Parks Canada has reported a positive development for a threatened fish species making a comeback to its original environment in Banff National Park. Following more than ten years of effort, the federal agency confirmed that westslope cutthroat trout are starting to naturally reproduce and repopulate Hidden Lake, near Lake Louise. Shelley Humphries, an aquatics specialist for Parks Canada’s Lake Louise, Yoho, and Kootenay field unit, expressed satisfaction that the trout population is now self-sustaining.
The initiative to remove brook trout began in 2011 but was unsuccessful. Rotenone, a natural fish poison, was used to eliminate brook trout in 2018 and 2019. Starting in 2021, eggs were introduced into Hidden Lake for four consecutive years, resulting in successful spawning and the appearance of fully grown fish this year. Monitoring will continue, with the goal of observing the fish use streams and creeks beyond Hidden Lake.
Westslope cutthroat trout, once prevalent from the northern to the southern regions of Banff National Park, faced a decline due to recreational fishing and the introduction of non-native species like brook trout in the 1900s. This led to the displacement of westslope cutthroat trout from most of its traditional waterways, leaving them in only about 10% of their original habitat area. Parks Canada is now undertaking efforts to protect and reintroduce the at-risk fish species in various mountain lakes and creeks, including Helen Lake, Cascade Creek, Katherine Lake, and Corral Creek. Plans are also underway to extend similar conservation work to threatened bull trout populations.
Shelley Humphries emphasized the ecological benefits of this project, highlighting its positive impact on other species like birds of prey and bears compared to brook trout. She stressed the importance of safeguarding endangered species, stating that Parks Canada’s primary objective is to actively protect and preserve these species.