Melting Glaciers May Create 3,800 Miles of New Salmon Habitat by 2100

A Pacific salmon swims in a shallow part of the river. It's body is settled on smooth rocks, and its dorsal fin sticks out of the water. The river is surrounded by rocky cliff sides and evergreen trees.
Approximately 315 different glaciers between British Columbia and Alaska have the potential to create new salmon habitat. Freshwaters Illustrated

As climate change reshapes our planet, scientists are working to unravel what the future may look like. In a recent study, a team of scientists modeled glacier retreat in the Pacific mountain region of North America and found that as glaciers in the region shrink, they could create around 3,800 miles of new habitat for Pacific salmon by the end of this century, Amit Malewar reports for the Tech Explorist. The team published their results this month in the journal Nature Communications.

“This showcases how climate change is fundamentally transforming ecosystems; what is now under ice is becoming a brand-new river,” co-author Jonathan Moore, an ecologist at Simon Fraser University in Canada, tells Kate Baggaley for Popular Science. “We can’t just manage for current salmon habitat, we also need to think about how we can manage for future salmon habitat.”

Within their study range between southern British Columbia and Alaska, the team looked for glaciers situated at the headwaters of existing rivers that had the potential to carve out new streams as they melt. Plus, those streams must connect to the ocean—where salmon spend most of their lives—but they can’t have steep inclines. About 315 different glaciers fit those requirements, the Tech Explorist reports.

Their models showed that some new streams could lead to an increase as high as 27 percent in salmon-accessible habitats, according to a press release

“Once conditions stabilize in the newly formed streams, salmon can colonize these areas quite quickly,” lead author Kara Pitman, a spatial analyst at Simon Fraser University in Canada, says in the press release. “It’s a common misconception that all salmon return home to the streams they were born in. Most do, but some individuals will stray—migrating into new streams to spawn and, if conditions are favorable, the population can increase rapidly.”

This information could help conserve future salmon habitat. As the ice thaws, the land could become available for destructive practices like mining, but knowing where these streams will appear could inform conservation plans.

But this doesn’t necessarily mean good news for Pacific salmon, Popular Science reports

“On one hand, this amount of new salmon habitat will provide local opportunities for some salmon populations,” Pitman says in the press release. “On the other hand, climate change and other human impacts continue to threaten salmon survival—via warming rivers, changes in stream flows and poor ocean conditions.”

Though the team predicted where new habitat may open up, they didn’t factor in conditions like temperatures. If the new streams are too warm, they’ll be uninhabitable. Plus, the survival of salmon also depends on ocean conditions—if they aren’t surviving in the ocean, freshwater habitats won’t lead to population growth, Popular Science reports.

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