By Sabri Ben-Achour
Environmental groups and politicians are campaigning to find out why "intersex" fish continue to show up in the Potomac river and its tributaries.
It's been seven years since male bass in the Potomac were found to have eggs and egg precursors growing in their reproductive tissues.
"That is not normal, something is wrong," says Hendrik Belin, who heads the environmental group Potomac Conservancy. His group is launching a campaign to press for more research into the phenomenon.
"We're looking at the problem and we can solve it, but it's going to require greater public demand for answers," he says.
Rep. Jim Moran (D-VA) says he is trying to fund more research.
"The fish are invariably the canary in the coalmine, warning us about something," says Moran.
Scientists suspect that "something" is endocrine disruptors, found in many household and agricultural products - fertilizers, prescription drugs, antibiotic soaps. These compounds, even in trace amounts, are thought to affect fish's immune systems and development--and they routinely show up in tests of municipal drinking water systems, including Washington's.