Surprising Blue Crab Population Develops in Maine | Chesapeake Bay Magazine

Across the Chesapeake Bay, the blue crab, Callinectes sapidus, is an instantly recognizable and
iconic species. It’s the Maryland State Crustacean, the namesake and mascot of a workforce within the Atlantic
League of Skilled Baseball, and the bottom of essentially the most priceless fishery within the Bay.

Up within the Gulf of Maine, outdoors the crabs’ historic vary, these creatures are a supply of shock. However over the previous few years, it has turn out to be increasingly more widespread for individuals to seek out blue crabs. Lobster fishermen and ladies are catching them of their lobster pots. Divers are seeing them once they seek for scallops. Beachgoers are recognizing them in tide swimming pools.

Warming Maine waters is probably going why individuals at the moment are seeing blue crabs extra incessantly. Traditionally, the crabs couldn’t survive for lengthy within the Gulf as a result of the waters are too chilly. However local weather change is growing ocean temperatures globally, and particularly close to Maine, maybe permitting the crabs to turn out to be everlasting residents.

South of Portland, Maine, on the Wells Nationwide Estuarine Analysis Reserve, Analysis Affiliate Laura Crane and her colleagues have been trapping grownup blue crabs for 3 years to watch native inhabitants numbers, catching virtually 100 crabs.

“We don’t wish to make claims but that it is a everlasting inhabitants,” Crane mentioned. “If we’re discovering blue crabs for 5 or ten years in the identical areas, that begins to be a extra compelling argument that that is a everlasting inhabitants.”

Extra crabs in Maine doesn’t imply fewer crabs elsewhere, although. “It’s not that the entire inhabitants has shifted northward, it’s simply that they’ve expanded to extra locations,” David Johnson, affiliate professor on the Virginia Institute of Marine Science (VIMS), mentioned.

How the crabs are literally entering into the Gulf is unsure, though each Crane and Johnson talked about that ocean currents are probably shifting larvae round Cape Cod. Surveys on the Wells Reserve have recorded blue crab larvae since 2016.

But, a “lacking puzzle piece” for Crane is the dearth of egg-bearing feminine crabs of their surveys. “That may be a robust indicator that the crabs are reproducing within the system,” she mentioned.

Nobody is aware of but what a everlasting blue crab inhabitants within the Gulf of Maine would imply for the individuals and animals who at present reside there.

“Blue crabs eat something. They’ll combat you over an outdated boot,” Johnson mentioned. He’s simply beginning analysis on how crabs will have an effect on prey populations and the way the crabs would possibly adapt to suit their new ecosystem.

Crane is very keen on how blue crabs will work together with the European Inexperienced Crab, a problematic invasive species.

“We’re questioning if the blue crab can turn out to be a brand new predator or competitor of the inexperienced crab, serving to to tamp down their inhabitants,” she mentioned. “That might be one potential profit of getting blue crabs.”

One other potential profit is that “blue crabs are scrumptious,” as Crane put it. In just a few a long time, relying on how the inhabitants grows, there might be a blue crab fishery up in Maine, too.

For now, there’s a lot that’s nonetheless unknown. However Crane famous that increasingly more researchers from across the Gulf are beginning to become involved on this analysis, serving to to uncover what adjustments this iconic species will convey to Maine.

-Emma Johnson