A NOAA-funded Baywide winter dredge survey which was begun by the states in the late 1980s to provide better information about the blue crab stock also showed a 34 percent decrease in adult crab abundance between 1990 and 1995. Those results fueled concerns by some scientists that blue crab catches, which were gradually increasing as other Bay fisheries declined, were taking too many females out of the population before they could reproduce. But the stock assessment panel found no evidence that current fishing levels on female crabs are threatening the populations reproduction potential. The stock assessment panel agreed that the adult crab population had declined in recent years, but noted that the decline was measured from a period of unusually high blue crab abundance in during the 1980s. In analyzing a variety of data from the past several decades, the scientists concluded that the present stock level is actually near its long-term average, and not close to its low, which was reported in 1968.
Blue crabs live throughout the Bay.
In the fall and spring, females migrate to the mouth of the Chesapeake where they release their eggs. A single female may contain between 750,000 to 8 million eggs. The larval crabs live near the surface of coastal waters outside the Bay for several weeks before returning to the Chesapeake. When that threshold was compared with three decades of fishing data, the scientists found that fishing pressure had never reached that critical point, though in some years it was approached. Unlike longer-lived finfish, such as striped bass, where managers have several years to respond to stock declines, management actions would need to be taken more quickly for blue crabs, it noted.