Members of the Shawnigan Residents Association will be busy this summer pulling invasive Eurasian water-milfoil from Shawnigan Lake.
The SRA has received permission from the Ministry of Forests, Lands, Natural Resource Operations and Rural Development to remove the EWM, an introduced invasive aquatic plant that has been in Shawnigan Lake since the late 1970s, this summer.
Netta Bos, who is in charge of the project, called “Tick, Tock, Tick, Tock, Milfoil at Your Dock?”, for the SRA, said the area’s residents are becoming increasingly concerned with the milfoil in the lake, so the Cowichan Valley Regional District approached the SRA to see if they would take on the challenge.
But she said that, no matter how much invasive milfoil will be removed, it will never be completely eradicated from the lake.
“All we can hope to do is minimize its presence,” Bos said.
“If all the people living on the waterfront approach its removal in the same manner, we could have some success in that.”
EWM grows rapidly and can form densely tangled mats of vegetation near the water surface that shade out native aquatic plants.
In addition to ecological and water quality impacts, dense growth of milfoil can negatively impact recreational and aesthetic values.
In Shawnigan Lake, the invasive milfoil is typically found along most of the shoreline in shallow water that is between one and four metres deep, which represents approximately 13 per cent of the lake.
It’s suspected that the recent increase in milfoil in the lake may be the result of human-introduced nutrients from erosion from activities like forestry, farming, soil dumping, leaking septic infrastructure, and the application of fertilizer to ornamental planting, agricultural fields or pastures.
Bos said Eurasian water-milfoil is spread by fragmentation, and if all the pieces are not collected when removed, it will spread even faster through the lake.
“Only SRA members will be permitted to remove the milfoil because it’s illegal to handle or touch wildlife in B.C. without permission, and we do have a video on the association’s website (www.thesra.ca/milfoil) explaining to members how to properly hand pick it,” she said. “Work on removing the milfoil must not start before June 15 and must be complete before the plant flowers, which usually occurs sometime in late August. Once the plant starts flowering, it will be too brittle to remove without excessive fragmentation.”
Bos said it’s not known if the project will go beyond one year, but the SRA is collecting a database of waterfront owners’ names and addresses so information on this, and other issues facing the lake, can be easily disseminated through the lake community.