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October 2007

In the weeks immediately after we learned our lake studies found a small outbreak of Eurasian water-milfoil (EWM) in Berry Lake, we followed the DNR’s recommendation and tried to remove it by hand.  Two major efforts involving SCUBA divers and snorkelers with pontoon boat and canoe/kayak support teams removed a lot of the EWM biomass but we were unable to remove all of it.

When the EWM resisted hand pulling, the only option was to prepare for the second front of the EWM battle:  our scheduled fall chemical treatment.

Chemical treatments can be expensive and they must be conducted cautiously to preserve the native plant communities that compete with EWM and provide a diverse habitat for fish and wildlife.

To ensure the most judicious application possible, we selected what we believe is Wisconsin’s most experienced chemical applicator.  To ensure we remove as much EWM as possible at the most affordable cost in the short term and to keep EWM from coming back over the long term, we are developing a EWM Volunteer Monitoring program.


The complete EWM Volunteer Monitoring program will be launched next year but it is already developed sufficiently to begin training volunteers.

EWM Volunteer Monitors are taught to distinguish between the invasive EWM and the beneficial native Northern milfoil.  They learn how to identify likely EWM plants while passing by in a boat and how to obtain a sample while containing fragments that can spread the infestation.  The volunteers will look for EWM on a regular basis and report any suspected EWM so we can confirm the find.  Confirmed finds will be assigned the most appropriate demise.  We will employ hand pulling by SCUBA divers in deep water or by snorkelers in shallower water. Under the right conditions, the EWM will be treated with chemicals.

With our fall chemical treatment scheduled for the latter half of October, we started training EWM Volunteer Monitors on October 13 and 14 by locating and marking EWM with GPS waypoints and plastic jugs anchored at the site.

Most of the EWM plants are scattered so individual plants must be found and “spot treated.” Finding individual plants can be very time consuming and costly when done by a chemical applicator unfamiliar with the lake and EWM locations.  Our volunteers gain experience by finding, sampling, identifying and marking the locations of EWM.  Our floating bottles and GPS waypoints not only help ensure the more complete eradication of EWM but they keep costs down.


examining EWM fragments

Berry Lake property owner Bill Stiles examines a EWM fragment created during sampling.  EWM fragments are the primary way EWM spreads.  Taking samples to distinguish between EWM and the beneficial northern milfoil can create fragments.  EWM Volunteer Monitors know the importance of netting fragments and removing them from the lake.

making anchors from bricks

Underhill resident Mike Elko creates two "anchors" out of one brick.  Plastic jugs anchored with brick halves mark EWM to ensure faster and more complete location on treatment day.












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