Study Finds Melting Glaciers Could Produce Thousands of Kilometers of New Pacific Salmon Habitat

Researchers from Simon Fraser University and NOAA’s Northwest Fisheries Science Center found retreating glaciers in Alaska and British Columbia could open up new stream habitats for Pacific salmon. The findings were published today in the scientific journal Nature Communications.

The researchers modeled glacier retreat under different climate change scenarios, essentially “peeling back the ice” from 46,000 glaciers between southern British Columbia and southcentral Alaska. They looked at how much favorable salmon habitat would be created when the underlying bedrock is exposed, and new streams flow over the landscape.

New and favorable streams, in this case, means relatively flat streams connected to the ocean that have retreating glaciers at their headwaters. The researchers identified 315 glaciers that fit that bill.

Under a moderate climate scenario, researchers predicted those glaciers to reveal around 6,150 kilometers of potential new salmon habitat throughout the Pacific mountains of western North America by 2100. That’s a distance nearly equal to the length of the Mississippi River.

“We predict that most of the emerging salmon habitat will occur in Alaska and the transboundary region, at the British Columbia‒Alaska border, where large coastal glaciers still exist,” says the study’s lead author, Dr. Kara Pitman of Simon Fraser University. The researchers predict that the Gulf of Alaska sub-region will see the most gains—a 27 percent increase in salmon-accessible habitat by 2100.