Bioassays

The Fishing and Hunting integrated science team focuses on contaminant and pathogen exposures in the environment that could impact the presence and vitality of fish and wildlife populations that drive commercial, recreational and subsistence activities such as hunting and fishing. If actual risks are identified this project will inform how to economically and effectively minimize risk by providing...

Scientists optimized existing endocrine active chemical screening tests to improve their precision, accuracy, and ability to screen more samples in a shorter time-frame. The optimization was done to more rapidly obtain results from the bioassays so that research on the risks of endocrine active chemical exposure can proceed more rapidly.

The Chesapeake Bay is the largest estuary in the United States and provides critical resources to fish, wildlife and people. For more than a decade, recreational fish species have been plagued with skin lesions and intersex conditions (the presence of male and female sex characteristics in the same fish) that biologists attributed to exposures to endocrine disrupting chemicals (EDCs)...

A riparian zone rich in terrestrial insects can provide an alternate food source for fish in metal-impacted watersheds.

U.S. Geological Survey (USGS) scientists developed 129 sediment-toxicity benchmarks for use in evaluating currently used pesticides in whole sediment.

Estrogens are recognized as modulators of immune responses in mammals, but how these effects might occur in fish was not understood. U.S. Geological Survey (USGS) scientists published findings that fish white blood cells (leukocytes) have specific estrogen receptors (ERs)—a discovery that moves scientists one step closer to understanding the connection between exposure to estrogenic substances and...

Testing of U.S. streams has detected glucocorticoid and androgen biological activity. In a collaborative study between the National Cancer Institute (NCI), Laboratory of Receptor Biology and Gene Expression, the U.S. Geological Survey (USGS), and others, scientists studied the potential for the biological activity in streams of glucocorticoids and androgens hormones—both potential endocrine...

“Legacy contaminants” and “contaminants of emerging concern” that persist in the environment are affecting the health of fish and wildlife in the Chesapeake Bay and its watershed. State continue to report impaired water resources due to the persistence and toxicity of some previously banned pollutants. In addition, other contaminants of emerging concern are released to the environment at levels...

Chemical contaminants including herbicides, veterinary pharmaceuticals, and biogenic hormones have been detected at fish nesting sites in the Potomac River watershed where endocrine disruption in smallmouth bass ( Micropterus dolomieu ) was also observed. Although these contaminants are known to originate from a variety of human and animal-waste sources, results of a recent U.S. Geological Survey...

The slick scum or biofilm that covers most rocks in streams can accumulate contaminants that disrupt reproductive and other endocrine systems in fish. This is the finding of a team of U.S. Geological Survey (USGS) and University of Colorado Boulder scientists as described in a recent article in Environmental Science and Technology ( Writer and others, 2011 ). Biofilms are a mixture of algae...

U.S. Geological Survey (USGS) scientists studying the effects of harmful algal blooms on lake water quality found that blooms of blue-green algae (cyanobacteria) in Midwestern lakes produced mixtures of cyanotoxins and taste-and-odor causing compounds, which co-occurred in lake water samples. Cyanotoxins can cause allergic and/or respiratory issues, attack the liver and kidneys, or affect the...

For some fish living downstream of sewage treatment plants the answer is yes. U.S. Geological Survey (USGS) scientists and their colleagues published a paper in Environmental Science and Technology documenting that specific antidepressants and their degradates found in wastewater discharged into streams by municipal wastewater treatment plants are taken up into the bodies of fish living downstream...