Sublethal Effects

The presence of testicular oocytes (intersex) in male smallmouth bass ( Micropterus dolomieu) in the Missisquoi River in Vermont varied over the period of the study and was not related to concentrations of known endocrine disrupting chemicals in the River. Although previous studies have shown linkages between endocrine disrupting chemical exposures and intersex in fish, these results indicate that...

U.S. Geological Survey (USGS) and academic scientists partnered to identify challenges and provide considerations for future scientific study designs to advance our understanding of the often subtle sublethal effects of contaminants on individuals, populations, communities, and entire aquatic food webs.

Science from the U.S. Geological Survey (USGS) and other entities has shown that a mixture of natural and synthetic estrogens and other similar chemicals are discharged from wastewater treatment plants (WWTPs) to streams and rivers.

The Fishing, Hunting, and Subsistence Living 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...

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 creative combination of radiography and techniques borrowed from meat processing and gold prospecting led to a better method for determining the lead content in ground squirrels shot by hunters to evaluate potential exposure risk to avian scavengers such as golden eagles ( Aquila chrysaetos).

Tree swallow nestlings at most study sites in the Great Lakes basin were minimally exposed to organic contaminants.

The incidence of particular skin and liver tumors on white suckers collected from some Wisconsin rivers corresponded to the degree of urban development within the watershed. Further research is needed to understand the relationship between exposure to urban-sourced contaminants and the initiation, promotion, and potential for population-level effects of these tumors.

Changes in the regulation and use of some organic chemicals have caused environmental concentrations to stabilize or decline during the past 35 years coincident with a rebound in the osprey ( Pandion haliaetus) population of the Chesapeake Bay.

Tree swallow eggs at most study sites in the Great Lakes basin were minimally exposed to legacy organic contaminants and brominated flame retardants.

The first known hepatitis B virus to infect fish (white sucker; Catostomus commersonii) has been discovered by U.S. Geological Survey (USGS) scientists.

A recent study by the U.S. Geological Survey (USGS) provides some of the first environmental contaminants data for a species of passerine bird (perching birds) in Alaska but leaves unanswered questions as to the cause of beak abnormalities found in this species.Beginning in the late 1990s, biologists and members of the public reported an unusual number of beak abnormalities among black-capped...