DASH removes 900 pounds of invasive plants from Lake Chelan

Welcome to the blog Lone Pine
An area off Key Bay where milfoil was removed using an airlift.

by Richard Uhlhorn

Eurasian Water Milfoil is shown here collected in a rake throw sample near the Old
Mill Bay Park boat launch on Lake Chelan in September 2021.

Four Peaks Environmental Services conducted an invasive aquatic species survey on Lake Chelan and found 520 acres of Eurasian Milfoil and Curley Leaf Pondweed along the shoreline of Wapato Basin and stretching into the lower regions of the Lucerne Basin where there is heavy recreational boat use.

This increase of invasive species over the past eight years has increased concerns on how to manage the invasion. The Lake Chelan Research Institute (LCRI) began looking at methods of managing this issue and settled on DASH (Diver Assisted Suction Harvesting) as the preferred method of removing the invasive species from the lake bottom.

Lake Defense Force uses a diver operated airlift off a work boat.

With $25,000 of private funding the LCRI hired Lake Defense Force to conduct a sample test of two areas over a six day period… Key Bay and Minneapolis Beach. This test will help determine an Integrated Aquatic Management Plan for the lake.

The airlift used by the team pulls invasive species up by the roots. Once captured, it is bagged for removal. According to Alex Garry, Lake Defense Force General Manager, the dive team can suck up between 1,500 and 5,000 square feet per day.

A Lake Defense Force employee puts milfoil and pond weed into a bag.

DASH is an alternative to using chemical applications to remove milfoil and pond weed. The use of chemical herbicides is not a preferred method in Lake Chelan.

Operating off Minneapolis Beach.

The diving company comes back to a treated area and removes any recurring bloom on the bottom by hand. “We have, over time eradicated invasive species from lakes,” said Garry.

A Lake Defense Force diver works at removing Eurasian Milfoil from the bottom of Lake Chelan at Minneapolis Beach.

Because Lake Chelan is a reservoir which is lowered in the winter for power production, much of the invasive species is killed by freezing. This year’s cold spring has delayed the growth of invasive plants in Lake Chelan. Much of the plants removed were thought to have sprouted on the bottom within the last several weeks.

LCRI executive director, Phil Long, stated that the test was extremely successful and will help determine a management plan and financial resources needed to implement it. “We hit high use areas which confirmed the continued spread of invasive aquatic plant species in Lake Chelan,” stated Long. “It’s interesting that a lot of the plants are blooming under anchored boats.”

The Research Institute used an underwater ROV to check areas of milfoil and pond weed.

Over the five and half days Lake Defense Force operated, they removed 900 pounds (20 bags) of milfoil and pond weed, most of which was removed from Minneapolis Beach.

An area cleaned by the diving team in Key Bay.

Lake Chelan Research Institute conducts monthly water quality research on the lake and is partially funded by local government entities. Organizations and individuals can donate money and time as volunteers to help keep the lake quality at its optimum. Visit https://lakechelanresearchinstitute.com/ for more information.

Another group helping educate the public about Lake Chelan is the Keep It Blue Program at https://www.keepitbluelakechelan.org/.

Author: allthingslakechelan

I have been a journalist, photojournalist and reporter in the Lake Chelan Valley since 1988; first with the Wenatchee World, then 15 years at the Lake Chelan Mirror and another 12 years at GoLakeChelan. Currently, I am semi-retired but can't give up the media gig which is why I started All Things Lake Chelan blog. I also have two social media platforms; allthingslakechelan/facebook and lakechelansportsandrecration/facebook. I am also a professional photographer with many credits with major outlets around the world.

2 thoughts on “DASH removes 900 pounds of invasive plants from Lake Chelan”

  1. So happy that you are working on getting rid of the milfoile, will we have stations for boaters to clean their boats of weeds before they launch into Lake Chelan?


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