On a late-April morning just before 4 a.m., Lucien LeBlanc sits in a captain’s chair aboard his 50-foot fishing vessel the John Harold, named for his grandfather.

Five screens glow as the vessel cuts through inky darkness toward the open ocean and his first lobster trap line about 25 nautical miles away. He moves to the kitchen to put away groceries.

—Lucien LeBlanc, lobster fisherman

Warming waters around Nova Scotia have created a sweet spot for the crustacean over the past decade. LeBlanc and his fellow fishermen are hauling in more lobster, for highest-ever prices ranging from $7 to $13 per pound depending on the time of year — more than triple the $3 prices as recently as 2008’s recession.

The Nova Scotian catch makes up the majority of Canada’s lobster industry, bringing more than $750 million in 2018 — about double the $382 million brought in for 2012.

“It’s been a double boom for me. It’s been a stock boom, there’s been more lobsters than I’ve ever seen before; as well as the economics have been working real well, the market’s strong,” says LeBlanc.

Never miss the latest news from the Star. Sign up for our newsletters to get today’s top stories, your favourite columnists and more in your inbox.

The upswing has allowed him to pay off debt, build an upgraded fishing boat and given him “hope for the future,” LeBlanc says.

But it may not last. The same northwest Atlantic warming that helped create a lobster haven may soon push them out – or even cause their mass deaths.

The ocean here is changing. The waters are warming above the global average both at the surface and in deep waters, according to this year’s first-ever State of the Atlantic Ocean report, which cites as reasons rising air temperatures driven by climate change (1 degree per century since the 1870s) and changes in currents.

Acidification is also increasing as more man-made carbon dioxide emissions enter the ocean. The carbon dioxide dissolves in surface water to form carbonic acid, which is corrosive to calcium carbonate — the compound lobster and other crustaceans need to produce their protective shells. At the same time, the waters are becoming less oxygenated as deeper waters mix less with surface waters. When oxygen levels are too low, called hypoxia, species may flee an area before they suffocate.

Many fishermen and scientists feel an urgency to understand what changes are still to come, warning that it’s easy for complacency to set in as the good times roll.

“There’s an unease,” says LeBlanc, who has outfitted the John Harold to double as a tourist vessel and rely less on the fishery. “Financially, I treat it like it’s my last year ... I try to.”