"Male Bass in Many US Rivers Feminized, Study Finds"

"Government scientists figure that one out of five male black bass in American river basins have egg cells growing inside their sexual organs, a sign of how widespread fish feminizing has become.

The findings come from the U.S. Geological Survey in its first comprehensive examination of intersex fish in America, a problem linked to women's birth control pills and other hormone treatments that seep into rivers. Sporadic reports of feminized fish have been reported for a few years.

The agency looked at past data from nine river basins -- covering about two-thirds of the country -- and found that about 6 percent of the nearly 1,500 male fish had a bit of female in them. The study looked at 16 different species, with most not affected.

But the fish most feminized are two of the most sought-after freshwater sportfish: the largemouth and smallmouth, which are part of the black bass family."

Seth Borenstein reports for the Associated Press September 14, 2009.