Flip Side of Melting Glaciers May Benefit Salmon

More than 300 melting glaciers between British Columbia and Alaska have the potential to create 3,800 miles of new salmon habitat by 2100, according to a study by a team of scientists modeling glacier retreat in the Pacific mountain region of North America at Simon Fraser University, in Canada, published in the journal Nature Communications. Co-author ecologist Jonathan Moore says, “This showcases how climate change is fundamentally transforming ecosystems; what is now under ice is becoming a brand-new river.” The team looked for glaciers situated at the headwaters of rivers that had the potential to carve out new streams as they melt. The qualifying streams would connect to the ocean, where salmon spend most of their lives, but without steep inclines. The models showed that some new streams could yield increases as high as 27 percent in salmon-accessible habitats.

Lead author and spatial analyst Kara Pitman notes, “Once conditions stabilize in the newly formed streams, salmon can colonize these areas quite quickly. 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.” As the glaciers continue to thaw, that land might become available for mining, but knowing where the streams will appear can help direct conservation plans.