come from the functional morphology of its powerful prehensile frontal appendages that, combined with large spherical eyes, are thought to have played a key role in the recognition and capture of swimming or epibenthic prey. The swimming and steering of this arthropod was achieved by the beating of multiple setose exopods and a flap-like telson. The appendage morphology of Isoxys indicates possible phylogenetical relationships with the megacheirans, a widespread group of assumed predator arthropods characterized by a pre-oral ‘great appendage’. Evidence from functional morphology and taphonomy suggests that Isoxys was able to migrate through the water column and was possibly exploiting hyperbenthic niches for food. Although certainly not unique, the case of Isoxys supports the idea that off-bottom animal interactions such as predation, associated with complex feeding strategies and behaviours (e.g. vertical migration and hunting) were established by the Early Cambrian. It also suggests that a prototype of a pelagic food chain had already started to build-up at least in the lower levels of the water column.

Vannier, J.; Garcia-Bellido, D.C.; Hu, S.-X.; Chen, A.-L.

2009-01-01

156

Effects of acidification on metal availability to aquatic biota, with special reference to filamentous algae.  

PubMed

A survey of 34 shield lakes in Ontario and Quebec, pH 4.4 to 7.1, was made to evaluate which metals should be considered of concern as a risk to aquatic biota or consumers when lakes are acid stressed. A set of predictions, concerning the mobilization by man, the mobility, the chemical speciation, and the toxicity or bioaccumulation of metals in acid-stressed waters, were used as a basis for designing the study and organizing the results. Attached algae were used as biomonitors to assess metal bioavailability. The study concluded that zinc, lead, aluminum, and mercury were of concern in acid-stressed lakes, while the situation for manganese was unresolved, and cadmium was not studied. Nickel and copper were of concern only when a point source was involved. The study also concluded that the attached algal community had some value as a biomonitor, for metals in acid-stressed as well as metal-polluted surface waters. PMID:4076097

Stokes, P M; Bailey, R C; Groulx, G R

1985-11-01

157

New basal eutherian mammal from the Early Cretaceous Jehol biota, Liaoning, China  

PubMed Central

A new genus and species of eutherian mammal, Acristatherium yanensis gen. et sp. nov., is described from the Early Cretaceous Jehol biota, China. The new taxon is based on a partial skull that is preserved in three dimensions from the Lujiatun bed of the Yixian Formation and dated 123.2±1.0?Ma. Its right upper and lower dentitions are nearly complete and it has a dental formula 4.1.5.3/3.1.5.3. The new mammal reveals several craniodental characteristics of Early Cretaceous eutherians previously unknown in fossil records of therians, such as a possible vestige of the septomaxilla. The craniodental features of the new taxon are compared with those of relevant Early Cretaceous eutherians and therians. Phylogenetic analyses based on a data matrix containing 70 taxa and 408 characters place A. yanensis as the most basal eutherian in the selected group. The morphological differences between Acristatherium and Eomaia indicate that eutherians already had a significant degree of generic diversification ca 125?Ma.

Hu, Yaoming; Meng, Jin; Li, Chuankui; Wang, Yuanqing

2010-01-01

158

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

PubMed

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

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

2012-06-06

159

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

PubMed

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

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

2013-06-24

160

Contrasting Food Web Factor and Body Size Relationships with Hg and Se Concentrations in Marine Biota  

PubMed Central

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

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

2013-01-01

161

Contrasting food web factor and body size relationships with hg and se concentrations in marine biota.  

PubMed

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

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

2013-09-03

162

The 40Ar\\/39Ar dating of the early Jehol Biota from Fengning, Hebei Province, northern China  

Microsoft Academic Search

The bird fossil-bearing deposits at the Jiecaigou section, correlative to the Dabeigou Formation, in Fengning, Hebei Province, northern China, is well known for yielding a fossil assemblage representing the earliest evolutionary stage of the Jehol Biota. The precise age of the fossil-bearing deposits, however, is unknown. The 40Ar\\/39Ar age spectrum obtained on bulk K-feldspars from the tuff layer about 2

H. Y. He; X. L. Wang; F. Jin; Z. H. Zhou; F. Wang; L. K. Yang; X. Ding; A. Boven; R. X. Zhu

2006-01-01

163

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

Microsoft Academic Search

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

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

1996-01-01

164

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

Microsoft Academic Search

Over 1999–2002, an extensive series of contaminant studies was conducted on freshwater biota of Canada's Arctic and Subarctic regions. The majority of inorganic contaminant studies focused on mercury and fish. While mercury concentrations were low in benthic feeding fish such as whitefish, predatory fish such as lake trout, pike, and walleye frequently had mercury levels which exceeded 0.2 ?g\\/g, the

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

2005-01-01

165

Tables of dose conversion coefficients for estimating internal and external radiation exposures to terrestrial and aquatic biota  

Microsoft Academic Search

Dose conversion coefficients (DCCs) for assessment of internal and external radiation exposures to terrestrial and aquatic\\u000a biota are compiled for 75 radionuclides, for 14 terrestrial and 22 aquatic reference organisms. DCC values for internal exposure\\u000a are calculated based on a homogeneous distribution of the radionuclides in both types of organisms. DCC values for external\\u000a exposure of aquatic organisms are calculated

A. Ulanovsky; G. Pröhl

2008-01-01

166

Population Structure of Plasmid-Containing Strains of Streptococcus mutans, a Member of the Human Indigenous Biota  

Microsoft Academic Search

There are suggestions that the phylogeny of Streptococcus mutans, a member of the human indigenous biota that is transmitted mostly mother to child, might parallel the evolutionary history of its human host. The relatedness and phylogeny of plasmid-containing strains of S. mutans were examined based on chromosomal DNA fingerprints (CDF), a hypervariable region (HVR) of a 5.6-kb plasmid, the rRNA

Page W. Caufield; Deepak Saxena; David Fitch; Yihong Li

2007-01-01

167

Introduced earthworms in agricultural and reclaimed land: their ecology and influences on soil properties, plant production and other soil biota  

Microsoft Academic Search

Accidental and deliberate introductions of earthworms into agricultural and reclaimed land are natural experiments that provide\\u000a opportunities to understand the attributes of successful invaders and their impacts on local biota and ecosystem processes.\\u000a We consider various case studies (e.g., earthworm invasions in agricultural soils in Australia and Brazil) and deliberate\\u000a introductions of earthworms into reclaimed mine sites, landfills and cutaway

G. H. Baker; G. Brown; K. Butt; J. P. Curry; J. Scullion

168

Oil spill in the Río de la Plata estuary, Argentina: 1. Biogeochemical assessment of waters, sediments, soils and biota  

Microsoft Academic Search

Aliphatic (ALI) and aromatic (ARO) hydrocarbon concentrations, composition and sources were evaluated in waters, sediments, soils and biota to assess the impact of ?1000 tons of oil spilled in Río de la Plata coastal waters. Total ALI levels ranged from 0.4–262 ?g\\/l in waters, 0.01–87 ?g\\/g in sediments, 5–39 ?g\\/g in bivalves, 12–323 ?g\\/g in macrophytes to 948–5187 ?g\\/g in

J. C. Colombo; A. Barreda; C. Bilos; N. Cappelletti; S. Demichelis; P. Lombardi; M. C. Migoya; C. Skorupka; G. Suárez

2005-01-01

169

Biota-sediment accumulation factors for Dechlorane Plus in bottom fish from an electronic waste recycling site, South China  

Microsoft Academic Search

Biota-sediment accumulation factors (BSAFs) for Dechlorane Plus (DP), a highly chlorinated flame retardant, were determined in three bottom fish species, i.e., crucian carp, mud carp, and northern snakehead from an electronic waste recycling site in South China. The average BSAFs are 0.007, 0.01, and 0.06 for syn-DP, and 0.003, 0.025, and 0.001 for anti-DP in crucian carp, mud carp, and

Ying Zhang; Jiang-Ping Wu; Xiao-Jun Luo; Yu-Xin Sun; Ling Mo; She-Jun Chen; Bi-Xian Mai

170

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

PubMed

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

Jones, David A; Nithyanandan, Manickam

2012-11-28

171

Evidence for the transfer of polychlorinated biphenyls, polychlorinated dibenzo-p-dioxins, and polychlorinated dibenzofurans from soil into biota.  

PubMed

The concentrations of six indicator and co-planar polychlorinated biphenyls (PCBs), 17 polychlorinated dibenzo-p-dioxins, and polychlorinated dibenzofurans (PCDD/Fs) were determined in soil and associated biota samples collected from a polluted and wasted farmland in southern China. The sum of six indicator PCBs (Nos 28, 52, 101, 138, 153 and 180) concentrations in biota samples were proportional to the total amount of PCBs that transferred from soil to the corresponding biota samples, and the sum six indicator PCB congeners in samples were about 20% of the total PCBs, respectively. The ratios of the sum six indicator PCBs and the total PCBs in samples collected in the same area were approximately equal. The sums of six indicator PCBs were proportional to the total PCBs that transferred from soil to plant, while the co-planar PCBs were not. Analysis of individual PCB and PCDD/F congener signatures in soil revealed the original pollutant source after transportation and biodegradation for 14 years using principal component analysis (PCA). The pattern of PCBs in soils and plants could reflect the original pollution source after transportation and biodegradation for 14 years, while the pattern of PCBs in the terrestrial animals could not reflect the primary source. The consumption foods in this region such as foraging chicken eggs, foraging duck eggs, and loach (Misgurnus anguillicaudatus) were highly contaminated, the total toxicity equivalent (TEQ) was up to 784 pg WHO-TEQ/g on basis lipid in foraging chicken eggs. PMID:16574199

Zhao, Xingru; Zheng, Minghui; Zhang, Bing; Zhang, Qinghua; Liu, Wenbin

2006-03-06

172

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

PubMed

Produced water has been described as the largest volume waste stream in the exploration and production process of oil and gas. It is accompanied by discharges of naturally occurring radionuclides raising concerns over the potential radiological impacts of produced water on marine biota. In the Northern European marine environment, radioactivity in produced water has received substantial attention owing to the OSPAR Radioactive Substances Strategy which aims at achieving 'concentrations in the environment near background values for naturally occurring radioactive substances'. This review provides an overview of published research on the impacts to biota from naturally occurring radionuclides discharged in produced water by the offshore oil and gas industry. In addition to summarising studies and data that deal directly with the issue of dose and effect, the review also considers studies related to the impact of added chemicals on the fate of discharged radionuclides. The review clearly illustrates that only a limited number of studies have investigated possible impacts on biota from naturally occurring radionuclides present in produced water. Hence, although these studies indicate that the risk to the environment from naturally occurring radionuclides discharged in produced water is negligible, the substantial uncertainties involved in the assessments of impact make it difficult to be conclusive. With regard to the complexity involved in the problem under consideration there is a pressing need to supplement existing data and acquire new knowledge. Finally, the present work identifies some knowledge gaps to indicate future research requirements. PMID:23022586

Hosseini, Ali; Brown, Justin E; Gwynn, Justin P; Dowdall, Mark

2012-09-26

173

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

PubMed Central

The mechanisms underlying the taxonomic assembly of montane biotas are still poorly understood. Most hypotheses have assumed that the diversification of montane biotas is loosely coupled to Earth history and have emphasized instead the importance of multiple long-distance dispersal events and biotic interactions, particularly competition, for structuring the taxonomic composition and distribution of montane biotic elements. Here we use phylogenetic and biogeographic analyses of species in the parrot genus Pionus to demonstrate that standing diversity within montane lineages is directly attributable to events of Earth history. Phylogenetic relationships confirm three independent biogeographic disjunctions between montane lineages, on one hand, and lowland dry-forest/wet-forest lineages on the other. Temporal estimates of lineage diversification are consistent with the interpretation that the three lineages were transported passively to high elevations by mountain building, and that subsequent diversification within the Andes was driven primarily by Pleistocene climatic oscillations and their large-scale effects on habitat change. These results support a mechanistic link between diversification and Earth history and have general implications for explaining high altitudinal disjuncts and the origin of montane biotas.

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

2007-01-01

174

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

PubMed

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

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

2011-10-01

175

Cyanobacterial toxins: a qualitative meta-analysis of concentrations, dosage and effects in freshwater, estuarine and marine biota.  

PubMed

This paper reviews the rapidly expanding literature on the ecological effects of cyanobacterial toxins. The study employs a qualitative meta-analysis from the literature examining results from a large number of independent studies and extracts general patterns from the literature or signals contradictions. The meta-analysis is set up by putting together two large tables--embodying a large and representative part of the literature (see Appendix A). The first table (Table A.1) reviews the presence (concentrations) of different cyanobacterial toxins in the tissues of various groups of aquatic biota after exposure via different routes, experimentally in the lab or via natural routes in the environment. The second table (Table A.2) reviews the dose dependent effect of toxins on biota. The great majority of studies deal with the presence and effects of microcystin, especially of the MC-LR congener. Although this may partly be justified--MC-LR is an abundant and highly toxic protein--our review also emphasizes what is known about (i) other MC congeners (a number of studies showed a preferred accumulation of the less toxic variant MC-RR in animal tissues), (ii) nodularin (data on a range of biota from studies on the Baltic Sea), (iii) neurotoxins like anatoxin-a(s), which are conspicuously often present at times when mass mortalities of birds occur, (iv) a few studies on the presence and effects of cylindrospermposin, as well as (v) the first examples of ecological effects of newly identified bioactive compounds, like microviridin-J. Data were reorganized to assess to what extent bioconcentration (uptake and concentration of toxins from the water) or biomagnification (uptake and concentration via the food) of cyanobacterial toxins occurs in ecosystems. There is little support for the occurrence of biomagnification, and this reduces the risk for biota at higher trophic levels. Rather than biomagnification biodilution seems to occur in the foodweb with toxins being subject to degradation and excretion at every level. Nevertheless toxins were present at all tropic levels, indicating that some vectorial transport must take place, and in sufficient quantities for effects to possibly occur. Feeding seemed to be the most important route for exposure of aquatic biota to cyanobacterial toxins. A fair number of studies focus on dissolved toxins, but in those studies purified toxin typically is used, and biota do not appear very sensitive to this form of exposure. More effects are found when crude cyanobacterial cell lysates are used, indicating that there may be synergistic effects between different bioactive compounds. Aquatic biota are by no means defenseless against toxic cyanobacteria. Several studies indicate that those species that are most frequently exposed to toxins in their natural environment are also the most tolerant. Protection includes behavioral mechanisms, detoxication of MC and NODLN by conjugation with glutathione, and fairly rapid depuration and excretion. A common theme in much of the ecological studies is that of modulating factors. Effects are seldom straightforward, but are dependent on factors like the (feeding) condition of the animals, environmental conditions and the history of exposure (acclimation and adaptation to toxic cyanobacteria). This makes it harder to generalize on what is known about ecological effects of cyanobacterial toxins. The paper concludes by summarizing the risks for birds, fish, macroinvertebrates and zooplankton. Although acute (lethal) effects are mentioned in the literature, mass mortalities of--especially--fish are more likely to be the result of multiple stress factors that co-occur during cyanobacterial blooms. Bivalves appear remarkably resistant, whilst the harmful effects of cyanobacteria on zooplankton vary widely and the specific contribution of toxins is hard to evaluate. PMID:18461789

Ibelings, Bas W; Havens, Karl E

2008-01-01

176

Soil biota effects on clonal growth and flowering in the forest herb Stachys sylvatica  

NASA Astrophysics Data System (ADS)

The composition of a soil community can vary drastically at extremely short distances. Therefore, plants from any given population can be expected to experience strong differences in belowground biotic interactions. Although it is well recognized that the soil biota plays a significant role in the structure and dynamics of plant communities, plastic responses in growth strategies as a function of soil biotic interactions have received little attention. In this study, we question whether the biotic soil context from two forest associated contrasting environments (the forest understory and the hedgerows) determines the balance between clonal growth and flowering of the perennial Stachys sylvatica. Using artificial soils, we compared the growth responses of this species following inoculation with the mycorrhizal and microbial community extracted either from rhizospheric soil of the forest understory or from the hedgerows. The microbial context had a strong effect on plant functional traits, determining the production of runners and inflorescences. Plants inoculated with the hedgerow community had a greater biomass, larger number of runners, and lower resource investment in flower production than was seen in plants inoculated with the understory microbial community. The obtained results illustrate that belowground biotic interactions are essential to understand basic plastic growth responses determinant for plant establishment and survival. The interactions with microbial communities from two contrasting habitats resulted in two different, and presumably adaptive, growth strategies that were optimal for the conditions prevalent in the environments compared; and they are as such an essential factor to understand plant-plant, plant-animal interactions and the dispersal capacities of clonal plants.

de la Peña, Eduardo; Bonte, Dries

2011-03-01

177

Properties and structure of peat humic acids depending on humification and precursor biota in bogs  

NASA Astrophysics Data System (ADS)

Humic substances form most of the organic component of soil, peat and natural waters, but their structure and properties very much differs depending on their source. The aim of this study is to characterize humic acids from raised bog peat profiles to evaluate the homogeneity of humic acids isolated from the bog bodies and study peat humification impact on properties of humic acids. A major impact on the structure of peat humic acids have raised bog biota (dominantly represented by bryophytes of different origin) void of lignin. For characterization of peat humic acids their elemental (CHNOS), functional (-COOH, phenolic OH) analysis, spectroscopic characterization (UV, fluorescence, FTIR, 1H NMR, CP/MAS 13C NMR, ESR) and degradation studies (Py-GC/MS) were done. Peat humic acids (HA) have an intermediate position between the living organic matter and coal organic matter and their structure is formed in a process in which more labile structures (carbohydrates, amino acids, etc.) are destroyed, but thermodynamically more stable aromatic and polyaromatic structures emerge. Comparatively, the studied peat HAs are at the start of the transformation process of living organic matter. Concentrations of carboxyl and phenolic hydroxyl groups changes depending on the depth of peat from which HAs have been isolated: and carboxylic acidity is increasing with depth of peat location and the humification degree. The ability to influence the surface tension of peat humic acids isolated from a well-characterized bog profile demonstrates dependence on age and humification degree. With increase of the humification degree and age of humic acids, their molecular complexity and ability to influence surface tension decreases; even so, the impact of the biological precursor (peat-forming bryophytes and plants) can be identified.

Klavins, Maris; Purmalis, Oskars

2013-04-01

178

MARINE AND ESTUARINE MULTI-SPECIES TEST SYSTEMS  

EPA Science Inventory

Environmental fate and effects studies of chemical contaminants conducted in marine and estuarine microcosm and mesocosm test systems are reviewed. ontaminant fate, persistence, and transport are discussed and related to exposure regimes that result in effects on marine biota. he...

179

Chemical fingerprinting of petroleum biomarkers in biota samples using retention-time locking chromatography and multivariate analysis.  

PubMed

This work was conducted to study a new separation and evaluation approach for the chemical fingerprinting of petroleum biomarkers in biota samples. The final aim of this work was to study the correlation between the observed effects in the shore habitats (mussels and limpets) and one pollution source: the oil spill of the Prestige tanker. The method combined a clean-up step of the biota extracts (mussels and limpets), the retention-time locking of the gas chromatographic set up, and the multivariate data analysis of the chromatograms. For clean-up, solid-phase extraction and gel permeation chromatography were compared, and 5g Florisil cartridges assured the lack of interfering compounds in the last extracts. In order to assure reproducible retention times and to avoid the realignment of the chromatograms, the retention-time locking feature of our gas chromatography-mass spectrometry (GC-MS) set up was used. Finally, in the case of multivariate analysis, the GC-MS chromatograms were treated, essentially by derivatization and by normalization, and all the chromatograms at m/z 191 (terpenes), m/z 217-218 (steranes and diasteranes) and m/z 231 (triaromatic steranes) were treated by means of principal component analysis. Furthermore, slightly different four oil samples from the Prestige oil spill were analyzed following the Nordtest method, and the GC-MS chromatograms were considered as the reference chemical fingerprints of the sources. In this sense, the correlation between the studied samples, including sediments and biota samples, and the source candidate was completed by means of a supervised pattern recognition method. As a result, the method proposed in this work was useful to identify the Prestige oil spill as the source of many of the analyzed samples. PMID:17544434

Bartolomé, Luis; Deusto, Miren; Etxebarria, Nestor; Navarro, Patricia; Usobiaga, Aresatz; Zuloaga, Olatz

2007-05-06

180

Interactions of Grazing History, Cattle Removal and Time since Rain Drive Divergent Short-Term Responses by Desert Biota  

PubMed Central

Arid grasslands are used worldwide for grazing by domestic livestock, generating debate about how this pastoral enterprise may influence native desert biota. One approach to resolving this question is to experimentally reduce livestock numbers and measure the effects. However, a key challenge in doing this is that historical grazing impacts are likely to be cumulative and may therefore confound comparisons of the short-term responses of desert biota to changes in stocking levels. Arid areas are also subject to infrequent flooding rainfalls that drive productivity and dramatically alter abundances of flora and fauna. We took advantage of an opportunity to study the recent effects of a property-scale cattle removal on two properties with similarly varied grazing histories in central Australia. Following the removal of cattle in 2006 and before and after a significant rainfall event at the beginning of 2007, we sampled vegetation and small vertebrates on eight occasions until October 2008. Our results revealed significant interactions of time of survey with both grazing history and grazing removal for vascular plants, small mammals and reptiles. The mammals exhibited a three-way interaction of time, grazing history and grazing removal, thus highlighting the importance of careful sampling designs and timing for future monitoring. The strongest response to the cessation of grazing after two years was depressed reproductive output of plants in areas where cattle continued to graze. Our results confirm that neither vegetation nor small vertebrates necessarily respond immediately to the removal of livestock, but that rainfall events and cumulative grazing history are key determinants of floral and faunal performance in grassland landscapes with low and variable rainfall. We suggest that improved assessments could be made of the health of arid grazing environments if long-term monitoring were implemented to track the complex interactions that influence how native biota respond to grazing.

Frank, Anke S. K.; Dickman, Chris R.; Wardle, Glenda M.; Greenville, Aaron C.

2013-01-01

181

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

PubMed

Contaminants in the Canadian Arctic have been studied over the last twelve years under the guidance of the Northern Contaminants Program. This paper summarizes results from that program from 1998 to 2003 with respect to terrestrial animals in the Canadian Arctic. The arctic terrestrial environment has few significant contaminant issues, particularly when compared with freshwater and marine environments. Both current and historical industrial activities in the north may have a continuing effect on biota in the immediate area, but effects tend to be localized. An investigation of arctic ground squirrels at a site in the Northwest Territories that had historically received applications of DDT concluded that DDT in arctic ground squirrels livers was the result of contamination and that this is an indication of the continuing effect of a local point source of DDT. Arsenic concentrations were higher in berries collected from areas around gold mines in the Northwest Territories than from control sites, suggesting that gold mining may significantly affect arsenic levels in berries in the Yellowknives Dene traditional territory. Although moose and caribou from the Canadian Arctic generally carry relatively low contaminant burdens, Yukon moose had high renal selenium concentrations, and moose and some woodland caribou from the same area had high renal cadmium levels, which may put some animals at risk of toxicological effects. Low hepatic copper levels in some caribou herds may indicate a shortage of copper for metabolic demands, particularly for females. Similarities in patterns of temporal fluctuations in renal element concentrations for moose and caribou suggest that environmental factors may be a major cause of fluctuations in renal concentrations of some elements. Concentrations of persistent organochlorines and metals in beaver and muskrat from the Northwest Territories, and carnivores from across the Canadian Arctic were very low and considered normal for terrestrial wildlife. Two new classes of persistent fluorinated contaminants, perfluorooctane sulfonate (PFOS) and perfluoroalkyl carboxylates (PFCAs) were found in arctic carnivores and were most abundant in arctic fox and least abundant in mink. Although trace element concentrations in king and common eider ducks were low and not of toxicological concern, the number of nematode parasites in common eiders was positively correlated with total and organic mercury concentrations. Future research should focus on cadmium in moose and caribou, mercury in caribou, and emerging contaminants, with an effort to sample moose and caribou annually where possible to explore the role of naturally occurring cycles in apparent temporal trends. PMID:16109438

Gamberg, Mary; Braune, Birgit; Davey, Eric; Elkin, Brett; Hoekstra, Paul F; Kennedy, David; Macdonald, Colin; Muir, Derek; Nirwal, Amar; Wayland, Mark; Zeeb, Barbara

2005-08-16

182

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

PubMed

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

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

2011-07-06

183

An integrated approach for bioaccumulation assessment in mussels: towards the development of Environmental Quality Standards for biota.  

PubMed

The possible use of chemical concentrations measured in mussels (Mytillus galloprovincialis) for compliance checking against Environmental Quality Standards (EQS) established for biota is analyzed with the help of an integrated model. The model consists of a 3D planktonic module that provides biomasses in the different compartments, i.e., phytoplankton, zooplankton and bacteria; a 3D fate module that provides the concentrations of contaminants in the water column and in the sediments; and a 3D bioaccumulation module that calculates internal concentrations in relevant biotic compartments. These modules feed a 0D growth and bioaccumulation module for mussels, based on the Dynamic Energy Budget (DEB) approach. The integrated model has been applied to study the bioaccumulation of persistent organic pollutants (POPs) in the Thau lagoon (France). The model correctly predicts the concentrations of polychlorinated biphenyls (PCBs) and polychlorinated dibenzodioxins and dibenzofurans (PCDD/Fs) in mussels as a function of the concentrations in the water column and in phytoplankton. It also sheds light on the origin of the complexity associated with the use of EQS for biota and their conversion to water column concentrations. The integrated model is potentially useful for regulatory purposes, for example in the context of the European Water Framework (WFD) and Marine Strategy Framework Directives (MSFD). PMID:21040971

Zaldívar, J M; Marinov, D; Dueri, S; Castro-Jiménez, J; Micheletti, C; Worth, A P

2010-10-30

184

Enantioselectivity of polychlorinated biphenyl atropisomers in sediment and biota from the Turtle/Brunswick River estuary, Georgia, USA.  

