Invasive zebra mussels 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.


Aquatic invasive species (AIS) are non-native organisms that have been brought from other places into Alberta’s water. These species cause, or have high potential to cause, harm to our environment, economy, and human health as they become established outside their natural range. Many AIS are very difficult to eradicate once they are established, so prevention is essential.

Below you can find the AIS pocket guide, which will help active stewards become more familiar with the 52 prohibited species as well as additional species and fish diseases of concern in Alberta.

If you suspect any of these species, please report them promptly, either through the AIS hotline at 1-855-336-BOAT (2628) or on EDDMapS Alberta.

Responses to AIS

The Alberta government is working closely with a variety of stakeholders. Together, we have developed a program that includes these components:

  • monitoring
  • rapid response planning
  • education and outreach
  • watercraft inspections
  • policy

The AIS Program response actions used to detect, assess and respond to AIS introduction in Alberta are guided by the Alberta Aquatic Invasive Species Early Detection Rapid Response Plan. This plan provides a consistent framework for response as well as to identify the roles and responsibilities of government and stakeholders. Additionally, the AIS Program provides annual reports highlighting the program year and the priorities for the upcoming year.

Keeping Alberta waters free of AIS is a high priority, and the province has formed an Inter-Provincial Territorial Agreement for Co-ordinated Regional Defence Against Invasive Species to keep these invaders out.

What you can do to help

There are a few main actions we ask you to take to help prevent the spread of AIS and diseases.

Don’t let it loose

Common aquarium and pond species can become invasive when released into the wild. Releasing pond water, fish, plants or other aquatic species is illegal in Alberta.

Domestic pets generally do not have the survival skills to live beyond their tank or pond. They can starve to death or may be eaten by predators in the wild. In some cases, they may survive, reproduce and spread, becoming aquatic invasive species. Even if your pet is native to the local environment, it should never be released, as it may be carrying diseases or parasites.

Clean, drain, 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 properly clean, drain and dry between uses.

Visit the pages below to find information boaters need to follow to help stop the spread of AIS:

Quick facts

How to clean, drain and dry your type of boat.

Quagga and zebra mussels

One of Alberta’s main concerns regarding invasive species is the possibility of invasive mussels. Specifically, quagga and zebra mussels, which pose a significant threat to Alberta's aquatic ecosystems and economy as they are virtually impossible to eradicate.

Quagga and zebra mussels

Zebra and quagga mussels are small and can be difficult to see when attached to boats and other equipment.

Do you think you've spotted a quagga or zebra mussel? Remember, an attached mussel is an invasive mussel.

Report it to Alberta's invasive species hotline at 1-855-336-BOAT (2628).

Invasive mussels are filter feeders that strain suspended matter and food particles out of the water, disrupting natural food chains and leading to a depleted fishery (fewer and smaller fish) as the fish don't have enough food.

Invasive mussels attach to hard substrates 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.

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

If a mussel infestation occurred in Alberta, the province is estimating a total cost of $75,000,000 annually to protect and replace 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 boat maintenance costs for the individual Albertan.

Zebra mussel (Dreissena polymorpha)

Zebra Mussel
  • originally from Russia, now found in various parts of North America, such as in Lake Winnipeg, Manitoba as of October 2013
  • 1 to 3 cm, triangular-shaped shell
  • live up to 5 years

Quagga mussel (Dreissena bugensis)

Quagga Mussel
  • originally from Ukraine, now found in various parts of North America, such as in the Colorado River system – a popular destination for Alberta snowbirds
  • 1 to 3 cm, D-shaped shell
  • live up to 5 years
  • more adaptable than zebra mussels – can attach to softer substrates and survive in colder water

For additional information on zebra and quagga mussels, visit:

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