Kejimkujik National Park in Nova Scotia has decided to halt its yearly brook trout survey due to the destructive impact of an invasive species on the local environment. The survey, which began in the 1990s involving volunteer fly fishers, aimed to track and assess brook trout catches to aid Parks Canada in monitoring the species.
Parks Canada revealed to CBC News that this year’s survey has been put on hold because chain pickerel, accounting for 90% of fish caught in the park in western Nova Scotia in 2025, have severely affected the brook trout population. The agency spokesperson stated that the current number of brook trout reported in the census is insufficient for statistical analysis due to the invasive species’ presence.
Chain pickerel, introduced illegally to Nova Scotia waters in 1945, made their debut at the park in 2018. Once established, these predators rapidly dominate the ecosystem by preying on various species, including fish, reptiles, frogs, and even ducklings.
Despite efforts by Kejimkujik staff to install fish barriers, flooding has hindered their effectiveness in containing the spread of chain pickerel. However, the agency remains committed to mitigation strategies and has already removed over 5,300 chain pickerel with ongoing efforts.
While the brook trout survey is paused, Parks Canada will continue monitoring the species through alternative methods such as angler diaries and deploying fyke nets annually to track native fish populations. Conservationists, like Ken Donnelly of Invasives Canada, suggest redirecting focus to areas where chain pickerel have not invaded for effective prevention.
Trevor Avery, a biology and mathematics professor at Acadia University, has been studying chain pickerel in Kejimkujik since their introduction. He emphasized the urgency of early intervention to manage the invasive species, proposing options ranging from using fish pesticides to targeted fishing for population control.
Andrew Lowles, resource manager at the Nova Scotia Department of Fisheries and Aquaculture, highlighted the historical importance of brook trout fisheries in Nova Scotia. While chain pickerel provide angling opportunities, their presence poses challenges to the local ecosystem and recreational fishing activities.
The situation at Kejimkujik National Park underscores the ongoing battle against invasive species and the importance of proactive conservation efforts to preserve native ecosystems and biodiversity.
