Warm water, low flow creates rough conditions for salmon in Miramichi River, N.B.

Many Maritime rivers are feeling the effects of the ongoing drought.

A summer of extreme heat and little rain has once again created rough conditions for salmon stocks in New Brunswick’s Miramichi River.

Portions of the river’s water temperature reached over 30 C in August, according to data from the federal department of fisheries and oceans.

The Atlantic Salmon Federation says salmon prefer a cooler water temperature below 20 C.

“It’s really simple, (salmon) like clean and cold water. So, if that’s going away that means we’re going to get in trouble,” said Valerie Ouellette, the federation’s vice president of research and environment. “Even if you don’t fish and don’t pass your time on the river, people should still have an interest in what’s going on with salmon. Because ultimately, it’s an indicator of what’s coming for us too.”

Ouellette said hot temperatures, coupled with “low flow” conditions on several parts of the Miramichi, made it a difficult summer for fish to move and find cooler, oxygenated water.

“We’ve seen some stretches of river that were pretty dry this summer, so there’s no fish moving there,” she said. “And for juvenile salmon, that may result in them moving to different habitats where they get more exposed to predation or competition for resources.”

The federal department issued multiple closures for anglers on the Miramichi River this summer because of high water temperatures and low water levels.

“There’s also no indication that will change in the coming years,” said David Roth, the federation’s program director. “If there’s any indication it will be the opposite, that there will be more closures.”

A 2025 federal government report recorded a 64 per cent decline in large adult Atlantic salmon returning to the Miramichi River between 2012 and 2024, with small salmon returns falling by as much as 86 per cent.

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