Parks Canada celebrates a positive outcome as a threatened fish species makes a comeback to its native environment in Banff National Park. Following over ten years of dedicated efforts, the federal agency reports that westslope cutthroat trout are returning to Hidden Lake near Lake Louise, where they are starting to spawn naturally and replenish their population.

Shelley Humphries, an aquatics specialist overseeing Parks Canada’s Lake Louise, Yoho, and Kootenay field unit, expressed satisfaction that the trout are now self-sustaining. She emphasized the significance of this achievement, noting that similar successful initiatives in the United States have led to the removal of species from the endangered list.

The project to restore the westslope cutthroat trout began in 2011 by attempting to naturally eliminate brook trout, which proved unsuccessful. Subsequently, in 2018 and 2019, the agency resorted to using rotenone, a natural fish toxin, to eradicate the brook trout. Starting in 2021, they introduced trout eggs into Hidden Lake for four consecutive years, resulting in successful spawning and the appearance of fully grown fish this year.

Humphries highlighted the importance of ongoing monitoring efforts, with the goal of observing the trout utilizing streams and creeks beyond Hidden Lake. She expressed optimism about the trout population’s overall health and outlined the expectation of seeing them spawn in various stream locations in the future, not solely in the headwater lake.

The westslope cutthroat trout, once abundant throughout Banff National Park and southern Alberta, faced habitat encroachment due to recreational fishing and the introduction of non-native species like brook trout in the 1900s. This led to a significant reduction in the trout’s traditional waterway coverage, limiting them to only 10% of their historical range.

Humphries acknowledged the past mistakes that contributed to this decline and emphasized the correctability of the situation, asserting that the fish are indeed rescuable. Parks Canada is engaged in similar conservation projects at Helen Lake, Cascade Creek, Katherine Lake, and Corral Creek, with plans underway to extend similar efforts to protect the threatened bull trout species.

Not only does this conservation work benefit the westslope cutthroat trout, but it also serves to support other species such as birds of prey and bears, more so than the invasive brook trout. Humphries reiterated Parks Canada’s commitment to safeguarding endangered species, emphasizing their determination to protect these species with unwavering dedication.