More bad news from the bay: The blue crab population is down 60 percent from 1988 levels, according to the latest survey by Maryland and Virginia scientists. This after prolonged bay-wide pollution cleanup efforts and a year of controls on gear, hours and licenses of Maryland crabbers.
The good news is that even scientists who have studied these "delectable beautiful swimmers" over a lifetime admit they don't know enough to confidently predict the crabs' future. In 1992, for example, the commercial crab harvest for both states was an all-time low of 54 million pounds; the next year saw a modern record, of 113 million pounds.
Watermen and biologists offer a variety of reasons why crab numbers seem to be down so far this winter (when they are hibernating and easily collected to count.) They include the freezing winter of 1993-94 that slowed growth, the abundance of rockfish eating up the young shellfish, shifting wind patterns that must push the currents carrying hatched crabs back from the ocean to the Bay.
But the main factor may be an unprecedented fishing pressure on blue crabs, as watermen struggle to make up for declining stocks of other commercial species: a sharp decline in the "catch per unit effort," as biologists term it.
Tougher restraints on licenses and harvesting may provide some relief. But these rules may not be able to be tightened quickly enough, without planning now, should the crab depletion continue its marked downturn through the year.
The life span of a blue crab is about two years, with females giving birth only once at 18 months. Pessimists worry that this is too short a period for effective human intervention to rescue a seriously threatened population, that foresighted protection is needed to prevent overfishing. Optimists cite the prolific egg-laying capability of the blue crab, each of which can lay millions of eggs, and the vagaries of nature. Besides, reported annual catches of blue crabs in the bay have always varied greatly.
One positive trend is emerging. The six-year annual survey of 1,200 sites in the entire bay is a major effort in expanding knowledge of this valuable natural resource. An Environmental Protection Agency study found that fisheries management experts had the least information about blue crabs than of any major commercial-recreational species in the Chesapeake.
Final results of the annual dredging survey won't be known until the end of this month, just as the state's crabbing season begins. The next step should be a "crab summit" of bay scientists to take stock and then develop viable, strong measures to be used if this year's harvest figures confirm the survey's plummeting population indicators.