2020 Blue Crab Winter Dredge Survey

Results from the 2020 Blue Crab Winter Dredge Survey show the Chesapeake Bay’s blue crab stock remains within healthy ranges.

The 2020 results showed that the Chesapeake Bay blue crab population maintains a healthy number of spawning-age female crabs. This year’s survey estimates 141 million adult female crabs were conserved, which is above the long-term average of 126 million.

Maryland, Virginia, and the Potomac River Fisheries Commission strive to conserve more than 70 million adult female crabs annually, which has now been achieved for the sixth consecutive year.

Additionally, the results showed there were 79 million adult male crabs, just above the long-term average of 77 million and similar to the estimate from 2019.

The number of juvenile crabs declined in 2020 to 185 million, from last year’s total of 323 million. Juvenile abundance is largely driven by environmental factors, such as currents, temperature, and winds, resulting in considerable year-to-year variability. Juvenile abundance this year is below the long-term average of 254 million.

The combined abundance of all ages of blue crabs declined by a third, from 594 million crabs in 2019 to 404 million crabs in 2020. a near-average abundance for the 30 years of survey results.

The Chesapeake Bay Stock Assessment Committee will review the results of the survey and plan to release a full analysis this summer.

The Winter Dredge Survey has been conducted cooperatively by the Maryland Department of Natural Resources (DNR) and the Virginia Institute of Marine Science (VIMS) since 1990. The results are reviewed annually in an effort to have consistent management efforts across the jurisdictions.

Throughout the survey, biologists use dredge equipment to capture, measure, record, and release blue crabs at 1,500 sites throughout the Chesapeake Bay from December through March.

sources: Maryland Department of Natural Resources, Virginia Institute of Marine Science