Steamers out of steam? Beloved bivalves aren't happy clams

The soft-shell clams that are harvested by hand and raked from the mud flats of Maine are becoming less plentiful, and the downward trend jeopardizes one of New England's oldest and most historic coastal industries.

Maine is the soft-shell clam capital of the country. But clammers harvested less than 1.5 million (0.68 million kilograms) pounds last year, the lowest total in a quarter century — down from nearly 8 million pounds (3.6 million kilograms) at the industry's height in the late 1970s.

The clamming industry was once second only to lobsters in value among Maine fisheries. And clams are steeped in Maine lore, playing a role in Robert McCloskey's 1953 picture book "One Morning in Maine" and serving as the focal point of the Yarmouth Clam Festival that has welcomed thousands of people to the coast for more than 50 years.

"Last year was one of the lowest totals since the '50s," said Chad Coffin, a Freeport clammer who heads the Maine Clammers Association. "There's still areas of the coast right now where there just isn't a lot of clams."

Clams in Maine face of a number of threats, including an uptick in predation from green crabs and milky ribbon worms, and the increasing acidification of the ocean. Shellfish toxins also sometimes necessitate shellfish harvesting closures, as they did in the state's eastern coast last year and southern coast this year.

Despite all this, Maine soft-shell clam diggers are hopeful for a stronger summer this year. The clammers' association says it's hoping for a bounce-back year because many clams seem to be reaching legal size, Coffin said.

But stabilizing the industry for the long term will mean adapting to changing environmental conditions, said Brian Beal, a professor of marine ecology at the University of Maine at Machias. The heightened predation from the crabs and worms has tracked in line with rising coastal water temperatures, which are predicted to keep rising, he said.

Beal said the predators are the biggest threat faced by the clams. One way for fishermen to cope with them is by employing strategies such as putting netting around areas of mud flats where clams grow and planting clam seed in protected areas, he said.

"If we don't adapt, we're going to be dead in the water," Beal said. "Unfortunately, our environment has changed."

The soft-shell clams are also known as "steamers" and they are often fried, used in chowder and, of course, steamed. They're a familiar sight in New England fish markets and grocery stores, where they are frequently sold fresh.

The clams are also harvested in smaller numbers in other states, including Massachusetts and New York. The catch has also dwindled in some of those states, such as Rhode Island, where clammers harvested barely 7,000 pounds (3,175 kilograms) of softshell clams in 2015 after frequently topping 100,000 pounds (45,359 kilograms) in the 2000s.

In Maine, state biologists are working on surveys and protection projects to try to preserve the clams, said Jeff Nichols, a spokesman for the state Department of Marine Resources. The number of clammers in the state has held steadily between 1,700 and 2,000 for most of the past ten years.

Coffin said he agrees with Beal that adaptation is key to reviving the industry before the crabs and worms make it impossible.

"It's not that there's not clams," he said. "It's that they don't survive."