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A deep dive into Maine's response, one county at a time.

Volunteers are trying to renew Gouldsboro’s clam flats, wiped out by warming waters and green crabs

On a sunny, warm November day, a group of local volunteers work by the harbor in Gouldsboro. Michael Cronin picks out several small green crabs from a nursery tray of young softshell clams.

“I’m a clam digger, I’ve been a fisherman just about all my life,” Cronin says. He made a living off clam digging for years, but he says he doesn’t get the same haul he used to. Now, there are only a handful of clam diggers left in town because of it.

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Esta Pratt-Kielley
Maine Public
Michael Cronin and Janeeka Andersoni sort through a tray of softshell clams, looking for green crabs. They are volunteers with the Shellfish Resilience Lab, Gouldsboro's project aimed at revitalizing the local clam flats.

“We used to have 20-30 diggers [in Gouldsboro], and there was plenty of clams every year – they repopulated themselves – there were areas that used to be good clamming areas and there’s nothing there now.”

Warming ocean temperatures have caused an explosion in the invasive crab population over the last decade, which eat soft-shell clams.

Deep Dive Climate Driven

“The thing that puts the green crab population in check is very cold winters and several of them in a row, and we just aren't having that anymore. So the population is growing just incredibly,” says Kyle Pepperman, the associate director of Technology Transfer at Downeast Institute.

This story is part of our series "Climate Driven: A deep dive into Maine's response, one county at a time."

The number of clams harvested has declined by nearly 75% over the last 40 years due primarily to green crab predation, according to the Downeast Institute. It’s a well-documented problem that’s forcing towns to adapt.

For decades the Downeast Institute has grown softshell clams from seed – both for research, and to sell to municipalities to replenish their dwindling populations. But it’s not cheap for towns to purchase them. So, Pepperman had an idea – why don’t towns grow their own clams?

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Esta Pratt-Kielley
Maine Public
A group of young softshell clams that grew in nursery trays floating in the harbor from July to mid-November.

“It was a question really, of, ‘is it possible for a town to run their own operation small scale, and make it work and save some money?’” says Bill Zoellick, the volunteer manager of the Gouldsboro Shore Initiative, a local project that is trying to address changes to the town’s shore.

Zoellick and other local volunteers started a “Shellfish Resilience Lab” in hopes of revitalizing the local fishery, which has been a part of the town’s economy and culture for generations.

“Clam harvesting is not only a traditional thing, it's a way that people can make a good living without a big investment. And, you know, the harvesters and Gouldsboro still make a good living, send kids college, stuff like that,” Zoellick says. “So it's an important fishery from a social and economic standpoint in the community.”

Zoellick says the ultimate goal of the shellfish lab is to bring the mud flats back to productivity and stay ahead of climate changes along Gouldsboro’s shore.

The shellfish lab is growing clams from seed, about the size of a grain of sand, to something that’s big enough to put in the mud so the population can regrow. They are comparing clam growth, mortality, and cost with two methods: an indoor pump system that brings water from the bay into tanks holding the clams, and a protective nursery tray system that floats on the water during the warmer months. They have about 250,000 clams growing inside the lab, and 50,000 in five trays that they placed in the harbor over the summer.

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Esta Pratt-Kielley
Maine Public
Volunteers bring in the five nursery trays holding 50,000 softshell clams to check on them in November.

In late November, volunteers took the trays out of the bay to check on them. In the three months out in the trays, the clams grew about 20% larger than those in the indoor lab. But more died in the trays, because dozens of green crabs got in and ate them, despite the protective container. Pepperman says it is likely that crabs grew faster and possibly reproduced more this year due to extended warm temperatures.

“It's been very warm. So those crabs are still preying, when they really shouldn't be this time of year,” Pepperman says. “They should be just kind of buried down in the mud, but they're not. They're out eating clams.”

green crab in clam tray_clam lab.jpg
Esta Pratt-Kielley
Maine Public
A volunteer holds a green crab that got into the protective nursery tray.

Gouldsboro’s Shellfish Warden Mike Pinkham says they hoped the clams would grow larger, but it’s all part of the research. For now, they’ll continue to adjust their methods and document their work, with the goal of eventually sharing successful findings with other coastal communities.

“It would mean a lot for this community. It would also mean a lot for our surrounding communities. Because if we figure this out for us, it gives somebody else a starting point because we started at ground zero,” Pinkham says.

Pepperman says the bigger picture is education and helping towns to be resilient to change.

“[We’re] telling people to be proactive… and think about conservation in a meaningful way,” Pepperman says. “Because things are changing, and we want to keep this industry alive.”

In the face of a warming planet, Gouldsboro and other coastal communities must keep trying to adapt, or risk losing the softshell clam fishery forever.