The Gulf of St. Lawrence reached its highest recorded average temperature in a century in 2015, scientists say.

The temperature 150 metres below the surface reached 6 C last year, the warmest in 100 years of observation.

Peter Galbraith, a research scientist with Department of Fisheries and Oceans, led the study and said he's not surprised by the finding.

"We've been seeing this coming, and it's not stopping," he said.

The record temperature may be related to climate change, he said.

Martin Castonguay, another DFO biologist, said the warmer temperatures will be a boon for some species, and prove less hospitable to those that favour colder waters, like snow crab, halibut and shrimp.

"Those are more Arctic-type species that are near the southern part of their range in the Gulf," Castonguay said.

At the moment, the rising temperature is not an immediate threat to the Gulf's inhabitants, he said.