The EXCOM’s data-dependent approach to controlling Hybrid Eurasian Water Milfoil (HEWM) now has us recommending to members that we push forward with a pledge drive to raise funds for mechanical control. Details below…
Recall our success in treating HEWM-infested areas of Lost Land Lake with Reward herbicide in June of 2017 (click here to open new window for full story). The unexpected efficacy of treatment combined with healthy regrowth of desirable native plants in treated areas caused us to question the need for a previously discussed fund-raiser to buy and operate an Eco-Harvester to mechanically remove nuisance plants.
Also recall that several dense beds of Hybrid Eurasian Water Milfoil in Steamboat Bay were NOT treated in 2017 in order to save money and serve as a “control” of sorts to compare against treated areas in northern and western areas of Lost Land Lake. Due to cooler-than-normal weather in spring of 2017, all plants, including HEWM, got a late start and never reached the density observed in 2016. However, HEWM in Steamboat Bay did not go away. It remains now as the single largest potential source of plant fragments to be spread by man or beast to other parts of the lake (or lakes).
By majority vote, the QLIA EXCOM decided at our March 13, 2018 meeting to spend up to $5,000 (75% reimbursable under WDNR’s continuing grant authorization) to map Hybrid Eurasian Water Milfoil in Steamboat Bay and treat it with Reward herbicide in late spring before the long stems of HEWM “top out” and begin to lay across the surface where they would be highly vulnerable to fragmentation and translocation. This decision was CONDITIONED on the continued scarcity of HEWM and the dominance of native plants in areas treated with Reward herbicide in 2017. Dave and Sandy Neuswanger spent a morning mapping the HEWM in Steamboat Bay and determined that 4.6 acres would require treatment.
Unfortunately, Norm Bratteig’s late June inspection of areas treated with Reward herbicide in 2017 revealed that HEWM had returned to form significant stands of the nuisance vegetation in at least half the area treated in 2017. This was disappointing news to EXCOM members who had hoped we could manage this problem with occasional, affordable spot treatments of an approved herbicide. Nevertheless, we now have a clear path going forward.
Having eliminated or exhausted all reasonable biological and chemical treatment options, we are now left with the option we thought most likely when our Aquatic Plant Management Plan was updated in 2017.
Because HEWM has returned with vigor in formerly treated areas, we will proceed with private fund-raising and a grant request to buy an expensive (>$70,000) Eco-Harvester to control HEWM mechanically. This will be a prime topic for discussion at our July 29, 2018 General Membership meeting.