FREEPORT – The Freeport-based Maine Clammers Association and others concerned with the damage that green crabs are inflicting on the state’s clamming industry are taking another step in fighting the problem, with a Green Crab Summit, scheduled on Dec. 16 at the University of Maine.

Armed with information from a Maine Department of Marine Resources study, which involved traps set in 31 Maine towns on Aug. 28, participants at the Green Crab Summit will explore solutions. The green crabs, an invasive species not valued for harvesting, are believed to be depleting clams by feeding on baby clams.

Kohl Kanwit, director of public health for the Department of Marine Resources, said last week that the summit will provide information on the late-summer study, and more.

“That’s going to be the next big thing that’s happening, and it’s going to be quite a big event, I would think,” Kanwit said. “Geneticists at the summit will help determine where the crabs are from. They might be more cold-hearty than we suspected.”

Kanwit said that in the one-day study, Freeport had the “peak catch” of 575 crabs in its traps. But Stockton Springs – much farther north – had the high average of 191, she said.

Volunteers from 29 municipalities ranging from Biddeford to Lubec teamed up with scientists from the state and the Maine Sea Grant College Program at the University of Maine for the study. A total of 221 traps were fished, and every participating town reported catching at least some green crabs. Ninety-four percent of the traps had at least one green crab, the Department of Marine Resources reports.

Stockton Springs had the highest average catch per trap, followed closely by Freeport, Waldoboro, Biddeford, Scarborough, Trenton and Brunswick, Kanwit said. She did not have numbers of those averages, other than Stockton Springs.

It has been speculated that the green grabs, native to Europe, arrived in this country in the ballast of ships. There is a belief that their numbers have increased due to global warming’s effect on ocean temperatures.

The Green Crab Summit will reveal more data, Kanwit said.

“It took quite a while for us to get the data sheets back,” she said. “But we’ve set up a data base. We’re going to do a full presentation at the Green Crab Summit.”

Trapping, Kanwit said, is only a partial solution to this menace.

“It needs to be done in conjunction with fencing,” she said.

Marine Resources Commissioner Patrick Keliher has suggested that finding a way to make harvesting the green crab commercially viable would be a big step in the eradication, as well.

Kanwit said that the biggest objective of the study was to increase awareness of the problem.

“One of the things that we were trying to do was, A., be aware if we had a problem with green crabs or not, and B., what to do about it,” she said. “The survey was a snapshot. The biggest problem was the southern coast, from Biddeford to Frenchman’s Bay. But it’s not just a southern Maine problem.”

Garret Simmons, owner of wholesaler S & S Seafood of Freeport, has his reservation made for the Green Crab Summit. His business, after all, is all about clams.

“I’ve registered,” Simmons said. “Some scientists from Canada will be there, with some insights on trapping, and marketing. I’ve tried (green crabs). They’re OK. They’re just small. If they have economic value, it stands to reason we can keep a check on that. They’re wreaking havoc with the clams.”

Simmons, who clammed prior to becoming a dealer, said his numbers are down only about 15 percent right now. Last year, S & S had $2.1 million in clam sales, some to the Boston market, he said.

But the clamming industry has reached the tipping point, he said.

“By the looks of the numbers, the effects are coming soon,” he said. “The crabs are eating all the little clams, when they’re still near the surface and more vulnerable. Within the next year or so, we’re going to see more drastic changes. It looks to me we don’t have a lot of juvenile stuff coming up. We’re looking at an abrupt change. The crash has already happened in some towns.”

The town of Freeport, meanwhile, dedicated $100,000 to study clam flats and decide how to deal with the declining clam population and the encroachment of the green crab. Tom Kay, the town’s shellfish warden, said that information has been gathered in the study, which began in mid-May.

“The physical part is winding down,” Kay said. “We’re waiting for input from scientists. We expect that before the end of the year.”

Freeport is believed to be the only municipality in the state to be spearheading such an effort.

Chad Coffin, president of the Maine Clammers Association, said last week that the Freeport study shows that trapping methodology needs to change – less time in the water, and later in the season.

“We learned a tremendous amount about the crabs – their behavior and their habitat,” Coffin said. “To make trapping more effective, traps should be set in late August, September, October or even November. In late fall, the traps are full of females. Males burrow in August and September. Then females get voracious and fill the traps. You want to catch those females. They keep their sperm for 18 months. And you catch more crabs by keeping them less time. They want fresh bait, not rotting bait. The length of time the traps are set in the water dramatically increases the number of crabs caught.”

Coffin also said that ocean acidification is a problem, but clams are spawning in their current environment.

“We need to focus on water quality and resource protection,” he said. “Resource protection is as important as anything at this point. It’s been quite a learning experience here in Freeport, that’s for sure.”


A Green Grab Summit will be held Monday, Dec. 16, from 9 a.m.-5 p.m., at the Wells Conference Center, University of Maine, Orono. It is open to the public, though space is limited. Register no later than Dec. 9 at It is sponsored by the Maine Clammers Association, SeaGrant and the Maine Department of Marine Resources. For more information, see

Clammer Jim Harriman of Freeport carries traps containing green crabs in his boat, near Porter’s Landing, in November.

Only subscribers are eligible to post comments. Please subscribe or to participate in the conversation. Here’s why.

Use the form below to reset your password. When you've submitted your account email, we will send an email with a reset code.