2008 Statewide Strategic Plan for Eurasian Watermilfoil in Idaho

2007
Total project cost: $82,660
ISDA Funds: $12,000
Match: $70,660
2. Bingham County, Blackfoot, Idaho
This project aims to inform boaters and the general public to be on the lookout for
Eurasian Watermilfoil. Waterways signage will be installed throughout the Upper
Snake River water system. Project cooperators include Bingham County,
Fremont County, Upper Snake River CWMA, Henry’s Fork CWMA, and the Idaho
Weed Awareness Campaign.
2007
Total project cost: $4,444
ISDA Funds: $2,564
Match: $1,880
XI. Applied Research and Related Work
The Idaho Invasive Species Council’s Milfoil Task Force conducted research into
the use of bottom barriers for the control of Eurasian watermilfoil in North Idaho’s
lakes. In addition, CABI Europe recently conducted a feasibility study into the
potential for a classical biological control program for Eurasian watermilfoil in the
United States. The Milfoil Task Force work was funded by the Idaho State
Department of Agriculture. The CABI biological control feasibility study was
funded by the US Army Corps of Engineers. A summary of the Task Force’s
research program and the CABI biocontrol feasibility study is provided here in
summary form.
A. Bottom Modifications Summary
The objective is to complete research to determine bottom modifications that
control and prevent establishment of Eurasian watermilfoil. This study involves
one lake bottom modification treatment using fabric panels. The project was a
cooperative effort between the University of Idaho, the Coeur d’Alene Tribe and
ACE Diving.
The primary experiment was designed to answer the question: “How long should a
weed fabric panel be left in place to kill Eurasian watermilfoil?” Experimental plots
containing moderate to dense Eurasian watermilfoil growth were “treated” with 10
foot x 10 foot fabric panels in May 2006. These panels were removed at
approximately one month intervals. Each removal interval was repeated in four
plots. Following initial barrier panel trials in 2005, it appeared that approximately
10 weeks are needed to provide control of milfoil. The 2006 study indicates that
the eight week benthic barrier coverage time resulted in the greatest reduction of
Eurasian watermilfoil biomass with the least reduction in native plant biomass.
These panels would be used in the course of a control program to provide a nonchemical
method of control that would not require divers to find every plant within
42