Vancouver Island’s low snowpack likely to affect salmon populations: researchers

Researchers say that low snowpack levels on Vancouver Island are likely to stress salmon populations that are already dealing with the impacts of habitat degradation, overfishing and warmer waters.

The latest snowpack report from the province shows that Vancouver Island’s snowpack levels sat at 44 per cent of normal, as of April 1.

Scientists say that lower snowpack levels mean that accumulated snow will melt quickly this spring — leading to lower water levels and drying pools when adult salmon try to make their way back up rivers in the fall from their spawning grounds.

Researchers say the province should work with local communities to preserve watersheds and salmon populations, and mitigate the impact of climate change to help struggling salmon.

“Especially with the warmer temperatures that we could get hit with the summer, it could be a recipe for disaster,” said Watershed Watch Salmon Society executive director Aaron Hill of the low snowpack.

Hill says there’s a pattern of drought and floods that the province has been going through that is leading to major stress on salmon populations.

Tom Balfour, a habitat biologist with the Redd Fish Restoration Society on the west coast of Vancouver Island, says that some pools where juvenile salmon gather in the summer could see die-offs on a scale large enough to impact larger salmon populations.

He added that faster snowmelt due to low snowpack levels means that the life cycle of salmon can be affected dramatically as they adjust to more water in the spring.

The biologist says the public should push for governments to implement longer-term conservation and restoration measures for watersheds, but also keep an eye out for trapped fish and drying pools this spring and summer.

“One thing we definitely don’t have enough of in this province, is that kind of monitoring,” he said.

“So really it’s on us, the public, to take notice and raise the alarm when things are happening.”

Call for more local collaboration

John Richardson, a professor at the University of B.C.’s forest and conservation sciences department, says that streams and lakes with lesser water volumes due to lower snowmelt could lead salmon to be more vulnerable to predation.      

He said that there should be efforts among the province’s forestry industry to actively keep more trees near smaller streams, which would provide valuable shade.

The professor argues that smaller streams can have higher water temperatures as they feed into larger rivers and streams, stressing out salmon that are sensitive to high temperatures.

“[Stream shading] is one of the things we refer to as climate-proofing. It’s one of the very few things we can do in terms of climate change that will allow us to maybe … moderate some of the changes to stream temperatures associated with global climate change,” he said.

Hill says he wants the province to take a stronger role in drought planning and prevention.

“Particularly, we need to see them give more support to local governments and First Nations to create local water sustainability plans that will help them carry out projects that will reduce the impacts of drought,” he said.