New Chesapeake Bay Blue Crab Stock Assessment Shows Rebuilding Efforts Should Continue
8/9/2011 | Posted by jdavidsburgTags: Blue Crab, Commercial, Recreational
Sets Higher Abundance Level Requirements and Population Targets
NEWPORT NEWS, VA./ANNAPOLIS, MD (August 9, 2011) – A new scientific assessment of the Chesapeake Bay Blue Crab population released today indicates significantly more work needs to be done to fully rebuild the stock to sustainable levels. The new assessment from the National Oceanic and Atmospheric Administration reveals that — while the stock has increased substantially in response to three years of rebuilding efforts by Virginia, Maryland and the Potomac River Fisheries Commission — the stock was more depleted than originally believed and will take longer to rebuild than had been expected.
"The crab stock is improving throughout the Bay. Collectively, we have made a lot of progress over the past three years. But this new science indicates we still have a way to go to achieve our goal of having a biologically stable stock with a robust harvest," said Jack Travelstead, Virginia's Fisheries Chief. "This is a sea-change in how we will manage the fishery."
The assessment, which sets a new overfishing threshold as well as a new safe abundance level for female crabs, took three years to complete and represents the best available science on the stock's reproductive capabilities, lifespan, gender and size distributions. The assessment underwent rigorous scientific scrutiny in a peer review by Dr. Julian Addison of France, Dr. Cathy Dichmont of Australia and Dr. Billy Ernst of Chile.
"Having a more accurate approach to blue crab management benefits not only the population, but also our hardworking watermen, the seafood industry and recreational crabbers across the Chesapeake Bay region," said Tom O'Connell, Director of the Maryland Department of Natural Resources Fisheries Service. "The new safe female abundance level and overfishing threshold will dictate how the fishery is managed in the years to come."
Until now, fishery managers used an interim target of 200 million total adult crabs in the bay as the threshold of a healthy stock and considered overfishing to occur if 53 percent of adult (age 1+) crabs were harvested in a year. Regulations were established to meet these benchmarks, which were based on 2005 bay-wide crab assessment data.
The new stock assessment sets a new healthy-species abundance level of 215 million female crabs, with overfishing occurring if 34 percent of the female crabs are harvested in a year. Put into context, this means that fishery managers have only come close to achieving this level of female abundance three times over the past 22 years, in 2010, 1993 and 1991.
These more stringent assessments of the stock's health will allow fishery managers to set more precise female harvest limits in order to fully rebuild the stock. Virginia, Maryland and the PRFC remain committed to working together to rebuild the bay's crab population to meet the new female population threshold and abundance target.
"This is the best available science and we must, under Virginia law, use this to craft more precise harvest regulations to achieve our goal," Travelstead said. "We do not yet know exactly what those regulations will look like. That will be discussed and decided over the next few weeks, but it doesn't appear Virginia will be in a position to relax harvest restrictions at this point."
The Virginia Marine Resources Commission is scheduled to discuss the new stock assessment and vote on whether to close the winter crab dredge fishery for the fourth year in a row, as well as other crab conservation measures, on Aug. 23.
"The results of the new assessment are not expected to result in significant changes to the existing framework that will be used to manage Maryland's 2012 fishery," added O'Connell. "We will continue to focus on bushel limits and closures to achieve our targets, using harvest and winter dredge survey information to make these decisions. Maryland's Blue Crab Industry Advisory Committee will meet later in the fall to identify industry-preferred 2012 management strategies for females."
In September the Chesapeake Bay Stock Assessment Committee will meet to consider the new assessment, examine data from the past two years and provide management recommendations to Maryland, Virginia and the Potomac River Fisheries Commission.
"The Potomac River Fisheries Commission remains committed to continuing the Bay-wide coordinated efforts to rebuild the cabs stocks and maintain a healthy fishery," said A.C. Carpenter, Commission Executive Secretary.
The bay-wide crab harvest in 2010 was in the 90 million-pound range, confirming that a healthy harvesting industry can coexist with regulations designed to rebuild a self-sustaining, healthy blue crab population.
Through a historic collaboration in 2008, Maryland, Virginia and the Potomac River Fisheries Commission took strong, coordinated action to reduce harvest pressure on female crabs by 34 percent. At that time, scientists deemed conservation measures necessary as blue crabs suffered near historic lows in spawning stock.
"Overall, crabs in the bay are doing well. Implementing recommendations developed in the stock assessment, like focusing fishing regulations on female crabs, will help even more," said Dr. Tom Miller, University of Maryland Center for Environmental Science, lead author of the stock assessment.
The stock assessment can be viewed in its entirety at http://hjort.cbl.umces.edu/crabs/Assessment.html