Survey finds sharp decline of crabs in bay

by Bill Nachman - Posted on May 01, 2013 - 02:42 PM

A recent survey shows the number of spawning-age female crabs is up, but poor reproduction means fewer crabs overall in the Chesapeake Bay.

Results of the annual scientific winter dredge survey of the bay-wide blue crab population, a study conducted by the Virginia Institute of Marine Science and the Maryland Department of Natural Resources, show that the overall abundance of blue crabs dropped significantly, from 765 million to 300 million crabs. John Bull, a spokesman for the Virginia Marine Resources Commission, said this drop was because the number of juvenile crabs plummeted from 581 million to a mere 111 million.

"This is disappointing, but it is not a disaster and not without precedent," said Jack Travelstead, head of VMRC. "Crab spawning naturally fluctuates and can be impacted by wind, tide, weather and increased predation on juvenile crabs by other species," he said. "Clearly, we are in no position to expand the commercial harvest this year."

While the overall crab population in the bay survey dropped, Bull said, the good news is the number of spawning-age females increased substantially, from 95 million to 147 million. That number is well above the scientifically-established, healthy-abundance threshold of 70 million, he said.

Adult females are a key to the join Virginia-Maryland stock rebuilding program that began in 2008, Bull said.

Rom Lipcius, a professor at VIMS, said one reason that many juvenile crabs did not flourish was because of the large influx of juvenile red drum (known as puppy drum) into warm bay waters last year. "Puppy drum are opportunistic feeders and will target high density food sources, and juvenile crabs last year were found in high densities."