Facts and FAQs about AIS

Zebra mussels are small, clam-like aquatic animals native to Eastern Europe and Western Asia. They are 1-3 cm (0.4-1.2 inches) long, have triangular or “D” shaped shells, and most have light and dark brown bands on their shells.

Zebra mussels were discovered in Lake Erie in the mid-1980s. They were accidentally transferred from their native range by cargo ships. Within a decade, the mussels had spread throughout the Great Lakes and many inland water bodies in the Mississippi watershed to the Gulf of Mexico.

Since then, they have spread to hundreds of other water bodies, mainly in eastern North America.

Facts:

• Aggressively invade new areas and reproduce quickly. Females produce upwards of one million eggs per year.
• Colonize almost any hard underwater surface, including watercraft hulls and can interfere with engine cooling systems.
• Power plants, water treatment plants, and cottages can be negatively affected by clogged intake structures.
• Threaten native fish and wildlife by reducing algae and food resources at the base of the food chain.
• Costly nuisance to boaters, commercial fishers, anglers, and beach-goers. They can reduce recreational potential by littering beaches with sharp shells and producing foul odours from decaying, dead zebra mussels.
• Adult zebra mussels can survive out of water up to 30 days depending on temperature and humidity. Zebra mussel veligers (larvae) are not visible to the naked eye and can survive in very little water.

In the coming months, Parks Canada will be working with partner organizations to analyze results and determine the best course of action to limit the spread of zebra mussels. A series of public meetings will be held to engage stakeholders and the public. More information will be shared when it is available.

At this time, access to Clear Lake has not changed. The boat launch area remains closed until 2024.

In the coming months, Parks Canada will be working with partner organizations to analyze results and determine the best course of action to limit the spread of zebra mussels. A series of public meetings will be held to engage stakeholders and the public. More information will be shared when it is available.

More information will be shared when it is available.

At this time, no decisions have been made for next year’s boating season.

In the coming months, Parks Canada will be working with partner organizations to analyze results and determine the best course of action to limit the spread of zebra mussels. A series of public meetings will be held to engage stakeholders and the public. More information will be shared when it is available.

More information will be shared when it is available.

Public engagement sessions will be held this winter. More information will be shared when it is available.

In January 2023, Parks Canada was notified that one water sample taken in August 2022 tested positive for mussel eDNA. In November 2023, Parks Canada confirmed the presence of live zebra mussels at Boat Cove on Clear Lake. This is the first time that zebra mussels have been found in Riding Mountain National Park.

Zebra mussels are not harmful to humans but can significantly affect aquatic biodiversity.

Ensure that you are following Riding Mountain National Park. fishing regulations

Starting in 2022, smallmouth bass is no longer subject to the game fish Catch and Possession Limit in RMNP. As a result, anglers who possess a valid fishing license are authorized to catch and possess as many smallmouth bass as they like. If you catch a smallmouth bass, retain it, euthanize it, and take it to the AIS inspection station at the Boat Cove. There, Parks Canada staff will measure the fish and collect information about where and when the fish was caught. Afterwards, you can choose to keep the fish or donate it for further research on population characteristics like age, health, and diet.

Thank you for doing your part to protect the ecological integrity of Clear Lake!

Walleye were introduced through federal stocking programs from the 1920s through the 1960s, ceasing in 1968. Over the last 60 years, Parks Canada’s perspective on stocking non-native fish species has evolved. Introducing non-native species can have unintended consequences for aquatic ecosystems, such as impacts to community dynamics like competition for food or habitat resources and spreading disease.

While the ecosystem impacts of the walleye introduction are unknown, they have been naturally reproducing and co-existing with Clear Lake’s native fish species for nearly a century and can be considered naturalized, meaning that they do not disrupt the native ecosystem.