May 28, 2013

In Maine, green crabs threaten clamming

Freeport funds study as clammers take the offensive.

By Matt Byrne
Staff Writer

FREEPORT - They lurk underfoot and in the shallows, waiting for the tide to take them to their prey.

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Chad Coffin, president of the Maine Clammers Association, sorts through a trap off the coast of Freeport Friday, looking for green crabs. He believes the proliferation of these crabs could have a “dire” impact on soft-shell clams.

Gabe Souza/Staff Photographer

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Clammers enter and exit S&S Seafood in Freeport. Many are volunteering to help in a study funded by the Town of Freeport about invasive green crabs.

Gabe Souza/Staff Photographer

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Down by the thatch grass, dozens can be heard skittering and chittering in their nests.

In droves, they are conquering the clam flats, devouring soft-shell clams and taking a bite out of the livelihood of many in this town.

Green crabs -- a hungry, multiplying army of them -- present an impending crisis for clammers and their multimillion-dollar fishery.

"They're consuming everything in the environment, even plants," said Chad Coffin, president of the Maine Clammers Association, whose group is preparing an all-out offensive against the species.

"We may be facing the end of the commercially viable soft-shell (clam) population," he said. "I think it is dire."

Green crabs have been seen along southern Maine's coast since 1904, but a recent confluence of mild winters and steadily warming waters has helped them thrive.

Clammers who have raked the mud flats for years say green crabs are quickly chewing through the clam beds, devouring the millimeters-wide baby clams known as "spat," the foundation of future years' harvests.

Scientists have by no means forgotten the crab, but academic funding to examine its effects or monitor its population is practically nil, said Brian Beal, the marine ecologist at the University of Maine who specializes in shellfish.

Now, the Town of Freeport will fund the first study on a meaningful scale to determine whether trapping, fencing and netting techniques are effective ways to stem the waves of the 10-legged invaders.

Three coves along the Harraseeket River will host multiple experiments overseen by Beal and an independent consultant, who will track crabs' movement, numbers and effect on clams in the study area.

How are green crabs affecting the $25 million clamming industry, Maine's third-largest fishery, with more than 1,700 registered diggers?

"That's a great question, and it doesn't really have a good answer because no one is tracking this stuff," Beal said.

Freeport's study, while small-scale relative to research efforts in other fisheries, shows the town's willingness to acknowledge the prospect of a clamming collapse if trends continue unabated.

"For the first time, let's do trapping and let's do fencing and let's do netting and combine all this stuff together," Beal said.

The project will employ volunteer clammers who have agreed to fish 80 green-crab traps in the Harraseeket until November.

After Beal gets permits from the Army Corps of Engineers, he plans to install hundreds of feet of plastic fencing in the mud across the mouths of the coves to deter green crabs, which don't swim and in theory cannot crawl through the barrier.

Inside the coves, Beal plans to stake off 50-foot-by-50-foot areas to determine how well fencing prevents crabs from entering and gauge the effectiveness of the various deterrents.

The town has committed about $65,000 this year to fund the work, and will likely consider continuing the study next season, said Beal.

The environmental factors that are believed to underlie green crabs' population explosion mimic a micro-trend in the 1950s, believed to have been caused by mild weather.

The crabs were seen closer to shore and in sandy nests, rather than remaining in the intertidal areas where they usually live.

Coffin said the Maine Clammers Association is focusing on educating clammers and other fishermen about the crab's threat to coastal ecosystems.

He said some are in denial. "A lot of fishermen don't realize the impact these (crabs) have had. They say, 'They're not eating our clams.' Well, what is?"

Coffin and his cohorts say they will soon reinvigorate the clammers association, which was founded in 2008 largely to pressure local shellfish authorities to open clam flats that had been closed for years.

(Continued on page 2)

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Additional Photos

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A green crab

Gabe Souza/Staff Photographer

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Chad Coffin holds handfuls of green crabs. He hopes to revitalize the Maine Clammers Association. “We have a lot more crabs to kill,” he says.

Gabe Souza/Staff Photographer


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