Hope On The Half-shell

November 20, 1994|By Timothy B. Wheeler | Timothy B. Wheeler,Sun Staff Writer

Two straight years of wet spring weather have loosened the stranglehold of parasitic diseases on oysters in the Chesapeake Bay, prompting watermen and state officials to predict a rebound from Maryland's slumping harvests.

With watermen now catching oysters in parts of the Chesapeake that have yielded almost nothing for nearly a decade, state officials talk optimistically about doubling last year's record-low harvest of 79,568 bushels.

Maryland has embarked on a broad effort to restore the oyster industry, including the raising of disease-free shellfish in a state-run hatchery. But those fledgling attempts are not expected to yield significant results for years, if ever. Even if the Maryland harvest this season does double, it would be a far cry from the catches of 1 million bushels or more that were typical until a decade ago.

But after six years of declining harvests, the worst may be over, according to W. Peter Jensen, fisheries director for the state Department of Natural Resources. "It has created new hope on the Eastern Shore," he said last week. "People are starting to say they see a future."

Scientists, however, caution that the turnaround is likely to be short-lived. They warn that the diseases Dermo and MSX probably will return with a vengeance in a year or two, when spring weather resumes more typical patterns.

"The respite is really just a glitch, rather than a change," said Kennedy T. Paynter, an oyster disease researcher at the University of Maryland in College Park. "It probably doesn't represent a long-term hange, but who knows?"

Once the pillar of the bay's seafood industry, oysters have been on a century-long decline triggered by over-harvesting and worsened in recent years by disease. Though not harmful to humans, Dermo and MSX are fatal to oysters.

First detected in the Chesapeake in the 1950s, the diseases waxed and waned until the late 1980s, when they devastated the oyster industry in Maryland and Virginia and spread throughout the bay.

Though much remains mysterious about how the single-celled organisms spread and kill oysters, Dermo and MSX seem to become most virulent during prolonged droughts, when the bay turns saltier than normal. But a deluge of fresh water can knock back the parasites.

Rains to the rescue

Heavy rains and snow melt have produced two of the wettest springs in the last 50 years, according to George E. Krantz, an oyster researcher at the Oxford Biological Laboratory, a federal-state marine research facility on the Eastern Shore. Heavy rains last summer also produced record fresh-water flows into the bay in August, according to state officials.

State biologists checking on oyster bars this fall found nearly a 40 percent decline in the number of shellfish with Dermo, the more persistent of the two parasites.

Preliminary results from the survey indicate that about 52 precent of oysters sampled had Dermo, compared with 85 percent the year before. MSX, which had been found in nearly 20 percent of oysters checked, now has nearly disappeared, showing up in less than 1 percent of shellfish checked.

Moreover, oysters that do have parasites are less intensely infected this fall, so fewer are dying.

Lower Shore watermen, who had to hunt for oysters in distant parts of the bay, are now working closer to home -- in the Little Choptank River, Fishing Bay and Tangier Sound.

"We have oysters that are living in places we haven't had in five years," said Larry W. Simns, president of the Maryland Watermen's Association. "I feel like the weather has saved us."

Mr. Simns said the recovery is too small and uncertain to warrant abandoning the state restoration program. "We need to continue doing everything we can and hope nature helps us," he said.

Planting the crop

As part of that program, Southern Maryland watermen took a day off from oystering last week to "plant" the first crop from a new state oyster hatchery, at Piney Point in St. Mary's County.

"Before, Mother Nature took care of everything," said Tucker Brown, a third-generation waterman from St. Mary's who took part in the planting.

"It's not exactly happening that way now."

Ten boats from St. Mary's and Charles counties scattered 2.6 million baby oysters on a 3-acre patch of Cohouck Bar in the upper Wicomico River, which flows into the Potomac.

Those could grow to become 7,400 bushels in two or three years. Though shellfish diseases have not been intense there, many of the baby oysters will succumb to blue crabs and other predators.

Another 4.5 million young oysters were put overboard on a bed of freshly planted shell in Breton Bay, another Potomac tributary.

The spreading of baby oysters is part of the restoration program adopted last year by a 40-member commission of watermen, oyster packers, fisheries scientists, state officials and environmentalists.

But some scientists note that hatcheries are expensive to operate, and cannot produce enough oysters to replenish the Chesapeake.

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