Does treating lakes with herbicides to kill invasive aquatic plants do more harm than good?
Invasive species can have serious ecological and economic impacts. One way to minimize their negative effects is to reduce the size of their populations.
Over the years, considerable effort has been directed toward developing techniques to kill or otherwise remove invasive species from the land and water. As an example, lakes are often treated with herbicides to kill invasive aquatic plants.
It is clear that herbicides kill these invasive aquatic plants. Yet the situation is not so simple because herbicides can also kill native aquatic plants and can have other effects as well.
Read this open access paper on the FACETS website.
Because of this complexity, lake managers must consider factors beyond “will herbicide treatment kill the invasive species?” They must also consider the downside of herbicide treatment and weigh that against the harm being done by the invasive species.
If herbicide treatments are found to be more harmful than the invasive species they are intended to control, it would mean that the benefits, at least from an environmental perspective, do not outweigh the costs.
We compared the effects of the invasive aquatic plant, Eurasian watermilfoil, with the effects of lake-wide herbicide treatment commonly used against this species. We used a large data set from Wisconsin to examine how native aquatic plant species responded to these two factors.
We found that invasive Eurasian watermilfoil was not associated with native aquatic plant reductions. In contrast, lake-wide herbicide treatment was associated with declines in native plant species and changes in the makeup of the plant community.
When treating lakes with herbicides to control invasive aquatic plants, our study indicates that from an environmental perspective the cure is worse than the disease.
Our study highlights the need to weight the costs and benefits of environmental management actions to ensure good stewardship of the environment.
Read the paper — Is the cure worse than the disease? Comparing the ecological effects of an invasive aquatic plant and the herbicide treatments used to control it by Alison Mikulyuk, Ellen Kujawa, Michelle E. Nault, Scott Van Egeren, Kelly I. Wagner, Martha Barton, Jennifer Hauxwell and M. Jake Vander Zanden.
