Annual Winter Dredge Survey Finds Normal Fluctuation
News Release, Maryland Department of Natural Resources
The Maryland Department of Natural Resources announced the results of the 2020 Blue Crab Winter Dredge Survey, a cooperative effort with the Virginia Institute of Marine Science, which estimates the number of blue crabs in the Chesapeake Bay annually.
The 2020 results showed that the Chesapeake Bay blue crab population maintains a healthy number of spawning-age female crabs. Maryland, Virginia, and the Potomac River Fisheries Commission strive to conserve more than 70 million adult female crabs annually to ensure enough young crabs can be produced to sustain the population, which has now been achieved for the sixth consecutive year. This year’s survey estimates 141 million adult female crabs were conserved, which is above the long-term average of 126 million.
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 total abundance of blue crab in the Chesapeake Bay in 2020 was 405 million crabs, a near-average abundance for the 30 years of survey results.
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, therefore year-to-year variability is expected.
“While there are some expected fluctuations, our collective management efforts continue to enable the population to stay resilient and sustainable,” Maryland Department of Natural Resources Secretary Jeannie Haddaway-Riccio said. “Maryland blue crabs remain an iconic part of our heritage and our environment.”
Although juvenile abundance this year is below the long-term average of 254 million, it remains an improvement from the 2018 recruitment and well above the low of 105 million reported in 1992.
“The results indicate the population remains in a healthy, sustainable condition,” Maryland Natural Resources Fisheries Monitoring and Assessment Director Michael Luisi said. “Continued diligence to our management plan for blue crabs will ensure protection of the resource and sustainability of the fishery.”
The Chesapeake Bay Stock Assessment Committee will review the survey results and release its full analysis in its 2020 Blue Crab Advisory Report this summer.
The Department will begin discussions with the Blue Crab Industry Advisory Committee to provide guidance to the Department concerning the course of action for 2020 that promotes the health of the Chesapeake Bay blue crab population and its fisheries.
The Winter Dredge Survey has been conducted cooperatively by the Maryland Department of Natural Resources and the Virginia Institute of Marine Science since 1990 and 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. Detailed information is on the Maryland DNR website.