A Mystery of Fish Mortality

MORGAN FORD, Va. -- Something in the Shenandoah River is turning the smallmouth bass thin and listless and causing sunfish to break out in blisters that look like cigarette burns. Something in the water is making both species weaken and die, leaving the river bottom flecked with white bellies.

Something is doing all this. After five years of tests, more than $600,000 in government money and uncounted numbers of dead fish, that's still as much as anybody knows.

Since 2002, fish have been dying in the Shenandoah and other western tributaries of the Potomac River, and scientists have been racing to find the cause. They have considered viruses, oxygen-depleted "dead zones" and runoff from chicken farms, but they have found nothing definitive. At the same time, the search has been complicated by die-offs this year in two rivers outside the Potomac watershed: the Cowpasture and upper James.

At the center of the mystery is the Shenandoah, whose easy fishing and picturesque setting have long attracted visitors from the Washington area. Here, the impact has been ecological, economic and emotional, as locals try to understand how this beloved waterway became something that kills fish.
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