Aquatic Weed Management Case Study

large lake management

Managing Invasive Water Soldier in a Canadian Waterway

Canada’s Trent-Severn Waterway provides a link between Lake Ontario in the southeast and Georgian Bay in the northwest, allowing boat navigation for its entire 240- mile length through a system of rivers and lakes, and 41 locks. Water Soldier (Stratoides aloides), an invasive aquatic plant that forms impenetrable mats on the water surface, infested an area of approximately 700 acres within the Trent-Severn Waterway. The infestation was first reported in the Trent River, in September of 2008, and is considered the only known Water Soldier infestation in all of North America. From there, Water Soldier spread through Lake Seymour and approximately 20 miles downstream. A multi– agency working group including the Ontario Ministry of Natural Resources and Forestry, Ontario Federation of Anglers and Hunters, Parks Canada and other agencies determined that aquatic herbicide treatments were required to control and contain the spread of Water Soldier to new areas within the Trent-Severn Waterway.

In fall 2015, SOLitude was deemed the best equipped company in North America to manage the project and was awarded a contract to apply an aquatic herbicide to more than 300 acres of Water Soldier infested habitat within the Trent-Severn Waterway. This contract represented the largest aquatic herbicide application to date in Ontario. Water Soldier inhabits primarily shallow water (less than four feet deep) with soft, muddy substrates. Effective treatment with the herbicide required the use of airboats and experienced applicators to navigate and treat the infestation successfully.

Before any work could begin, the SOLitude team needed to overcome the logistical hurdles of a US firm working in Canada. This required establishing staff credentials and undergoing security clearance in order to obtain work permits in Ontario. It also required the firm to obtain a license and insurance to apply pesticides in Ontario. In addition, trucks, boats, and application equipment needed to be “imported” to Canada at the border crossing, adding time and considerable cost to the project.

The initial application took place in October 2015, following the end of Ontario’s “cabin season.” The SOLitude team exceeded expectations and effectively treated 360 acres in just two days. Based on SOLitude’s outstanding performance in 2015, the company was awarded the contracts to conduct treatments in 2016 and 2017.

The 2017 treatment was planned to manage the entire Water Soldier infestation, which encompassed more than 700 acres throughout Lake Seymour and the additional sites. To achieve the goal of treating the entire infestation in a five-day timeframe per contract, SOLitude provided eight team members with four treatment airboats and two support boats for the project. Each treatment airboat was run by an applicator holding an Ontario Aquatic Exterminators license, and applications were tracked using GPS guidance and pre-loaded treatment plots. Since the herbicide used is only available in one-gallon containers in Canada, this meant hand-pouring and rinsing more than 1,400 containers. Upon completion of the application, SOLitude successfully treated 724 acres in three days, including all four project sites.

The Trent-Severn Waterway presented a rare and complex opportunity to manage a Water Soldier infestation. SOLitude stepped up to the challenge, improving the health of the aquatic ecosystem and bringing the waterbody closer to a state of long-term ecological balance.

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SOLitude Lake Management is an environmental firm committed to providing full-service solutions that improve water quality, preserve natural resources, and reduce our environmental footprint. Our services include lake, pond, wetland and fisheries management programs, algae and aquatic weed control, mechanical harvesting, hydro-raking, installation and maintenance of fountains and aeration systems, water quality testing and restoration, bathymetry, lake vegetation studies, biological assessments, habitat assessments, invasive species management and nuisance wildlife management. Services, consulting and aquatic products are available to clients nationwide, including homeowners associations, multi-family and apartment communities, golf courses, commercial developments, ranches, private landowners, reservoirs, recreational and public lakes, municipalities, parks, and state and federal agencies. Learn more about SOLitude Lake Management and purchase products at

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