Rising mercury levels in Arctic marine mammals, especially beluga whales, is due to the changing climate, a federal scientist says.

Temperatures in the Mackenzie Basin have risen by three degrees in 30 years, said marine biologist Dr. Gary Stern, who is with the Fisheries and Oceans Department and part of a team aboard the Amundsen Research Icebreaker.

The changes have resulted in more forest fires, warmer water and melting permafrost which, in turn, sends more mercury into the Beaufort Sea.

The loss of thick multi-year ice is also a factor, he said.

"You are getting beluga actually being able to access areas within the Beaufort Sea that they haven't previously been able to access," Stern said.

"Some of those areas … have higher levels of mercury in them so as things change these animals can now reach these locations and feed."

Mercury affects the reproductive and immune systems of beluga whales, he said.

The Department of Fisheries and Oceans is working with hunters who provide samples from the whales they kill for food, he said.

Although the mercury levels are on the rise, people are not being discouraged from eating whale meat because the benefits still outweigh the risks, he said.