Otter Lake

Otter Lake’s milfoil problem is bigger than Farm Lake

Local Journalism Initiative / The Equity / October 16, 2024 / LJI reporter, Otter Lake, Sophie Kuijper Dickson

Sophie Kuijper Dickson, LJI Journalist

A biologist brought in by the Municipality of Otter Lake to assess the presence of Eurasian watermilfoil found the invasive aquatic plant in three of the six lakes surveyed this August.

The report produced by biologist Annie Parent, received by the municipality at the end of September, found that Clark Lake, Leslie Lake and Hughes Lake seem to be free of contamination, although the biologist states that this does not mean it isn’t growing there.

Parent did however find several places where milfoil was growing in McCuaig Lake, Little Hughes Lake, and Otter Lake. Its presence in these three lakes is in addition to Farm Lake and Little Cayamant Lake, where the invasive species was first discovered in 2023.

The rapid growth of milfoil on Farm Lake led the municipality to close the lake’s boat launch this summer, leaving it open for cottagers to get on and off the lake on weekends, and put buoys on the lake to mark the contaminated areas.

The freshwater plant, nicknamed the zombie plant because of how difficult it is to kill, is of concern to the municipality because it outcompetes native lake species, reducing biodiversity and leading to poor water quality.

It grows to the surface of the water during the spring and summer, and dies out in the winter, at which point its decomposition consumes oxygen in the water, a process which can be harmful to aquatic life.

“It would be so thick that it would make swimming completely difficult, like a mat,” said Jennifer Quaile, pro-mayor of Otter Lake, describing the damage the plant could cause.

Also, boating becomes a problem because it’s a fragile kind of plant and it will wrap around your propeller to the point where you’ll get stuck.”

Also this August, the municipality had a whole team of biologists conduct a more extensive mapping effort on Farm Lake and Little Cayamant Lake. The results of that work are expected in early November, according to Quaile, and will indicate not only where each growth is, but how much of it there is in each location.

This information will be used to determine which strategy the municipality should employ to get rid of the milfoil. The options, according to Quaile, are placing a tarp over the affected areas of the lake, or having divers remove the milfoil plants at their base.

“If you’ve got a patch of growth and there’s 80 per cent milfoil, they’re going to suggest we use the tarp, if it’s a large area with that much milfoil. And that will kill off the natural plant as well, but it’s worth it,” Quaile said. “Pulling it out by hand is recommended in smaller areas.”

Maps included in Parent’s report mark the locations on each lake where the milfoil was found, but the report states there may be more, as the survey done did not investigate every corner of each lake.
Quaile said she was surprised the plant hasn’t reached all lakes yet.

“And the biologist was surprised too because the conditions are quite favourable. Leslie lake is a shallow lake and the plant grows quite well when the sunlight can get to it. And again with Hughes, because there’s a creek that runs out of Farm into Hughes,” Qualie said. “So I think there’s a lot of factors that even the scientists aren’t sure of yet.”

While the mitigation work being done on Farm Lake is ahead of the other four lakes where the milfoil has been found to date, Quaile said council will work with a committee that includes representatives from each lake’s association to determine how best to proceed.

“Once we have our strategies figured out with the committee’s recommendations to council, we’ll go and get public feedback.”

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Invasive plant species found in two local lakes

Local Journalism Initiative / The Equity / May 29, 2024 / Charles Dickson, LJI reporter, Otter Lake

Community briefed on presence of Eurasian milfoil in Farm Lake and Petit Lac Cayamant

Charles Dickson, LJI Reporter

Sixty-five people attended a public forum in Otter Lake on Saturday morning to hear from the municipal council about Eurasian water milfoil, an invasive plant species that has been found in Farm Lake and Petit Lac Cayamant.
The meeting, held at the RA Centre, was opened by Otter Lake mayor Terry Lafleur who then turned it over for presentations by councillors Jennifer Quaile and Robin Zacharias.
As described in the presentations, milfoil is a perennial plant that grows profusely in summer and dies in the fall, using up oxygen as it decomposes, choking the lake and killing native plant species and fish.
Councillor Quaile described how anything that disturbs the plants such as boats, waves and people raking them can easily cause fragments to break off and move to another location where the leaves become roots that latch onto the bottom of the lake and produce new plants.
Dense mats of the plant can make swimming unpleasant and can wrap around propellors and paddles making boating difficult, if not impossible.
Economic consequences include reductions in waterfront property values, lost tourism causing local businesses to suffer, and high costs of controlling the problem which can lead to higher taxes.
Councillor Zacharias outlined a range of strategies to eradicate milfoil including laying large burlap tarps on top of the plants to suffocate them, hiring divers to pull the plants out by the root, and using a Health Canada-approved herbicide to kill the invasive species.
Methods of preventing the spread of the plant within a lake include marking milfoil patches with buoys to help boaters avoid driving through them, as well as limiting boat traffic around launch areas where the problem is at its worst, especially in July and August when the plant has grown up to the surface of the water.

“The most common way it propagates, it gets chopped up in a prop, and then it just goes and floats through until it clings somewhere and starts growing again,” Mayor Lafleur told THE EQUITY.
“We really want to try to get a handle on it, especially at the boat launch because, if you’re just docking your boat and you’re going in and you’re taking off, well you’re chopping up a whole bunch of it.”
Boat washing is a key means of preventing the spread of milfoil from one lake to another. Otter Lake set up a boat washing program in 2020.
Public education, citizens reporting sightings of milfoil patches, and shoreline management to keep nutrients that promote the plant’s growth from flowing from the land into the water all feature in the municipality’s proposed plans.
Late last year, after finding Petit Lac Cayamant and Farm Lake listed on a Ministry of Environment website as possibly containing Eurasian water milfoil, the municipality hired a biologist to inspect the lakes who confirmed the presence of the invasive species.
One of the municipality’s next steps will be to inspect six more lakes in the area: Clarke, Leslie, Otter, Hughes, Little Hughes and McCuaig.
“Doing nothing is not an option. We’ve got to do something,” Councillor Zacharias said. “The question is what do we do?”
In the lively question and answer period that followed the presentation, members of the audience brought forward many ideas that promise to help answer Councillor Zacharias’ excellent questions. Originating in Europe and Asia, Eurasian Water Milfoil was carried to North Americas in the ballast of large ships.

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