Roanoke Times
Copyright (c) 1995, Landmark Communications, Inc.
DATE: TUESDAY, May 8, 1990 TAG: 9005080034
SECTION: SPORTS PAGE: B4 EDITION: METRO
SOURCE: BILL COCHRAN
DATELINE: LENGTH: Medium
Mark that name well. Zebra mussel, Dreissena polymorpha. It has potential for becoming a nightmare in the '90s.
The Virginia Department of Game and Inland Fisheries is preparing to add the ear-shaped, shelled critter to its list of aquatic outlaws, which includes the piranha, walking catfish and African clawed frog.
The department's board is scheduled to give final approval Friday to a regulation that will make it unlawful to import, cause to be imported, buy, sell or liberate zebra mussels within the commonwealth.
David Whitehurst, chief of the department's fish division, said if this striped nuisance muscles its way into Virginia it will be a threat to all types of water users, from fishermen to kids walking barefoot along a lake's shoreline.
For the angler, the big worry is that the zebra mussel will compete unfavorably with native aquatic species for food and spawning habitat.
"They are the size of a thumbnail, but each one of them can filter up to a liter of water per day," Whitehurst said.
That figure grows awesome when you consider that colonies of 30,000 to 100,000 mussels per-square meter have been reported in Lake Erie, he said.
"You are talking about one square meter filtering 100,000 liters of water per day."
As the water is filtered, or siphoned, through the animals, the plankton is removed. This could be disruptive to plankton-feeding baitfish and, in turn, affect sport fish, such as bass, crappie, walleye and stripers, that depend on the baitfish for survival.
It also is feared that mussel colonization in shallow water areas could result in the loss of spawning habitat.
There's more. Zebra mussels can attach to nearly any surface, including boat bottoms, marine engine and the equipment used to generate power and treat water.
Their shells have been known to damage boat cooling systems. Some beaches in the Great Lakes region are so littered with shells that bathers are wearing footwear to prevent cuts. Decomposing mussels create obnoxious odors. Navigation markers have been toppled under their weight.
Whitehurst sees the New River as the most likely entry point of the zebra mussel into Virginia.
"The mussel is very likely to get into the Ohio River drainage," he said. "Of course, the New River is part of that drainage."
If not that way, there is a good chance that some fisherman will trailer his boat to the Great Lakes and zebra mussels will get a free ride into Virginia when they attach to the craft or get into the livewell.
"The adults are extremely hardy and can live out of the water seven days," Whitehurst said. "If they were in a livewell where the moisture level was high, they easily could live 10 days."
Virginia's fish division lacks the funds and manpower to launch a major defense against these undesirables, Whitehurst said. He hopes power companies and other industries that use the state's waterways will kick in some money for education purposes.
Posters need to be placed at marinas, brochures need to be handed out informing boaters and anglers of the dangers of setting this creature loose in Virginia, he said.
"This animal may well be the worst exotic competitor for native aquatic fauna introduced into the country to date," Whitehurst said.
by CNB