Conservation Practices Help Lobsters Weather Climate Change

Jan 29, 2018

It’s no secret that the lobster fishery in southern New England is in trouble. The population has declined by almost eighty percent in the past few decades. In contrast, lobsters in the Gulf of Maine have exploded and the fishery has seen record landings. So, what gives? 

Rising water temperatures are a big part of the story. Baby lobsters have a set-point: 61.5°F. Go much above that, and first-year lobsters start dying off. That’s what has been happening during recent summers in places like Buzzards Bay and Narragansett Bay. Meanwhile, in the Gulf of Maine, which is one of the most rapidly warming ocean areas anywhere in the world, the increase in temperatures has put lobsters into their sweet spot.

But that’s not where the story ends. A new study used a computer model to tease apart the influence of environmental changes and conservation practices, which differ significantly between Maine and southern New England. For generations, Maine lobstermen have been throwing back fertile females (after cutting a notch out of their tails so that they can be recognized even when they’re not carrying eggs) and the biggest lobsters. Those practices didn’t hit southern New England until a decade ago.

The conclusion of the new analysis is a bitter pill for southern New England lobstermen, according to Andrew Pershing, chief scientific officer and head of the Ecosystem Modeling Lab at Gulf of Maine Research Institute.

“Had they done a management process more like what we have in Maine,” Pershing said, “they would have seen a smaller decline and probably would have more of a fishery than what they have now.”

There’s not much to be done about that now, but Pershing says it’s reaffirming for Maine lobstermen as they face declines in their catch due to continued warming, and also a cautionary tale for other fisheries.