“Results indicate the need to actively control invasive plants and possibly freshwater clams in Lake Chelan” — Phil Long
information released, photo above: Four Peaks staff members Drew Stang and Nate Hough-Snee sample invasive aquatic plant in Spaders Bay on Lake Chelan on Sept. 14, 2021.
A recent aquatic invasive species survey at Lake Chelan shows that invasive aquatic plants are more widely distributed in the Wapato Basin and lower Lucerne Basin of the lake compared to survey results from eight years ago.
The 2021 survey covered the entirety of the Lake Chelan shoreline and mapped 520 acres of invasive aquatic plants, predominantly Eurasian Watermilfoil and Curly Leaf Pondweed. The survey results also documented an increase in the northern extent of aquatic invasive plants within the lake, including shoreline locations in the lower Lucerne Basin frequently used by boaters.
“While most of the invasive aquatic plants were identified near developed and shallow shorelines in the Wapato Basin of the lake, we found that they have also spread up lake to other high-use areas,” said Drew Stang, one of the scientists who conducted the survey. “These new observations unfortunately confirm the continued spread of invasive aquatic plant species within Lake Chelan.”
The full report is available at: https://lakechelanresearchinstitute.com/ais-survey-2022/
The research not only documented invasive aquatic plants throughout Lake Chelan but also included a limited survey of invasive freshwater clams (Corbicula fluminea). Invasive freshwater clams were observed at several locations during the survey. Invasive clams are a concern because they have the potential to influence water quality and impact native species.
Anecdotal observations by Lake Chelan Research Institute and local fishing guides suggest that freshwater clams are increasing in Lake Chelan and that they may serve as a food source for lake trout. Additional study is needed to determine their extent, importance to fish, and impact on Lake Chelan water quality.