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Invasive mussels

Invasive quagga, zebra and golden mussels have major potential to cause harm to Alberta’s environment and economy if introduced.

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Aquatic invasive species

Place of origin

Quagga and zebra mussels originate from the Caspian and Black Sea regions in Eastern Europe. In 1986, zebra mussels were first discovered in Lake St. Clair (the Great Lakes). In 1989, quagga mussels were first discovered near Lake Erie. They were likely introduced through the discharge of ballast water from ships.

Since then, invasive mussels have spread throughout the Great Lakes and many waters in Manitoba, Ontario, Quebec, New Brunswick and the United States. 

Golden mussels are native to rivers and lakes in Southeast Asia and were first detected in North America in October 2024 in California’s Sacramento–San Joaquin Delta. Monitoring has since confirmed more locations in California. There are currently no known established populations of golden mussels in Canada.

Overland watercraft transport has been the main pathway of spread across Canada and the United States. Through annual monitoring, invasive mussels are currently not established in Alberta. For a map of confirmed locations, visit:

Identifying invasive mussels

Invasive mussels, which pose a significant threat to Alberta's aquatic ecosystems and economy, can be identified through key characteristics:

  • Quagga Mussel

    Quagga mussel (Dreissena rostriformis bugensis)

    • Up to 5 cm, D-shaped shell
    • Brown and yellow-white in colour, may have faint light-dark banding pattern
    • Native to Ukraine, now found in various parts of North America
    • Live up to 5 years
    • More adaptable than zebra mussels – can attach to softer substrates and survive in colder water.
  • Zebra Mussel

    Zebra mussel (Dreissena polymorpha)

    • Up to 3 cm, triangular-shaped shell
    • Brown and yellow-white in colour, usually with light-dark banding or zigzag pattern
    • Native to Russia, now found in various parts of North America
  • The shell of a golden mussel set against a white background, highlighting a golden yellow colour with some faint brown banding. The golden mussel is an aquatic invasive species that has recently been found in California’s Sacramento–San Joaquin Delta.

    Golden mussel (Limnoperna fortunei)

    • Up to 3 cm, longer wedge-shaped shells
    • Range from golden yellow to brown, may have faint banding pattern.
    • Unlike zebra and quagga mussels, they have a more uniform colour without striping.
    • Native to Southeast Asia, they were recently detected in California’s Sacramento–San Joaquin Delta.
    • In contrast to zebra and quagga which are limited to freshwater, Golden can tolerate brackish (slight salty) water as well

Invasive Species Hotline

Invasive mussels are not presently known to be in Alberta. A verified invasive mussel occurrence would be an emergency. If you suspect invasive mussels (Quagga, Zebra, or Golden) present in Alberta, please call the Environmental and Dangerous Goods Emergency Hotline. 

Spotting invasive mussels

If you encounter a suspected mussel and are unsure if it is native or invasive, see below for key characteristics. 

Remember, an attached mussel is an invasive mussel.

Native freshwater mussels and clams are present in Alberta. Typically, native mussels will be buried or freely floating on the bottom of water bodies. They prefer to live partially buried in sediment and do NOT attach themselves onto surfaces such as rocks, concrete, docks, boats, plants, etc. A mussel that is attached is an invasive mussel.

Suspected Invasive Mussel
Environmental and Dangerous Goods Emergency (EDGE) Hotline		All other inquires and information:
Aquatic Invasive Species (AIS) Hotline
Phone: 780-422-9600
Toll free: 1-800-272-9600		1-855-336-BOAT (2628)
[email protected]

To report a suspected invasive mussel (one observed attached to a surface like a boat, dock, rock, etc.),  contact the EDGE Hotline. 

Live operator will triage your report for swift response, if warranted.

For all non-emergency AIS concerns or information, call the AIS Hotline. For example:

  • Watercraft inspection and decontamination info/follow-up
  • Report a potential AIS, other than invasive mussels
  • For information on the watercraft inspection program.
  • For information on the rules and regulations regarding AIS.
  • Neighbouring jurisdiction/agency support
  • Requests for educational materials

Similar species

Image of size comparison featuring small invasive quagga and zebra mussels next to Alberta's native mussels, which are much larger on average.

Caption 1: Alberta’s native mussels (bottom row) are larger (adults often over 7cm in length) and have an elongated oval shape. They are free-floating and can be found buried or partially buried in the bottom of water bodies. In contrast, invasive mussels (top rows) are small, angular or D-shaped and attach themselves to surfaces.

Image comparing the appearance of fingernail clams as opposed to invasive mussels.

Caption 2: Fingernail (also called pill and pea) clams are small free-floating clams in Alberta. Though some are similar in size to invasive mussels, native clams are more rounded and symmetrical than invasive mussels and have thin, often transparent shells that are easily crushed.

Impacts of invasive mussels

  • Environmental impacts

    Invasive mussels are filter feeders that strain suspended matter and food particles out of the water. Excessive feeding by large invasive mussel populations disrupt natural food chains. This results in a depleted fishery (fewer and smaller fish) as the fish don't have enough food.

    It is difficult to determine if invasive mussels are alive in transport, so possession is prohibited, alive or dead in Alberta.

  • Impacts to infrastructure, recreation and economy

    Invasive mussels attach to surfaces in the water, blanketing any surface and reproducing at extremely fast rates. Females can produce up to one million eggs every year and there is no natural predator in Alberta. This allows for large populations in short timelines.

    Dense populations of invasive mussels clog water pipes and other submerged equipment, causing costly damage. Shells are sharp and can cause injury, impacting recreation when dead shells wash up on shore.

    Invasive mussels move from lake to lake by attaching themselves to watercraft and other recreational equipment. The adults can survive for 30 days out of water under ideal conditions, while the microscopic veligers (larval stage) can survive in standing water for long periods of time. 

    Currently, invasive mussels are found in eastern Canada and various parts of the United States. If a mussel infestation occurred in Alberta, the province is estimating millions annually to protect, clean, replace and duplicate water operated infrastructure (such as drinking water systems, power generation and irrigation), and in lost revenue from recreational fishing. This estimate includes decreasing property values and increased watercraft maintenance and utilities costs for the individual Albertan.

Video: Impacts of Zebra Mussels

Take action

Clean, drain and dry your gear

If you are transferring a watercraft or equipment used in water (that is, hip waders, life jackets, kayaks, construction equipment, etcetera) between waterbodies, make sure to practice clean, drain and dry efforts between uses. Visit the pages below to find information boaters need to follow to help stop the spread of AIS:

Get the facts on how to clean, drain and dry your type of watercraft:

Don’t Let It Loose

Moss balls, also known as marimo balls, are popular aquarium plants that have been found in the past to be contaminated with invasive mussels. Avoid introducing invasive species by never releasing aquarium contents, live bait, live food, or other organisms into waterbodies.

Zebra, quagga and golden mussels are prohibited species in Alberta under the federal Fisheries Act and Fisheries (Alberta) Act. Never import, own, sell or transport these species in Alberta. For more information, visit:

Additional resources

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