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Melting glaciers could give Pacific salmon new waters to call home

A host of other consequences from global climate change could still result in massive declines in salmon populations.

(CN) — A study released Tuesday reveals glacier retreat across western North America could offer Pacific salmon entirely new habitats in the not-so-distant future.

Pacific salmon, by most estimates, have not had it easy the past several decades. Overfishing, manmade habitat disruption and changes to their water availability as a result of warming temperatures and other climate change factors have put the stress on salmon populations. These realities have put a number of salmon species endangered species lists over the years and, in some cases, have even resulted in some groups going extinct.

While threats like climate change do not appear to be abating anytime soon, a new study has found that an unlikely consequence of melting glaciers across North America due to climate change may result in new habitable waters for these threatened Pacific salmon.

For the study, published Tuesday in Nature Communications, Kara Pitman from the Simon Fraser University and several colleagues modeled glacial retreat under different climate conditions. Using that data, they then created a synthetic stream network made up of hundreds of thousands of miles across North America to determine how many new streams could be created by the melt.

The results revealed that Pacific salmon could have access to miles of new water within just the next century. By 2100, according to the study, nearly 4,000 miles of new streams will be made available to Pacific salmon.

A good chunk of these new waters will also be well suited for their reproduction needs. When comparing their data model with stream gradient-based salmon habitat models, researchers found that around 1,200 miles of the new streams could be used for spawning and juvenile rearing, crucial areas for fish species like Pacific salmon that rely on migration waters for their offspring.

Pitman, first author of Tuesday’s study, says she hopes policymakers will take these new findings into account as they work to understand and prepare for the future of Pacific salmon.

“My hope for policymakers and lawmakers is that the findings from our work will be integrated into land use plans, protected areas, or environmental assessments,” Pitman said in an email. “For example, most environmental assessments consider the impact a development may have on the current state of salmon habitat, but do not focus on future salmon habitat. Thus, if we undergo environmental assessments without considering the future we are failing to protect our salmon futures.

"My hope is that lawmakers and policymakers can consider the results from our work and think of ways to incorporate where climate change may impact future habitat of important species, and work towards integrating these future states into acts, such as the environmental assessment.”

The study authors stress, however, that their results are in no way intended to convey a brighter outlook on climate change and its influence on salmon.

Glacier retreat is just one of many climate change consequences, and other factors like heat waves, rises in sea levels and even flooding events can all cause untold damage to salmon populations within the next several decades. Melting glaciers itself is not even without some of this blame, as glacier retreat could also create new opportunities for mining industries that can result in severe salmon habitat degradation.

Ultimately, understanding the timing for these new habitats will be most crucial to tackling this problem moving forward. Researchers say that knowing when and where the waters will appear can help give policymakers the information they need to devise effective conservation plans and try to protect the habitats and health of these embattled salmon species.

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Categories / Environment, Science

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