Softshell clams, better known as steamers, are not the most famous bivalve on Martha’s Vineyard. And although a favored treat on the Island, nor are they second or third on the list.

Though often taking a backseat to quahaugs, scallops and oysters, the steamer fishery was once a valuable economic engine for a select group of local shellfishermen. Yet, after decades of decline, a fishery that in the past had supported more than a dozen summertime clammers on the Edgartown Great Pond now draws no more than five commercial harvesters there each summer.

“Like a lot of things shellfishing, it’s not as good as it used to be,” said Paul Bagnall, retired Edgartown shellfish constable who commercially clammed in the 1970s and 1980s. “It’s always been a boom or bust cycle out there, but it has been cycling down over the years.”

Recent state fisheries data released by the Martha’s Vineyard Commission portrays a turbulent industry. In 2015, for instance, 225.5 bushels were harvested on-Island, a number that rose to 1080 bushels in 2021 before dropping back down to 412 last year.

Historic levels were often much higher, with 1,765 bushels harvested in Edgartown alone in 1965.

Overall price-adjusted profits from the fishery have gone down as well. In 1965, the Edgartown fish warden’s report valued the total harvest at $17,650, equivalent to $171,501 today, according to the Bureau of Labor Statistics. That price-adjusted level is $70,000 more than any year recorded in state data going back to 2005. In 2021, the total harvest was valued at $92,089, while 2022 numbers came in at just $22,960. Meanwhile, the quahaug harvest was valued at $249,971 last year.

Seeding for softshell clams has been difficult. — Albert O. Fischer

“It’s not a great business to break into nowadays,” said Edgartown shellfish constable Rob Morrison of the steamer fishery.

Steamers are more sensitive to environmental conditions than hard shell quahaugs, Mr. Morrison said. The soft shells make them vulnerable to predation from local blue crabs and invasive greens and susceptible to shell weakening from ocean acidification.

“Steamer clams are something that’s been in decline coastwide for years,” he said.

Shellfish pathologist Roxanna Smolowitz said that the decline on the Vineyard began in the mid-1980s when MV Shellfish Group samples she tested at the Marine Biological Laboratory showed the first infection of neoplasia disease in Island steamers.

“It pretty much wiped out the softshell clams [in Edgartown Great Pond],” she recalled, though the disease does not affect humans. Since then, the dis

ease has become less lethal but still lingers in the background.

Yet, unlike scallops, quahaugs and oysters, all of which have benefited from public efforts at restoration after facing similar environmental challenges, attempts to seed softshell clams on Island have been largely unsuccessful.

“The general consensus is that they’re not very easy to grow,” said Emma Green-Beach, executive director of the shellfish group.

After an abortive attempt to cultivate steamers in the early 2000s, she said, the group hasn’t attempted to seed them in Island waters.

Like quahaugs, softshell clams live most of their lives burrowed in shoreside sands. Though the shellfish group has had some success growing steamer seed in the hatchery, when it came time to release them into the wild, the clams had difficulty adjusting.

“They seem to be particular about how or where or when they dig into the sand,” Ms. Green-Beach said, and when clams linger on the surface for too long, they end up getting devoured by crabs and other predators.  

Donnie Benefit, who began harvesting clams with his brother Doug nearly 50 years ago, said he has seen the number of clammers shrink along with the number of clams.

“There’s not really a good market,” he said. “If you had 15 people go, nobody would make any money.”

Mr. Benefit has vacillated between the conch and steamer fishery over the years depending on the market, while also managing dredge operations for Edgartown. Like many commercial softshell clammers, he employs an engine-powered hydraulic jet to harvest them.

“You just tow it behind you slowly . . . and it forces water through the sand,” he said, explaining how this stirs up the bottom and causes clams to rise to the top.

“It’s a pretty efficient way to harvest them,” Mr. Benefit said, as it prevents the delicate shells from being broken by clam rakes.

But it also creates a high barrier to entry, he added, and with the fishery as fickle as it is, new clammers are unlikely

to invest the time and money required for a jet harvesting rig.

The other method for harvesting steamers is hand digging and is typically practiced in tidal flats during low tide. Last year, however, one of the most promising tidal habitats in Katama Bay was wiped out when the Norton Point breach sent most of the steamers in that area out to sea.

Mr. Morrision said that last summer’s issues were compounded when the Edgartown Great Pond was closed to harvest after waters tested positive for fecal coliform bacteria. This summer, he anticipates that most of the pond will reopen to shellfishing.

Conditions in the Tisbury Great Pond are more difficult to parse — West Tisbury doesn’t report their bushel numbers, aiming to keep Edgartown clammers from dipping in to their waters — but town shellfish constable Ray Gale estimated that around 100 bushels were harvested this summer.  

“It made me want to quit being the shellfish constable and go myself because the price was so good,” he said.

Steamers now retail around $8 dollars a pound.  

But, he added, the fishery has been volatile in his town as well, with the pond closed last summer to protect new steamer seed.

“There’s still a lot of seed out on the bottom just lying there with the crabs chewing on them and the gulls working on them,” he said.

The harvest in other Island towns is much smaller, with just 14 commercial bushels last year in Chilmark, and another 10 in Tisbury.

“It’s usually a good side gig,” said Mike Holtham, manager of The Net Result.

Most of their suppliers, Mr. Holtham said, harvest some steamers in the summer while focusing on other fisheries for the rest of the year.  

And while steamers are sometimes sensitive creatures, Ms. Green-Beach said, they have their owns strengths, able to withstand a variety of salinities and oxygen levels, which could point the way to a more robust future.

Recently, she said, there has been a resurgence in interest in steamers, especially for recreational harvesters.

“From our perspective, we really want people out there harvesting their food,” she said. “And there is nothing like a fried, whole-belly steamer.”