Whales are dying. Ropes from lobster traps are partly to blame. That’s put lobsters — and the people who catch them — in the crosshairs of conservation groups.

“It’s been a gut punch from people across the country telling us we’re doing it wrong,” he said.

Sam Sewall, 24, aboard his father’s boat off the coast of York, Maine. Sewall is part of a multigenerational family of lobstermen. Jonathan Wiggs/Globe Staff

Up in the air 15 miles off Nantucket, Hsu spotted the telltale heart-shaped blow of an endangered North Atlantic right whale. It swam slowly, with several rope lines trailing behind it.

Hsu had seen this whale before, similarly entangled in the Gulf of St. Lawrence. It was Snow Cone, and this was her fifth entanglement. Hsu knew Snow Cone would not likely survive.

“It was like a punch in the gut,” Hsu said, echoing a lobsterman she’s never met.

Meanwhile, Serpa took the lobster meat and began cleaning, chopping, and prepping it for that night’s dinner. There were lobster rolls and lobster spaghetti to prepare to fill the eager bellies of his guests. Demand has been so strong lately, he can practically name his price.

The trio are entwined in a drama playing out in the rich waters of the Gulf of Maine, which faces an existential crisis as climate change shifts the migration patterns of lobsters and whales alike. The lobster industry, about as close to an icon of New England as there is, has become embroiled in a maelstrom as conservation groups seek to protect the last 340 North Atlantic right whales.

It’s a debate about science and sustainability, and it gets pretty technical pretty fast. But with the population of right whales declining 30 percent over the past decade, there’s a fundamental question facing restaurateurs and their customers: Is eating lobsters worth risking the extinction of an entire species?

Sous chef Harold Berrio makes a lobster roll at Little Whale Oyster Bar on Newbury Street in Boston. Despite a placement on the Monterey Bay Aquarium Seafood Watch list of seafood to avoid, lobster is still enjoyed by restaurant customers.Lane Turner/Globe Staff

“This is such a sensitive issue and it gets to I think a much broader question: What do we as a society want to be when it comes to our relationship with nature?” asks Barton Seaver, an award-winning chef and evangelist for sustainable seafood who lives in Freeport, Maine. “In this acute example, we pit the two most charismatic megafauna of the Atlantic Ocean against each other in what is essentially an existential question.”

How best to balance lobster fishing and whale safety is a long-running debate in the waters off New England, with conservation groups, lobstermen, and federal regulators now deliberating new measures to protect the whales. In July, a federal judge ruled that federal regulators need to do much more and effectively eliminate the risk of whale entanglement in lobster lines.

But things boiled over last month, when the influential Monterey Bay Aquarium added lobster and other vertical-line-caught fish to its Seafood Watch “red list” of foods to avoid. Then, a few days later, a federal judge sided with conservation groups in rejecting a challenge by New England lobstermen, who had argued that stronger federal regulations were too restrictive and based on flawed data.

Those regulations have required fisheries in the Gulf of Maine to implement measures to protect against entanglements. This May, fishermen had to close certain fishing areas, add more traps to each line in some places, and add weak links to their ropes to allow whales to break free should they become entangled. Since 2017, have documented 34 whales in US and Canadian waters that have died due to entanglements and vessel strikes.

Both sides view the matter as literally a battle for survival.

Keep the ropes in the water, says one side, and the right whales will die out. Force the lobster industry to cut back further, says the other, and an entire coastal economy — not to mention a way of life — faces peril.

All this raises big questions about how we define sustainability, about protecting an industry and the livelihoods it provides, about how we value an endangered species whose demise is directly linked to human actions.

Should one piece of the ecosystem outrank the others? Should we reconsider the lobster?

And those questions will eventually land on plates all over New England.

So far, lobster sales have remained steady since the Monterey Bay Aquarium red-listed the crustacean. Meal kit companies Blue Apron and Hello Fresh announced they would no longer sell lobster, but few other major retailers have followed. And though politicians in Maine have been up in arms, crusading against regulations they say will cripple the $1 billion industry, fears that restaurants would pull lobster from their menus have proved largely unfounded.

Senator Angus King of Maine speaks at an event in Portland last month decrying calls by a seafood watchdog group to take lobster off restaurant menus.Jonathan Wiggs/Globe Staff

Chefs such as Serpa didn’t flinch. Last month, as Maine Senator Angus King was lamping the judge’s decision, calling it “pseudoscientific,” “reckless,” and “absurd,” Serpa hosted a lobster clambake for a private party in his Newbury Street restaurant, Little Whale.

Years of experience have taught him that visitors to Boston want seafood, and seafood means lobsters. When lobster prices jumped to $70 a pound this spring, Serpa pulled lobster rolls off the menu at his other restaurant, Select Oyster Bar. But his servers complained: The guests wanted their rolls, they told him, “They’ll pay anything.” And they did, shelling out $65 a pop. None mentioned Monterey Bay’s red list. He doesn’t expect them to.

