August 30, 2015 –Male black bass and some sunfish in North Carolina rivers and streams are developing eggs in their testes, which can cause reproductive problems and potentially threaten populations, according to unpublished research.
The research adds to growing evidence that exposure to estrogen compounds is feminizing male fish across the U.S. and suggests that North Carolina fish might be particularly at risk.
“It’s a very interesting study and certainly adds to our understanding of what’s potentially going on in our rivers and with the intersex fish,” said Vicki Blazer, a U.S. Geological Survey fish biologist who was not involved in the study.
North Carolina State University researchers tested 20 streams and rivers throughout North Carolina during the 2012 spawning season for contaminants known to disrupt endocrine systems, such as industrial chemicals and pesticides. They also tested black bass – largemouth and smallmouth bass – and sunfish in the rivers for “intersex” characteristics, looking for eggs in the testes of males.