August 15, 2024 

The Water Soldier Working Group has confirmed the presence of an aquatic invasive plant called water soldier in Lake Simcoe waters for the first time.   

Water soldier is a perennial aquatic plant, prohibited under the provincial Invasive Species Act, that has long, thin, serrated leaves that grow in a circular pattern. They form dense mats that crowd out other vegetation and may alter water chemistry, impacting native aquatic species. Water soldier can be submerged up to 5 metres under water but floats to the surface in the summer. This poses a threat to summer recreational activities such as fishing, boating, and swimming. Boat motors can break up plants allowing them to spread and invade new areas.  Prior to being regulated as a prohibited invasive species, water soldier was used as an ornamental plant in water gardens, which is the most likely source of its introduction to the wild. 

Since receiving the initial report of water soldier in Lake Simcoe, members of the Water Soldier Working Group mobilized to survey the area and continue to explore management and treatment options. The Water Soldier Working Group members include provincial ministries, Indigenous organizations, municipalities, conservation authorities, universities, federal agencies, and other environmental organizations.   

“Ontario recognizes the importance of the prevention, early detection and management of invasive species that pose a threat to Ontario’s native species and ecosystems. If left unchecked, water soldier has the potential to invade lakes and rivers throughout Ontario and the Great Lakes basin ecosystem, causing significant harm to biodiversity and affecting property values, recreation, tourism and navigation in aquatic systems,” said Graydon Smith, Minister of Natural Resources. “That’s why we’re working diligently with our partners to further evaluate the extent of this invasion and develop plans for its control.” 

“The earlier an invasive species is detected, the better the chances of quick management,” says Colin Cassin, Policy Manager at the Invasive Species Centre. “I encourage people to learn more about water soldier, keep an eye on Lake Simcoe, and report any water soldier to EDDMapS or the Invading Species Hotline at 1-800-563-7711.”  

“Water soldier is an invasive aquatic plant that can spread quickly. It is known to alter shallow water habitats by crowding out native plants and impacting living space for fish species,” says Brian Ginn, Limnologist, Certified Lake Manager, Lake Simcoe Region Conservation Authority. “If not properly managed, it could have significant effects on both the ecology of Lake Simcoe and our recreational use of the lake.” 

What Community Members Can Do 

People can help prevent the further spread of water soldier by: 

  • Report sightings of water soldier through the EDDMapS or iNaturalist websites and mobile device applications, or by calling 1-800-563-7711. A good report includes an accurate location of the sighting and photos. 
  • Clean, Drain, Dry your boat when you leave Lake Simcoe and other waterbodies so that you aren’t moving water soldier or other invasive species on your boat. It’s the law in Ontario.  
  • Never buy or keep water soldier in your water garden. Water soldier is a prohibited species in Ontario under the Invasive Species Act. This means it is illegal to import, possess, deposit, release, transport, breed/grow, buy, sell, lease or trade water soldier.  
  • Dispose of water soldier in the garbage or on dry land in a manner that ensures that no part of the plant will re-enter the body of water or enter any other body of water.   

Additional Resources 

Image 1: Submerged invasive water soldier plant
Image 2: Floating invasive water soldier plant
Image 3: Clean, drain, dry infographic

About the Invasive Species Centre     

The Invasive Species Centre is a not-for-profit organization that mobilizes action against invasive species that harm the environment, economy, and society in Canada and beyond. Visit our website at www.invasivespeciescentre.ca to learn about invasive species, get information, take training courses, register for events, sign up to receive news, and take action on invasive species.    

For more information please contact: 

Deborah Sparks
Business Development and Communications Manager
Invasive Species Centre
media@invasivespeciescentre.ca
705-255-8301

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