Parks Canada has achieved a significant milestone in the recovery of a threatened fish species in Banff National Park. Over a decade of dedicated efforts have led to the natural spawning and resurgence of westslope cutthroat trout in Hidden Lake, near Lake Louise. Shelley Humphries, an aquatics specialist with Parks Canada, expressed delight in the self-sustainability of the population, stating that concerns for their survival have diminished.
The journey to restore the westslope cutthroat trout began in 2011 with attempts to eliminate brook trout, which proved unsuccessful. Subsequently, the use of rotenone, a natural fish toxin, effectively removed 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 mature fish this year.
Ongoing monitoring is planned to observe the fish’s expansion into streams and creeks beyond Hidden Lake. Humphries emphasized the importance of observing spawning in streams, anticipating future breeding in various locations, not solely confined to the headwater lake.
Westslope cutthroat trout, formerly abundant from northern Banff National Park to southern Alberta, faced habitat disruption due to recreational fishing and the introduction of non-native species like brook trout in the 1900s. This led to a sharp decline, confining the westslope cutthroat trout to a mere 10% of its original habitat. Humphries acknowledged the past mistakes and expressed confidence in rectifying them, emphasizing the immediate conservation potential of the species.
Parks Canada is engaged in similar conservation efforts in regions such as Helen Lake, Cascade Creek, Katherine Lake, and Corral Creek. Plans are underway to extend these initiatives to support threatened bull trout. Humphries highlighted the ecological benefits of these projects, emphasizing the positive impact on other wildlife, such as birds of prey and bears, compared to the presence of brook trout.
The overarching goal for Parks Canada is to safeguard endangered species like the westslope cutthroat trout and combat their decline. The agency remains committed to the preservation and restoration of at-risk species, ensuring their survival against all odds.