Experts hopeful of oyster's return to Chesapeake Bay

Watchdog group works to increase oyster population tenfold by '05.

August 17, 1999|By Francis X. Clines | Francis X. Clines,New York Times News Service

PORTSMOUTH, Va. -- The oyster scientist stepped out of the boat into the western branch of the Elizabeth River, seeming to defy nature and stand on the water itself.

"This is profound," said Robert D. Brumbaugh, a fisheries specialist, standing on the barely visible tip of what scientists say is a critical turning point in the beleaguered life of the once supreme Chesapeake Bay oyster: an oyster reef laboriously created by an armada of scientists and hundreds of citizen volunteers.

"It's been so long since oyster reefs have been hazards to navigation here," Brumbaugh said, proudly noting the "Danger: oyster reef" sign rising from the murky water sloshing over the tip of the reef at low tide.

The sign stands as far more than a throwback to the 19th century, when vast Chesapeake oyster reefs rose up fruitful as orchards toward the thousands of watermen who used to harvest their succulent treasure from skipjack sailboats. In fact, the reef warning is pointing firmly to the future.

"The return of oysters to Chesapeake Bay would probably be the greatest signal that we really are heading in the right direction," said William C. Baker, president of the Chesapeake Bay Foundation, a watchdog group of scientists and citizens that has worked with surrounding state governments for the last 30 years to repair and protect the bay. The foundation has been working toward a tenfold increase in the oyster population by 2005, using volunteers and the reef approach that is gathering momentum.

A new consensus report by the bay's principal scientists, after years of life-support experimentation on the oyster, has recommended an all-out commitment to three-dimensional reef construction not mere flat-bottom beds as the key to restoring the oyster to its central place in the life of the bay.

The agreement marks a moment of rare optimism about the tattered health of the oyster and, by extension, the bay itself, a vast resource of 64,000 square miles with a watershed population of 15 million people across six states. The oyster is a keystone species that had prodigiously filtered away impurities in the pristine heyday of the bay while propagating upward like coral reefs as magnets for other creatures.

"For the first time, we have a technical consensus across state lines," said Dr. Donald Boesch, president of the University of Maryland Center for Environmental Science. The report was produced by 10 marine scientists from Maryland, Virginia and North Carolina, led by Dr. Gene Burreson of the Virginia Institute of Marine Science.

The basic problem is that in the last four decades, gross overfishing and two protozoan diseases have devastated the oyster population to about 1 percent of its glory years of a century ago. The scientists concluded that 10 percent of the bay's historically best oyster grounds must be set aside for the creation of permanent reef sanctuaries.

A century ago, more than 20 million bushels of oysters were harvested annually from the bay. Five years ago, the take was fewer than 100,000 bushels and has rebounded only marginally while scientists have pursued long-term solutions.

Seventeenth-century ship logs and sketches of the bay's old reefs have been consulted in building the score of new reefs dotting the bay. Up to an acre each, they rise up to 12 feet above the floor sediment and cost up to $100,000 each. By far the most ambitious step building a ring of 10 one-acre reefs plus surrounding fields of shucked oyster shells 10 inches deep is to begin next year in the lower Rappahannock River, once an oyster mother lode that has gone fallow.

For all the shifting problems of the bay chronic river fishkills like the enormous one in late July from drought and toxic microbes called pfiesteria, dangerous runoffs of sediment and nutrients from the region's farms and lawns there are positive new signs, like the pelicans that have migrated to swoop about the bay. But the two keys to the bay's health remain the oyster and underwater grasses, Baker emphasized. An estimated 88 percent of grass acreage has been lost this century in various abuses of the bay. This loss is increasingly a threat to the crab population that has overtaken the oyster as the bay's main commercial harvest.

"If enough oysters can clear the water once more, the sunlight may penetrate and nurture the grasses and reoxygenate the water," Baker said. He summarized a cycle pinned to encouraging experiments with man-made reefs stocked with hatchery-produced, disease-resistant oysters.

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