The number of blue crabs in the Chesapeake Bay has tripled over the last five years to the highest total in nearly two decades. The dramatic rebound was caused by restrictions on catching female crabs imposed by Virginia and Maryland in 2008, according to Maryland fisheries scientists.
“One of the clearest indications that the health of the Bay is not a hopeless cause is the rebound of late of this blue crab population,” Maryland Governor Martin O’Malley said this morning at a press conference at a waterfront crab house in Annapolis, where he announced the results of a winter blue crab population survey.
“A few years ago, the future did not look bright,” said O’Malley. “Our female crabs were being overfished. Our fishery was at risk of complete collapse. The announcement today marks four years in a row of progress to restore the blue crab.”
A scientific dredge survey of blue crab populations from December through March estimated 764 million blue crabs in the nation’s largest estuary, up 66 percent from the 461 million in 2010, and nearly triple the 255 million in 2007, according to the Maryland Department of Natural Resources. That was when the numbers hit such a low that the federal government declared an economic emergency and provided funds to help devastated watermen.
In response to that crisis, O’Malley and then-Virginia Governor Tim Kaine in 2008 imposed restrictions on catching female crabs. These regulations reduced the harvest of females by 34 percent, outlawed recreational catching of female crabs in Maryland, and banned the wintertime dredging for fertilized females hibernating at the bottom of the Bay in Virginia.
“It is encouraging to not only see an improving crab population but also a management system that is working,” said Bill Goldsborough, director of Fisheries for the Chesapeake Bay Foundation. “We applaud DNR and Governor O'Malley and encourage them to stay the course and continue the science based management approach that has lead to this resurgence in the Chesapeake blue crab.”
Tom O’Connell, Director of the Fisheries Service at the Maryland Department of Natural Resources, said at the press conference that the state agency will continue with a policy of protecting females, although he said it may tinker slightly with the rules to allow some more flexibility for watermen.
"As we go forward, we are looking at maintaining a status quo situation in Maryland this year," O'Connell said. "We've been having discussions with the watermen, and there may be some minor adjustments that will be viewed as conservationally equivalent -- looking at the same harvest level, but working with the watermen to find increased opportunities...and allow them to make more" money by catching more crabs, O'Connell said.
Current Virginia Governor Robert F. McDonnell has continued with efforts to help conserve the Bay’s blue crab populations.
“This fishery appears to be in far better shape than it was just a few short years ago and is one of the most successful fishery stock rebuilding programs ever, anywhere,” said Doug Domenech, Virginia’s Secretary of Natural Resources.
Two curious facts about the blue crab resurgence:
1) The number of juvenile blue crabs in the Bay is the highest on record, with 587 million, nearly triple the previous year’s 207 million and higher than the previous record of 512 million set in 1997, according to the Maryland Department of Natural Resources. This huge increase in young crabs came despite a decrease in the estimated number of spawning-age female crabs --- perhaps the result of fluctuations from year to year in the accuracy of the survey system that scientists use to estimate crab populations.
2) The increase in the total number of blue crabs in the Bay over the last year came at a time when the Chesapeake had record poor water clarity because of heavy rains, including Tropical Storm Lee (as noted in yesterday’s Bay Daily). In part because of sediment washed into the Bay during these storms, the University of Maryland gave the Bay a “D plus” health rating for 2011, down from the “C minus” grade the year before.
The fact that blue crabs increased despite these murky waters suggests that they are hardy and mobile creatures, capable of moving away from “dead zones” more easily than other bottom-dwellers, said Lynn Fegley, Deputy Director of the Fisheries Service at the Maryland Department of Natural Resources.
"Blue crabs are an extremely resilient species, and the water quality was difficult this past year. But crabs are relatively tolerant of that," Fegley said. "And one interesting question is: How much better would the news have been (in terms of crab populations) if the water quality was significantly better?"
Efforts to meet new EPA pollution limits for the Chesapeake Bay (the Bay “Total Maximum Daily Load,” which is like a blueprint for saving the Bay) are expected to reduce runoff and other pollutants in the estuary by about 25 percent by 2025. This should cut the size of low-oxygen “dead zones,” and allow the survival of more clams and worms and other bottom dwellers that crabs eat.
By Tom Pelton
Chesapeake Bay Foundation
(Photo of blue crab from Chesapeake Bay Program. Photos of press conference by author)