A new survey led by the US Geological Survey (USGS) has found intersex fish, or fish that display traits of both genders, in at least three Pennsylvania River Basins. According to the USGS, “male” specimens recovered from the Susquehanna, Delaware, and Ohio river basins have been discovered to contain immature eggs in their testes. Experts are saying that the trait may have been caused by exposure to man-made chemicals that include hormone-mimicking compounds.
“Chemical compounds associated with estrogenic endocrine disruption, in particular estrone, a natural estrogen, were also associated with the extent and severity of these effects in bass,” said fish biologist Vicki Blazer.
“The sources of estrogenic chemicals are most likely complex mixtures from both agricultural sources, such as animal wastes, pesticides and herbicides, and human sources from waste water treatment plant effluent and other sewage discharges,” she added.