Saving Salmon: Innovative Cooling Techniques in Canada's Rivers

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Atlantic salmon embark on an extraordinary journey from the ocean to their river origins in Canada to spawn.

However, their numbers are dwindling, and new challenges are emerging.

Over the past fifty years, Canada's salmon populations have significantly decreased due to a range of factors including acid rain, overfishing, pollution, and damming.

The new threat to salmon is rising water temperatures caused by climate change and human water management practices, potentially reaching lethal levels for the fish.

Kathryn Smith, a researcher from Dalhousie University, has developed innovative techniques to artificially cool Canada's rivers and streams.

One method involves directing a portion of the river's flow through an underground trench, cooling the water by a few degrees, providing a temporary refuge for fish.

The second method actively pumps cold groundwater into rivers, which can be up to 20 degrees Celsius cooler, attracting fish effectively.

Smith's experiments in Nova Scotia demonstrated that both methods were successful at cooling water and luring fish, with the active system showing more dramatic results.

The next phase is to expand these experiments across the region, potentially offering solutions for protecting salmon populations.

Temperature plays a crucial role in the survival of salmon, and climate change is exacerbating the challenges.

Rising river temperatures due to climate change are a global issue, affecting rivers and fish populations worldwide.

While these artificial cooling methods show promise, there are challenges to address, including water chemistry, overfishing, and involving diverse perspectives in decision-making.

Smith's groundbreaking work opens new avenues to combat the threats posed by global warming, striving for more resilient ecosystems and the survival of species like the Atlantic salmon.