Inuit hunters fear an upcoming ruling on an Arctic mine expansion could hasten the ongoing decline of a narwhal population that they rely on for food. 

Harvesters from Pond Inlet on the northern coast of Baffin Island say numbers of the iconic, single-tusked whale are already a small fraction of what they were before the Mary River iron mine began operating.

They say a decision expected Friday from the Nunavut Impact Review Board could make things even worse by allowing the mine to nearly double the amount of ship traffic through nearby waters.

"We're used to seeing thousands and thousands of narwhal," said Enooki Inuarak. "We used to go to sleep hearing the narwhals breathe.

"The last couple years, there has been barely any."

In a letter sent last week to the Nunavut Impact Review Board, the Mittimatalik Hunters and Trappers Organization says the mine is already harming their ability to harvest the important food source. 

"Narwhal are less abundant ... narwhal behaviours are changing, and ... hunters are having limited success in their attempts to harvest," the letter says. 

The Mary River mine is owned by Baffinland Iron Mines Corp. The mine, considered one of the world's richest iron deposits, opened in 2015 and ships about six million tonnes of ore a year. The company has said the mine's expansion would create 325 jobs. 

Aerial surveys conducted for Baffinland suggest summer narwhal numbers in Eclipse Sound declined to about 2,600 in 2021 from 20,000 in 2004.

Meanwhile, shipping in the area — mostly traffic to and from the mine — has increased dramatically. In 2021, nearly 245 trips were made to and from Milne Inlet, where the mine's ore is loaded. In 2015, that figure was 42.

Baffinland said it expects to see 168 visits by ore carriers if the expansion is approved. Josh Jones at the Scripps Institute of Oceanography, who is studying the proposal, said that would mean more than 450 individual transits by carriers, icebreakers and other mine-associated vessels.  

Other research has linked marine traffic and whale behaviour, said Kristin Westdal, Arctic science director for the environmental group Oceans North. She said vessels create underwater noise that interferes with the animal's ability to locate prey and communicate.

"That research clearly points to an increasing level of sound, sound which overlaps with that of narwhal frequencies. 

"The animals are responding to the vessels. They're moving away, they're changing direction."

Baffinland disagrees that constant, low-level disruptions are driving the narwhal away. 

"Based on the expert advice of marine biologists ... with the application of the mitigation measures proposed under the Phase 2 proposal, increased shipping does not represent a significant risk to narwhal," Baffinland spokesman Peter Akman said in an email. 

He suggested the Eclipse Sound narwhal have simply migrated to Admiralty Inlet on the other side of Baffin Island. Changing ice conditions or "prey/predator dynamics" — killer whales are present in the area — may also be factors, he wrote. 

That doesn't help Pond Inlet hunters, who must ask permission to hunt in another community's waters. 

"For countless generations we relied on them for our diet," Inuarak said. "It's part of our life.

"We're here because of the wildlife." 

Baffinland has promised to impose nine-knot speed limits throughout the shipping corridor, lower than limits in whale habitats elsewhere. It also said it will reduce transits in shoulder seasons, reducing the need for icebreakers. 

That won't help, said Westdal.

She said the number of transits should be reduced and icebreaking should be "off the table," restricting Baffinland to the open-water season. She noted that Eclipse Sound is in Tallurutiup Imanga, a national marine preserve. 

"We think you can have the marine park and the community and the mine," Westdal said. "But if we keep going in this trajectory, we're just going to have the mine."

The hunters and trappers of Pond Inlet have called for similar measures. 

"The Board (should) consider requiring Baffinland to implement adaptive management measures in order to protect the marine environment and to limit impacts to narwhal and Inuit harvesting rights," says their letter. 

Baffinland said its willing to talk. 

"If our monitoring programs ... identify reasonable linkages between the project and unacceptable changes to narwhal and/or harvesting in the future, Baffinland will respond accordingly," Akman wrote.

He said that could include changes to the shipping season, ship speeds and transit restrictions.

Inuarak is aware of the importance of jobs, but he said only a few people in Pond Inlet depend on the mine. Food is more important, he said.

"It impacts our culture and our traditions. We're being pushed back to the point we have to defend our way of life and our food source." 

This report by The Canadian Press was first published May 11, 2022. 

— Follow Bob Weber on Twitter at @row1960

Bob Weber, The Canadian Press