Chesapeake Bay blue crab survey shows mixed results From Staff Reports View Comments The annual survey of blue crabs in the Chesapeake Bay showed a mixed bag, with the population of mature female crabs up while juvenile crab numbers declined to the lowest level since the survey began in 1990. The Maryland Department of Natural Resources announced the results of the 2021 Blue Crab Winter Dredge Survey, a cooperative effort with the Virginia Institute of Marine Science, which annually estimates the number of blue crabs in the Chesapeake Bay. The survey results showed that the number of spawning age mature female crabs increased from 141 million in 2020 to 158 million in 2021. This year’s survey estimate is above the long-term average of 126 million spawning age female crabs, DNR said in a release.