Trouble Again for the Blue Crab
The female harvest is the tipping point
Maryland’s favorite crustacean is in serious trouble, according to Maryland Department of Natural Resources’ 2013 Winter Dredge Survey for blue crabs. Once again, the species is teetering at the edge of collapse.
The numbers approach population levels in 2008, when the feds labeled the fishery a disaster.
DNR reads this year’s numbers differently: “crabbing is at safe levels,” according to a recent press release. “The crabbing harvest remained at a safe level for the sixth consecutive year.”
That interpretation begs comment.
During the six-year period of presumably safe harvest levels, the overall crab population plunged by at least 70 percent. Is that not alarming?
Commercial and recreational harvest limits are the primary management tools for controlling crab populations. But they went virtually unused for six straight years.
Anson Hines, senior scientist at the Smithsonian Environmental Research Center in Edgewater, confirms fears about continuing difficulties with Chesapeake blue crab populations.
In the 2008 crisis, part of the problem was harvest quotas based on flawed science. DNR had long claimed that the female blue crab spawned only once in her lifetime, so any size mature female could be taken without reducing the species’ ability to reproduce.
When that science was revisited, it was found that mature females spawn again and again. The overall female population, quite possibly, was the key to blue crab stability.
By then, crab numbers were so low that the natural resources departments in both Maryland and Virginia — plus the Potomac River Fishery — began cooperating to rebuild the devastated species for the first time ever.
In 2008-2009, winter dredging of dormant females in the Virginia portion of the Bay was halted. Maryland attempted to reduce fishing of females down the Bay in the fall. These actions achieved unprecedented protection for females throughout the Bay.
These moves were a particularly big deal for Virginia because the crabbing industry in the lower Chesapeake depends significantly on female crabs. As the females prefer the higher salinity of the southern waters, their numbers are densest there. That’s also where all blue crabs spawn. This sparsely populated area relies on commercial fishing for jobs and income. Most of the cost of the fishery reduction was absorbed by Virginia watermen.
The cutback led to a swift and extraordinary population resurgence. Within two years, the blue crab population rebuilt itself. The Bay saw some of its best recent crabbing seasons.
But with that population build-up came commercial demands for renewed access to the females.
During all of these periods of crisis, harvest of females continued under varying degrees of limitation throughout the Bay.
The harvest of immature female blue crabs by the soft crab industry has never abated. Tens of thousands of small (three-and-a-half-inch minimum size), immature, never-spawned peeler and soft-phase females are harvested with scant control over limits.
Just four years ago, recognizing at some level a population decline in progress, DNR made keeping female hard crabs by recreational crabbers illegal.
That move generally transferred that portion of the recreational harvest over to the commercial sector. DNR did little else to abate the harvest of the sooks. What followed was the ecological crisis of 2014.
This situation points to a serious and continuing shortcoming in the philosophy and management of the species. Based on DNR’s own statistics, from 1990 to 2000 the population of reproductive females in the lower Bay declined by more than 80 percent during the spawning season. The population remained at record low levels until 2008 and triggered the declaration of disaster.
Now again in 2014, populations are back to seriously low levels, quite possibly because of the continuing and substantial commercial harvest of female crabs. Is that policy wise?