The salmon of the Salish Sea, long revered as keystone species and cultural icons, are facing unprecedented challenges due to climate change. As warming temperatures and erratic weather patterns disrupt the salmon life cycle, the survival of this sacred fish hangs in the balance.
Drawing on decades of experience with salmon, retired Fisheries and Oceans Canada (DFO) Watershed Enhancement Manager Dave Ewart provides a sobering account of how climate change is reshaping the environment for salmon and the communities that depend on them.
For years, the Cortes Island Streamkeepers, in collaboration with the Klahoose Nation, have worked tirelessly to enhance salmon habitats and support local hatcheries. However, climate change has undermined these efforts. Streamkeepers have witnessed gravel and eggs washed out to sea, fish waiting endlessly for fall rain that never came, and passageways restored at great expense only to sit empty. The urgency to act has never been greater, as salmon struggle to adapt to a rapidly changing environment.
The impact of warming waters
Ewart, who has spent over 40 years working with salmon on the BC coast, recalls a time when salmon survival rates were robust, and the seasons were predictable. “In the 1980s, survival rates from ocean entry to river return ranged from 5% to 20%,” he explains. But by the 1990s, those rates plummeted to as low as 1%, with Chinook salmon faring even worse. The culprit? Warming ocean waters, which disrupt the availability and quality of food for salmon.
In 2000, thousands of pink salmon died before spawning due to low water levels
“Ocean productivity has become variable and unstable,” Ewart says, emphasizing that the Pacific Ocean, once considered a limitless resource, is now a critical bottleneck for salmon survival. Rising water temperatures also exacerbate disease, reduce egg viability, and create mismatches between salmon migration and the availability of food in the ocean.
Rivers in crisis
The effects of climate change are equally devastating in freshwater habitats. Ewart describes how erratic weather patterns have led to more frequent and severe flooding, which destroys salmon eggs and alters river courses. At the same time, prolonged droughts in late summer and fall leave rivers too warm and shallow for salmon to migrate and spawn. “Instead of a big flood every ten years, the late 1990s brought two or three big floods almost every year,” he recalls.
Warming ocean waters disrupt the availability and quality of food for salmon
On Vancouver Island’s Quinsam River, historic salmon migration routes have dried up, forcing fish to congregate in lower river sections where they are vulnerable to predators. In 2000, thousands of pink salmon died before spawning due to low water levels. They were blocked at a series of pinch points on the upper river which, at higher water, was passable. In the upper watershed, the main supply lakes were going dry and risking stopping flow to the river. BC Hydro was responsible for operating a series of water diversions in the area but misjudged the available water – the rains never came to replenish the reservoirs. In response, streamkeepers and BC Hydro installed large pumps to maintain flow to the river from the lakes. This had never been done before. It is happening more and more.
An interesting fact about Quinsam pink salmon: they are thriving despite climate change because the Campbell River is unusually cold. The Campbell watershed is dammed and the lower river benefits from cold water being drawn off the lower lakes thermocline. This keeps salmon holding in the river in excellent cold conditions. When the Quinsam River cools down in late September, the pinks migrate from the Campbell into the Quinsam where they spawn.
A stark reality for Cortes Island
The challenges are particularly acute on Cortes Island, where the Klahoose Nation and the Cortes Island Streamkeepers have worked to sustain local salmon populations. In recent years, declining water availability in the spring forced the difficult decision to stop raising Coho salmon, which require more time in freshwater. Instead, the focus has shifted to chum salmon, which spend less time in streams and are better suited to the island’s changing conditions.
Habitat restoration can play a vital role in mitigating the effects of climate change
Even so, chum salmon face significant hurdles. In 2022, a prolonged drought left hundreds of chum stranded at the mouth of Basil Creek, where they fell prey to predators. When rains finally arrived, they triggered a catastrophic flood that displaced incubators and caused landslides. “This was another example of how erratic the weather has become and how it affects salmon,” Ewart observes.
What can be done?
Ewart believes that hatcheries and habitat restoration can play a vital role in mitigating the effects of climate change on salmon. Key strategies include finding ways to provide cool water during critical life stages, increasing egg-to-fry survival rates, restoring spawning gravel, holding pools, and estuary habitats, and enhancing water storage and accessing groundwater sources to maintain river flows.
We owe it to future generations, to First Nations, to the fish, and all who depend on them.
However, Ewart stresses that these measures are only part of the solution. “In the bigger picture, we need to monitor and stop climate change,” he asserts. Without decisive action to reduce greenhouse gas emissions and limit global warming, the future of salmon – and the ecosystems and cultures they sustain – remains uncertain. This action needs to come very fast – as climate campaigner Bill McKibben says, winning slowly on climate is just another way to lose – this is a timed test.
A call to action
The plight of salmon in the Salish Sea is a stark reminder of the urgent need to address climate change. We owe it to future generations, to First Nations, to the fish, and all who depend on them. The Cortes Island Streamkeepers invite everyone to join the fight for real, deep, and fast habitat protection, including meaningful climate action. There are many ways to get involved with organizations that need support.
Max Thaysen has lived on Cortes Island since 2007. He has served as president of Friends of Cortes Island, and he is currently a story producer for the Cortes Currents Radio Magazine. This article is adapted by the author from David Ewart’s April 2024 report Climate Change and Salmon, which can be read in full on friendsofcortesisland.org.
