Counting blue crabs with the winter dredge survey

Researchers from the Virginia Institute of Marine Science (VIMS) conduct the 2015-2016 blue crab winter dredge survey in the lower portion of the Chesapeake Bay on March 8, 2016.

From December through March of each year, the Maryland Department of Natural Resources (DNR) and VIMS conduct the winter dredge survey in the Maryland and Virginia portions of the Bay, respectively. Between the two agencies, 1,500 sites are visited over the course of three and a half months. Dormant blue crabs are hauled out of the mud to be weighed, measured and have their sex determined before getting tossed back into the water.

At the conclusion of the survey, researchers have an estimate of the number of blue crabs living in the Chesapeake Bay. The data helps fisheries managers determine how many of the crustaceans can be harvested without hampering the crab’s recovery.

Each summer, the Chesapeake Bay Stock Assessment Committee (CBSAC) releases its Chesapeake Bay Blue Crab Advisory Report, providing guidance to support blue crab management. As part of the Chesapeake Bay Program, CBSAC—which includes representatives from state agencies, academic institutions and federal fisheries experts—supports the Sustainable Fisheries Goal Implementation Team. Last year, numbers from the winter dredge survey helped these experts determine the blue crab stock was sustainable.

Learn more about the winter dredge survey.