CLWA successfully treats Eurasian Watermilfoil
Under contract to the CLWA, Clear Water Lake Management, with drone assistance from Zero Gravity Aerial, completed a treatment of invasive EWM in Crystal Lake on June 29, 2022. Thanks to excellent weather conditions, the regrowth could be fully treated. Inspection in late July revealed an 85% to 90% reduction of the plant density (biomass).
Due to these positive results, an additional treatment planned for July 2022 was cancelled: this is consistent with CLWA’s goal of using only the absolute minimal treatment. Any interventions in future years will be subject to continued monitoring and evaluation.
Begun last year, this work is authorized by the Michigan Department of Environment, Great Lakes, and Energy under Aquatic Nuisance Control Permit No. ANC9805924.
Last year the CLWA team carried out two treatments on approximately 7 acres of EWM infestation, including very heavy growth at the east end of the lake. An inspection of regrowth in mid-June 2022 showed that the extent (footprint) of the plant had decreased to 5 acres and that the biomass was now very sparse: a footprint reduction of almost 30% and a biomass reduction of 90%. These results reflect a high rate of success.
Unfortunately a few small new colonies of EWM have appeared since 2021. These are – tellingly – in the area of the Lobb-road end secondary launch site, which is heavily used by boaters but has no provision for hitchhiking invasives to be removed by boat washing.
If you have questions, see FAQs about Eurasian watermilfoil.