PubMed

To investigate the potential for enantioselective transformation and accumulation, the enantiomer distributions of seven polychlorinated biphenyl (PCB) atropisomers were measured in the sediment and biota from a sub-tropical estuary heavily contaminated with Aroclor 1268, a technical mixture of highly chlorinated PCB congeners. Enantiomer fractions (EFs) of PCBs 91, 95, 136, 149, 174, 176, and 183 in marsh sediment, invertebrate, forage and predatory fish species, and bottlenose dolphins were determined. Non-racemic EFs greater than 0.75 were found in sediments for PCBs 136 and 174, likely the result of microbial dechlorination. Although enantiomer fractions in grass shrimp (Palaemonetes spp.) mirrored those of sediment, fish species had EFs that differed significantly from sediment or grass shrimp. Similarly, bottlenose dolphins were also found to contain non-racemic quantities of PCBs 91, 136, 174, 176, and 183. Non-racemic EFs in these biota were likely a result of both uptake of non-racemic proportions of PCBs from the diet and enantioselective biotransformation. PMID:21392808

Ross, Matthew S; Pulster, Erin L; Ejsmont, Malgorzata B; Chow, Elaine A; Hessel, Colin M; Maruya, Keith A; Wong, Charles S

2011-03-09

185

Occurrence and biomagnification of polychlorinated naphthalenes and non- and mono-ortho PCBs in Lake Ontario sediment and biota.  

PubMed

Biota and surface sediments collected from Lake Ontario were analyzed for polychlorinated naphthalenes (PCNs) and non- and mono-ortho-substituted polychlorinated biphenyls (n/ m-o-PCBs) to compare bioaccumulation behavior of these classes of dioxin-like chemicals in a food web from the Great Lakes. Mean sigmaPCN concentrations (tri-octaCN) ranged from 14 +/- 9 pg/g in plankton to 3500 +/- 3200 pg/g (wet weight) in lake trout while sediments contained from 21 to 38 ng/g (dry weight). Principal components analysis of PCN congener patterns indicated that chlorine substitution determined which congeners favored accumulation (e.g., CN-42, -52, -60, -66, -67, and -73), while others may be subject to metabolism. The bioaccumulative congeners exhibited similar trophic magnification factors (TMFs; 1.23-1.42) and biomagnification factors (BMFs; 5.5-8.6) to the n/m-o-PCBs for the trout/weighted diet relation, although BMFs for a benthic feeding relationship (slimy sculpin/Diporeia) indicated that the n/m-o-PCBs were more bioavailablethroughthe benthic pathway. PCNs contribute significantly to the burden of dioxin-like compounds in Lake Ontario biota, contributing between 12 and 22% of total PCN + PCB TEQ in lake trout and up to 69% in benthic organisms. PMID:18351067

Helm, Paul A; Gewurtz, Sarah B; Whittle, D Michael; Marvin, Chris H; Fisk, Aaron T; Tomy, Gregg T

2008-02-15

186

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

SciTech Connect

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 were extremely toxic (> 0.01-0.1 mg/L), 11 highly toxic (> 0.1 {minus} 1.0 mg/L), 20 moderately toxic (> 1.0 {minus} 10.0 mg/L), and 4 slightly toxic (> 10 {minus} 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 alkanes.

Smith, S.B.; Savino, J.F.; Blouin, M.A. (Fish and Wildlife Service, Ann Arbor, MI (USA))

1988-01-01

187

Effects of land use on the water quality and biota of three streams in the Piedmont province of North Carolina  

USGS Publications Warehouse

Three small streams in North Carolina 's northern Piedmont were studied to compare the effects of land use in their watersheds on water quality characteristics and aquatic biota. Devil 's Cradle Creek (agricultural watershed) had more than two times the sediment yield of Smith Creek (forested watershed) (0.34 tons/acre compared to 0.13 tons/acre), and Marsh Creek (urban watershed) had more than four times the yield of Smith Creek (0.59 tons/acre). Concentrations of nutrients were consistently highest in Devil 's Craddle Creek. Concentrations of total copper, iron, and lead in samples from each of the three streams at times exceeded State water quality standards as did concentrations of total zinc in samples from both Smith and Marsh Creeks. Successively lower aquatic invertebrate taxa richness was found in the forested, the agricultural, and the urban watershed streams. Invertebrate biota in Smith Creek was dominated by insects, such as Ephemeroptera, that are intolerant to stress from pollution, whereas Devil 's Cradle Creek was dominated by the more tolerant Diptera, and Marsh Creek was dominated by the most pollution-tolerant group, the Oligochaeta. Fish communities in the forested and agricultural watershed streams were characterized by more species and more individuals of each species, relative to a limited community in urban Marsh Creek. Three independent variables closely linked to land use--suspended-sediment yield, suspended-sediment load, and total lead concentrations in stream water--are inversely associated with the biological communities of the streams.

Crawford, J. K.; Lenat, D. R.

1989-01-01

188

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

SciTech Connect

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

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

2008-10-09

189

Mercury in Sediment, Water, and Biota of Sinclair Inlet, Puget Sound, Washington, 1989-2007  

USGS Publications Warehouse

Historical records of mercury contamination in dated sediment cores from Sinclair Inlet are coincidental with activities at the U.S. Navy Puget Sound Naval Shipyard; peak total mercury concentrations occurred around World War II. After World War II, better metallurgical management practices and environmental regulations reduced mercury contamination, but total mercury concentrations in surface sediment of Sinclair Inlet have decreased slowly because of the low rate of sedimentation relative to the vertical mixing within sediment. The slopes of linear regressions between the total mercury and total organic carbon concentrations of sediment offshore of Puget Sound urban areas was the best indicator of general mercury contamination above pre-industrial levels. Prior to the 2000-01 remediation, this indicator placed Sinclair Inlet in the tier of estuaries with the highest level of mercury contamination, along with Bellingham Bay in northern Puget Sound and Elliott Bay near Seattle. This indicator also suggests that the 2000/2001 remediation dredging had significant positive effect on Sinclair Inlet as a whole. In 2007, about 80 percent of the area of the Bremerton naval complex had sediment total mercury concentrations within about 0.5 milligrams per kilogram of the Sinclair Inlet regression. Three areas adjacent to the waterfront of the Bremerton naval complex have total mercury concentrations above this range and indicate a possible terrestrial source from waterfront areas of Bremerton naval complex. Total mercury concentrations in unfiltered Sinclair Inlet marine waters are about three times higher than those of central Puget Sound, but the small numbers of samples and complex physical and geochemical processes make it difficult to interpret the geographical distribution of mercury in marine waters from Sinclair Inlet. Total mercury concentrations in various biota species were compared among geographical locations and included data of composite samples, individual specimens, and caged mussels. Total mercury concentrations in muscle and liver of English sole from Sinclair Inlet ranked in the upper quarter and third, respectively, of Puget Sound locations. For other species, concentrations from Sinclair Inlet were within the mid-range of locations (for example, Chinook salmon). Total mercury concentrations of the long-lived and higher trophic rockfish in composites and individual specimens from Sinclair Inlet tended to be the highest in Puget Sound. For a given size, sand sole, graceful crab, staghorn sculpin, surf perch, and sea cucumber individuals collected from Sinclair Inlet had higher total mercury concentrations than individuals collected from non-urban estuaries. Total mercury concentrations in individual English sole and ratfish were not significantly different than in individuals of various sizes collected from either urban or non-urban estuaries in Puget Sound. Total mercury concentrations in English sole collected from Sinclair Inlet after the 2000-2001 dredging appear to have lower total mercury concentrations than those collected before (1996) the dredging project. The highest total mercury concentrations of mussels caged in 2002 were not within the Bremerton naval complex, but within the Port Orchard Marina and inner Sinclair Inlet.

Paulson, Anthony J.; Keys, Morgan E.; Scholting, Kelly L.

2010-01-01

190

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

SciTech Connect

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.

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

1993-11-01

191

ELF (Extremely Low Frequency) Communication System Ecological Monitoring Program: Electromagnetic Field Measurements and Engineering Support - 1987.  

National Technical Information Service (NTIS)

A long-term program for studying possible effects from the operation of the Navy's ELF Communications System is being conducted on biota and ecosystems components in northwestern Wisconsin and the Upper Peninsula of Michigan. Sixteen general types of orga...

D. P. Haradem J. E. Zapotosky J. R. Gauger

1988-01-01

192

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

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

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

2006-01-01

193

Impact of changing DOC concentrations on the potential distribution of acid sensitive biota in a boreal stream network  

NASA Astrophysics Data System (ADS)

DOC concentrations have increased in many surface waters in Europe and North America over the past few decades. As DOC exerts a strong influence on pH this DOC increase could have detrimental effects on acid sensitive biota in many streams and lakes. To investigate the potential implications of changes in the DOC concentration on stream water biota, we have used a mesoscale boreal stream network in northern Sweden as a case study. The network was sampled for stream water chemistry at 60 locations during both winter base flow and spring flood periods, representing the extremes experienced annually in these streams both in terms of discharge and acidity. The effect of changing DOC on pH was modeled for all sampling locations using an organic acid model, with input DOC concentrations for different scenarios adjusted by between -30% and +50% from measured present concentrations. The resulting effect on pH was then used to quantify the proportion of stream length in the catchment with pH below the acid thresholds of pH 5.5 and pH 5.0. The results suggest that a change in stream water DOC during base flow would have only a limited effect on pH and hence on the stream length with pH below the acid thresholds. During the spring flood on the other hand a change in DOC would strongly influence pH and the stream length with pH below the acid thresholds. For example an increase in DOC concentration of 30% at all sites would increase the proportion of stream length with pH below 5.5 from 37% to 65%, and the proportion of stream length with pH below 5.0 would increase from 18% to 27%. The results suggest that in poorly-buffered high DOC waters, even a marginal change in the DOC concentration could impact acid sensitive biota in a large portion of the aquatic landscape.

Laudon, H.; Buffam, I.

2007-09-01

194

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

SciTech Connect

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 BSAFs were less variable than were the BAFs with the exception of compounds with log K[sub ow] > 7. Many of the BSAFs exceeded 1.7, which is a calculated maximum value based on partitioning alone. Although BSAFs varied with sediment type and compound, the use of a BSAF of 4 as a screening level for neutral organic compounds in assessing dredge materials is supported by the present study.

Boese, B.L.; Lee, H. II; Randall, R. (Environmental Protection Agency, Newport, OR (United States). Pacific Ecosystems Branch); Winsor, M.; Echols, S.; Pelletier, J. (AScI, Newport, OR (United States). Hatfield Marine Science Center)

1995-02-01

195

Tables of dose conversion coefficients for estimating internal and external radiation exposures to terrestrial and aquatic biota.  

PubMed

Dose conversion coefficients (DCCs) for assessment of internal and external radiation exposures to terrestrial and aquatic biota are compiled for 75 radionuclides, for 14 terrestrial and 22 aquatic reference organisms. DCC values for internal exposure are calculated based on a homogeneous distribution of the radionuclides in both types of organisms. DCC values for external exposure of aquatic organisms are calculated for complete immersion in water. For external exposure of terrestrial organisms the soil is considered as a planar and homogenously contaminated volume source with a surface roughness of 3 mm and a thickness of 10 cm, respectively. For in-soil-organisms, DCC values for external exposure are given assuming that these organisms live in the middle of a uniformly contaminated 50 cm-thick soil layer. The tables can be used for assessment of exposures of animals and plants living in various habitats. The list of considered organisms covers the Reference Animals and Plants as adopted by the ICRP. PMID:18288480

Ulanovsky, A; Pröhl, G

2008-02-21

196

An herbal prescription, S-113m, consisting of biota, ginseng and schizandra, improves learning performance in senescence accelerated mouse.  

PubMed

The effect of an herbal prescription, S-113m, consisting of biota, ginseng and schizandra, on learning and memory performance was studied in the senescence accelerated mouse (SAM). A solid diet containing 1% (w/w) S-113m was given to SAM from 1 month of age. A behavioral experiment, started 4 or 9 months later, revealed prominent learning impairment in SAMP8, a senescence accelerated-prone mouse. Chronic ingestion of S-113m improved the memory retention disorder of SAMP8 in a passive avoidance test and increased the conditioned avoidance rate in a lever-press test at the age of 10 months. The preparation also facilitated the memory retention deficit in the passive avoidance test in 10-month-old SAMR1, a senescent resistant substrain. These results raise the possibility that S-113m might be useful for treating physiological aging and age-related memory deficits in human. PMID:8924907

Nishiyama, N; Chu, P J; Saito, H

1996-03-01

197

Fate of a broad spectrum of perfluorinated compounds in soils and biota from Tierra del Fuego and Antarctica.  

PubMed

In this study, the presence of 18 perfluorinated compounds was investigated in biota and environmental samples from the Antarctica and Tierra de Fuego, which were collected during a sampling campaign carried out along February and March 2010. 61 samples were analysed including fish, superficial soils, guano, algae, dung and tissues of Papua penguin by liquid chromatography coupled to tandem mass spectrometry. The concentrations of PFCs were ranging from 0.10 to 240 ng/g for most of the samples except for penguin dung, which presented levels between 95 and 603 ng/g for perfluorooctane sulfonate, and guano samples from Ushuaia, with concentration levels of 1190-2480 ng/g of perfluorohexanoic acid. PFCs acids presented, in general, the highest levels of concentration and perfluorooctanesulfonate was the most frequently found compound. The present study provides a significant amount of results, which globally supports the previous studies, related to the transport, deposition, biodegradation and bioaccumulation patterns of PFCs. PMID:22325444

Llorca, Marta; Farré, Marinella; Tavano, Máximo Sebastián; Alonso, Bruno; Koremblit, Gabriel; Barceló, Damià

2012-01-12

198

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

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

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

1979-01-01

199

Assessment of the consequences of the radioactive contamination of aquatic media and biota for the Chernobyl NPP cooling pond: model testing using Chernobyl data  

Microsoft Academic Search

The ‘Cooling Pond’ scenario was designed to test models for radioactive contamination of aquatic ecosystems, based on data from the Chernobyl Nuclear Power Plant cooling pond, which was heavily contaminated in 1986 as a result of the reactor accident. The calculation tasks include (a) reconstruction of the dynamics of radionuclide transfer and bioaccumulation in aquatic media and biota following the

I. I. Kryshev; T. G. Sazykina; F. O. Hoffman; K. M. Thiessen; B. G. Blaylock; Y. Feng; D. Galeriu; R. Heling; A. I. Kryshev; A. L. Kononovich; B. Watkins

1998-01-01

200

Bioturbation in Burgess Shale-type Lagerstätten — Case study of trace fossil–body fossil association from the Kaili Biota (Cambrian Series 3), Guizhou, China  

Microsoft Academic Search

Cruziana, Gordia, Planolites, Rusophycus, and Trichophycus are common ichnological elements of the Kaili Biota. New discoveries based on the examination of 323 specimens include eldoniids, echinoderms, trilobites, monoplacophorans, and non-biomineralizing arthropods that are associated with trace fossils. Based on the observed effects of bioturbation on the preservation of five different animal groups, it is clear that infaunal scavengers\\/deposit feeders were

Jih-Pai Lin; Yuan-Long Zhao; Imran A. Rahman; Shuhai Xiao; Yue Wang

2010-01-01

201

Mercury Pollution from a Chloralkali Source in a Tropical Lake and Its Biomagnification in Aquatic Biota: Link between Chemical Pollution, Biomarkers, and Human Health Concern  

Microsoft Academic Search

Mercury is a highly toxic heavy metal that can cause adverse ecological and toxicological impacts through the mechanism of biomagnification. Hg accumulation in aquatic biota may thus also pose a serious threat to humans and other fish-eating animals. The present work observed the transfer of Hg from abiotic (water and sediments) to biotic (algae, aquatic macrophytes, and fish) components, belonging

Prabhat Kumar Rai

2008-01-01

202

An Integrated Case Study for Evaluating the Impacts of an Oil Refinery Effluent on Aquatic Biota in the Delaware River: Integration and Analysis of Study Components  

Microsoft Academic Search

A series of statistical and graphical techniques incorporating a “weight of evidence” approach were used to interpret results from an integrated Triad case study designed to determine potential environmental impacts to aquatic biota in the Delaware River that may be linked to PAHs found in Motiva's oil refinery effluent. Sediment concentrations of various metals, PCBs and LMW PAHs exceeding both

Raymond W. Alden III; Lenwood W. Hall Jr; Daniel M. Dauer; Dennis T. Burton

2005-01-01

203

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

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)

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

1990-01-01

204

Pliocene age of Meyer Desert Fm. (Sirius Group) Terrestrial Biota at Oliver Bluffs, Dominion Range: a Comparison of Diatom Floras from Glacial, Wind and Ejecta Pathways  

Microsoft Academic Search

The age of the Meyer Desert Formation (Sirius Group) at Oliver Bluffs in the Transantarctic Mountains (TAM), and the terrestrial biota enclosed within these glacigene strata, has been a topic of discussion and disagreement. The Pliocene age derived from the occurrence of reworked late Miocene and early Pliocene marine diatoms within the enclosing sediments has been challenged by the assertion

D. M. Harwood

2004-01-01

205

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.  

National Technical Information Service (NTIS)

The purpose of this report is to describe, to the extent possible: (1) The occurrence and distribution of selected elements in water, sediment, and aquatic biota of the Yakima River Basin; (2) The temporal variation for element concentration in filtered w...

G. J. Fuhrer D. J. Cain S. W. McKenzie J. F. Rinella M. I. Hornberger J. K. Crawford K. A. Skach M. I. Hornberger

1999-01-01

206

Concentrations of chlorinated organic compounds in biota and bed sediment in streams of the San Joaquin Valley, California  

USGS Publications Warehouse

Samples of resident biota and bed sediments were collected in 1992 from 18 sites on or near the floor of the San Joaquin Valley, California, for analysis of 33 organochlorine compounds. The sites were divided into five groups on the basis of physiographic region and land use. Ten compounds were detected in tissue, and 15 compounds were detected in bed sediment. The most frequently detected compound in both media was p,p'-DDE. Concentrations of ??DDT (sum of o,p'- and p, p' forms of DDD, DDE, and DDT) were statistically different among groups of sites for both tissue and sediment (Kruskal- Wallis, p < 0.05). Concentrations in both media were highest in streams draining the west side of the valley. Concentrations of ??DDT in tissue were significantly correlated with specific conductance, pH, and total alkalinity (p < 0.05), which are indicators of the proportion of irrigation return flows in stream discharge. Concentrations in sediment on a dry-weight basis were not correlated with these water-quality parameters, but total organic carbon (TOC) normalized concentrations were significantly correlated with specific conductance and pH (p < 0.05). Regressions of the concentration of ??DDT in tissue, as a function of ??DDT in bed sediment, were significant and explained up to 76% of the variance in the data. The concentration of ??DDT in sediment may be related to mechanisms of soil transport to surface water with bioavailability of compounds related to the concentration of TOC in sediment. The results of this study did not indicate any clear advantage to using either bed sediment or tissues in studies of organochlorine chemicals in the environment. Some guidelines for protection of fish and wildlife were exceeded. Concentrations of organochlorine chemicals in biota, and perhaps sediment, have declined from concentrations measured in the 1970s and 1980s, but remain high compared to other regions of the United States.

Brown, L. R.

1997-01-01

207

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

NASA Astrophysics Data System (ADS)

The Triassic was a time of turmoil, as life recovered from the most devastating of all mass extinctions, the Permo-Triassic event 252 million years ago. The Triassic marine rock succession of southwest China provides unique documentation of the recovery of marine life through a series of well dated, exceptionally preserved fossil assemblages in the Daye, Guanling, Zhuganpo, and Xiaowa formations. New work shows the richness of the faunas of fishes and reptiles, and that recovery of vertebrate faunas was delayed by harsh environmental conditions and then occurred rapidly in the Anisian. The key faunas of fishes and reptiles come from a limited area in eastern Yunnan and western Guizhou provinces, and these may be dated relative to shared stratigraphic units, and their palaeoenvironments reconstructed. The Luoping and Panxian biotas, both from the Guanling Formation, are dated as Anisian (Pelsonian) on the basis of conodonts and radiometric dates, the former being slightly older than the latter. The Xingyi biota is from the Zhuganpo Formation, and is Ladinian or early Carnian, while the Guanling biota is from the overlying Xiaowa Formation, dated as Carnian. The first three biotas include extensive benthos and burrowing in the sediments, and they were located in restricted basins close to shore. Further, even though the Luoping and Panxian biotas are of similar age, their faunas differ significantly, reflecting perhaps palaeogeographically isolated basins. Between the time of the Xingyi and Guanling biotas, there was a major transgression, and the Guanling biota is entirely different in character from the other three, being dominated by pelagic forms such as large floating crinoids attached to logs, very large ichthyosaurs and thalattosaurs, and pseudoplanktonic bivalves, with no benthos and no burrowing. Phylogenetic study of the fishes and marine reptiles shows apparently explosive diversification among 20 actinopterygian lineages very early in the Early Triassic, but a later expansion of marine reptile groups, in the late Olenekian and early Anisian. This offset in diversification patterns is matched by comparisons of feeding guild categories and body size data. New research tools will shed considerable light on the phylogenetic and ecological implications of recovery of mairne vertebrates in the Triassic.

Benton, Michael J.; Zhang, Qiyue; Hu, Shixue; Chen, Zhong-Qiang; Wen, Wen; Liu, Jun; Huang, Jinyuan; Zhou, Changyong; Xie, Tao; Tong, Jinnan; Choo, Brian

2013-10-01

208

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

PubMed

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

Berger, Urs; Haukås, Marianne

2005-07-22

209

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

Microsoft Academic Search

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.

Janelle R. Griffith; Amy C. McDowell

1996-01-01

210

Biota-sediment accumulation factors for Dechlorane Plus in bottom fish from an electronic waste recycling site, South China.  

PubMed

Biota-sediment accumulation factors (BSAFs) for Dechlorane Plus (DP), a highly chlorinated flame retardant, were determined in three bottom fish species, i.e., crucian carp, mud carp, and northern snakehead from an electronic waste recycling site in South China. The average BSAFs are 0.007, 0.01, and 0.06 for syn-DP, and 0.003, 0.025, and 0.001 for anti-DP in crucian carp, mud carp, and northern snakehead, respectively, suggesting low bioaccumulation potential of DP isomers in these fish. However, the bioaccumulation factors (BAFs) determined previously in the same sample set indicated that both DP isomers were highly bioaccumulative (BAFs>5000) in most of the samples. This implies that BSAF values may be inherently inconsistent affecting their reliability as a bioaccumulation indicator. The BSAFs for DP isomers are two orders of magnitude lower than those (average of 0.43-2.28) for extremely hydrophobic polychlorinated biphenyls (CBs 199, 203, 207 and 208), but are comparable to those (average of 0.0001-0.009) for decabromodiphenyl ether (BDE 209) determined in the same sample set. Despite of the different chemical structures of the three compound classes, significantly negative correlations between logarithm of octanol-water partition coefficients (log K(OW)s) and BSAFs of these chemicals were found, indicating that hydrophobicity is one of the key factors influencing the bioaccumulation of these compounds. PMID:21705082

Zhang, Ying; Wu, Jiang-Ping; Luo, Xiao-Jun; Sun, Yu-Xin; Mo, Ling; Chen, She-Jun; Mai, Bi-Xian

2011-06-25

211

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

PubMed

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

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

2011-07-27

212

Determination of alkylphenol and alkylphenolethoxylates in biota by liquid chromatography with detection by tandem mass spectrometry and fluorescence spectroscopy.  

PubMed

A quantitative method for the simultaneous determination of octylphenol, nonylphenol and the corresponding ethoxylates (1 to 5) in biota is presented. Extraction methods were developed for egg and fish matrices based on accelerated solvent extraction followed by a solid-phase extraction cleanup, using octadecylsilica or aminopropyl cartridges. Identification and quantitation were accomplished by liquid chromatography-electrospray tandem mass spectrometry (LC-MS-MS) and compared to the traditional liquid chromatography with fluorescence spectroscopy detection. LC-MS-MS provides high sensitivity and specificity required for these complex matrices and an accurate quantitation with the use of 13C-labeled internal standards. Quantitation limits by LC-MS-MS ranged from 4 to 12 ng/g in eggs, and from 6 to 22 ng/g in fish samples. These methods were successfully applied to osprey eggs from the Chesapeake Bay and fish from the Great Lakes area. Total levels found in osprey egg samples were up to 18 ng/g wet mass and as high as 8.2 microg/g wet mass in the fish samples. PMID:14503813

Schmitz-Afonso, Isabelle; Loyo-Rosales, Jorge E; de la Paz Avilés, Maria; Rattner, Barnett A; Rice, Clifford P

2003-08-22

213

Increasing synchrony of high temperature and low flow in western North American streams: double trouble for coldwater biota?  

