Alberta bans watercraft, paddling activities to combat invasive species
Activities have been restricted in several waterways to stop the spread of aquatic invasive species.
Officials are closing several lakes and rivers to watercraft and paddling activities in Alberta National Parks, following confirmation that whirling disease, a fatal condition to finfish like trout and salmon, has been detected in Lake Louise.
Parks Canada says the presence of whirling disease in the lake is “almost certainly” the result of human activity.
Effective this spring, waterways in Jasper National Park, Banff, Yoho, Kootenay, and Waterton Lakes will be divided into three zones, with differing levels of water activities permitted.
“Aquatic invasive species (AIS) are spreading across western Canada and pose a serious threat to the park’s lakes and rivers,” Parks Canada says on its website.
“Even a single contaminated watercraft or piece of equipment can introduce invasive mussels, plants, or pathogens, which are often impossible to remove once established. AIS can damage fish populations, degrade water quality, foul beaches and shorelines, and restrict recreational access, changing the experiences visitors come here to enjoy.”
The full list of open and closed waterways is available on the Parks Canada website.
Map of Jasper National Park Water Activity Zones for 2026 (Parks Canada)
While whirling disease is not confirmed in Jasper National Park, it is considered a high-risk area for it to occur.
Mitigation can take ‘decades’
Whirling disease was first detected in Canada in Alberta’s Banff National Park in 2016.
Once present, experts say it is difficult to eradicate, but fish may naturally adapt over time, although this could take decades to occur. Marie Veillard, the aquatic invasive species project co-ordinator for Lake Louise, Yoho, and Kootenay field unit, told the Canadian Press earlier this month.
Once the disease is found, officials often opt for preventative strategies, like closures and restrictions.
Restrictions elsewhere have proven successful
In March 2024, Parks Canada announced extended closures and restrictions in British Columbia's Kootenay and Yoho National Parks and Alberta's Waterton Lakes National Park after discovering the whirling disease parasite in fish, expanding on measures first implemented in October 2023.
These restrictions — which will stay in place until March 31, 2027 — are showing signs of success: A July 2025 Facebook post from Kootenay and Yoho National Parks said the strategy has helped slow the spread of the disease.
What is whirling disease?
Examples of the deformities cause by whirling disease. (Alberta Invasive Species Council)
Whirling disease is primarily spread through human activity. The spores that spread infection can latch onto fishing or recreational equipment and migrate to other lakes if equipment isn’t properly cleaned before each use. Pets can also carry the spores from one waterway to another.
It also spreads naturally. The parasite that causes it, Myxobolus cerebralis, is an aquatic invasive parasite that moves through spores in the water.
Native to Europe, it was first detected in Pennsylvania commercial fish hatcheries in the 1950s.
According to the Government of Saskatchewan, these spores are highly adaptable and can persist in a waterbody for more than 20 years.
The parasite's life cycle involves two hosts: A tubificid worm (an aquatic worm) and a salmonid fish, according to the Government of Alberta.
Once a fish is infected, the parasite attacks its cartilage and skeletal tissues, causing deformities that include a characteristic "whirling" behaviour. The disease impairs the fish's ability to swim, feed, and evade predators.
Once fish die, spores persist in the water and contaminate the sediment.
It only infects finfish, like trout and salmon. Whirling disease does not infect humans or pets and does not pose a threat to human health, according to the Government of Canada.
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Header image: File photo of Japser National Park via Canva Pro.