view counter

Blue Crabs Crest Tipping Point

But when half of all crabs are ­harvested each year, we’ve got to work to keep the population steady

After almost three decades of effort, Maryland’s treasured Chesapeake Bay crustacean, the blue crab, has achieved a major scientific benchmark. The number of spawning females has at last reached the minimum target level for optimum species viability: 215 million sooks.
    The 2017 Winter Dredge Survey put the female population at well over the minimum, 254 million, an impressive 31 percent increase from the prior year. This is an important moment, as just four years ago (and five years prior to that), the female crab population had been ­driven to dangerous, even population-collapse, levels.
    Only relatively recently has the female blue crab population been recognized as key to maintaining sustainable levels of our beautiful (and delicious) swimmers. Females were once assumed (by regulators and scientists) to spawn only once in their lives. Hence, when mature, they could be harvested without consequence. That assumption proved false.
    The one hiccup in this year’s accomplishment was the accompanying news that juvenile crabs had inexplicably nosedived by 54 percent. The blue crab is known for fluctuating numbers and varying spawning successes, so this is not a necessarily alarming happenstance. However, these early low numbers will have a definite impact on commercial crabbers later this year, and most certainly the next, when these crabs reach ­harvest size.
    To protect overall numbers, the Maryland, Virginia and Potomac River Fisheries Commission has proposed shortening the crabbing season and imposing stricter bushel limits on female crabs. No changes to male crab limits were proposed.
    Both Maryland and Virginia will have to decide this month on actions and restrictions to protect and stabilize the general crab population. The very real danger is the possibility that Maryland may once again expand the currently limited female harvest to cover the shortfall of males for commercial watermen. (Recreational harvest of females has been outlawed.)
    The legal season for harvesting blue crabs can run into December, but Maryland Department of Natural Resources has ended the season early upon reaching its targeted harvest levels. Last year’s season ended Nov. 30. The year before, Nov. 19. Each year almost 50 percent of all blue crabs in the Bay are harvested.
    This is the first year since record keeping began that we have reached the minimum female target level for species viability. As blue crabs spawn from May through October, this will also be the first of record with an adequate female population providing for growth.
    The commercial sector has been lobbying hard for changes that would increase their incomes, most notably keeping the legal size for jimmies at five inches instead of five and one-fourth inches. Will females be the next target?
    The excessive harvest of female crabs is the odds-on suspect in the many crab population crises that have occurred cyclically throughout the history of crab management.
    The blue crab deserves to be regulated for overall population health.