Banff backcountry paddling off-limits after whirling disease detected in Lake Louise

Whirling disease, an aquatic invasive species that affects fish populations, has been found in Lake Louise, according to Parks Canada.

One of Canada’s most famous natural landmarks has fallen victim to a new aquatic invasive species, prompting a new level of restrictions in Banff National Park.

Parks Canada workers have identified a presence of whirling disease in Lake Louise, Alta.

“Whirling disease is an infectious disease that affects fish populations. It is not harmful to humans or other mammals, but it can have a significant effect upon trout, whitefish and salmon,” Parks Canada says.

“It’s unlikely that whirling disease was spread to Lake Louise through natural fish movement, because there’s a natural fish barrier between (the lake) and the Bow River,” explained Francois Masse, superintendent of the Lake Louise, Yoho and Kootenay field unit.

“It’s most likely whirling disease was introduced by mud or water on a watercraft or angling equipment.”

As a result — effective spring 2026 — paddling and the use of large inflatables, along with the use of waders or wading boots while fishing, will be banned at Lake Minnewanka, Bow Lake and Moraine Lake.

Visitors will still be able to use those devices at Lake Louise, as well as several other area lakes and the Bow River, downstream of Hector Lake.

“We understand the disappointment that visitors would like to continue recreating on these water bodies, but we are trying to find a balance between protection of our sensitive ecosystems as well as finding locations and opportunities for visitors to continue water activity recreation in the parks,” said Marie Veillard, the aquatic invasive species project co-ordinator for Lake Louise, Yoho and Kootenay field unit.