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These crabs may not be friends, but they can be food

Marissa McMahan of Manomet, a leading softshell green crab researcher, sorts green crabs with Paolo Tagliapietra, from Venice.Roger Warner

Fishermen, restaurateurs, and marine biologists from Maine to Cape Cod are working to turn lemons into lemonade — or, more precisely, pests into food.

Since arriving in New England from Europe 200 years ago, green crabs have destroyed salt marshes by burrowing and eroding their root systems and become voracious predators of soft-shell clams.

Now, a team of researchers wants to turn the invasive species into a marketable asset of the seafood industry.

“If they’re here to stay — which they seem to be — are there any ways to benefit from them?” asks Marissa McMahan, senior fisheries scientist at Manomet, an environmental research nonprofit headquartered in Plymouth.


Manomet was recently awarded a $267,440 Saltonstall-Kennedy Grant from the National Oceanic and Atmospheric Administration to work on establishing a green crab fishery industry in New England.

McMahan and her team of researchers and fishermen have spent two years researching the possibility of a green crab industry at a Manomet lab in Brunswick, Maine.

The grant pays for green crab population monitoring and exploration of best practices for production, marketing, and outreach to fishermen, chefs, and seafood dealers.

Adding green crabs to the seafood market could give fishermen in the Northeast a new, abundant source of income — and give marine life an escape from the aggressive predators.

“We’re trying to turn [green crabs] into a commercial product,” said Roger Warner, a fisherman and researcher who wrote a 2015 piece about the challenge for The Boston Globe Magazine. “Only if the seafood industry has incentives, will there be a large incentive to reduce [green crab] populations.”

Warner, the project founder and coordinator of the Ipswich-based Green Crab Research and Development Project, works side by side with Manomet in the lemons-to-lemonade project.

Currently, most green crabs are sold as low-cost bait for use in fisheries south of Cape Cod, Warner said, but they can be used in a variety of culinary creations.


Turning green crabs into a food source makes them more valuable, he said. The more profit fishermen can earn, the more likely they are to fish for the creatures. The more green crabs that are plucked from the ocean, the less an effect they have on marine habitats.

“The green crab invasion is a symptom of changing oceans,” Warner said. He added that focusing on one widely found species is a narrow but achievable way to help fishermen and the coastal environment. “We think we can make a difference, and we are coming up with some practical solutions and approaches to do so.”

The soft-shell green crab industry has strong roots in Venice, Italy, where they are considered a delicacy, McMahan said. Manomet worked with Venetian fishermen, who shared their technology and knowledge about molting signs, harvesting, and selling soft-shell green crabs.

The trick to harvesting green crabs, McMahan said, is knowing when they’re about to shed their shell. At that point, you pluck them from the water, then harvest them while they’re soft-shelled.

They sell for $25 to $50 per pound in Italy, so McMahan and her colleagues saw this as an opportunity for local fishermen in Cape Cod, Maine, and New Hampshire to rake in “lucrative” profits.

This past summer, Chris Jamison, a commercial fisherman working with McMahan, made the first sale of soft-shell green grabs to restaurants for $3 each. Restaurants “couldn’t get enough,” McMahan said, and the fisherman sold 60 to 100 crabs a week.


Heather Atwood, a food writer on Cape Ann, has tried a number of green crab recipes after Warner introduced her to them.

“The mission was to imagine something that would really make it worthwhile to harvest,” Atwood said.

For her first recipe, she sauteed 20 to 30 green crabs in a mirepoix stock with celery, carrots, onions, and bay leaves, added wine and water, and let the mixture simmer.

“It was the best fish stock I ever had,” Atwood said. She described the taste as a cross between fish and beef stock, with a savory “umami” taste that enhances all flavors it touches. With that stock, she made risotto.

“I saw the possibilities, but the market issue is tough,” she said. While commercially produced green crab stock would require taking a lot of green crabs out of the ocean, fishermen still wouldn’t be getting a meaningful price, she said.

Green crab stocks just wouldn’t pull in enough money to make the effort worth it for fishermen — on to the next dish.

Green crab roe is called mazanetta or masanete in Italy, and is available in females just before they spawn. It’s like a cross between fish caviar and the tomalley inside a lobster, Atwood said, but is full of flavor.

“We think that’s really the best way to go in terms of a commercial product,” Atwood said.


Finding incentives to rid the ocean of so many green crabs is a win-win for all — except the crabs.

McMahan is worried that climate change could dramatically affect the lobster industry, leaving fishermen with even fewer options. She grew up trapping lobsters with her family in Maine and now researches the effect of climate change on marine life.

“I’m really concerned [about climate change], and work towards diversifying fishery opportunities,” McMahan said. “So that if something were to happen to American lobster, fishermen would have something to fall back on.”

Morgan Hughes can be reached at morgan.hughes@globe.com.