Canadian fish may soon be up a creek.

Western Canada’s glaciers will shrink 70 percent by the end of the century as a result of climate change, a new study says, draining streams that supply hydroelectric dams across the region and provide habitats for salmon, trout and other cold-water fish.

Glaciers in the Canadian Rockies – blue-tinged mountains in the country's drier interior famed for their ice-fed lakes and streams – could retreat by as much as 90 percent.



“They’re essentially a bank: an input and an output. In the winter you’re putting in the deposit, and in the summer you’re drawing out the deposit as melt,” says Garry Clarke, the study's lead author and an emeritus professor at the University of British Columbia in Vancouver. “What we’re doing now is drawing down the bank account. We’re drawing out more than we’re putting in, and it’s eventually going to get to zero.”

Previous studies have predicted mountain glaciers will ultimately disappear, made smaller each year by ever-warmer summers and ever-shorter winters. Notably, 2014 marked the Earth’s hottest year since record-keeping began in 1880.



Glaciers in Canada's Columbia Icefield are expected to shrink dramatically, according to projections based on low- and high-carbon emissions forecasts developed by the U.N.'s Intergovernmental Panel on Climate Change.

Alan Neuhauser for USN&WR; Courtesy Garry Clarke

In this latest study published Monday, Clarke harnessed computer models, simulations and on-site observations to forecast the fate of individual glaciers across British Columbia and Alberta.

The results, he said – while not the worst that he feared – still proved “bleak.”

“We’re going to have a habitat rearrangement when these glaciers go,” he says. “If streams are still flowing, they’re going to be low or warm – warm-water streams are not conducive to trout and other cold-water fish.”



Neither, he added, are dry streams.

Hydroelectric facilities – which account for the bulk of British Columbia’s electricity supply, according to the province’s Ministry of Energy and Mines – will also see changes, albeit not as drastic. As streams run by, Clarke says, some dams will need to begin storing water earlier each year.

“It’s going to require a bit of rejigging of their schedule of collecting their water and releasing their water – they won’t get the August boost they’ve been getting – but if they store water earlier, they should be able to compensate for that,” Clarke says.



Central Asia and South America, he adds, will likely feel far more drastic consequences from glacier melt – signaling a far more urgent need for similar studies in those regions.

“The population base is a lot larger and the dependency on glaciers is high,” Clarke says. “People can’t walk blindly into the future. They have to see where we are and where we’re headed.”