February 28, 2025
Credit Valley Conservation (CVC) was a recipient of the 2024 Invasive Species Action Fund (ISAF). Their project involved a combination of strategies to address invasive species at Island Lake Conservation Area (ILCA). “The main goals were to leverage our experience with invasive species management to implement widespread control of priority invasive plant species across the property, and to engage the community in invasive control efforts and educate them on risk reduction,” stated Lee Merrill, the Coordinator of Terrestrial Restoration at CVC, when describing their project, titled Comprehensive Invasive Species Management at Island Lake Conservation Area.
ILCA is both an ecologically and recreationally important area. This 329-hectare property features diverse habitats, including streams, wetlands, shorelines, forests, and meadows. It is also a popular destination for fishing, kayaking, canoeing, and hiking and includes the Vicki Barron Trail, an 8 km trail surrounding the lake, which offers stunning views and is a highlight for visitors. Because ILCA sits at the top of the Credit River watershed, anything entering the lake can spread throughout the watershed, making invasive species management essential.
This project focused on controlling dog-strangling vine (DSV), Japanese knotweed, and European buckthorn. All three species have significant ecological impacts. DSV and European buckthorn are already widespread in the area, while Japanese Knotweed was recently detected and remains more localized. Controlling these species is essential to prevent their spread and allow native plants and biodiversity to thrive.
DSV management at ILCA started in 2013, and for eight years, efforts were highly successful, reducing its presence by over 90%, with localized eradications. However, due to changes in resources and program capacity, management efforts were scaled back and later paused during COVID-19. This allowed the species to reemerge in new areas and expand in some previously controlled patches. “With DSV, continued management is crucial,” said Lee. “You need to be ready for five-to-ten-year efforts to put towards it, and it’s challenging to get the resources to do that.” Re-initiating these control efforts was critical at ILCA. Thanks to recent management efforts, positive reductions in DSV distribution are expected in the upcoming field season, and Lee is hopeful that eradication is possible for this area.
Because Japanese knotweed is not as established at ILCA as DSV, the results of CVC’s management efforts for this species are even more promising. Two small populations of Japanese knotweed were discovered at ILCA in 2022 through a BioBlitz. As with all invasive species, early detection followed by a rapid response greatly reduces the cost and effort associated with management. The ability to include Japanese knotweed management during the most recent field season was a major step toward its eradication from the area. “Because we were able to implement these management efforts, I expect the results we observe this year—and our chances of long-term success—to be great, as opposed to if we had left those populations for multiple years and found ourselves in a situation similar to that of the dog-strangling vine,” explained Lee.
Community involvement through CVC’s Community Outreach program was also a vital component of the project. The surrounding community in Orangeville, including groups like Friends of Island Lake and the Headwater Streams Committee, is highly engaged in stewardship efforts. This enthusiasm contributes to the success of volunteer events, which play a key role in invasive species management. The volunteer events focused on controlling European buckthorn by removing seedlings and saplings through hand-pulling and the use of weed wrenches. “The volunteers were incredibly enthusiastic,” Lee said. “It’s impressive how much buckthorn can be removed when the team works together!”
Boat wash events were another important aspect of community engagement. CVC hosted four boat wash events at ILCA in partnership with the Ontario Federation of Anglers and Hunters (OFAH) Invading Species Awareness Program. These events featured a booth and boat wash station where boaters and the public learned about the legal requirements and importance of boat cleaning to prevent the spread of aquatic invasive species. “Many boaters were unaware of the legal requirements for boat cleaning,” Lee explained. “Educating them about the necessity and methods of decontamination has been an eye-opener, and the response has been overwhelmingly positive.” Lee was also pleased to announce that, with the support of OFAH’s Invading Species Awareness Program and the Ontario Phragmites Action program’s Invasive Phragmites Control Fund, they will be launching a self-serve boat wash station at ILCA that is free to use for boaters as they come and go from the lake.
Moving forward, CVC will continue its cycle of monitoring, managing, and reassessing invasive species at ILCA to ensure long-term success. “As always, the keys to successful invasive species management are persistence and remaining adaptive,” explains Lee. Despite the long-term commitment of managing these invasive species, the results are already positive. “After the first control efforts, you immediately see native species start to reinhabit those areas and start to thrive again,” Lee described.
When asked what advice he would give to other organizations tackling similar invasive species issues, Lee emphasized the importance of collaborating with conservation authorities, community groups, and organizations working on similar issues, as well as taking advantage of available resources. “Without ISAF funding, much of our invasive species management at ILCA would have continued to be on hold, allowing species like DSV and Japanese Knotweed to expand further,” he continued. “The funding enabled us to resume intensive control efforts, which will have lasting benefits to help towards the ultimate goal of eradicating these species from the property.”
To learn more about the Invasive Species Action Fund and past recipient projects, visit here. To receive updates on grant opportunities, subscribe to the Invasive Species Centre mailing list.
