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Description of Work USEPA Region 5 previously funded a study in 2011 evaluating the toxicity of nitrogen compounds to a select number of pond-dwelling amphibians. The objective of this new study will be to determine the toxicity of nitrogen compounds to stream-dwelling amphibians. Nitrogen contamination in aquatic systems results from the decomposition of organic matter, as well as through agricultural inputs, sewage effluents and industrial activities. Nitrogen in its various forms is of ecological concern because of its ubiquitous distribution and toxicity to aquatic life. Nitrogen compounds pose a hazard to aquatic larval stages of amphibians, affecting survival and development, and inducing deformities and behavioral...
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Description of Work Goal of this task is to conduct studies to determine the acute and chronic toxicity of sulfate (as sodium sulfate) to early life stages of: (1) fish (fathead minnow, Pimephales promelas), (2) snails (pond snail Lymnaea stagnalis), and (3) mussels (fatmucket, Lampsilis siliquoidea).
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Description of Work A number of field studies have shown that mayflies (Ephemeroptera) tend to be more sensitive than other benthic macroinvertebrate taxa to elevated levels of total dissolved solids in streams impacted by mining. Until relatively recently, difficulties with culturing have precluded the use of mayflies as laboratory toxicity testing organisms; however, researchers at Stroud Water Research Center have found parthenogenic species that readily reproduce under laboratory conditions, and researchers at the US EPA EERD laboratory have developed laboratory cultured diets for mayflies that will help to move toward standardization of methods. Recent efforts at the Illinois Natural History Survey built upon...
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Description of Work Elevated concentrations of major ions are associated with a variety of discharges to aquatic ecosystems, including urban wastewater, mountain top removal and valley fill operations, and coal bed methane production. There is considerable uncertainty regarding the toxicity of major ions to aquatic organisms, particularly given the variability of constituents that comprise these effluents. Because the relative toxicity of major ions is highly variable, predicting effects based on conductivity, total dissolved solids (TDS) or other composite measures may be simplistic. Furthermore, most of the available information on sensitivity of aquatic organisms to major ions has been derived from short-term...


    map background search result map search result map Toxicity Testing of Mayflies Generation of Chronic Toxicity Data for Sulfate Microcosms to Evaluate Elevated Major Ions Toxicity in Stream-Dwelling Amphibians Toxicity Testing of Mayflies Generation of Chronic Toxicity Data for Sulfate Microcosms to Evaluate Elevated Major Ions Toxicity in Stream-Dwelling Amphibians