Eurasian Watermilfoil
Eurasian Watermilfoil Drone Mapping 2024 Results
In September 2024, Palmerston Lake Association commissioned a survey of the lake for the presence of invasive Eurasian Watermilfoil (EWM). Using drone mapping technology, Wade Leonard captured images in five key zones.
The good news is that while Wade did identify some EWM in Palmerston Lake, he did not see the wide-spread infiltration he has seen in some other lakes in our region.
Three EWM colonies were confirmed, while the majority of the surveyed areas showed no signs of infestation. Observations suggest that the lake’s depth, steep shoreline drop-offs, and low nutrient levels serve as natural deterrents to widespread colonization.
This is a crucial step in our effort to understand the extent of EWM infiltration in our lake. Surveying will continue over the next years to monitor the spread of this invasive plant.
A huge thank you to Wade Leonard, Tylor Potvin and the “Above and Beyond with Drones” program at Granite Ridge Education Center.
See the presentation here.
Earlier posts continue below …
The PLA is implementing two important measures to defend the lake against EWM: on the July 1st, 2024 weekend, protective markers and signage were installed (see the panel to the left for more details). Later in the summer, a drone survey will be undertaken. Read about it and how you can help here.
Eurasian watermilfoil is an aggressive invasive aquatic plant and is present in our lake. See the locations in our lake with with reported sitings (enter Ompah, Ontario in the search bar). Please take great care. Fragments broken off by motor boats, fishing lures, or by pulling neighbouring weeds can root and cause the plant to spread.
What can you do?
- You can try to control growth near your shoreline by carefully hand-pulling eurasian water milfoil plants, being careful not to cause any fragments to break off and to get the entire root. (see below for how to identify this plant.)
- If you see floating fragments, carefully scoop them out of the water and dispose of them on land well away from the shore.
- See the Ontario Invasive Plant Council’s document on best management practices for Eurasian Water-Milfoil.
- Report a sighting. Take a photograph, note the GPS coordinates, and email the information to PalmerstonLakeAssociation@gmail.com. We will add the report to the distribution map for Ontario that is available here.
Eurasian watermilfoil can out-compete native aquatic plants and eventually choke off portions of the lake. Plants have been known to grow in water as deep as 10 metres.
Not to be confused with the native Northern Watermilfoil, the easiest way to identify Eurasian Watermilfoil is by counting the pairs of leaflets on each leaf. If there are more than 11 pairs, it’s Eurasian Watermilfoil. It also becomes limp when out of the water unlike the native milfoil which remains rigid.