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Experts sound alarm as thousands of beavers migrate north

A beaver in Québec in 2015
A beaver in Québec in 2015. René Richard/Dreamstime


Concerned researchers held their first meeting this month to discuss a catastrophic group arriving in the North: beavers.

The Arctic Beaver Observation Network, an Alaskan group, seeks to coordinate research and observation of the emerging threat to permafrost and ecosystems in Alaska, Canada, Europe and Russia.

At a two-day virtual conference, scientists, Indigenous leaders, land managers and local observers heard speakers discuss the proliferation of big and small beaver dams from Nunavik to Inuvik. 



“Now, it seems like every pond has become a beaver pond,” remarked Seth Kantner, an American fisherman and writer who was born and raised in northern Alaska. 

Experts explained that the ponds created by beaver dams can accelerate permafrost thaw in sensitive areas. There are concerns that beavers could impact water quality as they notoriously spread the Giardia parasite, which causes diarrheal disease.

While no one is quite sure why beavers are moving into the NWT, many speculate that as shrubs move north, so do beavers. 

Edward Struzik – author of Swamplands, a book exploring “the elusive charm and magic” of such landscapes – says he first heard about the issue from Wilfrid Laurier University researchers at the NWT’s Trail Valley Creek research station.



“I’d heard rumours that beavers were moving into the tundra in Alaska,” Struzik said, “but I didn’t think much of it until I got to Trail Valley Creek, where they had seven beaver dams in the tundra, 50 km north of Inuvik.

“It was remarkable to think that they had somehow waddled in from the treeline and set themselves up there.

“First you think maybe this is just one of those anomalies, you know, animals sometimes test out new territory, and usually climate or the landscape deters them and they die off. It was the same with barren-ground grizzly bears moving onto the Arctic islands. People thought it was an anomaly but now we’re seeing this massive northward migration of grizzly bears onto the Arctic islands, and beavers from the boreal forest onto the tundra.” 

Threat to fish, ways of life

Burton Ayles, a member of the Canadian and Inuvialuit Fisheries Joint Management Committee, said hunters and trappers have been recording an increase in beavers since 2005. In the past five years, they have become increasingly concerned.

“They are damming rivers in which the fish in the Delta move back and forth in the spring and fall, into overwintering areas and into spawning areas,” he said. 

Ayles said at-risk species like the Dolly Varden char will be especially affected.

“The Dolly Varden char really depend on certain individual streams. They feed in the summer in the Beaufort Sea but in the winter, it’s too cold for them and they need to return to the Babbage River,” he said.

“If even one beaver dam blocked them from returning over the winter, it could in a very short time completely destroy this unique fish population.”



Ayles says the beavers may threaten a way of life in communities that depend on fish.

“We’ve seen some dams near the Inuvik-Tuktoyaktuk Highway, where usually we see fish that come out of the Husky Lakes,” he said. “They come up the stream and go into the lakes at different times of the year. And if the beavers dam those streams, then they can’t get access to them.”

The joint management committee hasn’t arrived at a solution but is participating in beaver migration research. Ayles says a solution could be making beaver harvesting more economically viable.

A file photo of beaver fur mittens. Sarah Pruys/Cabin Radio
Beaver fur mittens. Sarah Pruys/Cabin Radio

“Inuvialuit have been raising concerns over increased numbers and expanding range of beavers with ENR,” said Mike Westwick, a spokesperson for the NWT government’s Department of Environment and Natural Resources.

“The fur prices for beaver are low and harvest pressure is low. We’re currently working with our co-management partners in the Beaufort Delta and with the Department of Fisheries and Oceans on a multi-pronged approach to help address concerns being raised by communities. 

“The concerns are also being taken into account as part of our ongoing review of the Genuine Mackenzie Valley Fur program – which includes support and incentives for harvesters.”

‘Not the best timing’

Not everyone thinks beaver migration is catastrophic.

Heidi Perryman, founder of beaver advocacy group Worth a Dam and organizer of an annual beaver festival in California, published an open letter in response to an interview given by Helen Wheeler on US public radio network NPR.



Wheeler, a wildlife ecologist based in the UK, gave a presentation at the Arctic Beaver Observation Network’s March conference and is planning to conduct her next study in the NWT. 

For the past 20 years, Perryman wrote, NOAA Fisheries – the US agency responsible for fisheries – has been “researching and reporting that beaver dams are in fact crucial to salmonids and provide deep, unfrozen pools where juveniles can grow and fatten.”

Her letter continued: “Obviously, as the planet warms, many species are extending their range looking for suitable forage or habitat. The newly beaver-created ponds will help sustain an ecosystem that we have forced to become nomadic with our failure to stop burning fossil fuels.

“What remains stunning to me is how eager NPR and others are to blame beavers for extending the effects of a warming climate. I’m assuming that there will be similar reports blaming glaciers when the oceans rise?”

Similarly, Swamplands author Struzik highlights the irony of calling beavers “colonizers.”

While research papers and news articles have used that term, any Canadian knows the link between beaver fur and the colonization of Canada. As Struzik notes, the beavers were here first.

Elders in the Yukon describe finding fossils of giant beavers more than two metres long who roamed during the last ice age.

“We’ve also found tiny miniature beavers in the North, fossils that are over four million years old,” said Struzik.

“They had a foothold in the tundra at some time and, for whatever reason, evolved in a different way where they became more adapted to a boreal forest ecosystem.

“So we do know they get around, these beavers. And now we’ve got them re-establishing themselves here in the North. They haven’t got the best timing, with the permafrost situation. But it’s going to be interesting to see what happens.”