Blue crabs, a beloved fixture of the Chesapeake Bay, are continuing to dwindle.
The population in Virginia and Maryland dipped this year to its second-lowest number since local officials began their annual dredge survey in 1990.
The Virginia Institute of Marine Science conducts the survey with Maryland’s Department of Natural Resources each winter, using a 6-foot-wide dredge with a mesh liner towed along the bottom of the bay. Officials count, measure and weigh crabs collected from each site.
The 2025 survey estimates the total crab population at 238 million. The all-time low was 226 million in 2022.
The decline includes all types of crabs: adult and juvenile, male and female.
Scientists are particularly interested in tracking the number of spawning females in the bay, which are crabs that are bigger than 2.4 inches that can produce more young crabs to boost the species.
This year’s estimate of adult female crabs, about 108 million, remains above the recommended threshold of 72.5 million but well below the ideal target of 196 million.
Blue crab populations vary widely each year because of factors such as weather and availability of crucial seagrass habitat.
The exact causes of the long-term trend “are still somewhat of a mystery to scientists,” the nonprofit Chesapeake Bay Foundation said in a news release.
Pollution in the bay, changing climate conditions and the rise of invasive predator blue catfish likely play a role.
“The latest blue crab numbers are extremely distressing,” Chris Moore, the Bay Foundation’s executive director in Virginia, said in a statement. “Blue crabs are a staple on our plates, in our water, and in our culture. We must protect them in order to ensure their important role in the Chesapeake Bay ecosystem and preserve sustainable harvests for the most valuable commercial fishery in the bay.”