USGS Publications Warehouse

Flow and temperature are strongly linked environmental factors driving ecosystem processes in streams. Stream temperature maxima (Tmax_w) and stream flow minima (Qmin) can create periods of stress for aquatic organisms. In mountainous areas, such as western North America, recent shifts toward an earlier spring peak flow and decreases in low flow during summer/fall have been reported. We hypothesized that an earlier peak flow could be shifting the timing of low flow and leading to a decrease in the interval between Tmax_w and Qmin. We also examined if years with extreme low Qmin were associated with years of extreme high Tmax_w. We tested these hypotheses using long32 term data from 22 minimally human-influenced streams for the period 1950-2010. We found trends toward a shorter time lag between Tmax_w and Qmin over time and a strong negative association between their magnitudes. Our findings show that aquatic biota may be increasingly experiencing narrower time windows to recover or adapt between these extreme events of low flow and high temperature. This study highlights the importance of evaluating multiple environmental drivers to better gauge the effects of the recent climate variability in freshwaters.

Arismendi, Ivan; Safeeq, Mohammad; Johnson, Sherri L.; Dunham, Jason B.; Haggerty, Roy

2013-01-01

214

Concentrations of some heavy metals in water, suspended solids, and biota species from Maluan Bay, China and their environmental significance.  

PubMed

Concentrations of heavy metals (Cu, Zn, Cd, and Pb) in surface water (including total recoverable, dissolved, suspended solids) and in aufwuchs encrusted on Moerella iridescens Benson from seven selected sites and two reference sites in Maluan Bay were investigated in order to understand current metal contamination due to industrialization and urbanization in Xiamen, China. The muscle tissues of the study species (Penceus penicillatus, Scylla serrata Forskal, Harengula zunasi Bleeker, Tillapia nilotica) from a trawling area within Maluan Bay were also analyzed in order to evaluate its safety as seafood. Based on the obtained data, metal concentrations in surface water were compared with Marine Seawater Quality Standards of China and the US EPA acute and chronic criteria, which showed that Maluan Bay may be subjected to different levels of contamination by the metals. Metal concentrations under study in the edible parts (muscle) of the investigated biota species were within the safety permissible levels for human consumption. Through Pearson's correlation analysis, the relationships between metal concentrations in surface water and in M. iridescens were evaluated. Copper concentrations in M. iridescens were more strongly positively correlated with particulate copper in suspended solids and total recoverable copper in water rather than with dissolved copper at the sampling sites. The data suggested that copper-rich suspended solids contributed substantially to copper accumulation by M. iridescens and played a critical role in the pathway of copper into the food chain. The conclusions of this investigation are likely to be applicable to other relevant scenarios. PMID:20508984

Wang, Zaosheng; Yan, Changzhou; Pan, Qikun; Yan, Yijun

2010-05-28

215

Upper Clear Creek watershed aquatic chemistry and biota surveys, 2004-5, Whiskeytown National Recreation Area, Shasta County, California  

USGS Publications Warehouse

The U.S. Geological Survey, in cooperation with the National Park Service and Whiskeytown National Recreation Area, performed a comprehensive aquatic biota survey of the upper Clear Creek watershed, Shasta County, California, during 2004-5. Data collected in this study can provide resource managers with information regarding aquatic resources, watershed degradation, and regional biodiversity within Whiskeytown National Recreation Area. Surveys of water chemistry, bed-sediment chemistry, algae assemblages, benthic macroinvertebrate assemblages, aquatic vertebrate assemblages, in-stream habitat characteristics, and sediment heterogeneity were conducted at 17 stream sites during both 2004 and 2005, with an additional 4 sites surveyed in 2005. A total of 67 bed-sediment samples were analyzed for major and trace inorganic element concentrations. Forty-six water samples were analyzed for trace metals and nutrients. A total of 224 taxa of invertebrates were collected during these surveys. Eleven fish species, seven of which were native, and two species of larval amphibians, were collected. A total of 24 genera of soft algae and 159 taxa of diatoms were identified. To date, this survey represents the most comprehensive inventory of aquatic resources within Whiskeytown National Recreation Area, and this information can serve as a baseline for future monitoring efforts and to inform management decisions.

Wulff, Marissa L.; May, Jason T.; Brown, Larry R.

2012-01-01

216

Determination of alkylphenol and alkylphenolethoxylates in biota by liquid chromatography with detection by tandem mass spectrometry and fluorescence spectroscopy  

USGS Publications Warehouse

A quantitative method for the simultaneous determination of octylphenol, nonylphenol and the corresponding ethoxylates (1 to 5) in biota is presented. Extraction methods were developed for egg and fish matrices based on accelerated solvent extraction followed by a solid-phase extraction cleanup, using octadecylsilica or aminopropyl cartridges. Identification and quantitation were accomplished by liquid chromatography-electrospray tandem mass spectrometry (LC-MS-MS) and compared to the traditional liquid chromatography with fluorescence spectroscopy detection. LC-MS-MS provides high sensitivity and specificity required for these complex matrices and an accurate quantitation with the use of 13C-labeled internal standards. Quantitation limits by LC-MS-MS ranged from 4 to 12 ng/g in eggs, and from 6 to 22 ng/g in fish samples. These methods were successfully applied to osprey eggs from the Chesapeake Bay and fish from the Great Lakes area. Total levels found in osprey egg samples were up to 18 ng/g wet mass and as high as 8.2 ug/g wet mass in the fish samples.

Schmitz-Afonso, I.; Loyo-Rosales, J.E.; de la Paz Aviles, M.; Rattner, B.A.; Rice, C.P.

2003-01-01

217

Determination of alkylphenol and alkylphenolethoxylates in biota by liquid chromatography with detection by tandem mass spectrometry and fluorescence spectroscopy  

USGS Publications Warehouse

A quantitative method for the simultaneous determination of octylphenol, nonylphenol and the corresponding ethoxylates (1 to 5) in biota is presented. Extraction methods were developed for egg and fish matrices based on accelerated solvent extraction followed by a solid-phase extraction cleanup, using octadecylsilica or aminopropyl cartridges. Identification and quantitation were accomplished by liquid chromatography-electrospray tandem mass spectrometry (LC-MS-MS) and compared to the traditional liquid chromatography with fluorescence spectroscopy detection. LC-MS-MS provides high sensitivity and specificity required for these complex matrices and an accurate quantitation with the use of 13C-labeled internal standards. Quantitation limits by LC-MS-MS ranged from 4 to 12 ng/g in eggs, and from 6 to 22 ng/g in fish samples. These methods were successfully applied to osprey eggs from the Chesapeake Bay and fish from the Great Lakes area. Total levels found in osprey egg samples were up to 18 ng/g wet mass and as high as 8.2 ??g/g wet mass in the fish samples. ?? Elsevier B.V. All rights reserved.

Schmitz-Afonso, I.; Loyo-Rosales, J. E.; De La, Paz, Aviles, M.; Rattner, B. A.; Rice, C. P.

2003-01-01

218

Review of samples of water, sediment, tailings, and biota at the Little Bonanza mercury mine, San Luis Obispo County, California  

USGS Publications Warehouse

Sample Sites and Methods Samples were collected to assess the concentrations of Hg and biogeochemically relevant constituents in tailings and wasterock piles at the Little Bonanza Hg mine. Tailings are present adjacent to a three-pipe retort used to process the Hg ore. The tailings occur in the upper 15 cm of the soil adjacent to the retort and slag from the retort is present on the surface. An area of disturbed soil and rock uphill from the retort was likely formed during construction of a dam that provided water for mining activities. Wasterock in these piles was sampled. The largest amount of tailings is exposed to the west of the retort in the bank of WF Las Tablas Creek. Water, sediment, and biota were sampled from WF Las Tablas Creek, which flows through the mine area. Sample-site locations are shown in figures 10 and 11 and listed in table 1. Samples were collected when streamflow was low and no precipitation had occurred.

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

2011-01-01

219

Biodiversity of soil biota and plants in abandoned arable fields and grasslands under restoration management  

Microsoft Academic Search

The currently widespread abandoning of agricultural land use in Western Europe offers new opportunities for ecological restoration and nature conservation. This is illustrated for abandoned arable fields and for permanent grasslands cut for hay after the cessation of fertilizer application. Although initiated by a sudden reduction of nutrient input to the system, the changing nutrient supply from the soil is

L. Brussaard; J. P. Bakker; H. Olff

1996-01-01

220

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

Microsoft Academic Search

Abstract. 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. Tomaintain biodiversity in aquatic systems it is important to manage the rate, timing, pattern, frequency and duration

Kimberley R. James; Belinda Cant; Tom Ryan

2003-01-01

221

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

Microsoft Academic Search

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

Kimberley R. JamesA; Tom RyanB

222

Prediction under Change (PUC): Water, Earth and Biota in the Anthropocene  

NASA Astrophysics Data System (ADS)

The world is facing severe water management challenges, in the context of population growth, degradation of a poorly distributed resource, and the considerable uncertainties posed by the effects of climate change. Sustainable management requires the ability to predict the space-time distribution of water resources, water quality and environmental health, to help balance the needs of both humans and the environment. The rapid rates of change that the water cycle and the environment are likely to experience as a result of increasing human impacts (e.g., climate change, land use and land cover changes) requires that prediction and management frameworks better capture coupling and feedbacks across the built, natural, and social systems that define the sustainability of water resources. As we ponder a changing environment - climate, hydrology, land use, biogeochemical cycles, human dynamics - there is an increasing need now to embrace the long-term evolution of linked sub-systems (climatic, hydrologic, geomorphic, ecological etc., as well as human) through a new generation of conceptual and quantitative models that either explicitly or implicitly include the interactions and feedbacks between these sub-systems. Their co-evolution is driven by exogenous variability imposed on the system by weather, climate and anthropogenic factors, and endogenous variability generated by the sub-systems themselves as a result of certain adaptive evolutionary processes. In this talk I will outline the fundamental issues involved in predictions at long time scales (decades) and large space scales (regions) in a fast changing environment, including significant paradigm shifts in the way we seek the fundamental understanding needed to underpin these predictions, including the need for sustained community efforts.

Sivapalan, M.

2011-12-01

223

Use of Biota-Sediment Accumulation Factors to assess similarity of nonionic organic chemical exposure to benthically-coupled organisms of differing trophic mode  

Microsoft Academic Search

The U.S. Environmental Protection Agency is in the process of developing Sediment Quality Criteria (SQC) to specify the acceptable degree of risk from sediment-mediated chemical exposure for the protection of benthically-coupled organisms. In this study, potential differences in chemical exposure for benthic organisms of differing habitats or feeding types were evaluated through the use of Biota-Sediment Accumulation Factors (BSAFs). It

G. A. Tracey; D. J. Hansen

1996-01-01

224

An Integrated Case Study for Evaluating the Impacts of an Oil Refinery Effluent on Aquatic Biota in the Delaware River: Sediment Quality Triad Studies  

Microsoft Academic Search

Triad studies consisting of chemical characterizations in sediment, sediment toxicity testing, and benthic community assessments were used to determine the impacts of Motiva Enterprises oil refinery effluent [primarily polynuclear aromatic hydorcarbons (PAHs)] on aquatic biota in the Delaware River. Triad studies were conducted at 15 near-field, mid-field, and far-field sites near the Refinery in the Delaware River during the spring

Lenwood W. Hall Jr; Daniel M. Dauer; Raymond W. Alden III; Allen D. Uhler; Joseph DiLorenzo; Dennis T. Burton; Ronald D. Anderson

2005-01-01

225

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

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

Urs Berger; Marianne Haukås

2005-01-01

226

Do site-specific radiocarbon measurements reflect localized distributions of (14)C in biota inhabiting a wetland with point contamination sources?  

PubMed

Duke Swamp is a wetland ecosystem that receives (14)C via a groundwater pathway originating from a waste management area on Atomic Energy Canada Limited's Chalk River Laboratories site. This groundwater reaches the surface of the swamp, resulting in relatively high (14)C levels over an area of 146 m(2). The objective of this study was to quantify (14)C concentrations in flora and fauna inhabiting areas of Duke Swamp over the gradient of (14)C activity concentrations in moss to determine whether (14)C specific activities in receptor biota reflect the localized nature of the groundwater source in the swamp. Representative receptor plants and animals, and corresponding air and soil samples were collected at six sites in Duke Swamp with (14)C specific activities in air that ranged from 1140 to 45,900 Bq/kg C. In general, it was found that specific activities of (14)C in biota tissues reflected those measured in environmental media collected from the same sampling site. The findings demonstrate that mosses could be used in monitoring programs to ensure protection of biota in areas with elevated (14)C, negating the need to capture and euthanize higher organisms. PMID:23712022

Yankovich, T; King-Sharp, K J; Benz, M L; Carr, J; Killey, R W D; Beresford, N A; Wood, M D

2013-05-24

227

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

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.

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

1993-01-01

228

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

SciTech Connect

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.

Voeller, Amy C.

1993-01-01

229

Integrated watershed study: An investigation of the biota in the Emerald Lake system and stream-channel experiments. Final report  

SciTech Connect

As part of the Integrated Watershed Study in the vicinity of Emerald Lake, Sequoia National Park, investigators conducted baseline monitoring of benthic invertebrates in the inflow streams and the outflow stream. During summer 1986 they carried out a series of acidification experiments in artificial stream channels located in the drainage of the Marble Fork of the Kaweah River. Twelve channels (2.4 m x 20 cm x 20 cm) were stocked with natural substrates, algae and invertebrates. In the treatment channels the pH was reduced to 4.6 and 5.2, using a mixture of nitric and sulfuric acids. Measurements of benthic densities, drift rates and algal densities were made before, during and after each acid treatment of 8 hours duration. Diatom populations declined in the acidified channels, while other periphyton species actually increased with the treatment.

Cooper, S.D.; Kratz, K.; Holmes, R.W.; Melack, J.M.

1988-05-05

230

Analysis of Marine Biota for Chemical Warfare Materials by Means of a Gas Chromatography/Mass Spectrometer System.  

National Technical Information Service (NTIS)

The U.S. Army Edgewood Chemical Biological Center's (ECBC) Directorate of Program Integration Environmental Monitoring Branch developed a procedure and conducted a Method Detection Limit (MDL) study for the analysis of Chemical Warfare Materials (CWM) in ...

B. E. Dusick J. L. Schwarz M. L. Avila

2011-01-01

231

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

SciTech Connect

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.

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

1995-08-01

232

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

PubMed

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

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

2005-10-12

233

Environmental contaminant concentrations in biota from the lower Savannah River, Georgia and South Carolina  

USGS Publications Warehouse

Planned harbor expansion and industrial developments may adversely affect the economically important aquatic resources of the lower Savannah River, including those at the Savannah National Wildlife Refuge. To establish the present level of chemical contamination in this system, we collected a total of 102 samples of nine species of fish and fiddler crabs (Uca pugilator) from eleven sites in the lower Savannah River and on the Savannah National Wildlife Refuge, and analyzed them for concentrations of organochlorine chemicals, aliphatic and aromatic petroleum hydrocarbons, and 13 elemental contaminants: aluminum, arsenic, cadmium, chromium, cobalt, copper, iron, lead, manganese, mercury, nickel, selenium, and zinc. Residues of DDT (mainly as DDE),trans-nonachlor, dieldrin, Aroclor? 1260, mirex, and petroleum hydrocarbons were common in fish from the lower Savannah River, but concentrations were below those warranting environmental concern. In general, the concentrations of elemental contaminants also were low; however, arsenic, cadmium, and chromium concentrations were elevated in fish from river stations near the city of Savannah, and lead was elevated in samples from the National Wildlife Refuge. Contamination of the lower Savannah River by organic and elemental contaminants, as indicated by concentrations in fishes and fiddler crabs, did not appear to pose a hazard.

Winger, P. V.; Schultz, D. P.; Johnson, W. W.

1990-01-01

234

Short- and medium-chain chlorinated paraffins in biota from the European Arctic -- differences in homologue group patterns.  

PubMed

Congener and homologue group patterns of chlorinated paraffins (CPs) in biota can be influenced by different processes, but these are not well studied yet. Short- (SCCPs) and medium-chain chlorinated paraffins (MCCPs) were quantified in liver from Arctic char and seabirds (little auk and kittiwake) collected at Bear Island (European Arctic) as well as in cod from Iceland and Norway. CP concentrations were between 5 and 88 ng/g wet weight (ww) for SCCPs and between 5 and 55 ng/g ww for MCCPs with one exception of 370 ng/g measured in a liver sample from little auk. The SCCP homologue group patterns were compared with those of technical mixtures and of SCCPs present in cod liver from the Baltic Sea. The latter showed a more common SCCP homologue distribution (sum of C(11) and C(12)>60%) in contrast to cod liver from the Northwest of Europe, which had a high abundance of C(10) and C(12) congeners. Seabirds from Bear Island contained an equally distributed SCCP homologue group pattern. In Arctic char, the SCCP distribution was closer to technical products, but with a high proportion (average of 18.9%) of C(10) congeners. A comparison of C(10)/C(12) ratios confirmed the higher abundance of C(10) congeners in samples from higher latitudes. For the first time, MCCPs could be detected in Arctic samples. The average proportion of C(14) congeners was 65.8%. The C(14)/C(15) abundance ratio was similar to technical mixtures. High-chlorinated CPs (Cl(>7)) were also detectable. The average chlorine content of the SCCPs was 61.9% (59.0-63.3%), and that of the MCCPs 55.8% (54.5-57.4%). PMID:16519923

Reth, Margot; Ciric, Anita; Christensen, Guttorm N; Heimstad, Eldbjørg S; Oehme, Michael

2006-03-06

235

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

NASA Astrophysics Data System (ADS)

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

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

2011-07-01

236

Optimisation of the headspace-solid phase microextraction for organomercury and organotin compound determination in sediment and biota.  

PubMed

Headspace solid-phase microextraction was optimised for the simultaneous preconcentration of methylmercury (MeHg+), monobutyltin, dibutyltin, tributyltin, monophenyltin (MPhT), diphenyltin (DPhT), and triphenyltin (TPhT) from sediments and biota. Extraction time (3-24 min), extraction temperature (20-90 degrees C), desorption time (1-10.4 min), desorption temperature (152-260 degrees C), and sample volume (5-22 mL) were simultaneously optimised, while variables such as fibre type (30 microm polydimethylsiloxane, PDMS), pH (acetic acid/sodium acetate, HOAc/NaOAc, 2 mol/L, pH approximately 4.8), the concentration of the derivatisation agent (sodium tetraethylborate, NaBEt4, 0.1% m/v), and the ionic strength (fixed by the buffer solution) were kept constant. The variables were optimised according to the experiments proposed by the MultiSimplex program and the responses were considered in order to establish the optimum conditions. The repeatability (relative standard deviation, RSD, 5-20.6%) and limits of detection (LODs, 0.05-0.97 ng/g) of the overall method were also estimated. The lowest precisions were obtained for DPhT and TPhT. The optimised preconcentration method was applied to the determination of MeHg+), butyl- and phenyltins in certified reference materials (IAEA-405 MeHg+) in estuarine sediment, BCR-646 butyl- and phenyltins in marine sediment, BCR-463 MeHg+ in tuna fish, DOLT-2 MeHg+ in dogfish liver, and BCR-477 butyltins in mussel tissue) by GC with microwave-induced plasma/atomic-emission detection. PMID:18240132

Delgado, Alejandra; Usobiaga, Aresatz; Prieto, Ailette; Zuloaga, Olatz; de Diego, Alberto; Madariaga, Juan M

2008-03-01

237

Metals in water, sediments, and biota of an offshore oil exploration area in the Potiguar Basin, Northeastern Brazil.  

PubMed

Metal concentrations were evaluated in water, bottom sediments, and biota in four field campaigns from 2002 to 2004 in the Potiguar Basin, northeastern Brazil, where offshore oil exploration occurs. Analyses were performed by inductively coupled plasma mass spectrometry and inductively coupled plasma optical emission spectrometry. Total metal concentrations in water (dissolved + particulate) and sediments were in the range expected for coastal and oceanic areas. Abnormally high concentrations in waters were only found for Ba (80 ?g l(-1)) and Mn (12 ?g l(-1)) at the releasing point of one of the outfalls, and for the other metals, concentrations in water were found in stations closer to shore, suggesting continental inputs. In bottom sediments, only Fe and Mn showed abnormal concentrations closer to the effluent releasing point. Metal spatial distribution in shelf sediments showed the influence of the silt-clay fraction distribution, with deeper stations at the edge of the continental shelf, which are much richer in silt-clay fraction showing higher concentrations than shallower sediments typically dominated by carbonates. Metal concentrations in estuarine (mollusks and crustaceans) and marine (fish) organisms showed highest concentrations in oysters (Crassostrea rhizophorae). Fish tissues metal concentrations were similar between the continental shelf influenced by the oil exploration area and a control site. The results were within the range of concentrations reported for pristine environments without metals contamination. The global results suggest small, if any, alteration in metal concentrations due to the oil exploration activity in the Potiguar Basin. For monitoring purposes, the continental inputs and the distribution of the clay-silt fraction need to be taken into consideration for interpreting environmental monitoring results. PMID:23014923

Lacerda, L D; Campos, R C; Santelli, R E

2012-09-27

238

Analysis of fluorotelomer alcohols, fluorotelomer acids, and short- and long-chain perfluorinated acids in water and biota.  

PubMed

Fluorotelomer alcohols and fluorotelomer acids have been proposed as a source of the perfluorinated carboxylic acids found in remote marine locations. To examine the sources and fate of perfluorinated acids in the environment, a method to determine a wide range of poly- and perfluorinated acids in environmental and biological matrices is needed. In this study, a method has been developed to measure a suite of neutral and acidic fluorochemicals including, fluorotelomer alcohols, fluorotelomer acids, and short- and long-chain perfluorinated acids, in water and biological samples. The method involves solid-phase extraction with weak anion exchange (WAX) cartridges, followed by sequential elution with sodium acetate buffer, methanol, and 0.1% NH4OH in methanol. For biological samples, prior to solid-phase extraction, tissues are digested in 0.5N potassium hydroxide/methanol, diluted in water, and passed through the WAX cartridge. Neutral compounds and telomer alcohols are separated from other poly- and perfluorinated acids. The method is robust (i.e., capable of measuring neutral and acidic compounds), and can be applied for the analysis of a range of poly- and perfluorinated acids, including telomer alcohols, telomer acids, perfluoroalkylcarboxylates, and perfluoroalkylsulfonates in water and biota. With the use of high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS), a method detection limit in the range of several tens to hundreds of parts-per-quadrillion (pg/L) in water and at a few tens to hundreds of parts-per-trillion (pg/g) levels in biological matrices can be achieved. PMID:16233874

Taniyasu, Sachi; Kannan, Kurunthachalam; So, Man Ka; Gulkowska, Anna; Sinclair, Ewan; Okazawa, Tsuyoshi; Yamashita, Nobuyoshi

2005-08-15

239

Simplified sample preparation method for triclosan and methyltriclosan determination in biota and foodstuff samples.  

PubMed

An improved method for the determination of triclosan (TCS) and methyltriclosan (MTCS) in fish and foodstuff samples is presented. Analytes were simultaneously extracted and purified using the matrix solid-phase dispersion (MSPD) technique, and then selectively determined by gas chromatography with tandem mass spectrometry (GC-MS/MS). Several combinations of dispersants, clean-up co-sorbents and extraction solvents were tested in order to obtain lipid-free extracts and quantitative recoveries for TCS and MTCS. Under optimised conditions, 0.5 g samples were dispersed using 1.5 g of neutral silica in a mortar with a pestle, and transferred to a polypropylene cartridge containing 3 g of silica impregnated with 10% of sulphuric acid (SiO2-H2SO4, 10%, w/w). Analytes were recovered with 10 mL of dichloromethane whereas lipids were oxidized in the layer of acidic silica. The extract was concentrated to dryness and re-constituted with 1 mL of ethyl acetate. Then, a fraction of 0.5 mL was mixed with 50 microL of N-methyl-N-(tert-butyldimethylsilyl)trifluoroacetamide (MTBSTFA) and injected in the GC-MS/MS system. The developed method provided absolute recoveries between 77 and 120% for different samples spiked at the low ng g(-1) level, quantification limits in the range of 1-2 ng g(-1) and a considerable simplicity in comparison with previously developed sample preparation approaches. Experiments carried out placing sliced food samples in direct contact with TCS-treated kitchenware surfaces showed the capability of the biocide to migrate into foodstuffs. PMID:18329035

Canosa, P; Rodríguez, I; Rubí, E; Ramil, M; Cela, R

2008-03-07

240

Environmental Impact of the Helen, Research, and Chicago Mercury Mines on Water, Sediment, and Biota in the Upper Dry Creek Watershed, Lake County, California  

USGS Publications Warehouse

The Helen, Research, and Chicago mercury (Hg) deposits are among the youngest Hg deposits in the Coast Range Hg mineral belt and are located in the southwestern part of the Clear Lake volcanic field in Lake County, California. The mine workings and tailings are located in the headwaters of Dry Creek. The Helen Hg mine is the largest mine in the watershed having produced about 7,600 flasks of Hg. The Chicago and Research Hg mines produced only a small amount of Hg, less than 30 flasks. Waste rock and tailings have eroded from the mines, and mine drainage from the Helen and Research mines contributes Hg-enriched mine wastes to the headwaters of Dry Creek and contaminate the creek further downstream. 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 geochemical constituents in tailings, sediment, water, and biota at the Helen, Research, and Chicago mines and in Dry Creek. This report is made in response to the USBLM request 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 Helen, Research, and Chicago mines as a means of reducing Hg transport to Dry Creek. This report summarizes data obtained from field sampling of mine tailings, waste rock, sediment, and water at the Helen, Research, and Chicago mines on April 19, 2001, during a storm event. Further sampling of water, sediment, and biota at the Helen mine area and the upper part of Dry Creek was completed on July 15, 2003, during low-flow conditions. 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 the water, sediment, and biota that are impacted by historic mining.

