Are bay crabs on way out? Experts split Critical count: An industry is at stake as Maryland tries to determine whether wild variations in the number of crabs in the bay represent a crisis or the course of nature.

March 04, 1996|By Timothy B. Wheeler | Timothy B. Wheeler,SUN STAFF

In aptly named Fishing Bay in Dorchester County, waterman Donald Pierce found so many blue crabs slumbering on the bottom this winter that he had trouble counting them all.

But across the Chesapeake Bay in St. Mary's County, waterman Lonnie Moore had trouble finding enough crabs to count when he checked a 15-mile stretch of the Potomac River last month.

Are there plenty of crabs in the bay, or a perilous few? That is the $187 million question for the Chesapeake's most valuable fishery. The answer continues to elude state officials and biologists, although the most recent scientific study was surprisingly optimistic.

The only thing that's certain, says L. Eugene Cronin, who has been studying crabs for more than 50 years, is that the crustaceans can fool you.

"Everything we know about crabs shows change -- ups and downs," Dr. Cronin, former director of Maryland's Chesapeake Biological Laboratory, told a House committee in Annapolis last week. "That's why it's been so hard to get a handle on them."

The contradictions have made abundantly clear just how much experts don't know about the blue crab; not even how long it can live.

"The picture appears brighter now," said Natural Resources Secretary John R. Griffin. But he added, "There [are] a lot of gaps in our knowledge."

In part because of the latest study's rosier outlook, the department has drafted milder limits for the 1996 crabbing season than the emergency restrictions imposed last fall, when state officials reacted to a slumping harvest.

The 1995 catch was 40 million pounds, down 10 percent from the long-term average. A shortened work week and shortened season reduced the fall harvest by an estimated 30 percent.

Are limits needed?

A group of watermen and Eastern Shore legislators now argue that the crab population is so healthy that no limits are needed, and Gov. Parris N. Glendening has held up the department's draft for review. State officials say restrictions are still likely, but the delay means that they probably cannot take effect until after the season starts April 1.

Last summer, the Chesapeake Bay Foundation, the Annapolis-based environmental group, declared that the fishery was "on the verge of collapse," and in late August the governor warned of a "crisis brewing" and announced emergency catch limits for the rest of the season.

Angry watermen and crab processors complained that the state had overreacted to natural fluctuations in the bay's bounty.

Their stance gained credence in January, when an as-yet unpublished government study concluded that crabs are plentiful.

The study -- a computer-assisted statistical assessment of the crab stock -- drew on surveys conducted over the past 50 years to devise mathematical "models" of the population. The National Oceanic and Atmospheric Administration's Chesapeake Bay office coordinated the study team of state and federal biologists.

The assessment concluded that although the number of crabs fluctuates from year to year, the species is generally as abundant today as in the 1960s and 1970s.

"We don't see evidence of overfishing," Ann Lange, a NOAA fisheries biologist, told legislators at a hearing in Annapolis last week.

"The study shows 'no threat,' " state Sen. Lowell J. Stoltzfus, an Eastern Shore Republican, said recently. "The fishery is indeed healthy, not on the verge of collapse."

The study has divided crab scientists because the findings contradict a widely held belief that the Chesapeake's crab population is under stress.

"There are basically two camps right now," said Romauld V. Lipcius, a crab researcher at the Virginia Institute of Marine Science and a skeptic about the NOAA study.

"I just don't believe it, that's all," said William A. Richkus, a fisheries scientist with Versar Inc., a consulting firm.

'Within reason'

"I think it's within reason," said Dr. Cronin, who is regarded in Maryland as the dean of crab scientists. However, he said the assessment was limited by the lack of consistent monitoring.

Indeed, the study patched together unrelated surveys conducted by Dr. Cronin beginning in the 1940s and a later count begun in 1968 by George R. Abbe, a researcher with the Academy of Natural Sciences.

The assessment also relied on unproven assumptions about the biology of blue crabs.

Scientists do not know, for instance, how long crabs might live if not caught. Predictions range from three to six years. The shorter a crab's maximum lifespan, the more can be harvested, because they would only die anyway.

The assessment went with a span of four years.

Nor do biologists know how many spawning females are needed to sustain the blue crab population. Other crustaceans have been able to survive with only 5 percent, and the assessment was pegged at 10 percent. However some experts argue that to be on the safe side, 20 percent ought to be spared.

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