The Ecological Impacts and Effectiveness of Control Methods for the Invasive Macrophyte Myriophyllum spicatum in Eastern Ontario Lakes

In this thesis, the impacts a year after the treatments of both burlap benthic barriers and mechanical cutting of M. spicatum on physical, chemical, and biological components of eastern Ontario lakes were investigated. One lake was selected for studying the burlap barrier treatment, and three lakes were selected across a nutrient gradient for the mechanical harvesting treatment to observe links between total phosphorus concentrations and macrophyte-zooplankton dynamics. The impacts of the treatments on this invasive species were minimal but there was a clear shift in zooplankton assemblage to more open-water types following the barrier application. Results from both treatments displayed minimal impacts to localized abiotic factors and zooplankton assemblages. While the change in zooplankton community structure at Malcolm Lake did appear to be partially driven by the burlap barrier treatment, zooplankton communities within both types of treatments were instead mainly driven by their surrounding environmental variables and seasonal variance.