Pollution Turns Male Fish Into Mutant Mommies

The Potomac river has become so polluted that most of its male fish have mutated and developed female traits—like carrying eggs in their testes. More than 80% of the river's male bass have some female characteristic, the Potomac Conservancy tells the Guardian, blaming drugs and other chemicals that have been flushed into the water. “We are still trying to get a handle on what chemicals are important,” said one biologist.

These fish are, remember, swimming in the same river that 90% of people in the greater Washington, DC, area get their drinking water from. “We need to get these toxins out of our river water,” said the Conservancy's president, calling on authorities to invest in technology to filter out suspect chemicals, and to enlist drug companies to create safer ways to dispose of their products. (More fish stories.)