Sublethal Effects

Short-term laboratory exposure of adult fathead minnows to the human contraceptive progestin, gestodene (GES), at environmentally relevant concentrations induced rapid and negative effects on reproductive health and suggests that wild fish may be similarly affected.

Scientists conducted laboratory experiments on levonorgestrel (a synthetic progestin) and observed differential effects to males (reproductive behavior) and females (masculinization) of eastern mosquitofish ( Gambusia holbrooki ).

Evidence indicating the presence of wastewaters from unconventional oil and gas (UOG) production was found in surface waters and surficial sediments near an UOG disposal facility in West Virginia.

Neonicotinoid insecticides (neonicotinoids) were present in a little more than half of the streams sampled across the United States and Puerto Rico, according to a new U.S. Geological Survey (USGS) study. This is the first national-scale study of the presence of neonicotinoids in urban and agricultural land use settings across the Nation and was completed as part of ongoing USGS investigations of...

U.S. Geological Survey (USGS) scientists determined that endocrine disrupting chemicals (EDCs) were present in wastewater treatment plant (WWTP) effluent, water, and fish tissue in urban waterways in the Great Lakes and upper Mississippi River Regions (Indiana, Illinois, Michigan, Minnesota, and Ohio) during 1999 through 2009.

Endocrine disrupting chemicals and indicators of endocrine disruption were found in several Minnesota lakes with surrounding urban, residential, agricultural, and forested land uses. The lakes do not directly receive discharges from industries or wastewater-treatment plants; however, they are used for recreation, and they receive water from widely scattered sources. The presence of both male and...

In two separate studies, U.S. Geological Survey (USGS) scientists demonstrated that hormones such as estrogen can biodegrade in stream and groundwater environments. This is an important finding because the science, regulatory, and environmental communities have concerns about the environmental fate of endocrine-disrupting chemicals, such as hormones, in the human wastewaters discharged to the...

An international team of scientists investigating mercury cycling in an experimental watershed in Ontario, Canada, conclusively demonstrated at the ecosystem scale that changes in mercury loadings are expected to result in proportional or near proportional changes in mercury bioaccumulation in fish. Policies to reduce atmospheric emissions of mercury are intended to reduce mercury bioaccumulation...

Intersex, the presence of both male and female characteristics within the same fish, is being observed in fish in more streams across the Nation. Intersex is one manifestation of endocrine disruption in fish. Endocrine disruption can result in adverse effects on the development of the brain and nervous system, the growth and function of the reproductive system, and the response to stressors in the...