Whirling disease detected in Lake Louise leads to new restrictions in mountain parks

New limits have been imposed on paddling and other water activities in some of Alberta’s most iconic mountain lakes after whirling disease was detected in Lake Louise for the first time last year.

Parks Canada has introduced a new system that groups lakes and rivers in mountain national parks into water‑activity zones, each with varying levels of restrictions to slow the spread of aquatic diseases.

Under the new rules, some of the region’s most visited lakes, including Bow Lake and Moraine Lake, will see bans on paddling, the use of large inflatables, and fishing with wading boots.

Whirling disease is an invasive parasite that can devastate fish populations.

“Bow Lake is home to species at risk,” said François Massé, Parks Canada superintendent at Lake Louise. “Moraine Lake has been identified as a key location in westslope cutthroat trout and bull trout restoration.”

Lake Louise, despite being the site of the first confirmed case of whirling disease in the area, will remain open to paddling and other water activities. Parks Canada says the lake does not carry the same conservation concerns as others in the region.

“It doesn’t have species‑at‑risk habitat, it’s not slated for a restoration project, and it doesn’t have potentially important migratory routes because there is a fish barrier on it,” said Marie Veillard with Parks Canada.

Other popular visitor spots, including Vermilion Lakes and Johnson Lake near Banff, will also remain open for paddling and recreational inflatables.

Officials say the new restrictions are part of a broader effort to stay ahead of the potential spread of whirling disease and other invasive aquatic threats.

Visitors are urged to check which zone their destination falls under and to follow the rules designed to protect vulnerable fish species and the ecosystems they depend on.