Aquatic Invasive Species and Whirling Disease

Aquatic invasive species alert: Zebra mussels found in moss balls

Invasive zebra mussels have been found in moss (marimo) balls imported into Alberta and commonly sold in pet and garden stores.

Zebra mussels pose a significant threat to Alberta’s aquatic ecosystems and water facilities. If you have purchased a moss ball since January 1, 2021, you must dispose of it according to new provincial guidelines. See:

Invasive Mussels in Moss (Marimo) Balls

FOR RETAILERS: Decontamination Protocol for Invasive Mussels in Moss Balls.

What aquatic invasive species are and why they matter

Aquatic invasive species (AIS) are non-native animals or plants that have been brought from other jurisdictions into Alberta’s waterways.

Species such as zebra and quagga mussels can spread quickly and live out of water for up to 30 days. Once introduced to a waterbody, they are virtually impossible to eradicate and can cause millions of dollars in damage to water-operated infrastructure and harm aquatic ecosystems.

Invasive plant species such as Eurasian water milfoil can crowd out native plants and threaten the wildlife that depend on them. They can reduce the biological diversity of ecosystems, impact water quality and interfere with recreational opportunities.

Whirling disease

Whirling disease is a disease of salmonid fishes, like trout and whitefish, and has recently been detected in Alberta.

This disease can cause high levels of mortality in some fish but does not impact human health. The disease is caused by a parasite and can be spread by spores that attach to gear used in water, like boats, waders, or through the movement of water, mud and infected fish.

Important! There is no treatment for whirling disease. Preventing the spread is the best response!

Stop the spread of aquatic hitchhikers and fish diseases

Albertans play an important role in protecting the province’s waterways from aquatic invasives and fish diseases. Everyone who enjoys Alberta’s lakes and rivers needs to be proactive about keeping our aquatic ecosystems healthy.

The movement of fish, mud and water can spread whirling disease and aquatic invasive species. Before moving a boat or any equipment (example: hip waders, life jackets, paddles) between water bodies, be sure to:

  1. Clean
    • Clean and inspect watercraft, trailer and gear.
    • Remove all mud, sand and plant material before leaving the shore.
    • Rinse, scrub or pressure wash your boat away from storm drains, ditches or waterways. Use hot water if possible (900˚C or hotter).
  2. Drain
    • On land before leaving the waterbody, drain all water from
      • bait buckets
      • ballasts
      • bilges
      • coolers
      • internal compartments
      • livewells
      • transom motors
    • Never release live bait into a waterbody or transfer aquatic plants or animals from one waterbody to another.
    • Remember to “Pull the Plug” because it is illegal to transport watercraft with the drain plug still in place.
  3. Dry
    • Dry the watercraft and gear completely between trips and allow the wet areas of your boat to air dry.
    • Leave compartments open and sponge out standing water.
    • Allow for a minimum of 24 hours drying time before entering new waters.

Protecting Alberta’s waterbodies

The provincial government is working to keep non-native aquatic invasive species (AIS) such as zebra and quagga mussels out of Alberta and prevent the spread of whirling disease. These programs include:

  1. Policy and Legislation
  2. Education and Outreach
  3. Watercraft Inspections
  4. Monitoring
  5. Response


For more information or to report aquatic invasive species or whirling disease, call the Aquatic Invasive Species (AIS) Hotline at:

Related Information

Updated: Jun 28, 2022