- The Washington Times - Sunday, July 6, 2003

BALTIMORE — A regal-looking blue crab rests, exhausted, in the corner of a giant, dark tank at a marine laboratory at the Inner Harbor. A million of her babies, hours old, swim around her in a powdery mist.

She has mated and hatched her eggs even though she has not left the tanks at the University of Maryland Biotechnology Institute.

She was hatched at the lab.

Researchers at the institute’s Center of Marine Biotechnology (COMB) are raising their second generation of blue crabs. They are monitoring 25,000 lab-bred crabs they released last year in the Chesapeake Bay, each tagged with a tiny piece of wire, with the hope of halting the collapse of the Bay’s blue-crab population.



So far, the little crabs, although born and coddled in captivity, are a success. They are breeding madly in small nooks along the coast of the upper Chesapeake Bay, said Anson Hines, a leader in the project and a marine ecologist at the Smithsonian Environmental Research Center in Edgewater.

The Smithsonian, along with the Virginia Institute of Marine Sciences, is part of a consortium founded two years ago with $100,000 from Maryland state legislators and $300,000 from Phillips Foods Inc. The Maryland Watermen’s Association also is contributing.

Crab populations in isolated areas near the release sites have doubled, Mr. Hines said. But researchers stress that their work at the institute is experimental.

“We know they’ve increased the populations at these experimental releases, but it’s not so clear what will happen on a larger scale,” Mr. Hines said.

Researchers believe last year’s tagged release was the largest for any species of crab. But they caution that their goal is to study the young crabs — not to donate them to the harvest of the watermen, said Yonathan Zohar, director of COMB.

The scientists want to avoid the impression they are founding a “put-and-take” system, the type of hatchery that releases crabs for watermen to pick up later. Other hatcheries, including those in Japan, have run that kind of operation for decades, Mr. Zohar said. Only recently have the Japanese begun studying what effect their lab-raised crabs are having on general populations, he said.

COMB’s program aims to bolster the breeding stocks of Bay crabs, which have dropped 85 percent since 1990.

To that end, researchers are releasing juvenile crabs, 2 months old and 1 inch long, and are monitoring them to see how well they survive and breed, Mr. Zohar said.

If their experiments continue to be successful, researchers say, they hope to release more breeding crabs. In the long run, that kind of program will be most helpful for the crab populations and most helpful for watermen, researchers said.

They envision hatcheries opening along the Eastern Shore, pumping out blue crabs until breeding stocks recuperate.

COMB’s success inside the lab is remarkable as well, researchers say. It is the first program to hatch a second generation of crabs from mothers raised from larvae.

Crabs of all sizes live an easy life at the hatchery at Columbus Center. Young crabs, once past the larval stages, are moved to tanks filled with a buffet of delicious brine shrimp. The plentiful shrimp are supplied in part to keep the crabs, voracious cannibals, from eating each other before they can be released.

Yards of wire mesh fill the tanks, giving the half-inch baby crabs a shelter and a hiding place.

In another tank, a female crab rests and waits to hatch the million eggs she has been carrying in a dark sack under her belly. It’s her second brood — a surprise to scientists, who long believed female crabs spawned just once in a lifetime.

Researchers set up the tanks so mothers are hatching eggs in staggered year-round shifts, instead of their usual spring spawnings. In one tank, it’s winter. In another, spring.

“Just by manipulating the environmental conditions, we get them to believe this is their spawning time,” Mr. Zohar said.

Mr. Zohar and his partners warn that the hatchery may be only part of a solution to the blue-crab problem.

“Even if it’s going to work, ours is not going to be the magic bullet,” he said. “Some people say we are coming up with a solution, saying there will be no regulations on watermen. But watermen are smarter than that.”

Larry Simns, president of the Maryland Watermen’s Association, agrees. The more scientists know about blue crabs, which have a complex life cycle and mating habits, the more watermen will benefit, he said.

“The hatchery is not to keep from regulating us. It’s to better regulate us,” he said.

Commercial harvests of blue crabs in Maryland have dwindled from 55 million pounds in 1993 to a low of 20 million pounds in 2000. In 2002, the catch was nearly 24 million pounds, still well below average.

Other states, including North Carolina and Virginia, are experimenting with blue-crab hatcheries, said Tom Wolcott, a professor in marine, earth and atmospheric sciences at North Carolina State University in Raleigh and a collaborator with Mr. Hines.

Mr. Wolcott supports hatchery research, but he warns of “meddling with natural selection.”

COMB is careful to take its mother crabs from the Chesapeake Bay to ensure the genetic purity of the Bay crab population. But keeping crabs within Chesapeake bloodlines is only part of the issue, Mr. Wolcott said.

“When you dump a gazillion offspring [of one crab pair], you are giving a huge competitive advantage to a few genetic makeups,” he said. “If that genetic makeup happens to have a vulnerability to a disease that comes along later, you are bringing in unknown risks.”

Mr. Zohar says the project includes studies to investigate the effects of spraying the Bay with offspring of a few parents.

He knows the project’s long-term success is not guaranteed.

“In view of what is happening in the Chesapeake Bay with the blue-crab population, this was one stone we couldn’t leave unturned,” Mr. Zohar said. “We just wanted to see if this was feasible.”

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