“The majority of the dining public does not know Monterey Bay,” Serpa said. “I honestly think there will be zero impact on the consumer side, and as a purchaser of that product, I’m not gonna note sell it.”

The lobster roll at Little Whale Oyster Bar. Michael Serpa is a well-known seafood chef who has kept lobster on the menu at his Newbury Street restaurant. Lane Turner/Globe Staff

Ben Conniff, cofounder of Luke’s Lobster, said the response has been similar at his 27 restaurants, which purchase between 5 and 6 million pounds of lobster a year. He gave a staff training on the red list but says he’s heard from just one customer about the Seafood Watch rating, who wanted to know more about how Luke’s sourced its lobsters.

Some scientists, though, say the red list is more than warranted. Amy Knowlton, a senior scientist at the Anderson Cabot Center for Ocean Life at the New England Aquarium, hasn’t eaten a lobster in 10 years.

“I know what these whales are facing out there,” Knowlton said. Whale entanglements, she notes, have spiked in the last decade, and she argues that enhanced preventative measures are the only way to ensure that no more whales are lost.

“I wish all this could have been put in place yesterday,” she said. “It’s so urgent and we are losing them so quickly.”

An endangered, female North Atlantic right whale known as Snow Cone was spotted south of Nantucket last month, dragging heavy fishing gear and in poor health.New England Aquarium, taken unde

But the prospect of stricter federal regulations could have a far larger economic impact than putting lobsters on any do-not-serve list.

Lobster is both pricey and super-perishable, and the profit margins for restaurants are already tight. If regulations result in a surge in prices, more chefs may take it off the menu.

“If you start regulating it you’re just going to see people stop purchasing it,” Serpa says. “Instead of a mom-and-pop operation buying it, they’ll say ‘We’ll buy hot dogs instead.’”

Then there’s the question of supply. Serpa’s seafood distributor, Kim Marden, co-owner of Captain Marden’s Seafoods, which sells 10,000 pounds of lobster a week, fears fewer traps or shorter fishing seasons could drive the cost of lobster even higher than this year’s, making it harder to both buy and sell it.

And for those actually doing the lobstering, “The stakes are much higher,” said Seaver. While the red list draws headlines, he worries the stronger restrictions on the number of lines and lobster traps in the water could force smaller operators to close up shop.

“It could be a knock-out blow,” he said.

The issue, as he sees it, is what we want our working coastlines to become, and what do we give up to protect an endangered species.

“If we are to take such a stand on this one aspect of the fishery, then where does that stand lead us?” Seaver said. “The second leading cause of death [for right whales] are vessel strikes. Are restaurants supposed to red-list European wine and Parmesan cheese and balsamic vinegar from Italy and literally anything that arrives from the global trade system? Is Cheesecake Factory going to take olive oil and pasta off their menus?”

The Lobster Cove restaurant in York, Maine.Jonathan Wiggs/Globe Staff

Kyle Foley, the director of the Sustainable Seafood Program at the Gulf of Maine Research Institute, believes the new federal conservation targets “will be really difficult to achieve without devastating fishermen’s businesses.” She said the option often floated by conservation groups as a possible solution — ropeless gear technology — is costly and still unproven.

“It’s certainly not ready for 5,000 fishermen to implement and purchase,” she said. “There are some really tough times coming for the industry.”

Both Seaver and Knowlton, of the New England Aquarium, believe federal subsidies could help lobstermen transition to ropeless gear, much as agricultural subsidies are distributed to farmers. Some have already begun to experiment with the expensive gear. But Seaver worries that the higher costs will mean only the biggest players keep fishing, while family-run lobster boats throw in the towel.

“With expanded costs comes reduced access. That’s just a universal truth,” he said. “This is a question of what do we want Maine to be.”

Out on the water, Sam Sewall asking himself that same question. Right now, he and his father have a built-in market in his cousin, Jeremy Sewall, owner of the Row 34 restaurants in Boston and Portsmouth. In the 34,000 hours his father has spent on his current boat, Sewall said he’s never spotted a single right whale, much less one entangled in rope from lobster traps.

“This would all be much easier to stomach if there was a body count,” he said.

As it stands, he said, Maine’s lobster industry is bearing the brunt of economic pain with little evidence that it has done the harm. Now, consumers, too, are being asked to sacrifice to keep the whales from being tangled in lobster lines.

But here’s the thing with entanglements of right whales: It’s hard to determine where it happens, and it’s hard to tell when they succumb. Right whales that die due to rope lines don’t always wash up on shore. They often sink to the bottom of the ocean, leaving no bodies to count, only ghosts.


Janelle Nanos can be reached at janelle.nanos@globe.com. Follow her on Twitter @janellenanos.