Young naturalist makes important discovery at Lake Rasmussen

by Skye Pelliccia, King County Noxious Weed Control

In 2020, a second grader named Maggie made a startling discovery: she found Egeria densa, a rare invasive aquatic plant, in Duvall’s Lake Rasmussen. Thanks to her keen eye, we were able to prevent this Class B noxious weed from spreading from this small lake. Controlling this small infestation prevented a much larger problem as the lake feeds into the Snoqualmie River, which reaches many other water bodies, including Lake Sammamish. Egeria (formerly called Brazilian elodea) forms dense mats that clog waterways. Its dense growth leaves little room for fish or beneficial vegetation, and significantly reduces a waterbody’s habitat and recreational value. The King County Noxious Weed team worked with Woodland Resource Services who, thanks to this report, carefully treated the Egeria infestation in 2021. Since then, our team has monitored Lake Rasmussen monthly, and are excited to share that there are still no signs of Egeria in the lake and the native plants are doing well. We will continue to monitor this lake for Egeria once or twice a year and hope that the plants found in 2020 will be the last. For more background on the project, read the noxious weed program’s 2021 blog post: Lake Rasmussen’s new aquatic noxious weed gets speedy action  (kingcountyweeds.com)   Or watch the charming video--featuring Maggie--created by King County’s Department of Natural Resources: Second grader prevents weed spread