Male Bass in Potomac Producing Eggs

Male Bass in Potomac Producing Eggs (WaPo A01)

The South Branch of the Potomac River is as clear as bottled water here, where it rolls over a bed of smooth stones about 230 miles upstream from Washington. But there is a mystery beneath this glassy surface. Many of the river’s male bass are producing eggs. Scientists believe this inversion of nature is being caused by pollution in the water. But they say the exact culprit is still unknown: It might be chicken estrogen left over in poultry manure, or perhaps human hormones dumped in the river with processed sewage. Chances are, it is not something that federal and state inspectors regularly test for in local waters.

The discovery has made the South Branch the latest example of an emerging national problem: Hormones, drugs and other man-made pollutants appear to be interfering with the chemical signals that make fish grow and reproduce. While researchers look for answers in West Virginia, other scientists are testing Rock Creek, and another group is seeking financial support to test the rest of the Potomac to see whether they can find the same troubling effects downstream.
“Whatever’s doing this to the fish may be the canary in the mineshaft,” said Margaret Janes, a West Virginia activist with the Appalachian Center for the Economy and the Environment.

Scientists say it’s still too early to tell what these findings will mean for the bass population in the South Branch; they aren’t sure whether the affected males are still able to reproduce. And no one is aware of any effects on human health in the Potomac watershed. But scientists believe that fish might be the first to absorb any dangerous chemicals that might later affect humans.
“They’re likely to be hit first,” said Mike Focazio, a researcher with the U.S. Geological Survey. “We look there, and it seems to be happening.”

The situation in West Virginia was discovered by accident, when scientists from the state and the geological survey were called in to investigate reports that fish in the South Branch were developing lesions and dying en masse. They dissected dozens of bass caught last summer, mainly smallmouth bass. They found no obvious cause for the lesions or deaths, but did discover that 42 percent of the male bass had developed eggs inside their sex organs.

The study surprised scientists. Though the South Branch has been cited for problems with bacteria from poultry manure, state officials said it did well on most aspects of water-quality testing. “We always have, and still do, look at this as one of our highest-quality fisheries,” said Patrick Campbell of the state Department of Environmental Protection. “It’s counter-intuitive to think we would have this type of problem out there.”


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James Joyner
About James Joyner
James Joyner is Professor and Department Head of Security Studies at Marine Corps University's Command and Staff College. He's a former Army officer and Desert Storm veteran. Views expressed here are his own. Follow James on Twitter @DrJJoyner.


  1. Bithead says:

    But notice the one possibility they don’t look at;
    That they don’t know these fish quite so well as they think.

    This may very well be a natural thing every few generations, no?

  2. McGehee says:

    Bithead, are you kidding? There’s no way this isn’t Bush’s fault! He and Cheney must have been sneaking down to the river and personally dumping Halliburton-produced pollution directly on these poor fish. Now the fish have to go through life with the stigma of being intergendered.

    Fish can be so cruel to other fish.

  3. McGehee says:

    And it’s a good thing there isn’t another debate. You just know Kerry would bring up these poor fish.

  4. LJD says:

    The scientists, named Pat, Robin, and Terry, were also unable to distinguish between male and female human beings.

    Further examination of their study determined that the fish were actually female, exploring their masculine side.

  5. Paul says:

    Actually many fish are transgender -no really- they are male young in life then they become female later.

    look up the mating habits of the Amphiprion ocellaris (or any of the Amphiprion’s as I recall) it is fascinating.

  6. paladin says:

    This is every woman’s fantasy!

  7. Two Cents says:

    I think it’s the girly-men hormones in the waste products draining into the Potomac from the State Department, the Democratic sides of the House and Senate, and the millions of journalists (all leftists) in Washington. (The Pentagon and White House must connect to some other drainage, ‘cuz there aren’t any girly-men–or girly-women in those two buildings!

  8. JakeV says:

    That’s it, Bithead, you give those liberal scientist what-for! Sayin that male bass layin eggs is probably the result of pollution, when maybe it’s just that every now and then a whole bunch of male bass in a certain confined geographical area, um… decide to start laying eggs! Or something!

    Who knows what other mysteries the rare and little-studied bass species may hold!

  9. John Lamar says:

    “I know the human being and fish can coexists peacefully.”

    George W. Bush September 29, 2000 Comment made in Saginaw, Michigan during presidential campaign.