Clear Lake, Man., typically a hub for wakeborders, anglers, and other watersport enthusiasts, has been quiet as of late. That’s because Parks Canada has banned motorized watercraft as it attempts to manage an outbreak of invasive zebra mussels. This spring marks the second year in a row motorboats have been banned from the lake.
Located three hours west of Winnipeg, Clear Lake is part of Riding Mountain National Park. Its shores are populated with campgrounds, cottages, and other properties. It’s a major draw for tourists. But zebra mussels have complicated its use.
“Parks Canada has made the difficult decision to continue to restrict the use of motorized watercraft on Clear Lake in 2025. This approach is a continuation of Parks Canada’s attempts to reduce zebra mussel spread in Clear Lake and the potential damage that may be caused to downstream waterbodies and related infrastructure,” the government agency said in a statement.
Native to the Black and Caspian seas region in southeastern Europe, zebra mussels are an invasive freshwater species. They first made their way to Canada in the 1980s, dumped into the Great Lakes through ships’ ballast discharge. They’ve since spread through much of eastern Canada, including Lake St. Clair, the St. Lawrence River, and the Saint John River Watershed.
As of 2020, Manitoba is the farthest west zebra mussels have been spotted in Canada, invading Lake Winnipeg, Red River, Nelson River, Lake Manitoba, and now Clear Lake.
The species often spreads through human activity, hitching a ride on the bottom of boats and then multiplying in a new body of water. Female zebra mussels release eggs in the spring when water temperatures reach 12 degrees Celsius. They can release a million eggs per year. The male zebra mussels fertilize those eggs, which become veligers or larval zebra mussels. Veligers are microscopic and can float on a water’s current for two to three weeks before developing a shell and attaching to a hard surface.
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Since zebra mussels reproduce so quickly, they outcompete native species, including fish, consuming large quantities of algae. This disrupts the waterbody’s ecosystem. They’ve also been known to damage boats, clog water intake pipes, and cause algal blooms, impacting water quality.
Clear Lake’s first indication of zebra mussels surfaced in August 2022. A water sample tested by Fisheries and Oceans Canada came back positive, showing the invasive species was present near Boat Cove in the south section of the lake. In May 2023, Parks Canada announced that trailered watercraft used in other lakes were banned from entering Clear Lake. To launch in Clear Lake, boats were fitted with a tag that sealed the boat to the trailer. The tag ensured the boat hadn’t been used in other bodies of water.
Despite these precautions, the zebra mussels got worse. In November 2023, Parks Canada staff found a clump of 48 adult zebra mussels near Boat Cove.
Fast forward to 2024 and Parks Canada banned all recreational watercraft, including non-motorized boats, from Clear Lake. In August, staff built an impermeable containment curtain around the section of Boat Cove where the zebra mussels were found. They then used potash, a molluscicide that doesn’t impact other species, to kill the zebra mussels.
But in September 2024, staff discovered that the species had already spread with hundreds of juvenile zebra mussels attached to docks in the lake’s east end.
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Currently, Parks Canada has adopted a preventative approach, trying to slow the species’ spread. As part of this, it will allow non-motorized watercraft onto Clear Lake this summer, such as canoes, kayaks, and paddleboards. But to launch on the lake, park visitors must purchase an annual permit that shows the boat is only allowed on Clear Lake. Alternatively, visitors can purchase an annual permit that allows them to launch on all of the park’s lakes except Clear Lake, including Lake Audy, Moon Lake, Lake Katherine, Whirlpool Lake, Grayling Lake, and Deep Lake.
All non-motorized watercraft and water-related equipment, including lifejackets and inflatable toys, will have to receive a Parks Canada inspection before entering any of the park’s lakes. The inspections run from 8 a.m. to 8 p.m. off Boat Cove Road in Wasagaming near Clear Lake. The inspection takes between 10 to 30 minutes and is valid for seven days.
Anyone who doesn’t comply with the permit or inspection process could be fined $25,000.
Moving forward, Parks Canada says it will look at the possibility of reintroducing motorboats onto Clear Lake while containing the spread of zebra mussels.
“In the coming year, Parks Canada will initiate a comprehensive research approach to determine how motorized watercraft affect ecological, socioeconomic, and cultural components of Clear Lake,” the government agency said. “Parks Canada appreciates resident and visitor engagement and recognizes the important place Clear Lake holds in their hearts.”
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