Fueling the tension is the rising price of lobster, which has attracted more Canadian fishermen to the lobster-rich waters of the so-called gray zone, the disputed territory fished mainly by Americans until a decade ago. Both countries allow their lobstermen to fish there and acquiesce to the presence of their neighboring fishermen, though each claims exclusive ownership of the waters.

The two countries have long shared the world’s longest border peaceably, but a centuries-old conflict over 277 square miles of disputed, increasingly lucrative waters has sown discord and threatens to shatter the tranquility between Maine and New Brunswick.

BAY OF FUNDY — There have been death threats on both sides of the watery divide between the United States and Canada, as lobstermen accuse each other of sabotaging lines, stealing gear, and setting traps atop those already in the water.


“This is a ticking time bomb out here,” said Brian Cates, 61, of Cutler, Maine, who has been fishing the contested waters in the Bay of Fundy since he was 9 years old. “It’s just a matter of time before someone gets killed.”

He recalled how a Canadian patrol boat several years ago hauled up his and his son’s traps, after a line drifted into Canadian waters. He sped over to the boat and threatened to ram it if the officers didn’t return his gear, telling them, “I’m going to sink you.”

The Canadians returned his gear.

But Canadian fishermen insist the Americans should get used to their presence.

“It’s our bottom, and we’re going to be there to stress our sovereignty,” said Brian Guptill, 51, president of the Grand Manan Fishermen’s Association, who has been fishing nearby since the 1980s, but plans to start fishing in the gray zone for the first time this summer. “I’m going to go there to raise hell for a while.”


He added, “There are going to be guys on both sides of the border slashing ropes and instigating problems.”

American and Canadian law enforcement authorities, who cooperate and speak with each other regularly as they enforce their respective laws, worry about the potential for violence.

“The tensions are definitely mounting,” said Mark Murray, a specialist in the Maine Marine Patrol for the past 17 years, as he and an armed officer puttered through the disputed waters on a recent afternoon.

In the past year, he and his colleagues said, they have received dozens of complaints from US fishermen related to the rising number of Canadians setting traps in the gray zone.

They have heard lobstermen vow to bring guns on the water and have received reports of US and Canadian boats pulling on the opposite ends of the same line. They recalled how one US lobsterman lost a thumb while trying to disentangle his traps from Canadian lines.

As a result, the Maine Marine Patrol has quadrupled the amount of time its officers patrol the gray zone, especially at night, when Canadian laws allow their fishermen to be on the water but Maine bans their lobstermen from working.

“We’ve heard guys say that if we won’t do our jobs, they’ll take matters into their own hands,” said Jason Leavitt, a Maine Marine Patrol officer.

Maine Marine Patrol specialist Mark Murray, left, and officer Jason Leavitt patroled the waters near the Machias Seal Island on May 7. Keith Bedford/Globe Staff/Globe Staff

The conflict began at the end of the Revolutionary War, when the newly independent Colonies received all islands within about 70 miles of the US shore. But the 1783 Treaty of Paris excluded any island that had been part of Nova Scotia.


The two sides emerged from this deal disputing only one speck of land at the mouth of the Bay of Fundy: Machias Seal Island, a treeless, 20-acre rock 10 miles from the Maine coast and 12 miles from Grand Manan Island, which is part of New Brunswick. The Canadians say a 17th-century British land grant proves the island was originally part of Nova Scotia.

Both Canadian and US officials declined requests for interviews. Drew Bailey, a spokesman for the US State Department, offered only a terse statement: “Our longstanding position is that the Machias Seal Island belongs to the United States.”

Officials from Fisheries and Oceans Canada wrote in an e-mail that while they have “excellent relationships” with US law enforcement, they believe they should have exclusive sovereignty over the area.

“Both the waters surrounding Machias Seal Island and the island itself are Canadian,” they wrote.

For centuries, the conflict remained muted. During World War I, the Canadians agreed to allow a small detachment of Marines onto the island to protect the area from German U-boats. Both US and Canadian boats have ferried tourists there for years to glimpse nesting grounds of Atlantic puffins.

Occasionally, people on both sides tried to stoke tensions. For years before he died in 2004, an American tour boat operator, Barna Norton, made an annual pilgrimage to the island to plant an American flag. The maple leaf flag flies over the island’s lighthouse, which Canadians built and have maintained for nearly 200 years to assert their sovereignty, and politicians occasionally make a show of flying out to visit the lighthouse keepers, their constituents.


Though the two countries have resolved other maritime disputes through arbitration, the Canadians have declined American proposals to do so with the gray area, arguing that their claim is beyond question.

Since 2002, Canada has relaxed its fishing regulations to allow more lobstermen to work in the gray zone, including when their lobster season shuts down between July and November.

The rising price of lobster has given Canada even more incentive to assert its sovereignty. Last year, Maine’s lobster catch was valued at a record $457 million, $87 million more than in 2013, the largest one-year increase on record and more than the total value of the fishery 21 years before, according to the Maine Department of Marine Resources.

Maine Marine Patrol specialist Mark Murray with lobsterman Brian Cates of Maine. Keith Bedford/Globe Staff/Globe Staff

Americans complain that the congested area now has tens of thousands of traps on the ocean floor and has become more complicated to fish.

“It’s like they want a war,” said Kristan Porter, 43, a lobsterman out of Cutler, Maine, who learned how to set traps in the area’s powerful tides from his grandfather and has been fishing about 400 traps in the gray zone for the past 20 years. “They keep trying to ratchet up the pressure and turn the knife. We just want them to leave us alone.”

The US fishermen say many of the Canadians don’t understand how to set traps in the area’s tricky tides, and their traps often get entangled with the Americans’. The US fishermen also complain that the Canadians don’t have to follow US conservation rules, such as throwing back larger lobsters that serve to replenish the population or having to use expensive lines designed to protect right whales.


The Canadians dismiss the Americans’ environmental concerns. They also noted that Canadian fisherman are limited to 375 traps per license, while most Maine fisherman can set 800 traps at a time.

“It’s Canadian water, plain and simple,” said Lawrence Cook, chair of the lobster fishing district in Grand Manan, who defied a death threat he got from an American lobsterman when he started fishing the gray zone in 2002. “So if it’s going to be fished, it’s going to be fished by Canadians.”

He added: “We are there to stay.”

David Abel can be reached at dabel@globe.com. Follow him on Twitter @davabel.