2018 Blue Crab Winter Dredge Survey

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chesapeake bay blue crabs
Blue Crabs

In May, the Maryland Department of Natural Resources (DNR) and Virginia Marine Resources Commission (VMRC) released the results from the 2018 Blue Crab Winter Dredge Survey, an annual assessment of the Chesapeake Bay’s blue crab stock.

The survey indicates a bay-wide crab population of 371 million, a decrease from last year’s estimate of 455 million, driven largely by a decrease in the number of adult crabs.

Colder than average temperatures during the winter months resulted in higher than normal mortality for adult crabs, according to Maryland DNR.

In addition, very low juvenile abundance last year resulted in lower adult male and female abundance estimates for 2018.

The recent survey estimates a total adult male and female crab abundance of 206 million

In 2018, the spawning female stock decreased 42 percent from 254 to 147 million, dropping below the target level of 215 million, but remaining well above safe levels.

Despite winter mortality, this year’s adult female crab abundance remains among the 10 highest of the nearly three decade old survey.

Adult male crab abundance declined 23 percent from 76 to 59 million.

The juvenile crab population (2.4 inches or less in carapace width ) increased 34 percent over last year, reaching approximately 167 million.

The Chesapeake Bay Stock Assessment Committee plans to release a full analysis this summer.

The annual Winter Dredge Survey has been conducted by the Maryland Department of Natural Resources and Virginia Institute of Marine Science since 1990. In the survey, biologists use dredge equipment to capture, measure, record and release blue crabs at 1,500 sites throughout Chesapeake Bay from December through March

sources: Maryland Department of Natural Resources, Virginia Marine Resources Commission

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