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

2009-01-01

241

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

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)

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

1988-01-01

242

Impact assessment of ionizing radiation on human and non-human biota from the vicinity of a near-surface radioactive waste repository.  

PubMed

This work describes the radiological assessment of the near-surface Maisiagala radioactive waste repository (Lithuania) over the period 2005-2012, with focus on water pathways and special emphasis on tritium. The study includes an assessment of the effect of post-closure upgrading, the durability of which is greater than 30 years. Both human and terrestrial non-human biota are considered, with local low-intensity forestry and small farms being the area of concern. The radiological exposure was evaluated using the RESRAD-OFFSITE, RESRAD-BIOTA and ERICA codes in combination with long-term data from a dedicated environmental monitoring programme. All measurements were performed at the Lithuanian Institute of Physics as part of this project. It is determined that, after repository upgrading, radiological exposure to humans are significantly lower than the human dose constraint of 0.2 mSv/year valid in the Republic of Lithuania. Likewise, for non-human biota, dose rates are below the ERICA/PROTECT screening levels. The potential annual effective inhalation dose that could be incurred by the highest-exposed human individual (which is due to tritiated water vapour airborne release over the most exposed area) does not exceed 0.1 ?Sv. Tritium-labelled drinking water appears to be the main pathway for human impact, representing about 83 % of the exposure. Annual committed effective dose (CED) values for members of the public consuming birch sap as medical practice are calculated to be several orders of magnitude below the CEDs for the same location associated with drinking of well water. The data presented here indicate that upper soil-layer samples may not provide a good indication of potential exposure to terrestrial deep-rooted trees, as demonstrated by an investigation of stratified (3)H in soil moisture, expressed on a wet soil mass basis, in an area with subsurface contamination. PMID:23377320

Nedveckaite, T; Gudelis, A; Vives i Batlle, J

2013-02-03

243

Trace elements and organic compounds in streambed sediment and aquatic biota from the Sacramento River Basin, California, October and November 1995  

USGS Publications Warehouse

Elevated levels of trace elements and hydrophobic organic compounds were detected in streambed sediments and aquatic biota [Asiatic clam (Corbicula fluminea) or bottom-feeding fish] of the Sacramento River Basin, California, during October and November 1995. Trace elements detected included cadmium, copper, mercury, lead, and zinc. Elevated levels of cadmium, copper, and zinc in the upper Sacramento River are attributed to a mining land use, and elevated levels of zinc and lead in an urban stream, and possibly in the lower Sacramento River, are attributed to urban runoff processes. Elevated levels of mercury in streambed sediment are attributed to either past mercury mining or to the use of mercury in past gold mining operations. Mercury mining was an important land use within the Coast Ranges in the past and gold mining was an important land use of the Sierra Nevada in the past. Mercury was the only trace element found in elevated levels in the tissue of aquatic biota, and those levels also could be attributed to either mining or urban runoff. Hydrophobic organic compounds also were detected in streambed sediments and aquatic biota. The most frequently detected compounds were DDT and its breakdown products, dieldrin, oxychlordane, and toxaphene. Differences were found in the types of compounds detected at agricultural sites and the urban site. Although both types of sites had measurable concentrations of DDT or its breakdown products, the urban site also had measurable concentrations of pesticides used for household pest control. Few semivolatile compounds were detected in the streambed sediments of any site. The semivolatile compound p-cresol, a coal-tar derivative associated with road maintenance, was found in the highest concentration.

MacCoy, Dorene E.; Domagalski, Joseph L.

1999-01-01

244

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

PubMed

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

Doulgeraki, Agapi I; Nychas, George-John E

2012-12-03

245

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

Microsoft Academic Search

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

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

2004-01-01

246

Occurrence and behavior of natural and anthropogenic (emerging and historical) halogenated compounds in marine biota from the Coast of Concepcion (Chile).  

PubMed

Fifty-five biota samples from the Coast of Concepcion (Chile) were analyzed for PBDEs, emerging brominated FRs, halogenated norbornenes and naturally-occurring MeO-PBDEs. PBDEs, MeO-PBDEs and halogenated norbornenes were detected at concentration levels ranging from 11 to 170, nd to 118 and nd to 5.8 ng/g lw, respectively. However, emerging brominated FRs such as decabromodiphenylethane (DBDPE), hexabromobenzene (HBB) and pentabromoethylbenzene (PBEB) were not detected in any sample. Bioaccumulation and bioconcentration processes were evaluated for the different families of compounds. Biomagnification factors (BMFs) were calculated, and some PBDE congeners (BDE-28, BDE-183 and BDE-209) as well as MeO-PBDEs presented BMF>1, being values of the naturally occurring MeO-PBDEs higher than those obtained for PBDEs. As regards halogenated norbornenes, BMF<1 were found. PMID:23735720

Barón, Enrique; Rudolph, Ignacio; Chiang, Gustavo; Barra, Ricardo; Eljarrat, Ethel; Barceló, Damià

2013-06-02

247

Soft-Bottom Benthic Assemblages and Levels of Contaminants in Sediments and Biota at Gray's Reef National Marine Sanctuary and Nearby Shelf Waters Off the Coast of Georgia (2000 and 2001).  

National Technical Information Service (NTIS)

A series of studies was initiated to assess the condition of benthic macroinfauna and chemical contaminant levels in sediments and biota of the Grays Reef National Marine Sanctuary (GRNMS) and nearby shelf waters off the coast of Georgia. Four key objecti...

C. Cooksey J. Hyland W. L. Balthis M. Fulton G. Scott

2004-01-01

248

Reconnaissance investigation of water quality, bottom sediment, and biota associated with irrigation drainage in the Salton Sea area, California, 1986-87  

USGS Publications Warehouse

Water, bottom sediment, and biota were sampled during 1986 and 1987 in the Salton Sea area to determine concentrations of trace elements and pesticides as part of the Department of Interior Irrigation Drainage Program. The sampling sites (12 water, 15 bottom sediment, and 5 biota) were located in the Coachella and Imperial Valleys. The focus of sampling was to determine the current or potential threat to the wildlife of the Salton National Wildlife Refuge from irrigation projects sponsored or operated by the Department of the Interior. Results of the investigation indicate that selenium is the major element of concern. Elevated concentrations of selenium in water were restricted to tile-drain effluent. The maximum selenium concentration of 300 microg/L was detected in a tile-drain sample, and the minimum concentration of 1 microg/L was detected in a composite sample of Salton Sea water. The median selenium concentration was 19 microg/L. In contrast to the water, the highest bottom-sediment selenium concentration of 3.3 mg/kg was in a composite sample from the Salton Sea. The selenium detected in samples of waterfowl and fish also are of concern, but, to date, no studies have been done in the Salton Sea area to determine if selenium has caused adverse biological effects. Concentrations of boron and manganese were elevated in tile-drain samples throughout the Imperial Valley. Boron concentrations in migratory waterfowl were at levels that could cause reproduction impairment. Elevated concentrations of chromium, nickel, and zinc were detected in the Whitewater River , but they were not associated with irrigation drainage. Organochlorine pesticide residues were detected in bottom sediment throughout the study area at levels approaching those measured more than 10 years ago. More detailed studies would be needed to determine if these residues are affecting the waterfowl. (USGS)

Setmire, J. G.; Wolfe, J. C.; Stroud, R. K.

1990-01-01

249

New 40Ar/ 39Ar dating results from the Shanwang Basin, eastern China: Constraints on the age of the Shanwang Formation and associated biota  

NASA Astrophysics Data System (ADS)

The fluvio-lacustrine sequence of the Shanwang Basin, eastern China, preserves a rich and important terrestrial fossil fauna and flora; the exceptional preservation of these fossils reveals the dynamics of ancient mammalian ecosystems and plant biology. However, the timing of this sedimentary sequence has been the subject of debate for decades. Here we contribute to this debate by presenting the detailed results of 40Ar/ 39Ar analysis of the basalts above, below, and within the Shanwang Formation. These dates place stringent constraints on the age of Shanwang Formation and associated biota. 40Ar/ 39Ar ages obtained from basalts of the Niushan and Yaoshan Formations, which underlie and overlie the Shanwang Formation, are 21.0 ± 2.5 Ma (2?, full external error) and 17.3 ± 1.5 Ma (2?, full external error), respectively. The 40Ar/ 39Ar age of the basalt in the Shanwang Formation is 17-18 Ma. Given the age constraints of the basalts of the Yaoshan and Shanwang Formations, the age of the Shanwang biota is estimated to be ca. 17 Ma, late Burdigalian of the Early Miocene, indicating that the deposition of this fauna coincided with the onset of the mid-Miocene Climatic Optimum. The results provide new age constraints on the Shanwang mammal fauna, and independently support interpretations that this fauna can be assigned to chronozone MN4, and correlated with middle Orleanian of the European Land Mammal Age, and to late Hemingfordian of the North American Land Mammal Age. Biological diversity of the Shanwang Formation could reflect the global-scale mid-Miocene Climatic Optimum.

He, Huaiyu; Deng, Chenglong; Pan, Yongxin; Deng, Tao; Luo, Zhaohua; Sun, Jimin; Zhu, Rixiang

2011-07-01

250

Changes in the properties of soils and soil biota in the impact zone of the aerotechnogenic emissions from the Kandalaksha aluminum smelter  

NASA Astrophysics Data System (ADS)

A comparative analysis of the changes in the properties of the soils and soil biota in the past ten years along the gradient of pollution with aerotechnogenic emission from the Kandalaksha aluminum smelter in response to a decrease in the emission volume has been performed. The concentrations of fluorine compounds (the priority pollutant) in the emissions and in the organic soil horizons in the impact zone significantly decreased in 2011 relative to 2001. The concentrations of Al decreased only in close vicinity to the smelter (up to 2 km). The concentrations of F, Ca, and Mg in the liquid phase were higher than those in the solid phase, and these elements migrated to greater distances from the source of the contamination (up to 15-20 km). The elements Si, Al, Fe, and P were contained mostly in the solid phase and were mainly deposited within the 5-km zone. The acidity of the litter near the smelter decreased by almost by two pH units in the nearest zone (<2 km). The decrease in the amount of contaminants in the emissions resulted in the narrowing of the zone of the maximum soil contamination from 2.5 to 1.5 km from the emission source; the zones of strong and moderate contamination narrowed by 5 km. The regularities of the changes in the numbers and biomasses of the main groups of microorganisms in the soils of the permanent sampling plots did not change during the past ten years. The emissions inhibited the development of the fungal biota. The prokaryotic part of the soil microbiota and, particularly, the actinomycetes proved to be tolerant to the emitted contaminants. It was suggested that the changes in the structure of the fungal and actinomycetal communities should be used to monitor the state of the soil ecosystems affected by the emissions from the aluminum smelter.

Evdokimova, G. A.; Korneikova, M. V.; Mozgova, N. P.

2013-10-01

251

Determination of cyclic volatile methylsiloxanes in water, sediment, soil, biota, and biosolid using large-volume injection-gas chromatography-mass spectrometry.  

PubMed

Several methods were developed to detect the cyclic volatile methylsiloxanes (cVMSs) including octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), and dodecamethylcyclohexasiloxane (D6) in water, sediment, soil, biota, and biosolid samples. Analytical techniques employed to optimize measurement of this compound class in various matrices included membrane-assisted solvent extraction in water, liquid-solid extraction for sediment, soil, biota, and biosolid samples. A subsequent analysis of the extract was conducted by large-volume injection-gas chromatography-mass spectrometry (LVI-GC-MS). These methods employed no evaporative techniques to avoid potential losses and contamination of the volatile siloxanes. To compensate for the inability to improve detection limits by concentrating final sample extract volumes we used a LVI-GC-MS. Contamination during analysis was minimized by using a septumless GC configuration to avoid cVMS's associated with septum bleed. These methods performed well achieving good linearity, low limits of detection, good precision, recovery, and a wide dynamic range. In addition, stability of cVMS in water and sediment was assessed under various storage conditions. D4 and D5 in Type-I (Milli-Q) water stored at 4°C were stable within 29d; however, significant depletion of D6 (60-70%) occurred only after 3d. Whereas cVMS in sewage influent and effluent were stable at 4°C within 21d. cVMS in sediment sealed in amber glass jars at -20°C and in pentane extracts in vials at -15°C were stable during 1month under both storage conditions. PMID:23211330

Wang, De-Gao; Alaee, Mehran; Steer, Helena; Tait, Tara; Williams, Zackery; Brimble, Samantha; Svoboda, Lewina; Barresi, Enzo; Dejong, Maryl; Schachtschneider, Joanne; Kaminski, Ed; Norwood, Warren; Sverko, Ed

2012-12-01

252

NEW ZEALAND PLANT-HERBIVORE SYSTEMS: PAST AND PRESENT  

Microsoft Academic Search

Summary: The history of the New Zealand biota over the last 7000 years may be divided into three phases. BC 5000 to AD 1000 was a period of comparative ecological stasis. That equilibrium was disrupted between AD 1000 and AD 1800 by the destruction of most of the New Zealand plant-herbivore systems, the co-evolutionary relationship between the plants and the

GRAEME CAUGHLEY

253

Rates, Fluxes, and Cycling in the Earth System: What Do We Know, What Are We Teaching?  

Microsoft Academic Search

Earth system science provides exciting new insights into the dynamics of the Earth. This approach emphasizes a special focus on the processes, pathways, and interfaces across different subsystems; the transfer of mass and energy throughout the Earth system; and the influence of biota and humanity on Earth processes (AGU, 1997). Consequently, rates, fluxes and global cycling are all concepts that

D. W. Mogk; C. A. Manduca

2004-01-01

254

Microbial ecology of terrestrial Antarctica: Are microbial systems at risk from human activities?  

Microsoft Academic Search

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

1996-01-01

255

Compilation of 1987 annual reports of the Navy ELF (Extremely Low Frequency) communications system ecological monitoring program, volume 2  

NASA Astrophysics Data System (ADS)

This is the sixth compilation of annual reports for the Navy's ELF Communications System Ecological Monitoring Program. The reports document the progress of ten studies performed during 1987 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.

1988-08-01

256

Compilation of 1987 annual reports of the Navy ELF (Extremely Low Frequency) communications system ecological monitoring program, volume 3  

NASA Astrophysics Data System (ADS)

This is the sixth compilation of annual reports for the Navy's ELF Communications System Ecological Monitoring Program. The reports document the progress of ten studies performed during 1987 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.

1988-08-01

257

A simple tool for the assessment of water quality in polluted lagoon systems: A case study for Küçükçekmece Lagoon, Turkey  

Microsoft Academic Search

Lagoon systems have particular ecological, morphological and hydrodynamic characteristics and act like transitional zones between inland and open waters. The aim of this study is to develop a Lagoon Water Quality Index (L-WQI) for environmental control of polluted lagoon systems by focusing on primary problems such as increasing stress on aquatic biota, eutrophication and organic pollution. The indicators used in

Mehmet Ümit Taner; Beyza Üstün; Ay?en Erdinçler

2011-01-01

258

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

SciTech Connect

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

NONE

1998-07-01

259

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

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

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

2004-08-13

260

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)

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.

Peterson, J.; Freeman, M. C.

2010-12-01

261

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

SciTech Connect

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

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

1983-07-01

262

Dispersion of Metals from Abandoned Mines and their Effects on Biota in the Methow River, Okanogan County, Washington : Annual Report 3/15/00-3/14/01.  

SciTech Connect

The University of Washington, College of Forest Resources and the Center for Streamside Studies in Seattle, Washington, is being funded by the Bonneville Power Administration to conduct a three-year research project to measure the watershed scale response of stream habitat to abandoned mine waste, the dispersion of metals, and their effects on biota in the Methow River basin. The purpose of this project is to determine if there are processes and pathways that result in the dispersion of metals from their source at abandoned mines to biological receptors in the Methow River. The objectives of this study are the following: (1) Assess ecological risk due to metal contamination from mines near the Methow; (2) Measure impact of metals from mines on groundwater and sediments in Methow River; (3) Measure response of organisms in the Methow River to excess metals in the sediments of the Methow River; (4) Recommend restoration guidelines and biological goals that target identified pathways and processes of metal pollution affecting salmon habitat in the Methow basin; and (5) Submit peer review journal publications. When concluded, this study will contribute to the advancement of current best management practices by describing the processes responsible for the release of metals from small abandoned mine sites in an arid environment, their dispersal pathways, and their chemical and biological impacts on the Methow River. Based on these processes and pathways, specific remediation recommendations will be proposed.

Peplow, Dan; Edmonds, Robert

2001-06-01

263

Long-term organic farming fosters below and aboveground biota: Implications for soil quality, biological control and productivity  

Microsoft Academic Search

Organic farming may contribute substantially to future agricultural production worldwide by improving soil quality and pest control, thereby reducing environmental impacts of conventional farming. We investigated in a comprehensive way soil chemical, as well as below and aboveground biological parameters of two organic and two conventional wheat farming systems that primarily differed in fertilization and weed management strategies. Contrast analyses

Klaus Birkhofer; T. Martijn Bezemer; Jaap Bloem; Michael Bonkowski; Søren Christensen; David Dubois; Fleming Ekelund; Andreas Fließbach; Lucie Gunst; Katarina Hedlund; Paul Mäder; Juha Mikola; Christophe Robin; Heikki Setälä; Fabienne Tatin-Froux; Wim H. Van der Putten; Stefan Scheu

2008-01-01

264

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

Microsoft Academic Search

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

Maria Mutti; Pamela Hallock

2003-01-01

265

Food-chain transfer of U-series radionuclides in a northern Saskatchewan aquatic system  

Microsoft Academic Search

Levels of Total U, 226Ra, and 210Pb in water, sediments, insects and fish were measured in a stream and a lake affected by U mill effluents and in three uncontaminated systems (one creek and two lakes). Radionuclide levels were significantly elevated in water, sediments and biota at contaminated sites. Radionuclide concentration declined with each successive trophic level due primarily to

Stella M. Swanson

1985-01-01

266

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

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.

Not Available

1989-08-01

267

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

PubMed Central

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.

Kneip, T J; Hazen, R E

1979-01-01

268

Toxicity of a secondary-treated sewage effluent to marine biota in Bass Strait, Australia: development of action trigger values for a toxicity monitoring program.  

PubMed

Melbourne Water's Eastern Treatment Plant (ETP) produces a secondary-treated sewage effluent which is chlorinated and discharged into Bass Strait at Boags Rocks, Victoria, Australia. Disappearance of the sensitive brown seaweed Hormosira banksii from rock platforms immediately adjacent to the shore-line discharge was identified in the early 1990s. Subsequently, Melbourne Water and CSIRO undertook an environmental impact assessment and review of land and marine effluent disposal options, which included ambient water quality monitoring, biological monitoring, bioaccumulation studies and toxicity testing of existing effluent to assess the nature and magnitude of the environmental effects. This paper presents data from the toxicity monitoring programs since 2001. Chronic toxicity testing using macroalgal germination and cell division (H. banksii), microalgal growth rate (Nitzschia closterium) and scallop larval development (Chlamys asperrima), confirmed that ammonia was the major cause of effluent toxicity. Results from this toxicity monitoring program were used to develop action trigger values for toxicity for each species, which were then used in a refined monitoring program in 2005-2007. An upgrade of the ETP is in progress to improve nitrification/denitrification in order to reduce ammonia concentrations and the toxicity of the effluent. Toxicity testing with a simulated upgraded effluent confirmed that ammonia concentrations and toxicity were reduced. Estimated "safe" dilutions of effluent, calculated using species sensitivity distributions, decreased from 1:140-300 for existing ETP effluent to 1:20 for nitrified effluent, further confirming that treatment improvements should reduce the impact on marine biota in the vicinity of the discharge. PMID:18241892

Adams, Merrin S; Stauber, Jennifer L; Binet, Monique T; Molloy, Robert; Gregory, David

2008-01-31

269

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

Microsoft Academic Search

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

Marjorie J. Wonham; James T. Carlton

2005-01-01

270

What's in the Biota Bag? Examining Australian Fossil Biota.  

ERIC Educational Resources Information Center

|Describes a classroom activity in which candy is used to represent some Australian fossils with students asked to examine specimens and locate on a map of Australia where it might have been discovered. (Author/MM)|

Van Rooy, Wilhelmina

2002-01-01

271

Effects of Additions of DOC on Pelagic Biota in a ClearwaterSystem: Results from a Whole Lake Experiment in NorthernSweden  

Microsoft Academic Search

  An oligotrophic clearwater lake, initially characterized by a pronounced dominance of autotrophic phytoplankton and mostly\\u000a by one species, the green alga Botryococcus, was subject to additions of dissolved organic carbon in the form of white sugar\\u000a (sucrose) during two consecutive years. The hypothesis tested was that it is organic carbon per se, and not other possible\\u000a effects of humic substances,

P. Blomqvist; M. Jansson; S. Drakare; A.-K. Bergström; L. Brydsten

2001-01-01

272

The case for vestiges of early solar system biota in carbonaceous chondrites: petroleum geochemical snapshots and possible future petroleum prospects on Mars expedition  

Microsoft Academic Search

This research documents the analysis and interpretation of selected Carbonaceous Chondrites (CC) including Murchison, Allende, NWA 3003, Dhofar 735, Orgueil, Tagish Lake and Vigarano using organic petrology, scanning electron microscopy, and petroleum geochemistry. The kerogen microstructures and bitumen within CCs closely resemble remnant 2.5 Ga terrestrial microbial-like structures and their biodegraded components and solid bitumen. In both instances, organoclasts are

Prasanta K. Mukhopadhyay; David J. Mossman; James M. Ehrman

2007-01-01

273

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

USGS Publications Warehouse

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

Braun, Christopher L.; Moring, James B.

2013-01-01

274

Options for managing hypoxic blackwater events in river systems: a review.  

PubMed

Blackwater events are characterised by a high concentration of dissolved organic carbon in the water column. They occur naturally in lowland rivers with forested floodplains and bring a variety of benefits to both aquatic and floodplain biota. However, particularly when accompanied by high temperatures, respiration of the organic carbon may cause blackwater to become hypoxic. This may lead to a range of lethal and sub-lethal effects on the aquatic biota. We review the current scientific knowledge concerning the management of blackwater and hypoxia, and examine how this knowledge may be applied to the management of hypoxic blackwater events in lowland river systems. A range of management options, which aim to either prevent the development of hypoxic blackwater or to reintroduce oxygen into deoxygenated waters, are reported. Mitigation options that may be applicable to lowland river systems include manipulating the season and magnitude of floods in regulated rivers, increasing roughness in flow paths, establishing oxygenated refugia for aquatic biota and introducing hydraulic structures that promote turbulence and re-aeration. With climatic changes trending towards a scenario where extreme events leading to the development of hypoxic blackwater are more probable, it is now vital to validate and optimise management options on local and regional scales and work towards closing knowledge gaps. With judicious management of regulated rivers, it is possible to minimise the impacts of hypoxic flows while preserving the benefits brought to floodplain and river ecosystems by seasonal flooding and carbon exchange. PMID:23137913

Kerr, Janice L; Baldwin, Darren S; Whitworth, Kerry L

2012-11-06

275

Mercury distribution in seawater discharged from a coal-fired power plant equipped with a seawater flue gas desulfurization system  

Microsoft Academic Search

Background and purpose  More and more coal-fired power plants equipped with seawater flue gas desulfurization systems have been built in coastal areas.\\u000a They release large amount of mercury (Hg)-containing waste seawater into the adjacent seas. However, very limited impact studies\\u000a have been carried out. Our research targeted the distribution of Hg in the seawater, sediment, biota, and atmosphere, and\\u000a its environmental

Xiyao Liu; Lumin Sun; Dongxing Yuan; Liqian Yin; Jinsheng Chen; Yaoxing Liu; Chengyu Liu; Ying Liang; Fangfang Lin

276

Compilation of 1986 annual reports of the Navy ELF (Extremely Low Frequency) communications system ecological monitoring program, volume 2  

NASA Astrophysics Data System (ADS)

The U.S. Navy is conducting a long-term program to monitor for possible effects from the operation of its Extremely Low Frequency (ELF) Communications System to resident biota and their ecological relationships. This report documents progress of the following studies: soil amoeba; soil and litter arthropoda and earthworm studies; biological studies on pollinating insects: megachilid bees; and small vertebrates: small mammals and nesting birds.

1987-07-01

277

Soil biota and soil properties in the surface rooting zone of mesquite ( Prosopis glandulosa ) in historical and recently desertified Chihuahuan Desert habitats  

Microsoft Academic Search

The woody legume, mesquite (Prosopis glandulosa) has expanded from its historical habitats (playas and arroyos) to recently occupied grassland and dune habitats during the desertification of perennial grasslands in the Chihuahuan Desert. We studied historical and recently occupied sites, having hypothesized that the trophic structure and population density of soil microarthropods and nematodes associated with the surface root system of

R. A. Virginia; W. M. Jarrell; W. G. Whitford; D. W. Freckman

1992-01-01

278

Compilation of 1990 annual reports of the Navy ELF communications system ecological monitoring program. Volume 1: Tabs A, B  

NASA Astrophysics Data System (ADS)

The Navy initiated studies in 1982 for possible bioelectromagnetic effects from operation of their ELF transmitters in Michigan and Wisconsin. Since then, resident biota have been monitored for effects while transmitters were operated at both intermittent low-power and continuous full-power conditions. This ninth compilation of investigator reports documents the technical progress of biological studies that were performed near the Michigan transmitter through 1989-1990. Near the Wisconsin transmitter, similar studies were completed during 1989. To date, investigators have not found any effects on biota from either an intermittent or a fully energized transmitter. Partial contents include: (1) development, installation and operation of the ambient monitoring system for air temperature, soil temperature, soil moisture, precipitation, global solar radiation, relative humidity, photo synthetically active radiation and soil chemistry; (2) tree productivity and growth of hardwoods and red pine; and (3) litter production including weight and nutrients.

