Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 15 of 15 for “"sediment toxicity"”.
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Sediment toxicity and bioaccumulation of toxicants in the zebra mussel, Dreissena polymorpha, at Times Beach, Buffalo, New York
… detection limits in the water column. In the sediment toxicant concentrations were as high as 549 mg/kg for total PAHs, 9 mg/kg for PCB Aroclor 1248, and 54, 99, 6, 355, 637, and 16 mg/kg for the metals: As, Ba, Cd, Cr, Pb, and Hg respectively. To predict contaminant bioavailability, elutriate …
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Comparative Toxicity of Eight Model Substances to the Sediment Dwelling Invertebrates Lumbriculus variegatus and Chironomus riparius
Existing ecotoxicity data for chemicals vary to a high extent between the environmental compartments water and sediment, since the evaluation of contaminants has historically focused on water exposition. Many anthropogenic chemicals and waste materials, including toxic organic and inorganic …
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Análisis Ecotoxicológico Integrado de la Contaminación Marina en los Sedimentos de la Costa De Murcia: El Caso de Portmán, Sudeste - España
… the most seriously heavy metal contaminated sediments of the Mediterranean Sea. From 1958 to 1991, approximately 50 million tons of mine tailings were dumped into the bay, completely filling up the bay and dispersing over an extensive area of the continental platform and continental slope. …
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Quantifying the presence of current-use insecticides and toxicity of sediments in urban residential watersheds in central Texas.
… concentration of current-use pesticides in the sediments of residential streams in central Texas. Additionally, the toxicity of these sediments to Hyalella azteca was evaluated. Sediment samples were collected from several sites in urban streams over the course of a pesticide application season. …
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Ecotoxicological Evaluation of Hollow Fill Drainages in Low Order Streams in the Appalachian Mountains of Virginia and West Virginia
… of hollow fill drainages included water/sediment chemistry, acute water column toxicity testing using <i>Ceriodaphnia dubia</i>, chronic sediment toxicity testing using <i>Daphnia magna</i>, benthic macroinvertebrate surveys, and <i>in situ</i> Asian clam (<i>Corbicula fluminea</i>) …
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Model of PAH and PCB bioaccumulation in Mya arenaria and application for site assessment in conjunction with sediment quality screening criteria
A review of six methods for deriving sediment quality criteria SQC was conducted. Each approach was analyzed according to cost, difficulty, applicability and reliability. Results of this analysis led to the recommendation that the state of Massachusetts should use a combination of the Equilibrium …
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The aquatic macrophyte Vallisneria americana as a biomonitor of site quality in Great Lakes areas of concern.
… accumulates contaminants primarily from the sediments. Both the leaf-to-root fresh mass ratio, and total fresh mass of V. americana plants showed similar results and could be used as approximate substitutes for the leaf-to-root surface area ratio. Mapping contours of leaf-to-root surface area …
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Abiotic and biotic factors influencing the decline of native unionid mussels in the Clinch River, Virginia
… the sensitive juvenile stage are the presence of sediment toxicants or adult Corbicula fluminea in the depositional areas, the preferred habitat of the juveniles. Before investigating the impacts of these factors, it was necessary to characterize the relationship of the juveniles with the sediment …
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Integrative Bioassessment of Acid Mine Drainage Impacts on the Upper Powell River Watershed, Southwestern Virginia
… conducted to investigate the nature of AMD ecotoxicity in the upper Powell River watershed. Emphasis was placed upon bioassessment methodologies and AMD impacts beyond the zone of pH depression. Major findings and processes developed included: 1) an Ecotoxicological Rating (ETR) system was …
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Current and historic freshwater mollusk distributions of the upper Coosa River Basin
… eutrophication , dewatering of tributaries and sediment toxicity appear to be major causes of species loss. Weiss Reservoir bypass on the mainstem Coosa River has the greatest potential for mollusk species restoration, and a minimum flow restoration schedule is currently under development. Holly …
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The Impacts of Acid Mine Drainage on the Black Creek Watershed, Wise County, Virginia
… analyses of both overlying water column and sediments. Using an upstream reach of Black Creek as a reference, short-term toxicity testing was employed, as well as a long-term purge study. The pH at sampling locations ranged from 2.75 to 7.87 SU, and conductivity ranged from 196 μmhos/cm to …
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Macrobenthic community and ecotoxicological status of the Nhlabane Estuary
… trace metal contamination of the estuary water, sediment and biota due to mining activities. The study aimed to describe the macrobenthic community of the Nhlabane Estuary during the post-drought period 1996-1999, to assess the ecotoxicological status of the Nhlabane Estuary in relation to dune …
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Chemical, Toxicological, and Microbial Characterization of New Orleans Sediments Following Hurricane Katrina
… Orleans, Louisiana. One month after the storm, sediment was collected and toxicity was tested using Japanese medaka (Oryzias latipes) embryos. Sediments with the highest contaminant levels showed the highest embryonic mortality and most delayed development. However, no sediment caused an …
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Identification of Ecosystem Stressors in Developing an Enhancement Plan for the Leading Creek Watershed, Meigs County, Ohio
… has shown significant problems relating to toxicity and habitat degradation in the watershed. Seventeen tributaries and ten mainstem stations were chosen to receive monthly monitoring as point source discharges, including biological, chemical, toxicological, and hydrological sampling. …