Methods for the Control of Eurasian Watermilfoil in Drag and Spruce Lakes


Methods for the Control of Eurasian Watermilfoil in Drag and Spruce Lakes


Veronica Turnbull

Host Organization

Drag and Spruce Lakes Property Owners' Association

Supervising Faculty

David Beresford



Location of Document



Drag and Spruce Lakes


Invasive Species


This study aims to determine the best practices for Eurasian watermilfoil control, the methods that have the best chance of success, and the most cost-effective solutions, while also focusing on how coconut fibre mats differ from burlap mats as a bottom barrier control technique. A thorough examination of over 30 peer-reviewed articles discussing Eurasian watermilfoil outbreaks in different areas and their control methods to eradicate such outbreaks were used. Nine methods of control were discovered through these articles, each vastly different in terms of time, effort, cost, equipment, and required knowledge for use. The methods of control described herein include rototilling, hand harvesting, bottom barriers, the milfoil weevil, lake drawdown, grass carp, suction harvesting, herbicides, and an integrated approach using two or more of the methods. Hand harvesting was one of the most cost-effective control methods for small areas, while bottom barriers were among the most cost-effective options for larger areas. The use of Euhrychiopsis lecontei, the milfoil weevil, was an option proven effective for use in the same region as Drag and Spruce Lakes and less costly than some other methods. This study has found that an integrated approach using hand harvesting and bottom barriers seems to be the most cost- and time-effective technique because it allows for optimal results in specific areas as needed without long-term harmful effects to native species. This integrated approach would also allow the Drag and Spruce Lakes Property Owners Association to continue providing their services and programming without significant lake access disruptions.


Trent University



Veronica Turnbull, Methods for the Control of Eurasian Watermilfoil in Drag and Spruce Lakes, Trent University, 2021