Zebra mussel DNA discovery ties up tour boat in Clear Lake

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This article was published 01/08/2024 (644 days ago), so information in it may no longer be current.

The Martese tour boat at Clear Lake will no longer be allowed to operate after an area near the lake’s marina tested positive for zebra mussel environmental DNA, Parks Canada announced Wednesday.

“This is not a confirmation of a live zebra mussel in the immediate area, but it is an indication that Parks Canada must step up its response,” Riding Mountain National Park’s external relations manager, Dameon Wall, said in an email. “As a result, the Martese will remain at dock for the foreseeable future.”

As a result, the massive containment curtain being installed in the lake to prevent the spread of zebra mussels from Boat Cove is being extended in size. It will now stretch from the west end of Boat Cove to the lake’s main beach, encircling the main pier, the Martese and the swimming area.

However, swimming, fishing and beach access will not be limited at this point. No decision has been made on whether to use potassium chloride, also known as potash, as a pesticide against the zebra mussels.

Wall said the boat operated by Keeseekoowenin Ojibway First Nation is not affected by the move. Boats operated by Parks Canada and a single boat used by the First Nation, as well as the Martese, had been the only exemptions to a ban blocking the use of watercraft on Clear Lake this season.

The Sun called the Clear Lake Marina for comment but was told no one was available. However, the marina’s website was updated Wednesday to say the operators “are heartbroken to announce that as of July 31, 2024, The Martese Cruises are shut down for the remainder of the 2024 season.”

The website added: “Although 2024 has been a year of sadness and difficult decisions, we are keeping our eyes on the light at the end of the tunnel. Clear Lake’s 2024 watercraft restrictions are temporary, and we look forward to the day that we can share this wonderful lake with you once again.”

Weather was getting in the way, but Parks Canada officials were hopeful that the containment curtain was going to be fully installed by the end of Wednesday afternoon.

“There is some section of the curtain that’s already in place,” Wall said in a phone interview.

“I don’t have an estimate on how many, but probably close to a couple of hundred metres we did manage to get some of that deployed earlier this week,” Wall said.

The curtain is part of Parks Canada’s strategy to deal with the discovery of zebra mussels in the largest body of water in Riding Mountain National Park.

Snorkellers recently found one live zebra mussel and one partial shell after previously finding a mussel in the lake last fall. Tests for environmental DNA from zebra mussels in Boat Cove have also come back positive.

To try to isolate Boat Cove and prevent the spread of the invasive species, the impermeable curtain is being deployed from the western edge of the cove to the pier to create a barrier between it and the rest of the lake.

When the work was first put out to tender earlier this year, documents said the curtain would be installed by a four-person dive team, covering an area two kilometres long, with a maximum depth of seven metres and a surface area of 10 to 30 hectares.

However, the encircled area will now be longer after Wednesday’s announcement. Wall was not yet sure what the size of the larger containment zone would be.

Aerial drone footage shared with the Sun by Parks Canada from the installation process on Tuesday shows what looks like a lengthy bundle of yellow material being dragged into place from the shore into the waters of the cove by a small boat with an outboard motor.

According to Wall, it’s the first time Parks Canada has used the curtains for zebra mussels. In 2017, the agency used them to prevent the spread of whirling disease among fish in Banff National Park’s Johnson Lake.

“There’s a float along the top and then the curtain itself is actually suspended from that float,” Wall said. “It is sort of bunched up and tied up when it’s being put in place.”

Once the curtain is in position, the staff will remove some ropes, which will allow weights to carry them to the lake floor and keep them in place.”

Currently, 200 meters of the South Shore Trail, the Boat Cove parking lot and adjacent shoreline as well as water in the cove from its western edge to the pier are closed to the public to allow for the curtain’s installation.

Wall did not know when that closure would be lifted. Violations of the closure order could result in charges under the National Parks Act.

Paddleboarders violating the watercraft prohibition on Clear Lake were charged under the act back in late June.

After the discovery of the live zebra mussel was announced earlier this month, snorkeling teams carried out further visual inspections in the lake. Wall said inspections have not uncovered any more signs of zebra mussels since then and he did not know when more results from DNA testing in the lake would be made available.

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