Mutant fish

The U.S. Geological Surveys has released a study finding abnormally high numbers of “intersex” fish in the Potomac River. From the AP article:

McLEAN, Va. - Some species of male fish in the Potomac River and its tributaries are developing female sexual traits at a frequency higher than scientists have seen before, raising concerns about pollutants in a waterway that provides drinking water for millions of people.

The so-called "intersex fish," which produce immature eggs in their testes, were discovered in the Potomac rivershed in 2003 and have also been found in other parts of the country.

But the frequency that the U.S. Geological Surveys found last year is much higher than what has been found elsewhere, said fish pathologist Vicki Blazer.

In some Potomac tributaries, nearly all of the male smallmouth bass caught in last year's survey were the abnormal fish. In the Potomac itself, seven of 13 largemouth bass exhibited female characteristics, including three that were producing eggs.

Although the frequency discovered was surprisingly high, Blazer cautioned that the sample size was relatively small, with about 10 male and 10 female fish taken from each of eight locations in Maryland, Virginia and the District of Columbia.

I find this more than a little disturbing.