A group of researchers from British Columbia has discovered a small ray of hope for salmon populations when it comes to climate change and melting glaciers in the Pacific mountain range.
In a study released Tuesday, December 7, Simon Fraser University researchers Kara Pitman and Jonathan Moore found retreating glaciers in western North America could create more than 6,000 kilometers of new habitat. potential for Pacific salmon by 2100. This is a distance almost equal in length to the Mississippi River.
In their study, the researchers modeled glacier retreat under different climate change scenarios, essentially “removing ice” from 46,000 glaciers between southern British Columbia and south-central Alaska. From there, they mapped the potential salmon habitats that could be created when the underlying bedrock is exposed and new streams flow into the landscape.
The couple discovered 315 glaciers, many in Alaska and on the BC-Alaska border, that could create desirable conditions for salmon, including ocean-accessible, low-gradient streams. with glaciers retreating to their source.
Once conditions stabilize in the newly formed streams, salmon can colonize these areas fairly quickly, Pitman said, debunking the common misconception that all salmon return home to streams. in which they were born.
âMost do, but some individuals will stray, migrating to new streams to spawn and, if conditions are right, the population can increase rapidly. “
These cases of glacier retreat are already underway. In Stonefly Creek in Glacier Bay, Alaska, retreating glaciers in the late 1970s revealed spawning habitat for salmon in the new stream that was colonized in 10 years by pink salmon which rapidly declined. reached more than 5,000 breeders.
While the newly created habitat can be a ray of light for salmon in some places, overall climate change poses serious challenges for salmon populations, the researchers warned.
âOn the one hand, this amount of new salmon habitat will provide local opportunities for some salmon populations,â Pitman said. “On the other hand, climate change and other human impacts continue to threaten the survival of salmon – via warming rivers, changing stream flows and poor ocean conditions.”
Moore added that with climate change rapidly transforming ecosystems, their study should be used to strengthen habitat protection to secure the future of salmon.
Climate change Salmon