Aquatic Invasive Species, Hydrilla, Found In Ontario And Canada For The First Time At Hillman Marsh Conservation Area

The aquatic invasive plant, hydrilla, has been detected for the first time in Ontario and Canada in the West Cell at Hillman Marsh Conservation Area located in Leamington.

Hydrilla (Hydrilla verticillata) can grow up to 2.5 centimeters per day and to lengths of 7.5 meters. This rapid growing invasive species can choke out native species and clog water intake pipes, boat motors and impede other recreational activities like swimming and paddling. Hydrilla is a prohibited invasive species under Ontario’s Invasive Species Act 2015.

Essex Region Conservation Authority is working closely with the Ministry of Natural Resources, the Invasive Species Centre, the Ontario Federation of Anglers and Hunters and many other partners to evaluate the extent of the infestation, contain the spread, and develop plans to control this invasive species.

To date, surveys have shown the infestation to be limited to the contained wetland area of the West Cell of Hillman Marsh that is not directly connected to Lake Erie.

In a pro-active effort to contain the spread of this invasive plant, ERCA will be immediately closing the West Cell of Hillman Marsh, including the trail and boardwalk, to boating, walking and hunting. Hydrilla is easily spread when boat propellers, kayaks, canoes, trailers, fishing and hunting gear, pets or people inadvertently carry attached plant fragments to new areas.

The Conservation Authority is asking the public for assistance in refraining from accessing this area.

People can help prevent the further spread of hydrilla by:

• Learning how to recognise hydrilla by visiting the Invasive Species Centre Hydrilla Species Profile. MNR Profile, Ontario’s Invading Species Awareness Program Profile
• Reporting sightings of hydrilla through the EDDMapS or iNaturalist websites or mobile device applications or by calling the Invading Species Hotline 1 (800) 563-7711. A good report includes an accurate location of the sighting and photos.
• Clean, drain, and dry your watercraft, including motorized boats, canoes, and kayaks. It’s the law in Ontario.