1. What is Eurasian watermilfoil?

Eurasian watermilfoil is an invasive aquatic plant originating in Europe and Asia. It arrived in North America during the 1950s and since then has continued to spread. It forms dense plant beds at depths ranging one to 10 metres.

Eurasian watermilfoil has no natural predators to curb its proliferation. As well, the plant has another advantage to speed its reproduction: one small part of a stem can take root to create a new plant. Plant fragments can be transported from one lake to another by boats, trailers, fishing gear and other nautical equipment.

To better understand and be able to identify Eurasian watermilfoil, consult the Canadian Invasive Species Centre
https://invasivespeciescentre.ca/invasive-species/meet-the-species/invasive-aquatic-plants/eurasian-water-milfoil/

2. Problems caused by Eurasian watermilfoil

Experts agree that Eurasian watermilfoil is threatening the environment of our lakes. They recommend taking action against this plant not only because of its invasive character but also because it disturbs natural ecosystems and disrupts local biodiversity. It negatively impacts the reproduction of some fish and of indigenous aquatic plants. If it is allowed to spread freely, it can negatively impact activities like swimming and fishing. As well, its spread can lower lake property values, as seen in other regions in Quebec where Eurasian watermilfoil has spread uncontrolled. We know that, once established, it is very difficult to remove.

3. Situation on our two lakes

Every year, the APLC carries out inventories in the Cedar lakes to identify Eurasian watermilfoil weedbeds. Since 2015, watermilfoil has been spotted in Petit lac des Cèdres while, to date, the APLC has not yet detected its presence in Grand lac des Cèdres.

The results of the 2018 and 2019 inventories, which had been carried out by a team of volunteers supported by the ministry of forests, revealed that, in Petit lac des Cèdres, Eurasian watermilfoil covered a total area of ​​approximately 14,000 m². On the other hand, the 2022 inventory, completed by the firm Fyto, shows that the total area is estimated at 39,000m² of weedbed with a density of 25% and more of invasive plants.

Consult the complete results of the inventory in the 2023 OPERATION REPORT (French only) prepared by Fyto.

Summary of areas to treat in Petit lac des Cèdres

Type of weedbeds: A monospecific weedbed has a component of Eurasian watermilfoil in excess of 80%. The ministry allows the installation of tarps on these weedbeds only. For any other weedbed made up of native plants and less than 80% Eurasian watermilfoil, the ministry specifies the technique of uprooting.

4. Summary of the intervention strategies

The project to fight against Eurasian watermilfoil brings together several strategies aimed at curbing its growth in Petit lac des Cèdres and preventing its entry into Grand lac des Cèdres.

Consult financial plan 

Strategy 1 – The laying of reusable synthetic tarpaulins:

The technique consists of unrolling a tarpaulin on the entire weedbed and anchoring the tarp on the bottom of the lake with metal rods. The tarp prevents the growth of the plants while allowing the free flow of gasses through the tarp so that it remains wedged at the bottom of the lake.

The use of reusable tarps allows for rotation between weedbeds from year to year. The tarps are installed at the beginning of the season, removed after 8 to 10 weeks, then cleaned, and stored. The following year, divers do a check to make sure that the watermilfoil does not return to the treated weedbed, and they uproot any stems that may have survived. A synthetic tarp has a lifespan of eight to10 years. 

Strategy 2 – Removal of roots: 

One method, with encouraging results recently in the United States and Canada, is the removal of the plant and its roots by experienced divers. There is a protocol for this developed by the Réseau de surveillance volontaire des lacs (RSVL). This technique will only be used for weedbeds where watermilfoil is intermingled with native plants (mixed beds), where the use of tarps is prohibited by government. For beds with a Eurasian watermilfoil density greater than 80%, the tarps will be used.

Strategy 3 – Installation of buoys: 

At the same time, yellow buoys will be installed each spring for the summer season to mark the Eurasian watermilfoil sites in Petit lac des Cèdres. The objective is to make these sites easily identifiable so that people avoid entering these areas with their boats, fragmenting the plants and transporting pieces elsewhere, thus accelerating further growth.

Strategy 4 – Inventory and identification service for residents:

Plant inventory will occur each year at the end of the summer in accordance with the method prescribed by RSVL. The APLC will offer identification service to all residents who believe they have spotted plants outside of the previously identified areas.

Strategy 5 – Information and awareness campaign: 

This campaign will provide information on problems resulting from invasive species, using several communication methods aimed at informing residents:

• Reminder of the importance of boat washing before launching (in partnership with the Municipality of Messines)
• Warning to avoid zones encircled by yellow buoys
• Awareness meetings for owners who have properties near Eurasian watermilfoil

5. Activities

The pilot project, the fight against Eurasian watermilfoil, requires significant financial and human resources.

Activities scheduled for 2024

• Install buoys to mark the location of tarps covering weedbeds of Eurasian watermilfoil. The buoys are placed marking the centre of each tarp.
• Sign a $172,000 agreement with the Fédération de la Faune du Québec to continue efforts to control the Eurasian watermilfoil in Petit lac des Cèdres, thereby protecting lake trout habitat.
• Request and secure $10,500 in financial assistance from the Municipality of Messines.
• Launch a community fundraising campaign.
• Conduct an awareness campaign about invasive species and the importance of washing boats, targeting residents and visitors to our lakes.
• Develop an invasive species maintenance plan to be implemented in 2026, including training a team of volunteers to carry out annual inventories.
• Renew the contractual agreement for a third year with Fyto, a company specializing in the management of invasive species, to carry out the following activities:
  • Install 6,500 m² of tarps.
  • Treat 10,000 m² via manual uprooting.
  • Conduct an inventory of Petit lac des Cèdres in autumn 2024.
  • Conduct an inventory in the stream between the two lakes and the entrance to Grand lac des Cèdres in autumn 2024.
  • Produce an activity report.

