A small municipality in the Outaouais, with the help of the province of Quebec, is launching a study to investigate the impacts of an invasive aquatic plant that could be damaging the region’s lake ecosystems.
The Eurasian water milfoil grows in dense threads just below the surface of the water.
The fast-growing perennial plant poses a threat to aquatic ecosystems because of its aggressive and relentless growth that can displace native plants and potentially be detrimental to fish communities.
Roch Carpentier, the mayor of Sainte-Thérèse-de-la-Gatineau, bordering the extensive Lac des Trente et Un Milles just south of Maniwaki, said the lake’s natural wealth is a benefit to all. surrounding municipalities.
“We will do our best to help the lake,” he said.
Roch Carpentier, mayor of Sainte-Thérèse-de-la-Gatineau, says he hopes the Eurasian water milfou can be contained to preserve the lake’s cleanliness. (Christian Milette / Radio-Canada)
He said one of the main attractions of the lake is the cleanliness of its waters, and that excess vegetation could make navigation difficult and drive tourists away.
The municipality already plans to put burlap on the yarrow for the summer to try to contain it.
“We will never be able to make it disappear,” Carpentier said in French, but hopes the plant’s spread can be reduced.
The Eurasian water yarrow is so invasive in part because of the ease with which it spreads.
Even a small broken piece of the plant can generate a new vegetation envelope wherever it is installed. This can happen when ships traverse the vegetation mass and their rotating propellers disperse chunks through a mass of water.
Carpentier hopes lake users will respect the signs that can be installed to keep sailors away from the milfoil.
Study to compare the health of fish populations
The municipality has given the green light to a study on the health of fish populations in areas affected by aquatic milfoil.
“It’s an exotic and invasive species,” said Julie Deschenes, a biologist at the Quebec Ministry of Forests, Wildlife and Parks, in French. “We prefer not to have it.
“What we’re trying to see is whether this is still a habitat for fish.”
Julie Deschenes, a biologist with the Quebec Ministry of Forests, Wildlife and Parks, says the new study will determine whether the Eurasian water milfoil is harmful to the lake’s fish population. (Christian Milette / Radio-Canada)
The study will compare the population of fish in areas covered by the invasive plant and the number in places inhabited with native aquatic plants.
To study the fish population of the lake, the team will use a combination of traditional nets and an electric fishing technique that briefly knocks out the fish, allowing researchers to collect, identify, count and measure them. them and then release them back into the water.
The Lac des Trente et Un Milles study will use various fishing techniques to study the health of the fish population. (Christian Milette / Radio-Canada)
Non-native plant now widespread in several regions
The Eurasian water yarrow is not native to Canada, but it was introduced to North America in the 19th century – but it’s been done like home here for decades.
The plant was first seen in Canada on Lake Erie in 1961.
In later decades, it spread to all of the Great Lakes, the St. Lawrence River, and many smaller lakes in Ontario and Quebec. It is one of the most common invasive aquatic plants in Ontario.
In 2015, it was identified in New Brunswickwhere it has also spread rapidly.
A researcher measures a fish extracted from the Lac des Trente et Un Milles. The study aims to determine whether Eurasian water milfoil is harming the health of the lake’s fish population. (Christian Milette / Radio-Canada)
Hope for the tourism of the future
Marlène Thonnar, president of a corporation that hopes to turn Lac des Trente et Un Milles into a provincial park, said she hopes the results of the study will help educate lake visitors on how to help preserve the health of the lake. ‘ecosystem.
“If we have a lot of scientific information … to do [visitors] understanding what they have to do and what they can’t do to preserve the wonderful lake we have, that’s positive, ”he said.
Marlène Thonnar hopes the results of the study will help educate lake visitors about how to help preserve the health of the ecosystem and adds that time is of the essence. (Christian Milette / Radio-Canada)
He added that weather is essential as the Eurasian water milfou is rapidly spreading to the lake.
“We really have to be fast … in this exercise [to raise public awareness]”Said Tonnar.
The Lac des Trente et Un Milles study will run from July to the end of November.