Asian oyster testing delayed

Va. group planned to raise 1 million in Chesapeake

`The danger is the unknown'

Species seen as possible threat to native variety

May 18, 2002|By Heather Dewar | Heather Dewar,SUN STAFF

A Virginia seafood industry group has shelved plans to introduce a million Asian oysters into the Chesapeake Bay this summer, after scientists warned that the well-meaning attempt to save the bay's oyster industry might have disastrous results.

The Asian oyster, Crassostrea ariakensis, looks and tastes a lot like the native bay oyster, and early experiments suggest that it may be resistant to the diseases that have ravaged the native variety.

The Virginia Seafood Council, a trade group, wants to expand experiments with 60,000 Asian oysters that have been neutered in the laboratory and raised in the bay. The council asked the state to allow 39 seafood dealers to place a combined 1 million sterile young oysters, beginning this summer, in bay waters.

The council planned to market the oysters and see whether consumers would buy them. A hearing on the request was scheduled for June 18.

Some see the Asian oyster as a possible way out of a frustrating dilemma.

Because oysters are natural water filters and their beds provide shelter for young fish and crabs, the Chesapeake Bay needs a large population to help recover its once-robust health and restore its fisheries.

But scientists and policy-makers from Maryland and the federal government challenged the seafood council's proposal. They said the Asian oyster, which has no known natural enemies here, might wreak environmental havoc -- bringing with it some yet-undiscovered disease, crowding out the native oyster or doing some other, unforeseen damage.

They pointed to another Asian import, the zebra mussel, which grows so thickly in the Great Lakes that it has shut down power plants by clogging water lines.

"The danger is the unknown," said scientist Bill Goldsborough of the Chesapeake Bay Foundation. "There's an endless number of questions about how this animal would fit into the bay. ... At some point you have to take a leap of faith, but we don't know enough yet to do that."

Yesterday, after the Virginia scientists studying ariakensis said they could not support the council's proposal, the trade group withdrew its request for a state permit.

Frances W. Porter, the Virginia Seafood Council's executive director, said oyster experts at the Virginia Institute of Marine Science thought the method to be used to sterilize the young oysters was not reliable enough, with a failure rate of 1 percent to 2 percent. That means that out of 1 million oysters, about 10,000 to 20,000 could breed in bay waters.

"They thought the risk was too high" that the experimental oysters would escape and create wild colonies, Porter said. The scientists also worried that too many seafood companies were involved, making it hard to control the project, she said.

The seafood council will switch to a sterilization technique that is more reliable but takes much longer to produce a large number of juvenile oysters, Porter said.

The council will also reduce the number of dealers involved and add tougher monitoring requirements.

Porter said the group will present state officials with a revised plan, and wants to begin the experiment as soon as scientists can produce enough reliably sterile oysters. That could be as soon as this fall or the spring of 2003, she said.

"The project is going to go forward, and it is going to be beneficial, not only to the oyster industry but to the health of the Chesapeake Bay," Porter said.

"We're pleased with this action," said J. Charles Fox, secretary of the Maryland Department of Natural Resources, which opposed the plan. "There is tremendous promise with the non-native oyster, but this is one of those decisions that we can't do over again."

Larry Simns, president of the Maryland Watermen's Association, said the decision to delay "was the smart thing to do" until ariakensis is better understood.

A National Academy of Sciences report on the benefits and risks of introducing the Asian oyster is expected to be completed in June next year.

Oyster growers all over the world have experimented with introduced shellfish. In Ireland, France, and the Pacific Northwest, the industry relies on imported varieties, Simns said.

"I'm hoping that won't happen to us," Simns said. "I'm hoping Mother Nature will give us a good reproductive cycle this year ... and keep the disease down. But that's a lot of hope."

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