During the 2012 spawning season, North Carolina State University scientists checked 20 of the state's streams and rivers for bass with reproductive problems that could potentially threaten populations, as well as for contaminants known as endocrine disruptors. They found that 60 percent of 81 bass tested were intersex, meaning males showed signs of developing eggs in their testes.
“Males guard the nest, create spawning nests for young, and guard fertilized eggs,” researcher Crystal Lee Pow said. “ Males are crucial for hatching success, and their male behavior could be altered by exposure to contaminants and the presence of the intersex condition.”
They also detected 43 percent of the 135 pollutants that they were looking for, because of the belief that exposure to them are feminizing male fish in waters across the country. These compounds include hormones, as well as drugs, chemicals, and pesticides that mimic estrogen, which enter the water via runoff or wastewater treatment plants.
Because differences between waterways are still being analyzed, researchers haven't yet revealed which rivers contain bass that have been affected. One of those might be the Catawba, which feeds Lake Norman, site of the 2014 Bass Pro Shops Southern Open and 2015 Carhartt College Eastern Regional. Just a few miles to the east, scientists found that the Pee Dee River had the highest rate of intersex fish in nine U.S. river basins during a 2009 study.
Here's another story about this growing problem for our fisheries: Scientists Find More Mutated Intersex Bass in Nation's Waters.