Study finds Canada’s Arctic coastline eroding faster than anywhere else

Year by year, metre by metre, the Canadian Arctic is getting smaller.

A new international study has concluded that Canada’s Arctic coastline is eroding, on average, faster than anywhere else in the circumpolar world.

While they can’t yet prove it, scientists suspect that gradual washing-away along thousands of kilometres of gravelly northern shoreline is speeding up. And that steady erosion is already having profound effects on northerners, the majority of whom live along the coast.

“Every single element of the North is going to be affected, right from the engineering side to how the Inuit interact with their environment,” said Wayne Pollard, a McGill University geomorphologist who contributed to the massive, 10-country study that was released Sunday.

The project, undertaken by a consortium of international research groups, is the first to be able to compare different rates of erosion as well as consider its impact on northern people.

Much of Canada’s northern coast is composed of a kind of frozen goo — an unconsolidated pile of rubble and mud cemented into place by permafrost. It has always been subject to erosion from wind and waves.

The study concludes the vast Beaufort Sea coastline of the western Arctic is retreating faster than any other northern coastline.

On average, the sea washes away a metre of it every year. In some places, the erosion reaches eight metres a year.

Scientists haven’t been measuring the retreat long enough to make definitive conclusions on historical trends.

But the study points out that sea ice is crucial to protecting the shore. And sea ice, in the face of climate change, is undergoing its own retreat. This year’s sea ice maximum was tied for the lowest on record.

“It’s simple to understand,” said Volker Rachold of Germany’s Alfred Wegener Institute.

“You have a frozen, unconsolidated coastline which is stabilized by permafrost. If you had a sea-ice cover that reaches the coastline, nothing can happen — there is no direct contact.

“If you have longer open water seasons and the distance between the coast and the sea ice is getting bigger, you create more waves and that causes more erosion.”

Permafrost is also becoming less stable as temperatures in the North increase.

As a result of those factors, Rachold suspects the rate of erosion along the coast is increasing.

“We would assume so, yes.”

Pollard, who works extensively among the Inuvialuit of the N.W.T.’s Mackenzie Delta region, said the changes are already affecting traditional practices such as hunting seals, polar bears and beluga whales. People so attuned to their local environment that they can navigate in fog by the currents affecting their boats can no longer count on the old assumptions.

“There’s going to be shoals where there weren’t shoals before, there’s going to be storms coming from different directions,” he said. “It’s really starting to disrupt the traditional knowledge.”

Coastal erosion is an old story in communities such as Tuktoyaktuk in the N.W.T. The hamlet has long had to beef up its shoreline with concrete blocks, and has in the past lost backyards, roads and even a curling rink to the relentless waves.

For now, the hamlet is fighting the sea to a standstill.

The blocks “seem to have helped,” said administrator Tom Matus. “Still, more has to be done.”

In the east, Nunavut communities such as Hall Beach and Resolute are facing some of the same threats to their shorefronts.

Pollard said the study underlines how interconnected the shoreline is with both the human and natural world.

“There’s all these different elements of the natural environment which really do come together in a focused way at the shoreline,” he said. “The shoreline represents the interface between the marine system and terrestrial system and the climatic system.”

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