by Catherine Krikstan
April 27, 2015
The Chesapeake Bay’s blue crab population has seen a modest rise, increasing 38 percent since the population was counted last winter. While an increase in blue crabs is an indicator of Bay health, the adult female crab population remains below its target, indicating the variability of the blue crab population and the complexities of managing the fishery.
Maryland and Virginia measure the Bay’s blue crab population through an annual winter dredge survey. Over the course of three and a half months, scientists visit 1,500 sites around the Bay, using metal dredges to pull up crabs over-wintering in the mud.
Results of the 2015 winter dredge survey show the Bay’s total blue crab population has increased from 297 million to 411 million since last winter. Results also show the number of spawning-age females has risen from a depleted 69 million to 101 million. The number of juvenile crabs has jumped from 199 million to 269 million, which is just above the long-term average.
According to the Maryland Department of Natural Resources (DNR), the cold winter and resulting low water temperatures contributed to a “substantial mortality” among blue crabs, killing an estimated 19 percent of adults.
“We are pleased that crab numbers increased despite the harsh winter temperatures,” said DNR Secretary Mark Belton in a media release.
The Chesapeake Bay Program tracks the adult female blue crab population as an indicator of Bay health. The Chesapeake Bay Stock Assessment Committee (CBSAC), which includes scientists and representatives from the federal government, state governments and academic institutions, will use this data to make recommendations on sustaining the blue crab population in its 2015 Blue Crab Advisory Report, expected to be released this summer.