Zapotosky, J. E.

1991-08-01

279

Determination of selenomethionine and seleno-methyl-selenocysteine in biota by ultrasonic-assisted enzymatic digestion and multi-shot stir bar sorptive extraction-thermal desorption-gas chromatography-mass spectrometry.  

PubMed

A method based on stir bar sorptive extraction (SBSE) and thermal desorption (TD)-gas chromatography-mass spectrometry (GC-MS) has been optimized for the determination of seleno-methyl-selenocysteine (SeMetSeCys) and selenomethionine (SeMet) in biota samples. Aliquots of freeze-dried tissue, a mixture of protease XIV-lipase and water were sonicated for 2min. After extraction, the extract was separated by centrifugation and subjected to derivatization and SBSE-TD-GC-MS. The parameters affecting derivatization, absorption and desorption steps were investigated. The optimized conditions consist of a derivatization with 40?L of ethyl chloroformate (ECF) in 400?L of a water:ethanol:pyridine (60:32:8) mixture, followed by dilution to 1.5mL of 70g NaClL(-1) in water at neutral pH and an extraction step using 10mm×1mm PDMS stir bar, stirring at 800rpm for 20min at room temperature (23±1°C). Three stir bars were used for the extraction of three different aliquots of the same sample and then placed in a single glass desorption liner and simultaneously desorbed for GC-MS analysis. The desorption step required the following conditions: 300°C (desorption temperature), 6min (desorption time), 50mLmin(-1) (vent flow) and -5°C (cryotrapping temperature). The method provided precise (8.1%) and accurate results in the mgSekg(-1) range (using the selected-ion monitoring-SIM mode) against certified reference material SELM-1 yeast, with recoveries higher than 80% for spiked algae and clams samples. PMID:23497851

Mellano, F; Bujalance, M; Giráldez, I; Ruiz-Azcona, P; Sánchez-Rodas, D; Morales, E

2013-02-16

280

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

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)

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

1988-01-01

281

Reconnaissance investigation of water quality, bottom sediment, and biota associated with irrigation drainage in the Owyhee and Vale Projects, Oregon and Idaho, 1990-91  

USGS Publications Warehouse

A reconnaissance investigation was conducted during 1990--91 in the Owyhee and Vale projects in eastern Oregon and southwestern Idaho, as well as at a number of sites in the Snake River and tributaries to the Snake River in the area of study. The objective of the study was to determine if agricultural drainwater entering the study area was causing, or had the potential to cause, significant harmful effects to human health, fish and wildlife, or may adversely affect the suitability of water for beneficial uses. Approximately 153,000 acres of land are irrigated annually within the areas of the Owyhee and Vale projects. Large quantities of water are required because of the semiarid climate and relatively high evaporation rates. Several reservoirs in the area are filled annually during the wet, nonirrigation season to sustain irrigation during the dry summer months. During the irrigation season, this impounded water, along with direct diversions from the Malheur, Owyhee, and Snake Rivers, is transported to the irrigated areas through a series of diversion tunnels, siphons, canals, aqueducts, ditches, and drains. Major crops grown in the area include sugar beets, alfalfa hay and other hay crops, onions, and winter wheat. Minor crops include corn, potatoes, mint, various seed crops, and fruit. In 1987, it was estimated that the following amounts of pesticides were used in the project areas: 2,4-D (21,000 lbs [pounds]), chlorpyrifos (1,000 lbs), dacthal (40,000 lbs), dicamba (320 lbs), endosulfan (2,500 lbs), ethion (11,000 lbs), malathion (24,000 lbs), parathion (5,000 lbs), and phorate (11,000 lbs). Median concentrations and values for total dissolved solids, alkalinity, sodium adsorption ratio, and hardness in the Vale project area were greater than 1.5 times those values observed in the Owyhee project area or at other Snake River locations. During irrigation (August 1990), total dissolved solids, alkalinity, sodium adsorption ratio, and hardness values increased in a downstream manner. Constituent values at drainwater sites generally were comparable to concentrations below the irrigated ureas in the Owyhee and Vale project areas. The trace elements arsenic, boron, copper, molybdenum, vanadium, and zinc were detected in most water samples; cadmium, chromium, lead, and selenium were detected in some samples at concentrations generally near the analytical reporting limit; mercury was not detected in any samples. In some water samples, concentrations of arsenic, boron, cadmium, copper, and lead exceeded State or Federal water-quality standards or criteria. Most trace elements in bottom sediment were detected at concentrations within the expected 95-percent baseline range for soils from the Western United States. Concentrations that exceeded the 95-percent baseline range for study area soils were: (1) arsenic and lead in one sample from a site in the Vale project area; (2) mercury, lead, and tin in one sample from a site in the Snake River system; (3) manganese in two samples from two sites in the Snake River system; and (4) manganese from one sample from a site in the Vale project area. Fifteen pesticides and metabolites were detected in whole-water samples collected from sites in the study area. DDT, plus its metabolites (DDE and DDD), dieldrin, endrin, 2,4-D, dicamba, and dacthal were detected in samples collected from seven or more sites. Other pesticides detected included chlorpyrifos, endosulfan, ethion, malathion, parathion, phorate, and lindane. Most of the detected pesticide concentrations generally were largest in drainwater and at the most downstream sampling locations in the Owyhee and Vale project areas. Concentrations exceeded water-quality criteria established for the protection of freshwater aquatic life in 86 percent of the whole-water samples analyzed for DDT plus its metabolites, 71 percent of the dieldrin samples, 14 percent of the endrin samples, and 10 percent of the parathion samples. Eight pesticides and

Rinella, F. A.; Mullins, W. H.; Schuler, C. A.

1994-01-01

282

Compilation of 1986 annual reports of the Navy ELF (extremely low frequency) communications system ecological-monitoring program. Volume 2. Tabs D-G. Annual progress report, January-December 1986  

SciTech Connect

The U.S. Navy is conducting a long-term program to monitor for possible effects from the operation of its Extremely Low Frequency (ELF) Communications System to resident biota and their ecological relationships. This report documents progress of the following studies: Soil Amoeba; Soil and Litter Arthropoda and Earthworm Studies; Biological Studies on Pollinating insects: Megachilid Bees; and Small Vertebrates: Small Mammals and Nesting Birds.

Not Available

1987-07-01

283

Biota and biological parameters as environmental indicators  

USGS Publications Warehouse

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)

Edited by Greeson, Phillip E.

1981-01-01

284

Ecological Linkages between aboveground and belowground biota  

Microsoft Academic Search

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,

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

2004-01-01

285

Toxaphene in Great Lakes biota and air  

NASA Astrophysics Data System (ADS)

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.

Glassmeyer, Susan Theresa

1998-11-01

286

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

USGS Publications Warehouse

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

Braun, Christopher L.; Moring, James B.

2013-01-01

287

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

SciTech Connect

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.

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

1999-09-01

288

Role of the hydrological cycle in regulating the planetary climate system of a simple nonlinear dynamical model  

NASA Astrophysics Data System (ADS)

We present the construction of a dynamic area fraction model (DAFM), representing a new class of models for an earth-like planet. The model presented here has no spatial dimensions, but contains coupled parameterizations for all the major components of the hydrological cycle involving liquid, solid and vapor phases. We investigate the nature of feedback processes with this model in regulating Earth's climate as a highly nonlinear coupled system. The model includes solar radiation, evapotranspiration from dynamically competing trees and grasses, an ocean, an ice cap, precipitation, dynamic clouds, and a static carbon greenhouse effect. This model therefore shares some of the characteristics of an Earth System Model of Intermediate complexity. We perform two experiments with this model to determine the potential effects of positive and negative feedbacks due to a dynamic hydrological cycle, and due to the relative distribution of trees and grasses, in regulating global mean temperature. In the first experiment, we vary the intensity of insolation on the model's surface both with and without an active (fully coupled) water cycle. In the second, we test the strength of feedbacks with biota in a fully coupled model by varying the optimal growing temperature for our two plant species (trees and grasses). We find that the negative feedbacks associated with the water cycle are far more powerful than those associated with the biota, but that the biota still play a significant role in shaping the model climate. third experiment, we vary the heat and moisture transport coefficient in an attempt to represent changing atmospheric circulations.

Nordstrom, K. M.; Gupta, V. K.; Chase, T. N.

2005-07-01

289

Compilation of 1985 annual reports of the Navy elf (extremely low frequency) communications system ecological monitoring program. Volume 1. Tabs A-C. Annual progress report, January-December 1985  

SciTech Connect

This is the fourth compilation of annual reports for the Navy's ELF Communications System Ecological Monitoring Program. The reports document the progress of ten studies performed during 1985 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. This volume consists of three reports: Herbaceous Plant Cover and Tree Studies; Litter Decomposition and Microflora; and The Effects of Exposing the Slime MOld Physarum polycephalum to Electromagnetic Fields.

Becker, C.; Bruhn, J.; Cattelino, P.; Fuller, L.; Jurgensen, M.

1986-07-01

290

Extremely Low Frequency (ELF) communications system ecological monitoring program summary of 1990 progress  

NASA Astrophysics Data System (ADS)

A long term ecological monitoring program is being conducted to monitor for possible electromagnetic effects that operation of the U.S. Navy's ELF Communications System might have to resident biota and their ecological relationships. Monitoring studies were selected through a peer reviewed and a competitive bidding process in mid-1982, and work on most studies began in late summer of that year. Preliminary activities of the program consisted of site selection, characterization of critical study aspects, and validation of assumptions made in original proposals. Data collection for studies at the Naval Radio Transmitting Facility (NRTF)-Clam Lake, Wisconsin was completed, as scheduled, during 1990. Data collection for studies at the NRTF-Republic, Michigan is planned to continue through 1992. This report summarizes the progress of the monitoring program during 1990. To date, investigators conclude that effects have occurred on biota exposed to EM fields produced by either a fully operational or an intermittently energized ELF transmission produced by either a fully operational or an intermittently energized ELF transmitting facility.

Abromavage, M. M.; Zapotosky, J. E.

1991-12-01

291

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

PubMed Central

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.

Meybeck, Michel

2003-01-01

292

Metal biogeochemistry in surface-water systems; a review of principles and concepts  

USGS Publications Warehouse

Metals are ubiquitous in natural surface-water systems, both as dissolved constituents and as particulate constituents. Although concentrations of many metals are generally very low (hence the common term 'trace metals'), their effects on the water quality and the biota of surfacewater systems are likely to be substantial. Biogeochemical partitioning of metals results in a diversity of forms, including hydrated or 'free' ions, colloids, precipitates, adsorbed phases, and various coordination complexes with dissolved organic and inorganic ligands. Much research has been dedicated to answering questions about the complexities of metal behavior and effects in aquatic systems. Voluminous literature on the subject has been produced. This paper synthesizes the findings of aquatic metal studies and describes some general concepts that emerge from such a synthesis. Emphasis is on sources, occurrence, partitioning, transport, and biological interactions of metals in freshwater systems of North America. Biological interactions, in this case, refer to bioavailability, effects of metals on ecological characteristics and functions of aquatic systems, and roles of biota in controlling metal partitioning. This discussion is devoted primarily to the elements aluminum, arsenic, cadmium, chromium, copper, iron, lead, manganese, mercury, nickel, and zinc and secondarily to cobalt, molybdenum, selenium, silver, and vanadium. Sources of these elements are both natural and anthropogenic. Significant anthropogenic sources are atmospheric deposition, discharges of municipal and industrial wastes, mine drainage, and urban and agricultural runoff. Biogeochemical partitioning of metals is controlled by various characteristics of the water and sediments in which the metals are found. Among the most important controlling factors are pH, oxidation-reduction potential, hydrologic features, sediment grain size, and the existence and nature of clay minerals, organic matter, and hydrous oxides of manganese and iron. Partitioning is also controlled by biological processes that provide mechanisms for detoxification of metals and for enhanced uptake of nutritive metals. Partitioning is important largely because availability to biota is highly variable among different phases. Hence, accumulation in biological tissues and toxicity of an element are dependent not only on total concentration of the element but also on the factors that control partitioning.

Elder, John F.

1988-01-01

293

Diversification in the tropical pacific: comparisons between marine and terrestrial systems and the importance of founder speciation.  

PubMed

Patterns of distribution and processes of differentiation have often been contrasted between terrestrial and marine biotas. The islands of Oceania offer an excellent setting to explore this contrast, because the geographic setting for terrestrial and shallow-water, benthic, marine organisms are the same: the myriad islands strewn across the vast Pacific. The size of species ranges and the geographic distribution of endemism are two biogeographic attributes that are thought to differ markedly between terrestrial and marine biotas in the Pacific. While terrestrial species are frequently confined to single islands or archipelagoes throughout Oceania, marine species tend to have wide to very wide distributions, and are rarely restricted to single island groups except for the most isolated archipelagoes. We explore the conditions under which species can reach an island by dispersal and differentiate. Genetic differentiation can occur either through founder speciation or vicariance; these processes are requisite ends of a continuum. We show that founder speciation is most likely when few propagules enter the dispersal medium and survive well while they travel far. We argue that conditions favorable to founder speciation are common in marine as well as terrestrial systems, and that terrestrial-type, archipelagic-level endemism is likely common in marine taxa. We give examples of marine groups that show archipelagic level endemism on most Pacific island groups as well as of terrestrial species that are widespread. Thus both the patterns and processes of insular diversification are variable, and overlap more between land and sea than previously considered. PMID:21680372

Paulay, Gustav; Meyer, Chris

2002-11-01

294

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

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.

Maret, T. R.; Dutton, D. M.

1999-01-01

295

Accumulation of selenium in aquatic systems downstream of a uranium mining operation in northern Saskatchewan, Canada.  

PubMed

The objective of this study was to investigate the accumulation of selenium in lakes downstream of a uranium mine operation in northern Saskatchewan, Canada. Selenium concentrations in sediment and biota were elevated in exposure areas even though water concentrations were low (<5 microg/L). The pattern (from smallest to largest) of selenium accumulation was: periphytonsystems has the potential to bioaccumulate and reach levels that could impair fish reproduction. PMID:18346828

Muscatello, J R; Belknap, A M; Janz, D M

2008-03-17

296

The effect on ecological systems of remediation to protect human health.  

PubMed

Environmental remediation of contaminated eco-systems reduces stresses to these ecosystems, including stresses caused by the production, use, and storage of weapons of mass destruction. The effects of these various stressors on humans can be reduced by remediation or by blocking the exposure of humans, but blocking the exposure of resident biota is almost impossible. Remediation may involve trade-offs between reducing a minor risk to public health and increasing risks to workers and ecosystems. Remediation practices such as soil removal disrupt ecosystems, which take decades to recover. Without further human disturbances, and with low levels of exposure to stress-ors, ecosystems can recover from physical disruptions and spills. Remediation to remove negligible risk to humans can destroy delicate ecosystems for very little gain in public health. PMID:17666693

Burger, Joanna

2007-07-31

297

Paleogeography: an earth systems perspective  

Microsoft Academic Search

Paleogeography is the subdiscipline within the geosciences that studies the physical and biological geography of the geologic past, including the configuration and latitudinal distribution of continental landmasses, their topographic relief, climate and biota. In recent years, the study of paleogeography has evolved from simple continental reconstructions to more sophisticated paleocontinental maps that form the basis of paleoclimactic modeling by incorporating

Gerald M. Ross

1999-01-01

298

Mercury accumulation in biota of Thunder Creek, Saskatchewan  

Microsoft Academic Search

Thunder Creek is a typical prairie stream which flows through the city of Moose Jaw, Saskatchewan where it discharges into the Moose Jaw River (Figure I). Dredging of the Moose Jaw River and the confluence area of Thunder Creek to increase channel capacity began in October, 1978 as part of a Federal-Provinci al Agreement. Due to the concern that dredging

D. J. Munro; W. D. Gummer

1980-01-01

299

Mercury accumulation in biota of Thunder Creek, Saskatchewan  

SciTech Connect

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

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

1980-12-01

300

Diversification of rocky-shore biotas through geologic time  

Microsoft Academic Search

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

Markes E. Johnson; B. Gudveig Baarli

1999-01-01

301

Anthropogenic influences on hydrology and biota on the Glinscica stream  

Microsoft Academic Search

As the size of the urban population was increasing, stream corridors have become more and more physically changed to ensure flood safety and to increase urban surfaces. For this purpose dams, accumulations, banks and other objects on the stream corridors have been built. Besides, riparian vegetation has been removed; river corridors have been straightened and often made of concrete. In

M. Koprivsek

2009-01-01

302

Modelling Biota-Sediment Interactions in Estuarine Environments  

NASA Astrophysics Data System (ADS)

Future choices about the realization of hydrodynamic infrastructures in estuaries should be based on solid forecast about the changes they will generate in the environment. While complex numerical models are available for simulating sediment transport on physical basis, biologic elements are still hard to predict. This research project is aimed towards the integration of physical and biological insights in sediment transport models. As first step, we modeled the macrozoobenthic species spatial distribution in estuarine environments as function of those environmental variables that are relevant for sediment transport. As second step, we measured in laboratory conditions the effect of several macrozoobenthic species on sediment erodability. These observations describe ecological processes but are based on physical parameters. They can be used to parametrize semi-empirical models of biotic-mediated sediment dynamics, thus accounting for the biotic-induced deviations of sedimentary processes from purely physical expectations. This project is part of the innovative program Building with Nature (www.ecoshape.nl).

Cozzoli, Francesco; Bouma, Tjeerd; Yseabert, Tom; Herman, Peter

2013-04-01

303

Short-term bioconcentration studies of Np in freshwater biota  

SciTech Connect

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

Poston, T.M.; Klopfer, D.C.; Simmons, M.A. (Pacific Northwest Laboratory, Richland, WA (USA))

1990-12-01

304

Natural Radioactivity in Some Specimens of the Marine Biota.  

National Technical Information Service (NTIS)

Marine environment contamination by natural radionuclides (uranium and exp 238 U daughters) is evaluated using marine -fauna and flora elements concentrating fission - and radioactivated products released by nuclear facilities. Total alpha and beta radiom...

M. A. do Valle Matta

1980-01-01

305

Effects of Sewage on the Marine Biota: A Bibliography.  

National Technical Information Service (NTIS)

This bibliography contains 108 references to articles concerning marine waste disposal, marine sewage pollution, and the effects of sewage on the marine environment. The bibliography was originally intended to be a complete survey of the effects of pollut...

R. R. Corey M. M. Bundy

1977-01-01

306

ROLE OF BIOTA IN MINERAL TRANSFORMATIONS AND TRANSPORT  

Microsoft Academic Search

Microorganisms are likely to have played a significant role in the formation of the Australian regolith and in the transport and transformation of minerals within regolith materials. Single celled bacteria were the only forms of life on the planet for approximately 50% of earths history, first appearing about 4000 x 106 years before present (BP). More complex eukaryotic organisms such

Steve Rogers

2004-01-01

307

Distribution of Arsenic in the Sediments and Biota of  

Microsoft Academic Search

Sediment samples collected from the Waiakea Mill Pond, Wailoa River, and Hilo Bay were analyzed for arsenic. Arsenic was detectable in 10 of II sediment samples, and ranged in concentration from 2 to 715 ppm. Two species of plant and seven species of animal\\

Hilo Bay; LEON E. HALLACHER; ERNEST B. KHO; NANCY D. BERNARD; ANNIE M. ORCUTT; WALTER C. DUDLEY; THOMAS M. HAMMOND

308

Ecotoxicity of copper to aquatic biota: a review  

SciTech Connect

The toxic effects of copper on numerous aquatic flora and fauna has been studied intensely over the past 10 years. In general, there is a consensus that free cupric ions are more toxic if compared with other chemical forms such as organically complexed copper. Biological indicators exhibit a tremendously wide range of sensitivity to copper with toxic effects noted at pCu as low as 10 for some algae, while aquatic macrophytes appear to have a much higher tolerance for copper (pCu less than 5.0). The sensitivity of various groups of organisms seems discrepant and anomalous with accepted standards for drinking water and industrial discharges, and recommended rates of copper sulfate application to water bodies. The toxicity of copper, however, is mitigated by the presence of naturally occurring organic compounds in waters through complexation. The regulatory function of dissolved humic matter will continue to be a vital one for as long as copper is discharged into aquatic environments. 56 references.

Nor, Y.M.

1987-06-01

309

Solar-driven chemical energy source for a Martian biota  

Microsoft Academic Search

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

Benton C. Clark

1979-01-01

310

Causes and consequences of changes to New Zealand's fungal biota  

Microsoft Academic Search

This paper briefly reviews advances in knowledge of the non-lichenised fungi of New Zealand over the past 25 years. Since 1980, the number of species recorded from New Zealand has doubled, and molecular techniques have revolutionised studies on fungal phylogeny and our understanding of fungal distribution, biology and origins. The origins of New Zealand's fungi are diverse; a few appear

Peter R. Johnston

2010-01-01

311

Relationships between Metal Speciation and Metal Biota Interactions in Harbors.  

National Technical Information Service (NTIS)

My long term goal is to understand the interactions between trace metals and phytoplankton in neritic environments. This interaction is envisioned as a two-way process: Trace metals affect the growth, species composition, and biomass of phytoplankton. In ...

L. B. Brand

1998-01-01

312

Global warming, elevational ranges and the vulnerability of tropical biota  

Microsoft Academic Search

Tropical species with narrow elevational ranges may be thermally specialized and vulnerable to global warming. Local studies of distributions along elevational gradients reveal small-scale patterns but do not allow generalizations among geographic regions or taxa. We critically assessed data from 249 studies of species elevational distributions in the American, African, and Asia-Pacific tropics. Of these, 150 had sufficient data quality,

William F. Laurance; D. Carolina Useche; Luke P. Shoo; Sebastian K. Herzog; Michael Kessler; Federico Escobar; Gunnar Brehm; Jan C. Axmacher; I-Ching Chen; Lucrecia Arellano Gámez; Peter Hietz; Konrad Fiedler; Tomasz Pyrcz; Jan Wolf; Christopher L. Merkord; Catherine Cardelus; Andrew R. Marshall; Claudine Ah-Peng; Gregory H. Aplet; M. del Coro Arizmendi; William J. Baker; John Barone; Carsten A. Brühl; Rainer W. Bussmann; Daniele Cicuzza; Gerald Eilu; Mario E. Favila; Andreas Hemp; Claudia Hemp; Jürgen Homeier; Johanna Hurtado; Jill Jankowski; Gustavo Kattán; Jürgen Kluge; Thorsten Krömer; David C. Lees; Marcus Lehnert; John T. Longino; Jon Lovett; Patrick H. Martin; Bruce D. Patterson; Richard G. Pearson; Kelvin S.-H. Peh; Barbara Richardson; Michael Richardson; Michael J. Samways; Feyera Senbeta; Thomas B. Smith; Timothy M. A. Utteridge; James E. Watkins; Rohan Wilson; Stephen E. Williams; Chris D. Thomas

2011-01-01

313

Bioaccumulation of cesium-137 by biota in different aquatic environments  

Microsoft Academic Search

Macroalgae, isopods and fish species were exposed to 137Cs in brackish and sea water conditions for 18 days to determine radionuclide concentration factors. The concentration factors of 137Cs in brown shrimp and polychaete species were also investigated under brackish water conditions. At equilibrium, the concentration factors in macroalgae, isopod, fish, brown shrimp and polychate samples were found to be 2.5,

S. Topcuo?lu

2001-01-01

314

Suspended and Dissolved Solids Effects on Freshwater Biota: A Review.  

National Technical Information Service (NTIS)

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 includi...

D. L. Sorenson M. M. McCarthy E. J. Middlebrooks D. B. Porcella

1977-01-01

315

Monitoring of perfluorinated compounds in aquatic biota: an updated review.  

PubMed

The goal of this article is to summarize new biological monitoring information on perfluorinated compounds (PFCs) in aquatic ecosystems (post-2005) as a followup to our critical review published in 2006. A wider range of geographical locations (e.g., South America, Russia, Antarctica) and habitats (e.g., high-mountain lakes, deep-ocean, and offshore waters) have been investigated in recent years enabling a better understanding of the global distribution of PFCs in aquatic organisms. High concentrations of PFCs continue to be detected in invertebrates, fish, reptiles, and marine mammals worldwide. Perfluorooctane sulfonate (PFOS) is still the predominant PFC detected (mean concentrations up to 1900 ng/g ww) in addition to important concentrations of long-chain perfluoroalkyl carboxylates (PFCAs; sum PFCAs up to 400 ng/g ww). More studies have evaluated the bioaccumulation and biomagnification of these compounds in both freshwater and marine food webs. Several reports have indicated a decrease in PFOS levels over time in contrast to PFCA concentrations that have tended to increase in tissues of aquatic organisms at many locations. The detection of precursor metabolites and isomers has become more frequently reported in environmental assessments yielding important information on the sources and distribution of these contaminants. The integration of environmental/ecological characteristics (e.g., latitude/longitude, salinity, and/or trophic status at sampling locations) and biological variables (e.g., age, gender, life cycle, migration, diet composition, growth rate, food chain length, metabolism, and elimination) are essential elements in order to adequately study the environmental fate and distribution of PFCs and should be more frequently considered in study design. PMID:21542574

Houde, Magali; De Silva, Amila O; Muir, Derek C G; Letcher, Robert J

2011-05-04

316

Preliminary results about contaminants in the biota of Lake Baikal  

Microsoft Academic Search

Recent analyses of the muscle of several fish specimens and the muscle, liver and fat of the Baikal seal show low levels of heavy metals and organochlorine compounds.Present and past observations suggest that despite land-based sources of pollution, the general health status of the lake is good. However, because of increasing local air pollution, the long-range transport of pollutants emitted

A. Beim; E. Grocheva; A. Renzoni

2000-01-01

317

Interface modeling for predicting atmospheric transport of biota  

Treesearch

Description: The influx of foreign organisms and the growing resistance of resident organisms to ... Rapid transportation and increased world trade have introduced foreign pests into American agricultural areas. ... Country: United States. State:.

