Whirling disease detected at Lake Louise

Parks Canada has confirmed whirling disease in Lake Louise for the first time. The parasite Myxobolus cerebralis kills up to 90% of juvenile trout and has no treatment. It poses no risk to humans, but it’s devastating for fish populations, and once it’s in a watershed it can take decades to understand the full impact.

In response, paddling and wading have been banned at three backcountry lakes starting this spring: Moraine Lake, Bow Lake, and Lake Minnewanka. Lake Louise itself hasn’t been fully closed, but it’s now designated a water recreation zone, meaning you’re required to clean, drain, and dry all gear before and after use. That applies to kayaks, paddleboards, canoes, waders — anything that touches the water.

The restrictions are part of a broader response that’s been unfolding across the Rockies since whirling disease was first detected in BC in 2023, at Emerald Lake in Yoho National Park. Yoho and Kootenay National Parks have had a full ban on watercraft and angling in place since then, and that closure has been extended through March 31, 2026.

The disease spreads through contaminated water, mud, and equipment moved between waterbodies. Watercraft inspections and the clean-drain-dry protocol are the main line of defence. If you’re heading out this season, check conditions before you go and make sure your gear is clean.

More details on affected areas and current closures are available on the Parks Canada water activity regulations page. Further reading: Global News, The Weather Network, The Canadian Press, Cottage Life.