Parks Canada has reported a positive development in the recovery of a threatened fish species in Banff National Park. The westslope cutthroat trout, after more than ten years of effort, is starting to spawn naturally 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 are now self-sustaining.
The initiative to remove brook trout naturally began in 2011 but was unsuccessful. Subsequently, in 2018 and 2019, rotenone, a natural fish poison, was used to eliminate brook trout. Over a span of four years starting in 2021, eggs were introduced into Hidden Lake, resulting in successful spawning and the appearance of fully grown fish this year.
Humphries emphasized the ongoing monitoring efforts, with the hope that the trout will utilize streams and creeks beyond Hidden Lake. She noted the overall positive status of the trout population and expressed the desire to witness spawning in streams, anticipating future spawning locations beyond the headwater lake.
Historically, westslope cutthroat trout thrived across the northern end of Banff National Park to the southern tip of Alberta. However, the introduction of recreational fishing in the 1900s and non-native species like brook trout disrupted their habitat, leaving them in only about 10% of their traditional waterways. Parks Canada is actively working to rectify this past mistake and save the threatened species.
Parks Canada is engaged in similar conservation projects in locations such as Helen Lake, Cascade Creek, Katherine Lake, and Corral Creek, with plans underway to extend similar efforts to protect threatened bull trout. Humphries emphasized the ecological benefits for other species, such as birds of prey and bears, that can be achieved by managing the presence of brook trout.
The mission for Parks Canada is to safeguard endangered species and ensure they are not lost without a determined effort.