318

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...

319

Evolution of centralized nervous systems: two schools of evolutionary thought.  

PubMed

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

Northcutt, R Glenn

2012-06-20

320

ELF communications system ecological monitoring program: Aquatic ecosystem studies  

NASA Astrophysics Data System (ADS)

The U.S. Navy has completed a program that monitored biota and ecological miationships for possible effects from electromagnetic (EM) fields produced by its Extremely Low Frequency (ELF) Communications System. This report documents the results and conclusions of aquatic studies conducted near its transmitting antenna in Michigan. From 1982 through 1993 researchers from the Michigan State University (MSU) monitored aquatic flora and fauna on matched reaches of the Ford River. A treatment site was located immediately adjacent to the antenna, whereas a control site was situated at a distance downstream. Functional and structural components of the periphyton, insect, and fish communities were monitored. The research team also measured ambient factors such as temperature, discharge, and water quality indicators. Data were analyzed using a variety of statistical tests; however, BACI techniques were emphasized. Results indicated a relative increase in algal biomass at the treatment site after the antenna became fully operational, but no changes in any other parameter or organism. MSU concludes that algal biomass was affected by ELF EM exposure. Since neither the other ecological characteristics of the periphyton nor the insect and fish communities showed any effects, MSU infers little EM impact to riverine habitats.

Burton, Thomas M.; Stout, R. J.; Winterstein, Scott; Coon, Thomas; Novinger, Doug

1994-11-01

321

Increased Use of No-till Cropping Systems Improves Stream Ecosystem Quality  

NASA Astrophysics Data System (ADS)

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.

Yates, A. G.; Bailey, R. C.; Schwindt, J. A.

2005-05-01

322

Systeme multifonctions. (Multifunction system).  

National Technical Information Service (NTIS)

The development, the characteristics and the applications of a multifunction system are presented. The system is used on the RBES laboratory pipes, at Marcoule. The system was developed in order to allow, without time loss, the modification of the circuit...

J. Wauthier R. Fiori

1990-01-01

323

Aquatic toxicity assessment of the additive 6-methylcoumarine using four experimental systems.  

PubMed

The toxicity assessment of chemicals is one of the main issues in the current policies in order to protect the health of the environment and human beings. Food and cosmetic additives have been extensively studied in relation to their toxicity to humans, but data about their ecotoxicological effects are scarce. The aim of this study was to evaluate the toxic effects of the additive 6-methylcoumarine in the aquatic milieu using a test battery comprising experimental model systems from different trophic levels. The inhibition of bioluminiscence was studied in the bacteria Vibrio fischeri (decomposer), the inhibition of growth was evaluated in the alga Chlorella vulgaris (producer) and immobilization was studied in the cladoceran Daphnia magna (first consumer). Finally, several end points were evaluated in the RTG-2 salmonid fish cell line, including neutral red uptake, protein content, methylthiazol tetrazolium salt metabolization, glucose-6-phosphate dehydrogenase activity, lactate dehydrogenase activity and leakage, and morphology. The sensitivity of the test systems employed was as follows: V. fischeri > D. magna > C. vulgaris > RTG-2 cell line. The results show that 6-methylcoumarine is not expected to produce acute toxic effects on the aquatic biota. However, chronic and synergistic effects with other chemicals cannot be excluded and should be further investigated. PMID:18392883

Jos, A; Repetto, G; Ríos, J C; Del Peso, A; Salguero, M; Cameán, A M

2008-04-08

324

Microbial ecology of terrestrial Antarctica: Are microbial systems at risk from human activities?  

SciTech Connect

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.

White, G.J.

1996-08-01

325

Soil moisture's underestimated role in climate change impact modelling in low-energy systems.  

PubMed

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

le Roux, Peter Christiaan; Aalto, Juha; Luoto, Miska

2013-08-13

326

Legionnaires' disease bacteria in power plant cooling systems: Phase 2  

SciTech Connect

Legionnaires' Disease Bacteria (Legionella) are a normal component of the aquatic community. The study investigated various environmental factors that affect Legionella profiles in power plant cooling waters. The results indicate that each of the four factors investigated (incubation temperature, water quality, the presence and type of associated biota, and the nature of the indigenous Legionella population) is important in determining the Legionella profile of these waters. Simple predictive relationships were not found. At incubation temperatures of 32/sup 0/ and 37/sup 0/C, waters from a power plant where infectious Legionella were not observed stimulated the growth of stock Legionella cultures more than did waters from plants where infectious Legionella were prevalent. This observation is consistent with Phase I results, which showed that densities of Legionella were frequently reduced in closed-cycle cooling systems despite the often higher infectivity of Legionella in closed-cycle waters. In contrast, water from power plants where infectious Legionella were prevalent supported the growth of indigenous Legionella pneumophila at 42/sup 0/C, while water from a power plant where infectious Legionella were absent did not support growth of indigenous Legionella. Some Legionella are able to withstand a water temperature of 85/sup 0/C for several hours, thus proving more tolerant than was previously realized. Finally, the observation that water from two power plants where infectious Legionella were prevalent usually supported the growth of Group A Legionella at 45/sup 0/C indicates the presence, of soluble Legionella growth promoters in these waters. This test system could allow for future identification and control of these growth promoters and, hence, of Legionella. 25 refs., 23 figs., 10 tabs.

Tyndall, R.L.; Christensen, S.W.; Solomon, J.A.

1985-04-01

327

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...

328

Annual summary of the contents of the Oak Ridge Environmental Information System (OREIS) 1993 data base  

SciTech Connect

The data base of the Oak Ridge Environmental Information System (OREIS) contains data of known quality that can be accessed by OREIS users. OREIS meets data management/access requirements for environmental data as specified in the Federal Facility Agreement for the Oak Ridge Reservation and the State Oversight Agreement between the State of Tennessee and the Department of Energy. The types of environmental data within OREIS include measurement data from the following environmental disciplines: groundwater, surface water, sediment, soils, air, and biota. In addition to measurement data, the OREIS data base contains extensive descriptive and qualifier metadata to help define data quality and to enable end users to analyze the appropriateness of data for their purposes. Another important aspect of measurement data is their spatial context; OREIS maintains a comprehensive library of geographic data and tools to analyze and display spatial relationships of the data. As of November 1993, the OREIS data base consists of approximately 100,000 records associated with three environmental restoration projects along with coordinate data and background map data. The data base also contains 2,700 supporting codes and other reference data records. Geographic data include the S-16A base map for the Oak Ridge Reservation, boundaries for operable units, and high-resolution raster images for each of the sites.

McCord, R.A.; Herr, D.D.; Durfee, R.C.; Land, M.L.; Monroe, F.E.; Olson, R.J.; Thomas, J.K.; Tinnel, E.P.

1994-06-01

329

Mercury pollution in Ria de Aveiro (Portugal): a review of the system assessment.  

PubMed

The Ria de Aveiro (Portugal) is a coast al lagoon adjacent to the Atlantic Ocean and it has an inner bay (Laranjo bay) that received a highly contaminated effluent discharged by a mercury cell chlor-alkali plant from the 1950s until 1994. The aim of this study is to review in a holistic way several research studies that have been carried out in the Ria de Aveiro, in order to evaluate the remobilization of the mercury accumulated within the system and the recovery of the lagoon. The spatial distribution of the total mercury in the surrounding terrestrial environment has also been considered. Results indicate that the main mercury contamination problems in the Ria de Aveiro are confined to the Laranjo bay. Mercury export to the coastal waters and its impact on the nearshore compartments (water column, sediment and biota) are low. No direct effects of the mercury from nearby industrial activities were detected in Aveiro's urban soils, although historical mercury contamination is still affecting soil quality in the immediate vicinity of the chlor-alkali plant, located in Estarreja. Moreover, macrophyte harvesting for human direct or indirect use and the consumption of mussels, crabs and the sea bass from the Laranjo bay may constitute a health risk. Further studies focusing on developing skills for the restoration of the ecosystem are presently underway. PMID:18592386

Pereira, M E; Lillebø, A I; Pato, P; Válega, M; Coelho, J P; Lopes, C B; Rodrigues, S; Cachada, A; Otero, M; Pardal, M A; Duarte, A C

2008-07-01

330

The role of sediments in the chemistry of aquatic systems; proceedings of the sediment chemistry workshop  

USGS Publications Warehouse

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.

Edited by Bradford, Wesley L.; Horowitz, A. J.

1988-01-01

331

Compilation of 1992 annual reports of the Navy ELF communications system ecological monitoring program, volume 1  

NASA Astrophysics Data System (ADS)

During 1992, the U.S. Navy continued to conduct a program to monitor flora, fauna, and their ecological relationships for possible effects from electromagnetic (EM) fields produced by the Navy's Extremely Low Frequency (ELF) Communications System. Physiological, developmental, behavioral, and ecological variables for dominant biota in upland and riverine habitats near the Naval Radio Transmitting Facility at Republic, Michigan (NRTF-Republic) have been monitored since 1982. The NRTF-Republic was intermittently energized at low amperages beginning in early 1986. Electric current and periods of energization were then gradually increased until 1989, when the transmitter became a fully operational facility. A split-plot or blocked strategy was used to examine biological variables for possible effects from EM exposure. Reports compiled in this document present the progress of these studies through 1992. It is anticipated that data will continue to be collected through 1993. Final results and conclusions are expected after all data have been analyzed in 1994. Investigators for similar studies completed in Wisconsin concluded that there were no EM bioeffects from intermittent or full operation of the transmitter in that state.

Zapotosky, J. E.

1993-08-01

332

[Effects of heavy metal (copper and cadmium) coupled with Ulca pertusa on marine inorganic carbon system in simulated experiments].  

PubMed

Simulated experiments coupled with ocean biota dynamics were performed in laboratory. In these experiments, effects of heavy metal (copper and cadmium) coupled with Ulca pertusa on marine inorganic carbon system and CO2 fluxes were investigated. The results indicated that concentration changes (delta) of components in carbon dioxide system with time scale were correlated with the concentrations and kinds of heavy metal. In copper groups and cadmium groups (0.1 micromol x L(-1) and 1 micromol x L(-1)), DIC HCO3- and PCO2 significantly decreased comparing to the control experiment data( p = 0.01). However, when the heavy metal infusions were higher than the "critical concentration", the above mentioned parameters increased with time scale and their increments followed the uptrend with increasing heavy metal concentrations. The "critical concentration" in copper groups was much lower than that in cadmium groups, which attributed to the tolerance diversity of Ulca pertusa to copper and cadmium. Furthermore, CO2 fluxes under the influences of heavy metal were also regularly changed with time. Sea waters with low infusions of heavy metal represented as sinks to the atmosphere CO2. These sinks would probably convert into CO2 sources after a period of time. Sea waters with comparatively high amount of heavy metal were always to be CO2 sources, and their release fluxes of CO2 augmented along with the increasing infusions of heavy metal. PMID:17304838

Zheng, Guo-xia; Song, Jin-ming; Dai, Ji-cui

2006-12-01

333

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 ...

334

Paleoecology of benthic metazoans in the Early Cambrian Maotianshan Shale biota and the Middle Cambrian Burgess Shale biota: evidence for the Cambrian substrate revolution  

Microsoft Academic Search

As the depth and intensity of bioturbation increased through the Proterozoic–Phanerozoic transition, the substrates on which marine benthos lived changed from being relatively firm with a sharp sediment–water interface to having a high water content and blurry sediment–water interface. Microbial mats, once dominant on normal marine Proterozoic seafloors, were relegated to stressed settings lacking intense metazoan activity. This change in

Stephen Q. Dornbos; David J. Bottjer; Jun-Yuan Chen

2005-01-01

335

Dynamical System  

Microsoft Academic Search

SUMMARY This paper addresses the parameter estimation problem of an interval-based hybrid dynamical system (interval system). The interval system has a two-layer architecture that comprises a finite state automaton and multiple linear dynam- ical systems. The automaton controls the activation timing of the dynamical systems based on a stochastic transition model between intervals. Thus, the interval system can generate and

Takashi MATSUYAMA

336

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.

2011-08-11

337

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).  

National Technical Information Service (NTIS)

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 cal...

D. E. Prudic P. M. Barlow R. G. Niswonger R. S. Regan S. L. Markstrom

2008-01-01

338

Transport and accumulation of cesium-137 and mercury in the Clinch River and Watts Bar Reservoir system. Environmental Restoration Program  

SciTech Connect

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).

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

339

Transport and accumulation of cesium-137 and mercury in the Clinch River and Watts Bar Reservoir system  

SciTech Connect

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).

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

340

Genetic structure and breeding system of a rare understory herb, Dysosma versipellis (Berberidaceae), from temperate deciduous forests in China.  

PubMed

To evaluate the role of Quaternary refugial isolation in allopatric (incipient) speciation of East Asian temperate forest biotas, we analyzed amplified fragment length polymorphisms (AFLPs) and the breeding system in Dysosma versipellis. The study revealed that D. versipellis is mostly self-incompatible, genetically highly subdivided and depauperate at the population level (e.g., ?(ST) = 0.572/H(E) = 0.083), and characterized by a low pollen-to-seed migration ratio (r ? 4.0). The latter outcome likely reflects limited pollen flow in a low-seed disperser whose hypothesized "sapromyophilous" flowers undergo scarce, inefficient, and likely specialized cross-pollination by small Anoplodera beetles, rather than carrion flies as assumed previously. In consequence, fruit set in D. versipellis was strongly pollen-limited. Our AFLP data support the hypothesis of a long-standing cessation of gene flow between western and central eastern populations, consistent with previous chloroplast DNA data. This phylogeographic pattern supports the role of the Sichuan Basin as a floristic boundary separating the Sino-Himalayan vs. Sino-Japanese Forest subkingdoms. Our genetic data of D. versipellis also imply that temperate deciduous forest elements to the west and the east of this basin responded differently to Quaternary climate change, which may have triggered or is leading to allopatric (incipient) speciation. PMID:21622372

Guan, Bi-Cai; Fu, Cheng-Xing; Qiu, Ying-Xiong; Zhou, Shi-Liang; Comes, Hans Peter

2009-12-18

341

Evaluation of ecologically relevant bioassays for a lotic system impacted by a coal-mine effluent, using Isonychia.  

PubMed

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

Kennedy, A J; Cherry, D S; Currie, R J

2004-07-01

342

Compilation of 1993 annual reports of the Navy ELF Communications System Ecological Monitoring Program. Volume 2: Tabs C-F  

NASA Astrophysics Data System (ADS)

During 1993, the U.S. Navy continued to conduct a program to monitor flora, fauna, and their ecological relationships for possible effects from electromagnetic (EM) fields produced by the Navy's Extremely Low Frequency (ELF) Communications System. Physiological, developmental, behavioral, and ecological variables for dominant biota in upland and riverine habitats near the Naval Radio Transmitting Facility at Republic, Michigan (NRTF-Republic) have been monitored since 1982. The NRTF-Republic was intermittently energized at low amperages beginning in early 1986. Electric current and periods of energization were then gradually increased until 1989, when the transmitter became a fully operational facility. A split-plot or blocked strategy was used to examine biological variables for possible effects from EM exposure. Reports compiled in this document present the progress of these studies through 1993. Final results and conclusions are expected after all data have been analyzed in 1994. Investigators for similar studies completed in Wisconsin concluded that there were no EM bioeffects from intermittent or full operation of the transmitter in that state.

Zapotosky, J. E.

1994-04-01

343

Aesthetics Systems.  

National Technical Information Service (NTIS)

The formal structure of aesthetics systems is defined. Aesthetics systems provide for the essential tasks of interpretation and evaluation is aesthetic analysis. Kolmogorov's formulation of information theory is applicable. An aesthetics system for a clas...

J. Gips G. Stiny

1973-01-01

344

Rebreathing System.  

National Technical Information Service (NTIS)

The patent application is a constant volume rebreathing system when utilized in conjunction with an external air source, such as man. The rebreathing system forms a completely closed system between man and the environment. There is a stainless steel bello...

J. P. Conkle

1974-01-01

345

Systems Studies.  

National Technical Information Service (NTIS)

The Systems Studies Activity had two objectives: (1) to investigate nontechnical barriers to the deployment of biomass production and supply systems and (2) to enhance and extend existing systems models of bioenergy supply and use. For the first objective...

R. L. Graham

1998-01-01

346

Ensuring Dependable Systems of Systems  

Microsoft Academic Search

The emerging class of systems known as Systems of Systems (SoS) are composed of many distributed, heterogeneous and autonomous components. Such systems are typically separately designed and manufactured and evolve throughout their lifetime. However, they are expected to work together, often in safety-critical areas of operation such as civil transportation, military operations and space exploration. As such, the systems are

Robert Alexander; Martin Hall-May; Tim Kelly

347

Options for managing hypoxic blackwater in river systems: case studies and framework.  

PubMed

Hypoxic blackwater events occur when large amounts of organic material are leached into a water body (e.g., during floodplain inundation) and rapid metabolism of this carbon depletes oxygen from the water column, often with catastrophic effects on the aquatic environment. River regulation may have increased the frequency and severity of hypoxic blackwater events in lowland river systems, necessitating management intervention to mitigate the impacts of these events on aquatic biota. We examine the effectiveness of a range of mitigation interventions that have been used during large-scale hypoxic blackwater events in the Murray-Darling Basin, Australia and that may be applicable in other environments at risk from hypoxic blackwater. Strategies for hypoxia mitigation include: delivery of dilution flows; enhancement of physical re-aeration rates by increasing surface turbulence; and diversion of blackwater into shallow off-channel storages. We show that the impact of dilution water delivery is determined by relative volumes and water quality and can be predicted using simple models. At the dilution water inflow point, localized oxygenated plumes may also act as refuges. Physical re-aeration strategies generally result in only a small increase in dissolved oxygen but may be beneficial for local refuge protection. Dilution and natural re-aeration processes in large, shallow lake systems can be sufficient to compensate for hypoxic inflows and water processed in off-channel lakes may be able to be returned to the river channel as dilution flows. We provide a set of predictive models (as electronic supplementary material) for estimation of the re-aeration potential of intervention activities and a framework to guide the adaptive management of future hypoxic blackwater events. PMID:23912322

Whitworth, Kerry L; Kerr, Janice L; Mosley, Luke M; Conallin, John; Hardwick, Lorraine; Baldwin, Darren S

2013-08-03

348

Options for Managing Hypoxic Blackwater in River Systems: Case Studies and Framework  

NASA Astrophysics Data System (ADS)

Hypoxic blackwater events occur when large amounts of organic material are leached into a water body (e.g., during floodplain inundation) and rapid metabolism of this carbon depletes oxygen from the water column, often with catastrophic effects on the aquatic environment. River regulation may have increased the frequency and severity of hypoxic blackwater events in lowland river systems, necessitating management intervention to mitigate the impacts of these events on aquatic biota. We examine the effectiveness of a range of mitigation interventions that have been used during large-scale hypoxic blackwater events in the Murray-Darling Basin, Australia and that may be applicable in other environments at risk from hypoxic blackwater. Strategies for hypoxia mitigation include: delivery of dilution flows; enhancement of physical re-aeration rates by increasing surface turbulence; and diversion of blackwater into shallow off-channel storages. We show that the impact of dilution water delivery is determined by relative volumes and water quality and can be predicted using simple models. At the dilution water inflow point, localized oxygenated plumes may also act as refuges. Physical re-aeration strategies generally result in only a small increase in dissolved oxygen but may be beneficial for local refuge protection. Dilution and natural re-aeration processes in large, shallow lake systems can be sufficient to compensate for hypoxic inflows and water processed in off-channel lakes may be able to be returned to the river channel as dilution flows. We provide a set of predictive models (as electronic supplementary material) for estimation of the re-aeration potential of intervention activities and a framework to guide the adaptive management of future hypoxic blackwater events.

Whitworth, Kerry L.; Kerr, Janice L.; Mosley, Luke M.; Conallin, John; Hardwick, Lorraine; Baldwin, Darren S.

2013-10-01

349

Systems thinking or systems engineering  

Microsoft Academic Search

The problem faced by most systems organisations is how to develop and sustain staff with the appropriate systems skills and experience. To date, much has been made of the delineation of systems thinking and systems engineering. In this research, the partitioning of \\

Kate M. Gill

2009-01-01

350

Solar System  

NSDL National Science Digital Library

At the end of this project, you will be able to explain the components of the Solar System and know the order of the planets starting from the Sun. Objective Question: What is the Solar System? First, listen and read about the Solar System 1. How many planets make up our Solar System? 2. What is at the center of the Solar System? Next,listen and read about the Planets. 1. Can you name all of the planets? Finally, listen and watch The Solar System Movie. 1. Can you list the ...

Ms.west

2009-07-07

351

Capabilities and limitations of neutron imaging for studying soil-root system (Invited)  

Microsoft Academic Search

Soil is heterogeneous by nature. Additional heterogeneity is added to soil as a result of the activities of soil biota and vegetation. Plant roots and soil microorganisms exude organic and inorganic substances into the soil and change the soil properties in their vicinity. They take up water and nutrients and change the distribution of water and ions in the soil.

A. B. Moradi

2010-01-01

352

Stimulator system  

SciTech Connect

An electrical stimulator system is described incorporating rechargeable batteries and a charging circuit. A charging set and electrode support are alternatively connected to the stimulator system via a single common two-pole terminal. The system is designed to prevent current from flowing directly from the battery to the electrode support along the charging circuit while allowing charge current to flow in the opposite direction along the charging circuit if the charging set is connected to the system instead of the electrode support.

Hakansson, B.H.; Saario, R.A.

1984-02-14

353

Energy Systems  

NSDL National Science Digital Library

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.

Office Of Educational Partnerships

354

Systems Liaisons  

Microsoft Academic Search

As computer technology increases its role within academic libraries, one of the problems faced by systems librarians is maintaining the equipment and training needed for the technology without overworking the library's systems staff. This article describes the development of a group of systems liaisons within an academic library to serve as front line managers for computer hardware, software, and simpler

Pam Burton; Margaret Foote

2000-01-01

355

Solar System  

NSDL National Science Digital Library

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 ...

Wright, Ms.

2009-10-09

356

Anthropogenic influences on hydrology and biota on the Glinš?ica stream  

NASA Astrophysics Data System (ADS)

As the size of the urban population was increasing, stream corridors have become more and more physically changed to ensure flood safety and to increase urban surfaces. For this purpose dams, accumulations, banks and other objects on the stream corridors have been built. Besides, riparian vegetation has been removed; river corridors have been straightened and often made of concrete. In comparison with natural streams, physically changed river corridors have different values of physical, chemical and biotic parameters, which influence self-purification capacity of the streams. We were investigating in which way these parameters were modified due to human influenced changes to river streams on five sampling sites on the Glinš?ica stream. For comparison we took another sampling site on its tributary Pržanec. First sampling site is located in almost unregulated reach, whereas the other four in regulated reach. Last two sampling sites are located in the reach with concrete channel. Depth of the river, water flow and velocity, composition of organic and inorganic substratum, temperature, dissolved oxygen, conductivity, pH, nitrates and phosphates were studied and also samples of periphyton and macroinvertebrates were taken in all four seasons from spring 2005 till winter 2006. We have found out that downstream water quality decreases with increase of human-caused changes on the stream corridor. Water quality decreases mostly for the insufficiency of shading, which leads to increased water temperature, increased saturation with oxygen and increased pH on sunny summer days. Straightened and concrete river channels cause decreased depth of the river, increased water flow and increased velocity. The main problem for water organisms regarding changing and straightening river channels is that substrate, velocities and depth become homogeneous. This means that there are no different habitats, suitable for different species and that there is no shelter to hide from high velocities, high temperatures and predators. Conditions on the whole corridor are the same and suitable for only few species, so the biodiversity in human-changed river corridors usually declines. All these physical and chemical changes caused by anthropogenic alteration of stream corridors have also different influence on different species of organisms. In ecological part of this study, which was made on Biotechnical Faculty, University of Ljubljana, macroinvertebrates and periphyton in the Glinš?ica stream were studied. The investigation shows that influence of anthropogenic alteration is much bigger for macroinvertebrates community as for periphyton community. Changes of macroinvertebrates community were bigger from site to site in comparison with the same site in different seasons. Periphyton community shows different result: changes in community were bigger at the same location in different seasons as from site to site. Biodiversity of macroinvertebrates decreases on the sites with concrete channel, but the biggest value of biodiversity is reached almost by all measurements on physically changed site just before the concrete channel starts. Study of periphyton gives results that are even more surprising: the biggest values of biodiversity of diatoms community at spring and summer measurements were on the sites with the concrete channel. This investigation shows that anthropogenic changes on the stream corridor are not necessary negative for all species living in a stream, but if we want to ensure a good water quality, we have to ensure good living conditions for all the water organisms and the organisms living in surroundings of s stream.

