DNR: Stonewall Crappie Kill Probably Disease-Related

Charleston Gazette
31 May 2010
By John McCoy

West Virginia fisheries officials now suspect that disease, not pollution, caused a fish kill last week at Stonewall Jackson Lake.

“Given that the fish that were killed were predominantly a single species, and that our preliminary water-quality tests didn’t turn up anything unusual, the kill appears related to a disease issue and not from the discharge of a toxin,” said Bret Preston, the Division of Natural Resources’ head of warm-water fisheries.

About 1,000 fish – almost all crappie – turned up dead on May 24, Preston said. The kill occurred in the West Fork arm of the lake near Jacksonville. About 100 more dead fish were found later in the week near Oil Creek.

A biologist dispatched to the scene took water-quality samples and collected dying fish for post-mortem study. Inspectors from the Department of Environmental Protection soon arrived and conducted even more extensive water-quality tests.

Preston said none of the DNR’s water samples turned up anything abnormal. Kathy Cosco, a spokeswoman for the DEP, said the agency’s inspectors haven’t yet finalized their test results.

“They did say that the kill doesn’t appear to be pollution-related because it essentially only affected one kind of fish,” she added.

Some of the dead crappies were couriered to the U.S. Fish and Wildlife’s Northeast Fish Health Lab in Lamar, Pa., and to the U.S. Geological Survey’s Leetown Science Center.

“The pathologist who did the gross examination said no [potential cause] jumped out at him, but that’s not unusual,” Preston said. “We won’t know for sure what caused those fish to die until the folks at the labs take tissue cultures and look for bacterial and fungal infections.”

The tissue cultures “could take several weeks” to produce results, Preston added. “We won’t know anything for sure until then,” he said.

While they wait for the lab report, DNR officials have started searching the scientific literature for diseases that cause crappie-specific kills.

Preston said the leading suspect so far is Columnaris Disease, a malady caused by Flavobacterium columnarae, a fairly common bacterium. The disease affects crappies’ gill tissues and causes them to suffocate.

“I’ve seen reports and studies of Columnaris-caused, crappie-specific fish kills in lakes,” Preston said. “To my knowledge, though, we’ve never before experienced one in West Virginia. The pathology will tell us if our suspicions are correct.”

At about the same time as the Stonewall kill, Pennsylvania fisheries officials reported crappie kills in Pymatuning Reservoir and a smaller impoundment. Preston said the Pennsylvania kills are also under investigation.