What that means for watermen, the seafood industry and recreational crabbers isn't clear, but fisheries regulators say the study suggests that there's no room to relax catch limits — and that tighter curbs on the harvest of female crabs might be warranted.
The stock assessment done for the National Oceanic and Atmospheric Administration found that the crab population grew as a result of catch limits imposed by the states in 2008 to reduce the female crab harvest by one-third. Those curbs cost watermen income, though many acknowledge that the cutback helped rebuild the crab population.
The study by Maryland and Virginia scientists urges regulators to focus protection on female crabs so more survive to reproduce. In the past, fisheries managers had aimed to keep at least 200 million adult crabs in the bay, but the assessment recommended setting a target of 215 million female crabs alone. That threshold has only been reached three times in the past 22 years — last year and twice in the early 1990s, Maryland officials say.
Thomas J. Miller, a University of Maryland fisheries ecologist and lead author of the study, said the assessment suggests the bay's crab population is at a healthy level but that the number should grow by about 50 percent over the next four years if regulators stay the course, allowing for a similar increase in harvests.
"The measures put in place are working," said Peyton Robertson, director of NOAA's Chesapeake Bay office, though he acknowledged that they require sacrifice from watermen.
The Virginia Marine Resources Commission is scheduled to vote this month on whether to bar for the fourth straight year a winter crab fishery in which that state's watermen dredge slumbering crustaceans, the vast majority of them females, from the bay bottom.
The female crab numbers declined last winter, as did the overall population, according to an annual survey by the states, but it was still at a level considered safe, O'Connell said. This winter's survey likely will determine whether current catch limits are enough or new protections are needed, he said.
"We're getting there, but we've got a ways to go," said William Goldsborough, senior fisheries scientist with the Chesapeake Bay Foundation.