Koprivšek, M.

2009-04-01

357

Transfer of heavy metals to biota after remediation of contaminated soils with calcareous residues.  

NASA Astrophysics Data System (ADS)

A study was carried out to evaluate the assimilation of heavy metals by three types of horticultural plants (broccoli, lettuce and leek), different parts of which are destined for human and farm animals consumption (leaves, roots, fruits). Five consecutive crops of each vegetable were obtained in greenhouse. In a second stage, experiments were carried out with rabbits fed with such vegetables. The plants were cultivated in four types of soil. The first one was contaminated by heavy metals (S1), the second was a uncontaminated soil (blank soil) (S2), the third was the material obtained by mixing S1 with residues coming from demolition and construction activities (S3); while the fourth was the result of remediating S1 with lime residues coming from quarries (S4). The total metal content (As, Pb, Cd and Zn) of the soil samples, rizosphere, leached water and vegetable samples, were measured, and both the translocation and bioconcentration factors (TF and BCF, respectively) were calculated. In the second stage, the effect caused in rabbits fed with the vegetables was monitorized using both external observation and the analysis of blood, urine, and the levels of metals in muscles, liver and kidney. The statistical analysis of the results obtained showed that there were no significant differences in the heavy metal levels for the vegetables cultivated in S2, S3 and S4. The results for soil sample S1 did not have a normal distribution since the growing of the vegetables were not homogeneous and also strongly dependent on the type of vegetal. As regards the effect caused in rabbits, significant differences were observed for the animals fed with plants cultivated in S1 compared with the others.

Pérez-Sirvent, Carmen; Martínez-Sánchez, Maria Jose; Agudo, Ines; Gonzalez, Eva; Perez-Espinosa, Victor; Belen Martínez, Lucia; Hernández, Carmen; García-Fernandez, Antonio Juan; Bech, Jaime

2013-04-01

358

Woody Debris: Linking Stream Morphology and Aquatic Biota in Southeastern Coastal Plain Streams, USA  

NASA Astrophysics Data System (ADS)

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.

Thom, T. A.; Herod, J. J.

2005-05-01

359

Prediction of effects of daily flow fluctuations on stream biota. Technical completion report  

SciTech Connect

The short-term effects of regulated daily discharges on benthos communities were examined in a small Michigan trout stream. Flow regulation designs simulated fluctuations produced by storage and release for hydroelectric generation, as well as different constant daily stream diversions. Impacts on the dynamics of micro-distribution, species diversity, and behavior were evaluated on stable artificial substrates. Invertebrate drift rates were measured at different discharges during light and dark periods. The caddisfly G. nigrior became less active and oriented downstream when exposed to high discharge, and underwent movements to protected substrate faces. The mayfly Baetis vagans also changed micro-positioning in response to flow fluctuations, but total density changes generally were more pronounced. There was evidence for increased species diversity during low discharges.

Hooper, F.F.; Ottey, D.R.

1982-12-01

360

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...

361

Mercury Bioaccumulation by Aquatic Biota in Hydroelectric Reservoirs: Review and Consideration of the Mechanisms  

Microsoft Academic Search

The mercury bioaccumulation process in man-made reservoirs is a phenomenon recently (1969) recognized in several countries such as USA, Canada, Sweden, Finland, Brazil. In many cases, no specific pollution source is identified and many occurrences of elevated Hg levels in tissues of fish have been detected in regions considered to be remote from sources of Hg. In impoundments the increase

Marcello M. Veiga; Jennifer Hinton

362

Analysis of organic compounds, minerals and biota: Preparation for future Mars life detection missions  

NASA Astrophysics Data System (ADS)

In the present study we have measured the amino acid content of Mars analogue soil samples, and related those results to the microbial and mineralogical data of the soil samples. These were performed on soils collected near the Mars Desert Research Station (MDRS) in the Utah desert (Figure 1), during the EuroGeoMars 2009 campaign [2,3]. The Utah soil displays mineralogies similar to Mars, with sedimentary deposits of sands, evaporites, clays and gypsum [4].

Martins, Z.; Kotler, J. M.; Direito, S. O. L.; Sephton, M. A.; Stoker, C.; Foing, B. H.; Ehrenfreund, P.

2011-10-01

363

RISK ASSESSMENT OF THYROID HORMONE DISRUPTION AND MIXTURES IN MARINE BIOTA  

EPA Science Inventory

Varieties of chemicals alter thyroid hormones (THs) in vertabrates. The importance of THs during neurodevelopment, suggest that these chemicals would likely be developmental neurotoxicants. A number of epidemiological studies have demonstrated associations between exposure to p...

364

Two new carnivores from an unusual late Tertiary forest biota in eastern North America  

Microsoft Academic Search

Late Cenozoic terrestrial fossil records of North America are biased by a predominance of mid-latitude deposits, mostly in the western half of the continent. Consequently, the biological history of eastern North America, including the eastern deciduous forest, remains largely hidden. Unfortunately, vertebrate fossil sites from this vast region are rare, and few pertain to the critically important late Tertiary period,

Steven C. Wallace; Xiaoming Wang

2004-01-01

365

Selenium in aquatic biota inhabiting agricultural drains in the Salton Sea Basin, California.  

PubMed

Resource managers are concerned that water conservation practices in irrigated farmlands along the southern border of the Salton Sea, Imperial County, California, could increase selenium concentrations in agricultural drainwater and harm the desert pupfish (Cyprinodon macularius), a federally protected endangered species. As part of a broader attempt to address this concern, we conducted a 3-year investigation to collect baseline information on selenium concentrations in seven agricultural drains inhabited by pupfish. We collected water, sediment, selected aquatic food-chain taxa (particulate organic detritus, filamentous algae, net plankton, and midge [Chironomidae] larvae), and two poeciliid fishes (western mosquitofish Gambusia affinis and sailfin molly Poecilia latipinna) for selenium determinations. The two fish species served as ecological surrogates for pupfish, which we were not permitted to sacrifice. Dissolved selenium ranged from 0.70 to 32.8 ?g/L, with selenate as the major constituent. Total selenium concentrations in other environmental matrices varied widely among drains, with one drain (Trifolium 18) exhibiting especially high concentrations in detritus, 5.98-58.0 ?g Se/g; midge larvae, 12.7-50.6 ?g Se/g; mosquitofish, 13.2-20.2 ?g Se/g; and mollies, 12.8-30.4 ?g Se/g (all tissue concentrations are based on dry weights). Although toxic thresholds for selenium in fishes from the Salton Sea are still poorly understood, available evidence suggests that ambient concentrations of this element may not be sufficiently elevated to adversely affect reproductive success and survival in selenium-tolerant poeciliids and pupfish. PMID:21915593

Saiki, Michael K; Martin, Barbara A; May, Thomas W

2011-09-14

366

Polybrominated diphenyl ethers and organochlorine compounds in biota from the marine environment of East Greenland.  

PubMed

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

Vorkamp, Katrin; Christensen, Jan H; Riget, Frank

2004-09-20

367

Morphological variation in fossil crayfish of the Jehol biota, Liaoning Province, China and its texonomic discrimination  

Microsoft Academic Search

Twelve morphological characteristics in 61 fossil crayfish specimens, which came from the Upper Jurassic Yixian Formation,\\u000a are discussed respectively in the present paper. A study of these new and better preserved materials allows us to add to and\\u000a revise the original description for Family Cricoidoscelosidae. In our collection, no modifications of the second pleopod of\\u000a the males have yet been

Yanbin Shen; Frederick R. Schram; Rod S. Taylor

2001-01-01

368

Vulnerability of organic acid tolerant wetland biota to the effects of inorganic acidification  

Microsoft Academic Search

Inland waterbodies are often naturally acidic but are these ecosystems pre-adapted to inorganic acidification e.g., by acid sulfate soils (ASS)? We conducted a controlled mesocosm experiment with inorganically acidified wetland water and wetland sediment replicates to pH 3 from a naturally acidic (pH 3.9, conductivity=74µScm?1) wetland in south-western Australia. Following acidification, dissolved organic carbon and nitrogen declined, and chlorophyll a

Clinton D McCullough; Pierre Horwitz

2010-01-01

369

Vulnerability of organic acid tolerant wetland biota to the effects of inorganic acidification.  

PubMed

Inland waterbodies are often naturally acidic but are these ecosystems pre-adapted to inorganic acidification e.g., by acid sulfate soils (ASS)? We conducted a controlled mesocosm experiment with inorganically acidified wetland water and wetland sediment replicates to pH 3 from a naturally acidic (pH 3.9, conductivity=74microScm(-1)) wetland in south-western Australia. Following acidification, dissolved organic carbon and nitrogen declined, and chlorophyll a dropped to zero. Inorganic acidification mobilised metals from sediment sods with increased water concentrations of Cu, Fe, Mn, Ca, Mg and Al. Acidification showed no significant effect on diatom assemblage. Nonetheless, greatly reduced abundance and diversity of grazing zooplankton was observed. Macroinvertebrates generally showed abundance decreases, although filterer-collector taxa increased. Decreased primary production reduced functional diversity and consumer biomasses. These results suggest likely impact to ecosystem functioning of low pH, weakly-buffered and stained wetlands if exposed to inorganic acidification. PMID:20163829

McCullough, Clint D; Horwitz, Pierre

2010-02-16

370

Biota of Oklahoma Springs: Natural Biological Monitoring of Ground Water Quality.  

National Technical Information Service (NTIS)

A survey of the fishes and invertebrates of 49 Oklahoma springs, including locations in all major aquifers, was carried out in 1981 and 1982, with each spring sampled in both years. The objective of the research was to determine if faunal similarity was s...

W. J. Matthews J. J. Hoover W. B. Milstead

1983-01-01

371

Field and Microcosm Studies of Decomposition and Soil Biota in a Cold Desert Soil  

Microsoft Academic Search

In the extreme cold desert soil of the McMurdo Dry Valleys of Antarctica, we studied the effects of changing moisture and\\u000a temperature on rates of decomposition and the activity and abundance of soil organisms. Our objective was to understand how\\u000a moisture and temperature structure invertebrate communities and control important ecosystem processes and soil biotic activity\\u000a in this extreme environment. First,

Amy M. Treonis; Diana H. Wall; Ross A. Virginia

2002-01-01

372

Model of biota-sediment accumulation factor for polycyclic aromatic hydrocarbons  

SciTech Connect

A model of the BSAF is constructed for PAHs using a steady-state representation of a benthic food web of a small creek. Analyses of the data collected by others on sediment, crayfish and sunfish PAH indicate that for the crayfish, the BSAF (kg org C kg lipid{sup {minus}1}) range over log K{sub ow} is relatively narrow between 0.01 and 0.1. For the sunfish, a marked decline occurs in the station average BSAF with increasing log K{sub ow} to values ranging from 0.00001 to 0.005. A separation also occurs in the behavior of the PAH groups, with the unsubstituted PAHs constituting an approximately lower bound on the entire set of PAHs. Model calibration to crayfish and sunfish BSAF is accomplished through assignment of PAH (K{sub ow}) functions derived from laboratory data. The substituted naphthalenes in contrast to the unsubstituted PAHs are calculated to behave similarly to PCBs but lower by about one order of magnitude. Analyses of the model calibration indicate that (1) relative to the sunfish, the crayfish appear to exhibit reduced metabolism and higher gut assimilation efficiencies resulting in BSAFs different from sunfish BSAFs; (2) for the sunfish, the BSAF for unsubstituted PAHs declines rapidly with increasing K{sub ow} primarily because of low gut assimilation efficiency and increased metabolism and not because of reduced bioavailability of sediment PAH; and (3) the relative contribution of the food route and water route to the BSAF varies with K{sub ow}.

Thomann, R.V. [Manhattan Coll., Riverdale, NY (United States). Dept. of Environmental Engineering; Komlos, J. [Univ. of California, Santa Barbara, CA (United States)

1999-05-01

373

Taphonomy of Holocene cryptic biotas from St. Croix, Virgin Islands: Information loss and preservational biases  

NASA Astrophysics Data System (ADS)

Surveys of submarine caves and overhanging ledges from St. Croix, Virgin Islands, provide new insights into the preservational processes active therein and into the taphonomy of ancient counterparts. Comparisons of preservable, skeletonized versus nonpreservable, unskeletonized components of these modern cryptic communities indicate that there is significant information loss in areals coverage, taxonomic richness, and diversity of fossilized examples. Quantitative estimates of such losses have been made. In addition, skeletal differences between early and late stage successional groups suggest biased representation of the former in the geologic record. Nonpreservable later colonizers may further erase the record of skeletonized forms through destructive life processes. Such forms of taphonomic information loss are probable in ancient counterparts and must be considered in accurate reconstruction of cryptic paleocommunities. *Present address: Curriculum in Marine Sciences, University of North Carolina at Chapel Hill, 12-5 Venable Hall, Chapel Hill, North Carolina 27514

Rasmussen, Kenneth A.; Brett, Carlton E.

1985-08-01

374

Effects of Deicing Salts on Plant Biota and Soil - Experimental Phase.  

National Technical Information Service (NTIS)

This report covers the experimental phase of an investigation on effect of deicing compounds on vegetation and water supplies. The investigations involving roadside and other environments, coupled with laboratory and greenhouse research, give data and int...

R. E. Hanes L. W. Zelazny K. G. Verghese R. P. Bosshart E. W. Carson

1976-01-01

375

Selenium sediment toxicity thresholds and derivation of water quality criteria for freshwater biota of western streams  

SciTech Connect

Waterborne and sediment selenium (Se) data, in conjunction with selected physicochemical parameters, were collected from streams of the middle Arkansas River basin, Colorado, USA, to examine the factors affecting sediment Se accumulation in a lotic environment. An empirical model of dissolved-to-sediment Se transfer in western streams, as an interactive function of sediment organic carbon content, was developed and validated. Sediment Se and associated biological effects data were compiled from the literature, to provide an estimate of sediment Se concentration thresholds that have biological effects. Based on this preliminary analysis, sediment Se concentrations of 2.5 {micro}g/g would be a threshold based on predicted effects and concentrations of 4.0 {micro}g/g would be the observed threshold for dish and wildlife toxicity. The dissolved-to-sediment Se transfer model can be used to translate this type of sediment Se toxicity threshold to a site-specific chronic water-quality standard for western streams based on empirically derived sediment total organic carbon values.

Van Derveer, W.D. [Colorado Springs Utilities, CO (United States). Water Resources Dept.; Canton, S.P. [Chadwick Ecological Consultants, Inc., Littleton, CO (United States)

1997-06-01

376

Rapid toxicity screening tests for aquatic biota. 1. Methodology and experiments with Daphnia magna  

Microsoft Academic Search

A promising new and rapid toxicity screening test was developed, the concept and principles of which are presented. The method consists of visual observation of in vivo inhibition of an enzymatic process, using a fluorescent substrate. Juvenile Daphnia magna was exposed to a toxicant dilution series for 1 h, after which the substrate was added and the enzymatic inhibition was

C. R. Janssen; G. Persoone

1993-01-01

377

Rapid toxicity screening tests for aquatic biota. 1. Methodology and experiments with Daphnia magna  

SciTech Connect

A promising new and rapid toxicity screening test was developed, the concept and principles of which are presented. The method consists of visual observation of in vivo inhibition of an enzymatic process, using a fluorescent substrate. Juvenile Daphnia magna was exposed to a toxicant dilution series for 1 h, after which the substrate was added and the enzymatic inhibition was observed visually, using a long-wave UV light. The 1-h EC50 results of 11 pure compounds are presented and compared to the conventional 24- and 48-h Daphnia magna EC50s. All 1-h fluorescence EC50s were of the same order of magnitude and correlated very well with the 24- and 48-h EC50s. The sensitivity and reproducibility of this cost-effective screening test were compared to those of the Microtox[reg sign] test. The scope for application and the potential of this new rapid toxicity screening test are evaluated.

Janssen, C.R.; Persoone, G. (State Univ. of Ghent (Belgium))

1993-04-01

378

IMPACT OF NEARSTREAM VEGETATION AND STREAM MORPHOLOGY ON WATER QUALITY AND STREAM BIOTA  

EPA Science Inventory

As man modifies watersheds by removal of natural vegetation and stream channelization, disequilibria in both the terrestrial and aquatic environments result. These disequilibria are the major problem in controlling sediments and nutrients from non-point sources and improving the ...

379

Potential terrestrial fate and effects on soil biota of a coal liquefaction product spill  

SciTech Connect

Contaminated soil samples collected from the site of a coal liquefaction product spill were used to study potential fates and effects of this synthetic fuel. Simulated weathering in the laboratory caused significant changes in residual oil composition. Soil column leachates contained high phenol levels that decreased exponentially over time. Toxicity tests demonstrated that the oil-contaminated soil was phytotoxic and caused embryotoxic and teratogenic effects on eggs of the cricket Acheta domesticus.

Strayer, R.F.; Edwards, N.T.; Walton, B.T.; Charles-Shannon, V.

1983-01-01

380

Long Chain Perfluorinated Alkyl Acids Derivatisation and Identification in Biota and Abiota Matrices Using Gas Chromatography  

Microsoft Academic Search

An analytical method involving derivatisation of perfluorocarboxylic acids for their analysis in abiotic and biotic matrices\\u000a is presented. Derivatisation of the acid group to form a suitable alkyl ester provided a suitable compound for mass spectrometric\\u000a detection in gas chromatography\\/mass spectroscopy (GC\\/MS) instrumental analysis. The acid is esterified by an alkyl halide\\u000a i.e. benzyl bromide as the alkylating agent for

Francis Orata; Natalia Quinete; Rolf-Dieter Wilken

2009-01-01

381

Early maps as stepping stones for the reconstruction of historic ecological conditions and biota  

Microsoft Academic Search

We reconstructed the flora of a European region at a historical point in time from historical topographical maps that contain rather precise information about the condition and composition of habitats. The ecological information obtained from these maps can be enriched through the potential of broadly diversified archival information. This study is confined to grassland communities. Considerations in terms of phytosociology

Antje Jakupi; Peter-M. Steinsiek; Bernd Herrmann

2003-01-01

382

Effects of a Low-Head Dam and Water Abstraction on Migratory Tropical Stream Biota  

Microsoft Academic Search

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

Jonathan P. Benstead; James G. March; Catherine M. Pringle; Frederick N. Scatena

1999-01-01

383

How old is the Hawaiian biota? Geology and phylogeny suggest recent divergence.  

PubMed

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

Price, Jonathan P; Clague, David A

2002-12-01

384

Optimization of matrix solid-phase dispersion conditions for UV filters determination in biota samples  

Microsoft Academic Search

A low solvent consumption method for the determination of eight ultraviolet (UV) filters, displaying low to medium polarities, in freeze-dried samples of marine bivalves and fish is proposed. Matrix solid-phase dispersion (MSPD) and gas chromatography with mass spectrometry (GC-MS) were used as sample preparation and determination techniques, respectively. This work describes the influence of several parameters (type and amount of

Noelia Negreira; Isaac Rodríguez; Rosario Rodil; Elisa Rubí; Rafael Cela

2012-01-01

385

Factors affecting bioabsorption, metabolism, and storage of organic compounds by aquatic biota  

SciTech Connect

Biological concentration and transfer of organic chemicals through aquatic food webs can be influenced by a variety of environmental, biological, and biochemical factors. Bioaccumulation can be significantly altered by the presence of suspended matter or complex organic mixtures in the water column. In addition, the bioaccumulation factor of a compound is dependent on the species of an organism, its life stage, and the available food supply. Metabolic changes in structure of absorbed organics can alter both the rate and the mechanism of absorption and elimination of organics. In the case of quinoline absorption by trout, both the rate of absorption and the metabolic disposition depended upon whether exposure was through ingestion or through direct water column exposure. All of these factors can be used to explain why the physical properties of organic compounds (most notably octanol/water partition coefficients) are unreliable predictors of bioaccumulation potential. 24 refs., 1 tab.

Bean, R.M.; Dauble, D.D.; Thomas, B.L.; Hanf, R.W.; Chess, E.K.

1985-12-01

386

Selenium sediment toxicity thresholds and derivation of water quality criteria for freshwater biota of western streams  

Microsoft Academic Search

Waterborne and sediment selenium (Se) data, in conjunction with selected physicochemical parameters, were collected from streams of the middle Arkansas River basin, Colorado, USA, to examine the factors affecting sediment Se accumulation in a lotic environment. An empirical model of dissolved-to-sediment Se transfer in western streams, as an interactive function of sediment organic carbon content, was developed and validated. Sediment

William D. Van Derveer; Steven P. Canton

1997-01-01

387

Spatially Explicit Analysis of Metal Transfer to Biota: Influence of Soil Contamination and Landscape  

PubMed Central

Concepts and developments for a new field in ecotoxicology, referred to as “landscape ecotoxicology,” were proposed in the 1990s; however, to date, few studies have been developed in this emergent field. In fact, there is a strong interest in developing this area, both for renewing the concepts and tools used in ecotoxicology as well as for responding to practical issues, such as risk assessment. The aim of this study was to investigate the spatial heterogeneity of metal bioaccumulation in animals in order to identify the role of spatially explicit factors, such as landscape as well as total and extractable metal concentrations in soils. Over a smelter-impacted area, we studied the accumulation of trace metals (TMs: Cd, Pb and Zn) in invertebrates (the grove snail Cepaea sp and the glass snail Oxychilus draparnaudi) and vertebrates (the bank vole Myodes glareolus and the greater white-toothed shrew Crocidura russula). Total and CaCl2-extractable concentrations of TMs were measured in soils from woody patches where the animals were captured. TM concentrations in animals exhibited a high spatial heterogeneity. They increased with soil pollution and were better explained by total rather than CaCl2-extractable TM concentrations, except in Cepaea sp. TM levels in animals and their variations along the pollution gradient were modulated by the landscape, and this influence was species and metal specific. Median soil metal concentrations (predicted by universal kriging) were calculated in buffers of increasing size and were related to bioaccumulation. The spatial scale at which TM concentrations in animals and soils showed the strongest correlations varied between metals, species and landscapes. The potential underlying mechanisms of landscape influence (community functioning, behaviour, etc.) are discussed. Present results highlight the need for the further development of landscape ecotoxicology and multi-scale approaches, which would enhance our understanding of pollutant transfer and effects in ecosystems.

Fritsch, Clementine; Coeurdassier, Michael; Giraudoux, Patrick; Raoul, Francis; Douay, Francis; Rieffel, Dominique; de Vaufleury, Annette; Scheifler, Renaud

2011-01-01

388

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

Microsoft Academic Search

The accumulation of synthetic debris in marine and coastal environments is a consequence of the inten- sive and continuous release of these highly persistent materials. This study investigates the current status of marine debris ingestion by sea turtles and seabirds found along the southern Brazilian coast. All green turtles (n = 34) and 40% of the seabirds (14 of 35)

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

2009-01-01

389

Metals in the Water, Sediments and Biota of the Haw and New Hope Rivers, North Carolina.  

National Technical Information Service (NTIS)

Neutron activation analysis was used to investigate the concentrations of Co, Cr, Fe, K, Mn, Na, Sb, Sc and Zn in the filtrable (<0.45 micrometer), suspended particulate and sediment phases as well as in the benthic macroinvertebrates of two central North...

M. S. Shuman L. A. Smock C. L. Haynie

1977-01-01

390

Interaction of vent biota and hydrothermal deposits: Present evidence and future experimentation  

NASA Astrophysics Data System (ADS)

Actively-forming hydrothermal mineral deposits provide a source of energy for chemosynthesis and a substratum for colonization by adult and larval vent organisms. Since mineral deposition and organism growth can occur within similar time frames, their potential for interaction is substantial. The nature of this interaction is substantial. The nature of this interaction is the central theme of this paper. We review evidence for biological influences on deposit formation and destruction, and consider how the dynamics of sulfide chimney and mound growth may influence the distribution and composition of vent communities. Another theme that we develop concerns the mainly circumstantial nature of almost all evidence for biological-geological interaction. There exists very little experimental demonstration or solid statistical proof for links between biological or solid statistical proof for links between biological activity and mineral deposition processes at vents. This is not unusual for any new area of inquiry, particularly in a field that encompasses geological, chemical and biological data and observations. Indeed, these observations and ideas form the basis for suggestions for future experimental and field work. In order to encourage such experimentation, we discuss the types of evidence required to rigorously test the various hypothesis reviewed here.

Kim Juniper, S.; Sarrazin, Jozée

391

Effects of Biota on Backscatter: Experiments with the Portable Acoustic Laboratory (PAL).  

National Technical Information Service (NTIS)

This is a report of the field test of a 'portable acoustic laboratory,' a set of observational tools that can be used for in situ testing of the effects of organisms, biological processes, and benthic structures on underwater acoustic propagation in sedim...

C. D. Jones

2003-01-01

392

Impacts of New Highways and Subsequent Landscape Urbanization on Stream Habitat and Biota  

Microsoft Academic Search

New highways are pervasive, pernicious threats to stream ecosystems because of their short- and long-term physical, chemical, and biological impacts. Unfortunately, standard environmental impact statements (EISs) and environmental assessments (EAs) focus narrowly on the initial direct impacts of construction and ignore other long-term indirect impacts. More thorough consideration of highway impacts, and, ultimately, better land use decisions may be facilitated

Andrew P. Wheeler; Paul L. Angermeier; Amanda E. Rosenberger

2005-01-01

393

Bioinvasion in a Brazilian Bay: Filling Gaps in the Knowledge of Southwestern Atlantic Biota  

PubMed Central

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.

