June 17, 2014 — It's almost summer. Seafood restaurants from coast-to-coast are serving platter after platter of steaming crabs, ready for hammering and picking. The supply seems endless, but is it?
Not if we're talking about blue crabs from Chesapeake Bay.
The bay's iconic blue crab population has dropped to levels not seen since before restrictions were placed on the fishery more than five years ago. What's to blame?
A long and, by Mid-Atlantic standards, brutal winter has been fingered as one culprit. In one of the worst die-offs in recent history, more than a quarter of the Chesapeake's blue crabs perished in the frigid waters.
More than cold water to blame
But that's not the only factor, says disease ecologist Jeff Shields of the Virginia Institute of Marine Sciences in Gloucester Point, Va.
"Several commercially important crustacean populations, including blue crabs, have had declines linked to diseases," says Shields. "In most cases, though, the underlying causes have been difficult to pinpoint because crustacean pathogens [infectious agents] aren't very well known."
To help determine what's infecting Chesapeake blue crabs and other crustaceans, the National Science Foundation (NSF) awarded Shields a grant through the joint NSF-NIH Ecology and Evolution of Infectious Diseases Program.
"We know very little about how disease affects populations of marine invertebrates and even less about how disease might interact with other stressors, such as overfishing," says Dave Garrison, director of NSF's Biological Oceanography Program, which also funded the research.
"This study is a major step toward discovering new ways of wisely managing our coastal resources."
One Chesapeake Bay blue crab killer may be a single-celled parasitic dinoflagellate named Hematodinium, a scourge that infects blue crabs and is of concern in fisheries not only in the Chesapeake, but around the world.
Read the full story from the National Science Foundation