Habitat restoration work is underway in Kootenay National Park to reintroduce native westslope cutthroat trout.
Most recently, restoration work focused on Olive Lake, located right beside Highway 93, east of Radium Hot Springs.
Shelley Humphries, aquatic specialist for Lake Louise, Yoho and Kootenay National Parks says westslope cutthroat trout are an at-risk species in B.C.’s waters.
“They have been declining throughout their range. Kootenay National Park used to have lots of westslope cutthroat trout, Olive Lake in particular,” said Humphries.
“About 75 years ago, Parks Canada put bull trout in there and ever since, it has had the wrong fish species.”
On October 9, Humphries and the rest of her field team with Parks Canada began correcting that 75-year-old misstep.
“On Thursday (Oct 10), we put a fish toxicant called rotenone in the lake. That killed all of the bull trout in the lake and stream area,” explained Humphries.
While both fish species are varieties of trout, they differ enough to cause an imbalance in the ecosystem.
“The fish play very different roles in the ecosystem and an ecosystem that has evolved to have westslope cutthroat trout is working at its best when all the right pieces are there,” said Humphries.
“Bull trout spawn at a different time of year and they play a different role in the ecosystem, so they’re not often available to birds of prey at the right time of year.”
With the first stage of this ecosystem restoration work wrapped up, Humphries and her team will be back in the future to finish the job.
“In a year or two, once we get tests back using e-DNA (environmental DNA) to make sure all the bull trout are gone, we will put the westslope cutthroat trout that belong in the lake back in there,” said Humphries.
Be the first to know! Don’t miss out on breaking news and daily updates in your area. Sign up to MyEastKootenayNow News Alerts.
