Catches of female blue crabs were down by about a third in both Maryland and Virginia for 2008 according to estimates by fishery managers.
That achieved the objectives set by governors of both states last spring to curb female crab harvests by at least 34 percent to help increase numbers of the crustacean, whose population in the Bay has lingered near record-low levels for most of the last decade.
While harvest controls imposed on fishermen last year appear to have worked, scientists won't know whether they achieved the ultimate goal-boosting the overall population-until the annual Baywide blue crab survey is completed in April.
In Virginia, the total estimated crab harvest was 15.6 million pounds-a new low. The catch of female crabs was 9.4 million pounds, a 37 percent decline in the average over the last three years, according to the Virginia Marine Resources Commission.
Maryland Department of Natural Resources officials estimated the female catch to be 8.5 million to 10.5 million pounds, which would represent a decrease of 28-36 percent. They did not yet have an estimate for the total crab harvest.
Maryland numbers were in flux because officials based them on fishery independent data collected by biologists. The catches reported by watermen actually showed an unexpected increase.
But DNR officials suspect that watermen inflated their catches in the belief they would be used to set future limits because the department's 2008 catch limits were based on the past harvest history of individuals. Managers have eliminated that practice in new regulations.
"When management actions are directly tied to fishing reports, there is precedent for fishermen to alter reporting habits in order to position themselves for future reporting management actions," the department said in an analyses of the 2008 data. "There are numerous examples of this published in the fisheries science literature."
The department said watermen's reports differed sharply from annual surveys it conducts to monitor catches, and from reports submitted from crab dealers who are required to detail the amount of crabs they purchased by market category.
In all of the years since 2003, the estimated female harvest from those surveys has been slightly higher than those reported by watermen. But this year, the catches reported by watermen were 60 percent higher than the estimated harvest.
The department therefore based its 2008 catch estimate on reports from the other surveys, which suggested a female blue crab harvest of 8.5 million to 10.5 million pounds. Without new restrictions, the department estimates the catch would have been about 13 million pounds.
Final numbers are still being tabulated, but it appears the Baywide number for all crabs will be well below the previous record low catch of 44.2 million pounds in 2007.
The reduced catch of females was an effort to help rebuild the Bay's adult blue crab population to an interim Baywide goal of about 200 million, although scientists say it will likely take several years to reach that mark.
Since 1997, the number of adult crabs has averaged about 150 million. In contrast, adult crab abundance averaged about 300 million between 1990 and 1996.
Crab abundance is determined from the annual Baywide winter dredge survey, conducted by the Maryland DNR and the Virginia Institute of Marine Science, which samples crabs during the winter-when they are buried in the mud and stationary-allowing scientists to develop, with good precision, estimates of the number and ages of crabs present in the Bay.
Data from the survey, which is completed each April, is also used to predict the coming year's harvest.