Closed sign for herbicide treatment of hydrilla

An area is closed for 24 hours after initial endothall treatment

Management Options

Options for Controlling Aquatic Plants

The 4 Main Control Mechanisms:

  • Biological: reduce the growth of the plants by introducing predator species such as fish or insects
  • Chemical: applying herbicides that will kill or stunt the growth of the weeds
  • Mechanical: removing the plant (and/or roots) by cutting/dredging or harvesting
  • Physical: disturbing the plants ability to grow by altering the light, soil, or water conditions

Management Plans

A management plan includes the plant management goals and objectives, the control methods to be used and other management strategies such as education to prevent the spread . It takes into account many factors such as the current and future uses of the water body, the priorities of stakeholders, and the resources available (money, expertise, regulations, etc.). As an example, the Cayuga Lake Watershed Hydrilla Management Plan aims for complete eradication.

Some hydrilla management plans have aimed at complete eradication of hydrilla and have succeeded ( Successful Eradication in the US), while others have settled on containing the existing population. Areas with well-established infestations have lost the opportunity to completely get rid of the weeds (as seen on the Invasion Curve). Those communities are limited to control methods that regain some form of use during the boating/recreation season. Often they use mechanical or physical controls every year and chemicals every few years.

See summary of all options here.

Last updated July 26, 2019