Ignacio, Barbara L.; Julio, Luciana M.; Junqueira, Andrea O. R.; Ferreira-Silva, Maria A. G.

2010-01-01

394

The role of biota in retention of fine sediment in deltas  

NASA Astrophysics Data System (ADS)

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.

Littlewood, R. C.; Dayley, S.; Frederick, K.; Paola, C.

2010-12-01

395

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

Microsoft Academic Search

A dose per unit concentration database has been generated for application to ecosystem assessments within the FASSET framework. Organisms are represented by ellipsoids of appropriate dimensions, and the proportion of radiation absorbed within the organisms is calculated using a numerical method implemented in a series of spreadsheet-based programs. Energy-dependent absorbed fraction functions have been derived for calculating the total dose

J. Vives i. Batlle; S. R. Jones; J. M. Gómez-Ros

2004-01-01

396

Mercury Concentrations in Water, Sediment, and Biota from Lake Victoria, East Africa  

Microsoft Academic Search

Lake Victoria, East Africa, is the site of the world's most productive freshwater fishery. Mercury in muscle tissue of the 2+ and 3+ year old Nile perch (Lates niloticus), presently the largest constituent of the fishery, was 90 to 250 ng \\/g wet weight. This is similar to the range of mercury in fish muscle reported for the commercial fish

Patricia S. Ramlal; Fred W. B. Bugenyi; George W. Kling; Jerome O. Nriagu; John W. M. Rudd; Linda M. Campbell

2003-01-01

397

The Jehol Biota (Lower Cretaceous, China): new discoveries and future prospects.  

PubMed

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

Barrett, Paul M; Hilton, Jason M

2006-03-01

398

Discrimination of factors influencing biota of a stream receiving multiple-source perturbations.  

PubMed

Blaine Creek is a fifth-order stream located in eastern Kentucky that has been subject to contamination by oil brines, surface mining, and a coal fly ash settling pond discharge. Toxicity tests, effluent and receiving water chemical monitoring, and Blaine Creek benthic sampling were used to evaluate the effect of the ash pond effluent on the creek. Reproductive impairment of Ceriodaphnia was demonstrated at effluent concentrations ranging from 30 to 100%, but no instream impact on benthic invertebrates could be found at effluent flows that provided up to 65% of the creek's discharge. Correlation and regression analysis of physicochemical versus benthic monitoring data indicated that upstream oil brine contamination and scouring of the creek's predominately shifting sand substrate during rainfall events were the primary factors affecting the benthic fauna, and appeared to override potential effects from other sources. These results demonstrated the value of integrated field/laboratory investigations for effluent impact assessments. PMID:15092496

Van Hassel, J H; Cherry, D S; Hendricks, J C; Specht, W L

1988-01-01

399

Stream Channel Modification in Hawaii. Part A: Statewide Inventory of Streams, Habitat Factors and Associated Biota.  

National Technical Information Service (NTIS)

A state wide, exhaustive inventory of perennial streams with channel modifications, including a general survey of habitat factors and macrofauna, showed that there are at least 366 perennial streams in the five largest islands of Hawaii. Fifteen percent o...

A. S. Timbol J. A. Maciolek

1978-01-01

400

Bioinvasion in a Brazilian Bay: Filling Gaps in the Knowledge of Southwestern Atlantic Biota  

Microsoft Academic Search

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

Barbara L. Ignacio; Luciana M. Julio; Andrea O. R. Junqueira; Maria A. G. Ferreira-Silva

2010-01-01

401

Benthic Algae in High Altitude Streams of the Alps – a Neglected Component of the Aquatic Biota  

Microsoft Academic Search

This is a review on benthic algae from streams situated above the tree line in the Alps. It integrates published and unpublished\\u000a data from alpine streams in Austria and in the Trento Province (Northern Italy). The main focus is on the structural and taxonomic\\u000a composition of benthic algae including macro- and micro-algae and their contribution to the epilithic biofilm and

E. Rott; M. Cantonati; L. Füreder; P. Pfister

2006-01-01

402

Distribution of arsenic in the sediments and biota of Hilo Bay, Hawaii  

Microsoft Academic Search

Sediment samples collected from the Waiakea Mill Pond, Wailoa River, and Hilo Bay were analyzed for arsenic. Arsenic was detectable in 10 of 11 sediment samples, and ranged in concentration from 2 to 715 ppm. Two species of plant and seven species of animal were collected from the Waiakea Mill Pond and analyzed for arsenic. No arsenic was detected in

L. E. Hallacher; E. B. Kho; N. D. Bernard; A. M. Orcutt; W. C. Jr. Dudley; T. M. Hammond

1985-01-01

403

Coevolution between invasive and native plants driven by chemical competition and soil biota  

PubMed Central

Although reciprocal evolutionary responses between interacting species are a driving force behind the diversity of life, pairwise coevolution between plant competitors has received less attention than other species interactions and has been considered relatively less important in explaining ecological patterns. However, the success of species transported across biogeographic boundaries suggests a stronger role for evolutionary relationships in shaping plant interactions. Alliaria petiolata is a Eurasian species that has invaded North American forest understories, where it competes with native understory species in part by producing compounds that directly and indirectly slow the growth of competing species. Here I show that populations of A. petiolata from areas with a greater density of interspecific competitors invest more in a toxic allelochemical under common conditions. Furthermore, populations of a native competitor from areas with highly toxic invaders are more tolerant to competition from the invader, suggesting coevolutionary dynamics between the species. Field reciprocal transplants confirmed that native populations more tolerant to the invader had higher fitness when the invader was common, but these traits came at a cost when the invader was rare. Exotic species are often detrimentally dominant in their new range due to their evolutionary novelty; however, the development of new coevolutionary relationships may act to integrate exotic species into native communities.

Lankau, Richard A.

2012-01-01

404

Coevolution between invasive and native plants driven by chemical competition and soil biota.  

PubMed

Although reciprocal evolutionary responses between interacting species are a driving force behind the diversity of life, pairwise coevolution between plant competitors has received less attention than other species interactions and has been considered relatively less important in explaining ecological patterns. However, the success of species transported across biogeographic boundaries suggests a stronger role for evolutionary relationships in shaping plant interactions. Alliaria petiolata is a Eurasian species that has invaded North American forest understories, where it competes with native understory species in part by producing compounds that directly and indirectly slow the growth of competing species. Here I show that populations of A. petiolata from areas with a greater density of interspecific competitors invest more in a toxic allelochemical under common conditions. Furthermore, populations of a native competitor from areas with highly toxic invaders are more tolerant to competition from the invader, suggesting coevolutionary dynamics between the species. Field reciprocal transplants confirmed that native populations more tolerant to the invader had higher fitness when the invader was common, but these traits came at a cost when the invader was rare. Exotic species are often detrimentally dominant in their new range due to their evolutionary novelty; however, the development of new coevolutionary relationships may act to integrate exotic species into native communities. PMID:22733785

Lankau, Richard A

2012-06-25

405

Survey, Ecology, and Systematics of the Upper Potomac Estuary Biota: Aufwuchs Microfauna, Phase II.  

National Technical Information Service (NTIS)

Two model rivers, representing Potomac River sites at Hains Point, Blue Plains Sewage Treatment Plant, Broad Creek, and Piscataway Creek connected to a common reservoir containing upriver water, were studied. Each model consisted of four 24-gallon aquaria...

D. M. Spoon

1976-01-01

406

The Bering Land Bridge: a moisture barrier to the dispersal of steppe–tundra biota?  

Microsoft Academic Search

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

Scott A. Elias; Barnaby Crocker

2008-01-01

407

Allometric methodology for the calculation of biokinetic parameters for marine biota.  

PubMed

Biological half-lives of elimination (T(B1/2)) and concentration factors (CF) for different radionuclides and marine organisms were analysed. Tests were carried out in order to investigate the cases in which these parameters can be described by a simple power equation as a function of the volume of the organism, to verify the hypothesis of allometric scaling. Statistically significant trends were found for the CF of plutonium and americium and the T(B1/2) of technetium and radiocaesium across organisms. Some of these trends satisfy the theoretical expectation that allometric relations are a power function of the volume of the organism. For the CF, which relates to retention of a radionuclide, the mean exponent of the power function, -0.29+/-0.02, is close to the theoretical value of -0.25. For the T(B1/2) the mean exponent of the power function is lower at 0.16+/-0.01. The work improves the understanding of the metabolism of radionuclides within organisms for which no direct biokinetic information exists. The allometric relationships derived can be applied to calculate a T(B1/2) for caesium or technetium and a CF for plutonium and americium for any marine species. For the elements N, K, Np and Cm, the same allometric relationships as those derived for their analogues (99)Tc, (137)Cs, (239,240)Pu and (241)Am, respectively, can be applied, when no other data are available. PMID:17878058

Vives i Batlle, J; Wilson, R C; McDonald, P

2007-09-18

408

Behavior of Zn, Cu, Pb and Cd in biota of Yangtze Estuary  

Microsoft Academic Search

The contents of zinc, copper, lead and cadmium were measured in the dominant species (plants:Scripus triquetor andPhrgrmites australis, macrobenthos:Ilyoplax deschampsin, Helice tridens tientsinensis, Bullacta exarata and Corbicula fluminea, and migrating waders: Calidris ruficollis and C. alpina) of the ecosystem of Yangtze Estuary, China, from 1995–1998. Results\\u000a show that:\\u000a \\u000a \\u000a (1) \\u000a \\u000a Since the heavy metals stored in plants during growth seasons will

Jianjian Lu; Wenshan He; Kaiya Zhou; Yawen Tang; Shufeng Ye; Pingyue Sun

2001-01-01

409

Partial Least Square Analyses of Landscape and Surface Water Biota Associations in the Savannah River Basin  

EPA Science Inventory

Ecologists are often faced with problem of small sample size, correlated and large number of predictors, and high noise-to-signal relationships. This necessitates excluding important variables from the model when applying standard multiple or multivariate regression analyses. In ...

410

Americium and plutonium in water, biota, and sediment from the central Oregon coast  

SciTech Connect

Plutonium-239, 240 and americium-241 were measured in the mussel Mytilus californianus from the region of Coos Bay, OR. The flesh of this species has a plutonium concentration of about 90 fCi/kg, and an Am-241/Pu-239, 240 ratio that is high relative to mixed fallout, ranging between two and three. Transuranic concentrations in sediment, unfiltered water, and filterable particulates were also measured; none of these materials has an Am/Pu ratio as greatly elevated as the mussels, and there is no apparent difference in the Am/Pu ratio of terrestrial runoff and coastal water. Sediment core profiles do not allow accumulation rates or depositional histories to be identified, but it does not appear that material characterized by a high Am/Pu ratio has ever been introduced to this estuary. Other bivalves (Tresus capax and Macoma nasuta) and a polychaete (Abarenicola sp.) do not have an elevated Am/Pu ratio, although the absolute activity of plutonium in the infaunal bivalves is roughly four times that in the mussels.

Nielsen, R. D.

1982-06-01

411

Glutathione, glutathione S-transferase, and glutathione conjugates, complementary markers of oxidative stress in aquatic biota.  

PubMed

Contaminants are ubiquitous in the environment and their impacts are of increasing concern due to human population expansion and the generation of deleterious effects in aquatic species. Oxidative stress can result from the presence of persistent organic pollutants, metals, pesticides, toxins, pharmaceuticals, and nanomaterials, as well as changes in temperature or oxygen in water, the examined species, with differences in age, sex, or reproductive cycle of an individual. The antioxidant role of glutathione (GSH), accompanied by the formation of its disulfide dimer, GSSG, and metabolites in response to chemical stress, are highlighted in this review along with, to some extent, that of glutathione S-transferase (GST). The available literature concerning the use and analysis of these markers will be discussed, focusing on studies of aquatic organisms. The inclusion of GST within the suite of biomarkers used to assess the effects of xenobiotics is recommended to complement that of lipid peroxidation and mixed function oxygenation. Combining the analysis of GSH, GSSG, and conjugates would be beneficial in pinpointing the role of contaminants within the plethora of causes that could lead to the toxic effects of reactive oxygen species. PMID:22532120

Hellou, Jocelyne; Ross, Neil W; Moon, Thomas W

2012-04-25

412

Organic Pollutants in Coastal Waters, Sediments, and Biota: A Relevant Driver for Ecosystems During the Anthropocene?  

Microsoft Academic Search

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

Jordi Dachs; Laurence Méjanelle

2010-01-01

413

Gas chromatographic-mass spectrometric method for polycyclic aromatic hydrocarbon analysis in plant biota.  

PubMed

Using gas chromatography-mass spectrometry, a new method was developed for the identification and the quantification of polycyclic aromatic hydrocarbons (PAHs) in plants. This method was particularly optimised for PAH analyses in marine plants such as the halophytic species, Salicornia fragilis Ball et Tutin. The saponification of samples and their clean up by Florisil solid-phase extraction succeeded in eliminating pigments and natural compounds, which may interfere with GC-MS analysis. Moreover, a good recovery of the PAHs studied was obtained with percentages ranging from 88 to 116%. Application to the determination of PAH in a wide range of coastal halophytic plants is presented and validated the efficiency, the accuracy and the reproducibility of this method. PMID:16442550

Meudec, A; Dussauze, J; Jourdin, M; Deslandes, E; Poupart, N

2006-01-26

414

LEVELS OF SYNTHETIC MUSKS COMPOUNDS IN MUNICIPAL WASTEWATER FOR ESTIMATING BIOTA EXPOSURE IN RECEIVING WATERS  

EPA Science Inventory

Synthetic musk compounds are consumer chemicals manufactured as fragrance materials and consumed in very large quantities worldwide. Due to their high use and release, they have become ubiquitous in the environment. We analyzed water samples from the confluence of three municipal...

415

Understanding the influence of suspended solids on water quality and aquatic biota  

Microsoft Academic Search

Over the last 50 years the effects of suspended solids (SS) on fish and aquatic life have been studied intensively throughout the world. It is now accepted that SS are an extremely important cause of water quality deterioration leading to aesthetic issues, higher costs of water treatment, a decline in the fisheries resource, and serious ecological degradation of aquatic environments.

G. S. Bilottaa; R. E. Brazier

2008-01-01

416

Selenium Levels in Biota from Irrigation Drainwater Impoundments in the San Joaquin Valley, California  

Microsoft Academic Search

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

Douglas A. Barnum; David S. Gilmer

1988-01-01

417

Toxicological benchmarks for screening potential contaminants of concern for effects on aquatic biota: 1996 revision  

SciTech Connect

This report presents potential screening benchmarks for protection of aquatic life form contaminants in water. Because there is no guidance for screening for benchmarks, a set of alternative benchmarks is presented herein. This report presents the alternative benchmarks for chemicals that have been detected on the Oak Ridge Reservation. It also presents the data used to calculate the benchmarks and the sources of the data. It compares the benchmarks and discusses their relative conservatism and utility. Also included is the updates of benchmark values where appropriate, new benchmark values, secondary sources are replaced by primary sources, and a more complete documentation of the sources and derivation of all values are presented.

Suter, G.W. II [Oak Ridge National Lab., TN (United States)] [Oak Ridge National Lab., TN (United States); Tsao, C.L. [Duke Univ., Durham, NC (United States). School of the Environment] [Duke Univ., Durham, NC (United States). School of the Environment

1996-06-01

418

Soil biota and upper soil layer development in two contrasting post-mining chronosequences  

Microsoft Academic Search

Density and community composition of a wide spectrum of soil organisms (fungi, algae, testate amoebae, nematodes, enchytraeids, lumbricids, oribatid mites, diplopods, terrestrial isopods, collembolans and dipteran larvae), direct counts of bacteria, rate of cellulose decomposition and microstructure of upper soil layers were studied in two chronosequences of plots reclaimed from open-cast coal mining near Cottbus (Germany) and near Sokolov (Czech

Jan Frouz; Beate Keplin; Václav Pižl; Karel Tajovský; Josef Starý; Alena Lukešová; Alena Nováková; Vladim??r Bal??k; Ladislav Hán?l; Jan Materna; Christian Düker; Josef Chalupský; Josef Rusek; Thomas Heinkele

2001-01-01

419

ABILITY OF ECOSAR, TOPKAT, NEURAL NETWORKS, AND ASTER TO PREDICT TOXICITY OF CHEMICALS TO AQUATIC BIOTA  

EPA Science Inventory

The Canadian Environmental Protection Act (CEPA) which provides the basis for assessing and managing toxic substances in Canada, is being revised. Several new mandates have been introduced in the Act......

420

Paleoenvironmental analysis of a middle Wisconsinan biota site, southwestern Virginia, U.S.A  

Microsoft Academic Search

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

G. Richard Whittecar; Thomas C. Wynn; Charles S. Bartlett

2007-01-01

421

Pesticides at The Ebro River Delta: Occurrence and Toxicity in Water and Biota  

Microsoft Academic Search

\\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

Marianne Köck-Schulmeyer; Miren de Alda; Elena Martínez; Marinella Farré; Asunción Navarro; Antoni Ginebreda; Damià Barceló

422

Persistent Organic Pollutants in Water, Sediments, and Biota in the Ebro River Basin  

Microsoft Academic Search

\\u000a The Ebro river basin is one of the most studied basins in Spain. The Confederación Hidrográfica del Ebro (CHE), which is the organization in charge of the management of the basin, has different control networks that are operative\\u000a since 1992. Besides these control networks, there is also a contribution of scientific studies since 1988 to know the distribution\\u000a of persistent

Alícia Navarro-Ortega; Damià Barceló

423

Measurement of Lake Roosevelt biota in relation to reservoir operations: Draft appendices. Annual report 1992.  

National Technical Information Service (NTIS)

These appendices include: A RESERVOIR ELEVATION AND WATER RETENTION TIME: Daily reservoir levels and water retention time in 1992, Elevation vs area, Elevation vs gross storage; B ZOOPLANKTON: Zooplankton density, Zooplanktion biomass; C BENTHIC MACROINVE...

J. R. Griffith A. McDowell

1992-01-01

424

DETERMINATION OF SYNTHETIC MUSK COMPOUNDS IN MUNICIPAL WASTEWATER AND ESTIMATING BIOTA EXPOSURE IN THE RECEIVING WATERS  

EPA Science Inventory

Synthetic musk compounds are consumer chemicals manufactured as fragrance materials and consumed in very large quantities worldwide. Due to their high usage and release, they have become ubiquitous in the environment. The U.S. EPA (Las Vegas) developed surface water monitoring me...

425

HIGHLY SENSITIVE DIOXIN IMMUNOASSAY AND ITS APPLICATIONS TO SOIL AND BIOTA SAMPLES. (R825433)  

EPA Science Inventory

Tetrachlorodibenzo- p -dioxin (TCDD) is a well-known highly toxic compound that is present in nearly all components of the global ecosystem, including air, soil, sediment, fish and humans. Dioxin analysis is equipment intensive and expensive requiring low ppt or even ppq ...

426

Does soil biota benefit from organic farming in complex vs. simple landscapes?  

Microsoft Academic Search

Organic farming can counteract detrimental effects of agricultural intensification on farmland biodiversity. Enhancing biodiversity with agri-environmental schemes is hypothesized to be more efficient in simple than complex landscapes, a pattern confirmed for many aboveground taxa. Although belowground biodiversity is an important part of the agroecosystem, studies on the interacting effects of local and landscape intensification on the belowground detritivore community,

Andreas Flohre; Max Rudnick; Gyorgy Traser; Teja Tscharntke; Till Eggers

2011-01-01

427

The effects of mycorrhizal roots on litter decomposition, soil biota, and nutrients in a spodosolic soil  

Microsoft Academic Search

We studied the effects of mycorrhizal pitch pine (Pinus rigida) roots on litter decomposition, microbial biomass, nematode abundance and inorganic nutrients in the E horizon material of a spodosolic soil, using field microcosms created in a regenerating pitch pine stand in the New Jersey Pinelands. Pine roots stimulated litter decomposition by 18.7% by the end of the 29 month study.

Weixing Zhu; Joan G. Ehrenfeld

1996-01-01

428

Metal mixture toxicity to aquatic biota in laboratory experiments: Application of the WHAM-FTOX model.  

PubMed

The WHAM-FTOX model describes the combined toxic effects of protons and metal cations towards aquatic organisms through the toxicity function (FTOX), a linear combination of the products of organism-bound cation and a toxic potency coefficient (?i) for each cation. Organism-bound, metabolically-active, cation is quantified by the proxy variable, amount bound by humic acid (HA), as predicted by the WHAM chemical speciation model. We compared published measured accumulations of metals by living organisms (bacteria, algae, invertebrates) in different solutions, with WHAM predictions of metal binding to humic acid in the same solutions. After adjustment for differences in binding site density, the predictions were in reasonable line with observations (for logarithmic variables, r(2)=0.89, root mean squared deviation=0.44), supporting the use of HA binding as a proxy. Calculated loadings of H(+), Al, Cu, Zn, Cd, Pb and UO2 were used to fit observed toxic effects in 11 published mixture toxicity experiments involving bacteria, macrophytes, invertebrates and fish. Overall, WHAM-FTOX gave slightly better fits than a conventional additive model based on solution concentrations. From the derived values of ?i, the toxicity of bound cations can tentatively be ranked in the order: H

Tipping, E; Lofts, S

2013-08-16

429

Fossils with Little Relief: Using Lasers to Conserve, Image, and Analyze the Ediacara Biota  

Microsoft Academic Search

\\u000a Fifty years have now passed since the discovery of Charnia masoni and Charniodiscus concentricus in Charnwood Forest, UK. But what is Charnia? And how was it related to the great explosion of animal fossils at the base of the Cambrian that it immediately predates?\\u000a Recent studies focussing on the growth dynamics and morphology of the group have been greatly aided

Jonathan B. Antcliffe; Martin D. Brasier

430

Measurement of Lake Roosevelt Biota in Relation to Reservoir Operations : Appendices 1992.  

SciTech Connect

These appendices include: A RESERVOIR ELEVATION AND WATER RETENTION TIME: Daily reservoir levels and water retention time in 1992, Elevation vs area, Elevation vs gross storage; B ZOOPLANKTON: Zooplankton density, Zooplanktion biomass; C BENTHIC MACROINVERTEBRATE DATA: Benthic sampling record, Benthic sampling depths, Benthic orders identified, Mean weight values obtained for benthics, D WATER COLUMN PROFILE: Monthly water profiles.

Griffith, Janelle R.; McDowell, Amy C.

1996-01-01

431

Characterization of the water quality and biota of a stormwater wetland one year after its creation  

Microsoft Academic Search

Long-term monitoring of created wetlands provides valuable information about their development and functioning. Data gathered in the early stages of a created wetland?s development provide a benchmark for future assessment. The objective of this study was to examine the water quality and plant and animal communities of a 1-year old stormwater wetland that was created to intercept and detain roof

Anne E. Altor; William J. Mitsch

432

A mechanistic sub-model predicting the influence of potassium on radiocesium uptake in aquatic biota.  

PubMed

It is often argued that the quality of science is related to the possibilities of making accurate predictions. It has also long been argued that due to the complex nature of ecosystems, it will never be possible to predict important target variables, especially with more comprehensive dynamic models. New results in radioecology have, however, demonstrated that those arguments are no longer valid. The key to the predictive success lies in the structuring of the model. The accident at Chernobyl has, in fact, provided science with an intriguing opportunity to study how the pulse of 137Cs is transported through ecosystem pathways, thus revealing the basic structure of these ecosystems, i.e. which are the key and the less-important pathways. It is paradoxical to conclude that the Chernobyl accident is, perhaps, the most important factor behind the revolution in predictive ecosystem modelling which lies behind the decrease in the uncertainty factor from 10 to 0.25-0.5. The sub-model for the potassium moderator presented in this paper is an example of a mechanistically based sub-model used within the framework of a more comprehensive lake model for 137Cs. The K-moderator presented is derived from the existing knowledge on ion transport in biological membranes and takes into account ion equilibria modelled by the Nernst equation and the uptake kinetics quantified by the Michaelis-Menten model. It provides the type of structure to this overall lake model that helps to explain the excellent predictive power of this model. PMID:11381942

Håkanson, L; Fernandez, J A

2001-01-01

433

Technical Report of Biota, FEL Site 1, Lawrence Livermore National Laboratory: Final Report.  

National Technical Information Service (NTIS)

Lawrence Livermore National Laboratory is considering an expansion of laser test facilities adjacent to its existing LLNL Site 300 test location. Construction of a free-electron laser, known as the FEL Project, is being considered on approximately 3900 he...

D. W. Taylor W. Davilla S. Orloff

1986-01-01

434

Fission-track dating of haughton astrobleme and included biota, devon island, Canada.  

PubMed

Haughton Astrobleme is a major extraterrestrial impact structure located on Devon Island in the Canadian Arctic Archipelago, Northwest Territories. Apatite grains separated from shocked Precambrian gneiss contained in a polymict breccia from the center of the astrobleme yielded a fission-track date of 22.4 million +/- 1.4 million years before the present or early Miocene (Aquitanian). This provides a date for the impact event and an upper limit on the age of crater-filling lake sediments and a flora and vertebrate fauna occurring in them. A geologically precise date for these fossils provides an important biostratigraphic reference point for interpreting the biotic evolution of the Arctic. PMID:17834450

Omar, G; Johnson, K R; Hickey, L J; Robertson, P B; Dawson, M R; Barnosky, C W

1987-09-25

435

Revising the fundamentals of ecological knowledge: the biota–environment interaction  

Microsoft Academic Search

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,

Victor G. Gorshkov; Anastassia M. Makarieva; Vadim V. Gorshkov

2004-01-01

436

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

Microsoft Academic Search

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