VINALHAVEN, Me. — At 3:30 in the morning on a Friday in late May, the lobstermen ate breakfast. Outside, their boats bobbed in the labradorite water, lit only by the dull yellow of streetlamps across the bay. It was windy, too windy for fishing, but one by one the island’s fishermen showed up at the Surfside cafe anyway. Over pancakes and eggs, they grumbled about the season’s catch to date.
Some of the lobstermen said it was just too early in the season. Others feared that it was a sign of things to come. Since the early 1980s, climate change had warmed the Gulf of Maine’s cool waters to the ideal temperature for lobsters, which has helped grow Maine’s fishery fivefold to a half-billion-dollar industry, among the most valuable in the United States. But last year the state’s lobster landings dropped by 22 million pounds, to 111 million.
Now, scientists and some fishermen are worried that the waters might eventually warm too much for the lobsters, and are asking how much longer the boom can last.
“Climate change really helped us for the last 20 years,” said Dave Cousens, who stepped down as president of the Maine Lobstermen’s Association in March. But, he added, “Climate change is going to kill us, in probably the next 30.”
Scientists say a variety of factors have contributed to the boom, including overfishing of predators like cod and the lobstermen’s own conservation efforts. But without climate change, Maine’s lobster fishery would not be anywhere near as successful as it is today, said Richard A. Wahle, a professor at the University of Maine’s School of Marine Sciences.
The Gulf of Maine has warmed faster than 99 percent of the world’s oceans for much of this century, driven by climate change in combination with natural variation. By 2050, that warming could cut lobster populations in the gulf by up to 62 percent, the Gulf of Maine Research Institute says. That has left some lobstermen feeling anxious.
Fishing off the coast of Spruce Head, Me., one crisp overcast morning, Mr. Cousens, 60, hauled up trap after disappointing trap. It was early in the season, so few lobsters were expected. Even so, Mr. Cousens was disheartened. He said he worried that in the future, Maine’s fishermen might catch fewer lobsters during the peak summer season than they do now in the spring.
“We’re past the point of climate change helping us. We’re on the downward spiral,” Mr. Cousens said, as he dragged up a kelp-entangled trap. His crewman untied the trap’s bait bag and tossed the sour-smelling herring remains into the water, where a flock of sea gulls scuffled.
In the 1990s, Mr. Cousens said, he could haul up to 80,000 pounds of lobster per year. But last year, his earnings fell 30 percent. “You can’t do that too many years in a row,” he said.
As temperatures in the gulf have increased, the favorable conditions for lobster reproduction have shifted northeast, away from Mr. Cousens’s home on the coast and toward the islands of Vinalhaven and Stonington — and in the direction of Canadian waters.
“You don’t have to be a rocket scientist to say this does not bode well for us,” Mr. Cousens said. He worries about younger fishermen who have invested hundreds of thousands of dollars in boats, gear and trucks but who have never experienced the fishery outside of these boom years. “They’re basing their financial future,” Mr. Cousens said, on a “fantasyland.”
That does not worry Mr. Cousens’s 24-year-old son Samuel, even though his boat, Adrenaline, has sent him more than $200,000 into debt. “I just put my head down and work,” he said.
Often, the younger Mr. Cousens will fish 14-hour days, 35 miles from the mainland. This has become the norm for many younger fishermen, who are venturing farther offshore in bigger, faster, more expensive boats. Lobster populations are not only expanding northeast but are thriving in deeper waters as coastal waters continue to heat up, scientists say.
Offshore, the fishing is high-risk and high-reward, Mr. Cousens said. When you haul a trap up into a boat, he said, the feeling is exhilarating: You either see “dollar signs or dirt.”
Lobstering has always been a boom-and-bust business, but the conservation measures long enforced by Maine’s lobstermen may help stave off complete collapse, scientists say.
The lobstermen clip the tails of egg-bearing female lobsters and release them, a practice called V-notching that began voluntarily in the late 19th century and was later mandated by law. They throw back lobsters that already have V-notches, alongside lobsters that are smaller than 3.25 inches or larger than five, measured from the eye socket to the base of the tail. These measures help conserve the brood stock, ensuring that the lobsters continue to repopulate.
A study published this year in the Proceedings of the National Academies of Sciences found that these conservation measures had not only capitalized on the favorable conditions created by climate change but could also save the industry from sharp decline in the future.
“It allowed them to take advantage of the boom, and it’s going to give them some resiliency to the changes that we think are coming,” said Andrew Pershing, the chief scientist at the Gulf of Maine Research Institute and a lead author of the study.
To understand the role that the conservation measures played in the broader context of climate change, Dr. Pershing and his colleagues modeled the Maine fishery against those in Long Island Sound and Rhode Island, where such measures were not mandated. In those regions, warming waters led to an almost 80 percent decline in the lobster stock and the collapse of the fisheries.
In the afternoon, Mr. Cousens — who campaigned to enforce and increase conservation measures as president of the lobstermen’s association — notched about 50 female lobsters, their abdomens ripe with pearly black eggs. A seven- to eight-pound female can carry upward of 100,000 eggs, roughly 1 percent of which are likely to survive. “That’s a big bang for your buck,” Mr. Cousens said, as he plopped one of the freshly notched females overboard. “You want to be gentle with them,” he said. “That’s the future.”
James M. Acheson, a professor of anthropology at the University of Maine who has written about lobstermen’s attitudes toward conservation, said Maine lobstermen were “strongly, strongly in favor” of the laws because they were in their best interest. “Conservation works,” Dr. Acheson said.
Still, there is only so much the measures can do to prevent the decline of the fishery. The maximum water temperature that a lobster can tolerate is about 70 degrees Fahrenheit. Beyond that, “their system starts shutting down, one organ after another,” said Dr. Wahle. Consecutive days above this limit in Southern New England, he said, had lead to “mass mortality.”
For lobsters in the earliest stage of their life cycle, however, the impacts of warming waters are less well understood. And despite healthy numbers of brood stock, scientists have seen a collapse in larval lobsters in the Gulf of Maine in recent years. “We have a multimillion-dollar industry, and a woefully inadequate understanding,” said Curtis Brown, a lobsterman and marine biologist for Ready Seafood, one of the state’s largest exporters of lobster. A shell disease, which scientists have also attributed in part to warming waters, is another threat.
Given the ominous signs, some lobstermen, and lobsterwomen, are trying to branch out. This summer, Krista Tripp, 33, is buying a small oyster farm in Spruce Head to complement her lobster fishing.
Diversifying is hard, Ms. Tripp said. She had always wanted to be a lobsterwoman, ever since she watched her father and grandfather hauling, measuring and banding the claws of the lobsters, in what she said almost resembled a dance. “They were so good, they were so fast,” she said. “I knew that that’s what I wanted to do.”
But “with fishing going downhill,” Ms. Tripp said, she feels as though she is “playing catch-up” on the tail end of a booming industry. “I don’t want to put all my eggs in one basket,” she said.
This summer, she plans to spend her mornings lobstering and her afternoons on the farm, wading through the shallow mud flats. In the meantime, the lobstermen on Vinalhaven will continue to rise in the dark for breakfast at Surfside, just as they have every season for the past two decades. Eventually, the sun will come up, and they will go out onto the water. Whether they will always find their traps full, however, is another question.