top of page

How Do We Get Rid of SSW?

At the moment, there is no way to permanently rid our lakes of Starry stonewort. Research is ongoing both here and in the US into new control methods, but for the time being, SSW is here to stay.


Removal of any aquatic plants in the Trent Severn Waterway, including SSW, requires a permit from Parks Canada.


Removal must be managed by an experienced (with SSW) commercial harvester, and it's important to note, any harvesting will only be temporary. Attempting to eradicate SSW through use of herbicides or other chemicals is similarly dangerous and will yield only temporary results.

It is vital that we learn how NOT to spread this aggressive invasive species so that we can contain its growth to the areas of the lake where it already exists. It's equally important to understand that when we dredge our waterfronts to remove weeds, we may be removing an important control on the health and growth of SSW. A healthy aquatic ecosystem, full of both native and non-native aquatic plants, may be one of the best weapons we have in our SSW-fighting arsenal. Learning to love your weeds may run against the current, but those pesky weeds could be providing an aquatic atmosphere that will, in the long run, be inhospitable to the opportunistic SSW.

Starry stonewort at a glance

starry stonewort1.png

Reporting New Sightings

What to do if you if you've spotted SSW


​• If you think you’ve found SSW, report it using the Invading Species Hotline (1-800-563-7711) or on EDDMaps (Early Detection and Distribution Mapping System). Here's a link to EDDMaps 

• If possible include a photo of the area and the algae for verification


ZOOM Presentation: Dr. Brian Ginn

On July 28th, 2020, Dr. Brian Ginn of the Lake Simcoe Region Conservation Authority was our guest during a Zoom Starry stonewort presentation. He described this aggressive invasive's history in Ontario, its spread throughout the Trent-Severn Waterway, and the science behind current best management theories. Dr. Ginn's presentation was followed by an overview of the impacts of SSW and actions taking place with a variety of partners to reduce the spread and manage it in Ston(e)y Lake. Here is PART ONE of Dr. Ginn's presentation. To view more, click the link, below.

Taking  Action

As the extent of the infestation in Lower Stony became clear, EC and its association partners focussed on identifying any new areas of growth and educating the lake community about this new-to-us, aggressive invasive species via news articles, information sheets, social media posts and signs. This is one of the many signs EC posted around Ston(e)y and Clear Lakes at marinas, landings and boat launches warning boaters about the presence of SSW in our water and encouraging Clean, Drain and Dry practices (see detailed description below). Today, the focus continues to be on monitoring and mapping the spread of SSW and development of a safe management strategy (now published; see link above). Taking SSW off your propellor and throwing it in the lake will cause it to spread to new areas faster.

bottom of page