CHERITON, Va. - The Chesapeake Bay may have met the future of its oyster industry yesterday.
At a hatchery on Virginia's Eastern Shore, more than 250,000 baby oysters were lifted from protective tanks, dumped into orange mesh bags and delivered to watermen to be raised and eventually sold.
But these baby oysters are unlike any previously raised in quantity on the bay. These are of the Asian variety, a non-native species that watermen, government officials and some scientists see as a commercial alternative to the disease-ravaged native mollusk.
"I think this is a smart step, and one we need to take," A.J. Ershine, the Virginia Seafood Council's manager for the Asian oyster project, said as he lifted cylinders of oysters from the hatchery's long tanks.
"We need to do something. We need to try and see if this will work. Can the watermen grow these oysters? Can they market it?"
Yesterday's distribution was a milestone in the long-running debate over using the Asian Crassostrea ariakensis to revive the bay's ailing oyster industry. Previous experiments in putting such oysters into the bay were far more modest, a 6,000-oyster trial in 2000 and a 60,000-oyster test in 2001.
By the middle of next month, researchers at the Virginia Institute of Marine Science (VIMS) expect to have distributed the million Asian oysters they've raised to eight Virginia watermen. The watermen will grow the oysters at scattered sites in the bay, side by side with control samples of the native variety, Crassostrea virginica.
"This is the experiment that I think is going to give us a lot of the answers," said Chad Ballard, a member of the Virginia Marine Resource Council and owner of the clam hatchery where the Asian oysters have spent the past few weeks growing.
To prevent the Asian oyster from growing out of control - or introducing a disease that jeopardizes the health of the bay and its native oyster -VIMS scientists have created a sterile variety of the species, manipulating its genes to ensure that no more than one in 1,000 is able to reproduce. All of the Asian oysters will be kept in containers to ensure that none is accidentally lost or swept away in the water.
"The probability they will actually make a reproductive population is basically nil," said Stan Allen, the VIMS geneticist who developed the sterile production technique and oversees the experiment.
Allen and his colleagues used procedures on what he called a "careful, almost obsessive, scale." The first test batch of a million oysters this summer produced four out of 3,000 that were able to reproduce, slightly more than the government safety threshold of three in 3,000 but enough to persuade scientists to destroy that batch rather than risk putting it into the bay.
In the latest batch, two in 3,000 are able to reproduce.
The VIMS approach was endorsed over the summer by a National Research Council report. The scientific panel said efforts to revive the native oyster should not be abandoned, but it endorsed the controlled study of sterile Asian oysters.
The report concluded that the Asian species will never replace the native variety in terms of filtering pollutants from the bay, and it recommended up to five more years of study to determine whether fertile oysters can be safely introduced. The Chesapeake Bay Foundation and many other environmental groups have supported the panel's findings.
Maryland officials want to speed that up but concede that a summer 2004 target set by Gov. Robert L. Ehrlich Jr. to put reproductive Asian oysters into the bay is too ambitious.
Scientists know they're being closely watched. Yesterday's distribution drew national and regional media to Cherrystone Aqua Farms on the southern part of Virginia's Eastern Shore.
"Yes, there's a lot of pressure, but that doesn't mean we've backed off the science," Allen said. "There's a lot of pressure coming from people who don't get paychecks when there's no seafood industry, and I feel for them."
The million oysters to be distributed over the next few weeks come from one genetically manipulated male, the sperm of which was crossed with the eggs of about a dozen females.
The baby oysters appear normal but have a condition known as triploidy, meaning they have three sets of chromosomes. Not only are these oysters infertile, but they also tend to grow faster and plumper than fertile oysters because they can redirect reproductive energy to growth.
The control batch of native oysters is also sterile, ensuring a fair comparison. Scientists predict that the Asian oyster will fare much better, largely because it appears to be resistant to Dermo and MSX, diseases that have decimated the bay's native oyster population.
Oyster catches in Maryland, which reached more than 2.5 million bushels a year as recently as the 1980s, fell to less than 60,000 bushels last year.
