2011 Blue Crab Winter Dredge Survey

Virginia and Maryland fishery managers  have released results of the 2011 Blue Crab Winter Dredge Survey.  The study found that the Chesapeake Bay’s blue crab population is at its second highest level since 1997 and well above the target for the third year in a row.

Overall crab abundance, however, declined due to this past winter’s deep freeze that killed as many as 31 percent of Maryland’s adult crabs, compared to about 11 percent in 2010.

At 460 million crabs, the Chesapeake Bay’s blue crab population is at its second highest level since 1997, and nearly double the record low of 249 million in 2007. And, for watermen across the Bay, the unusually high crab abundance last year translated into a harvest of more than 89 million pounds — the highest since 1993.

Commenting on the winter kill,  Steven G. Bowman, Commissioner of the Virginia Marine Resources Commission remarked: “We cannot control the weather. It was a harsh winter and crab mortality was higher than normal. In fact, it was the worst we’ve seen since 1996.”

“This drop in abundance should be viewed as a speed bump in our stock rebuilding program, and just means it will take a bit longer to get to where we want to be with a stabilized crab stock of high abundance,” Commissioner Bowman added.” Some stock management challenges remain, but the evidence shows we’re going in the right direction.”

According to the survey, 254 million adult crabs survived the bitter cold winter in the Chesapeake, above the current population target for the third year in a row. This marks the first time since the early 1990s that the Bay has seen three consecutive years with the adult population was above the target (200 million crabs) and the harvest was below the target of 46 percent.

Estimates of abundance are developed separately for young of the year crabs, mature female crabs, and adult male crabs. Together, these groups of crabs will support the 2011 fishery and produce the next generation of crabs

In 2008, Maryland, Virginia and the Potomac River Fisheries Commission took action to reduce harvest pressure on female crabs by 34 percent. At that time, scientists deemed conservation measures necessary as blue crab suffered near historic lows in spawning stock.

“The coordinated management of blue crabs since 2008 clearly demonstrates the conservation gains that can be achieved when Chesapeake Bay jurisdictions act collectively toward a common vision – in this case a healthy blue crab population and sustainable fishery, said Peyton Robertson, director of the NOAA Chesapeake Bay Office.

In September 2008, NOAA’s National Marine Fisheries Service responded to Virginia’s and Maryland’s request for disaster assistance funding for watermen impacted by the declining blue crab population.

The primary assessment of the Bay’s blue crab population is conducted annually by the Maryland Department of Natural Resources and the Virginia Institute of Marine Science (VIMS).  Since 1990, the survey has employed crab dredges to sample blue crabs at 1,500 sites throughout the Chesapeake Bay from December through March. By sampling during winter when blue crabs are buried in the mud and stationary, scientists can develop, with good precision, estimates of the number of crabs present in the Bay.

“The overall crab abundance is down a bit from what it was last year at this time, but let’s keep that in context. We saw a huge bay-wide harvest in 2010, the largest since the early 1990s, and despite that the stock abundance continues to be higher than we’ve seen in many, many years,” Travelstead said.

source: Virginia Marine Resources Commission