Activities taken 2023

• Installed buoys to mark the location of tarps covering weedbeds of Eurasian watermilfoil.
• Submitted a new request for financial assistance to the Fédération de la Faune du Québec (FFQ) to continue our efforts to control the Eurasian watermilfoil infestation. In early 2024, the FFQ granted the Association $172,000 for this effort.
• Requested $10,500 in financial assistance from the Municipality of Messines.
• Raised a little more than $8,000 through a community fundraising campaign.
• Renewed a contractual agreement for a second year with Fyto.
• Installed 6,500 m² of tarps on the weedbeds in the northern part of Petit lac des Cèdres.
• Treated 10,000 m² through manual uprooting.
• Conducted an inventory of Petit lac des Cèdres, where we discovered two previously unknown weedbeds. The inventory found 18,500 m² of weedbeds with a density of more than 25% Eurasian watermilfoil in the lake and approximately 55,000 m² of weedbeds with a density less than 25%.
• Conducted an inventory of Grand lac des Cèdres, finding no Eurasian watermilfoil except for a few stems in the stream, which were removed.
• Produced the 2023 activity report, authored by the Fyto

Activities taken in 2022

• Placement of buoys marking the Eurasian watermilfoil beds
• Submission for financial aid to the program for the fight against invasive exotic plants, offered by the Fondation de la faune du Québec and decision of Fondation de la faune du Québec to provide grant of $64,900 for the project
• Fundraising campaign with residents: The APLC collected $11,295.25, which is in addition to the $20,276 collected in 2021
• Contract agreement with Fyto, a firm specializing in the management of invasive exotic plants
• Installation of tarps on weedbeds 3, 4, 5, 8, 9, 10, 12, 18 for a total area of ​​4,085 m² by Fyto divers
• Uprooting of Eurasion milfoil on weedbeds 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 18. In total, 1,313 kg of fresh biomass were uprooted from an area approximately 3,000 m^2. Work done by Fyto divers
• Removal of tarps in August 2022
• Survey of the Cedar lakes at the end of the summer by Fyto team. Adjustment of the total area by more than 25% of watermilfoil from 16,000 to 32,000 m²—a 50% increase
• Update of the FINANCIAL PLAN  for the project
• Submitting of 2022 OPERATIONAL RAPPORT (FRENCH ONLY)  prepared by the Fyto team

Actions taken in 2021

• Placement of buoys marking the Eurasian watermilfoil beds
• Request for permit for the placement of tarps
• Initial purchase of 1,500 square metres of reusable synthetic tarps
• Assembly of 50 rolls of tarp, and the construction of a motorized barge with a pulley and reinforcing metal bars to handle the unrolling of the tarps.
• Laying of the tarps on June 8 and 9, 2021, with three divers and a dozen volunteers to validate our methodology.
• Treatment of two weedbeds upstream on the lake, in line with the strategic action plan developed in cooperation with the provincial government.
• Removal of synthetic tarps on August 16th and 17th. After a visual inspection of the two target weedbeds, it seems that all the stems of watermilfoil are dead.
• Survey of the Cedar lakes at the end of the summer by trained volunteers from the APLC and an employee of the MFFP
• No uprooting activity scheduled this year due to COVID-19

Actions taken in 2020

• Placement of buoys to mark Eurasian watermilfoil areas
• Installation of movable sandwich boards to inform residents of the placement of the yellow buoys
• Removal of Eurasian watermilfoil roots (activity delayed until 2021 due to COVID-19)
• Inventory, at the end of the summer, of both lakes by volunteers trained by APLC
• Consultation and training with experts from Université Laval on tarp deployment techniques and other logistical considerations

Actions taken in 2019

• Placing buoys to identify Eurasian watermilfoil areas
• First root pulling activity in June with experienced divers and APLC volunteers.
• Meeting with residents who live near Eurasian watermilfoil plants to encourage them to avoid boating there
• Distribution of a flyer to inform residents of the presence of Eurasian watermilfoil and the reason for the yellow buoys
• Inventory of both lakes by APLC volunteers—two new plant areas spotted in Petit lac des Cèdres—a total of seven. No Eurasian watermilfoil plants found in Grand lac des Cèdres (section outside Kitigan Zibi reserve)
• Participation in a conference offered by the Lac des Plages association, innovator of the root removal technique
• Publication of an educational resource on the APLC website, explaining problems linked to exotic invasive species
• Installation of movable sandwich boards to inform residents of the placement of yellow buoys
• Information session about the pilot project at the APLC annual meeting

Actions taken in 2018

• Inventory of the two lakes by APLC volunteers—two new plants were seen in Petit lac des Cèdres, for a total of seven plants. No plants were found in Grand lac des Cèdres outside Kitigan Zibi reserve)
• Participation of APLC board members at a Eurasian watermilfoil conference offered by l’Université Laval à Québec
• Information workshop on invasive species for residents
• Approval by the APLC board of a pilot project to fight Eurasian watermilfoil
• Negotiation to obtain permission from the Municipality of Messines for root removal
• Installation at the boat launches of a sign informing visitors of the requirement to wash boats before launching

Actions taken in 2015

• First inventory of Eurasian watermilfoil in Grand lac des Cèdres and Petit lac des Cèdres by ABV des 7
• ABV des 7 report