Va. expected to introduce foreign oyster species in bay

Fisheries panel to vote on trial of Asian shellfish

February 25, 2003|By Timothy B. Wheeler | Timothy B. Wheeler,SUN STAFF

Virginia officials are poised to introduce up to a million Asian oysters into the Chesapeake Bay, despite warnings from scientists and federal agencies that their experiment to save the beleaguered seafood industry could go badly awry.

The Virginia Marine Resources Commission was scheduled to vote today on a proposal by seafood processors to raise the Asian oysters in controlled settings to see whether restaurants and other customers will buy them. The trial would start in June.

The Asian oyster, Crassostrea ariakensis, looks and tastes much like the native Eastern oyster. Previous tests have shown that it grows faster and is resistant to the diseases that have ravaged the bay's oyster population.

Virginia backers hope to pave the way for revival of that state's oyster industry, which disease has driven to the brink of collapse. Maryland's watermen and seafood industry, facing a record-low harvest this year, are pressing for similar studies.

"The reality is, if you don't do anything, there won't be any industry left to save in either state," said Wilford Kale, spokesman for the commission, which regulates Virginia fisheries.

But many scientists say that despite precautions, the experiment could result in the uncontrolled spread of Asian oysters. In the worst case, they could crowd out the native species not only in the bay, but along the Atlantic and Gulf coasts as well.

"We're basing a major introduction to the East Coast of the United States - it's not just a Maryland and Virginia issue - on very little data," said Frederick Kern, a biologist at the federal-state fisheries laboratory in Oxford, Talbot County, Md.

In response to scientists' concerns, the Virginia Seafood Council has modified its plan, first unveiled a year ago. The industry now proposes to use only hatchery-reared oysters genetically bred to be sterile, and it says they will be screened to weed out any that might still be capable of spawning.

The number of oyster-rearing sites has been scaled back from 39 to 10 - with two sites along the Atlantic Ocean and the rest in the bay. All oysters will be kept in plastic mesh bags and laid either in floating or submerged trays for easy retrieval.

Cautious support

The changes have won the cautious support of Maryland officials, the Chesapeake Bay Foundation and of some, but not all, scientists - most of whom remain skittish about unforeseen consequences of releasing a little-known oyster from China in the bay.

"It's their proposal that changed, not our standards," said William Goldsborough, senior fisheries scientist for the Annapolis-based Chesapeake Bay Foundation. The environmental group still opposes releasing the Asian oysters into the bay, he said, but is willing "to learn more about it."

Federal environmental agencies and two scientific groups, however, have called for imposing even more precautions to reduce the risks of an unintended spread of Asian oysters.

An international panel engaged by federal and state agencies to review the Virginia experiment last year is not due to report until June - about the time the Asian oysters would start going into the water.

"At present, there is insufficient scientific information available to thoroughly quantify and evaluate the risks and benefits of introducing this species into Virginia waters," the co-chairmen of the National Research Council panel wrote in a letter released yesterday.

The process used by the Virginia Institute of Marine Science to produce sterile baby oysters is not 100 percent effective, the scientists said. Past experience suggests there could be as many as 900 Asian oysters capable of reproducing, they estimated - an average of 90 per site.

"You really only have to have a male and female present in one tray to succeed in spawning," noted Kern. He wrote a similar warning as chairman of a scientific group advising the Chesapeake Bay Program, a federally backed effort to restore the bay.

The Bay Program scientists urged that the study end by June 2004 to reduce the risk that fertile oysters could grow large enough to reproduce. They called for frequent sampling for signs that the oysters might be able to spawn and recommended that plans be made to prevent the oyster trays being wrecked by a hurricane or storm, scattering the shellfish.

Virginia officials say that if they approve the project as expected, they will impose new limits or cancel it altogether should the scientific report in June raise any new concerns.

"I think we've done everything we can possibly do" to minimize risks of ecological harm, said William Pruitt, chairman of the nine-member Virginia panel. "I'm willing to take that chance and go forward with this experiment."

Precautions accepted

Baltimore Sun Articles
|
|
|
Please note the green-lined linked article text has been applied commercially without any involvement from our newsroom editors, reporters or any other editorial staff.