Types of Aquatic Plant Management

Explore the key methods for managing aquatic plants, their uses, and considerations to help protect and maintain healthy waterbodies.

This page provides an overview of various aquatic plant management techniques, explaining how each method works, its typical applications, and potential limitations to help waterbody managers and stakeholders make informed decisions. All the methods below require some level of permitting, except for the no management option. The methods are in alphabetical order and do not indicate any order of preference or success.

Overview of Aquatic Plant Management Methods

Management Method	Description and Key Considerations
Benthic Barriers	Bottom covers that block light and physically restrict rooted plant growth. Can impact non-target organisms. Typically used for pioneer infestations or small areas affecting water use. Barriers are usually ~10 feet wide and 25–100 feet long, making installation and maintenance challenging.
Biological Controls	Involves introducing organisms to manage plant infestations. Grass carp are the most common example but are prohibited in Massachusetts. Very few approved or effective biological controls are currently available.
Dredging	Primarily used to restore waterbody depth after significant sediment accumulation rather than directly managing plants. Requires extensive permitting and is costly, so it is used infrequently.
Dyes	Added to water to reduce light penetration and limit plant or algae growth. Permitted as a pesticide in Massachusetts and best suited for small ponds with limited outflow.
Diver-Assisted Suction Harvesting (DASH)	Divers hand-pull plants and place them into a suction device for collection on a surface boat. The suction does not remove roots. Highly selective and effective for moderately sized infestations, but labor intensive.
Hand-Pulling	Manual removal of plants by wading, snorkeling, diving, or working from a boat. Highly selective but labor intensive; best suited for pioneer infestations or small areas.
Herbicides and Algaecides	Pesticides used to control aquatic plants and algae. Herbicides vary by mode of action and target species and are widely used due to cost and labor efficiency. Algaecides are commonly used for algae-related health concerns or to improve herbicide effectiveness.
Hydroraking	Uses a floating backhoe with a rake to remove plant root masses and associated sediments. Effective for waterlilies, Phragmites in water, or floating islands. Not recommended for species that reproduce by fragmentation.
Mechanical Harvesting	Cuts and collects aquatic vegetation mechanically, similar to mowing an underwater lawn. Regrowth is expected, sometimes within weeks. Not recommended for species that reproduce via fragmentation.
Winter Drawdown	Lowers water levels in fall to expose sediments to freezing and drying over winter, killing susceptible vegetation. Effectiveness is highly weather dependent.
No Management	Generally not recommended due to ecological, economic, and recreational impacts of invasive plants. In some cases, waterbodies are left unmanaged due to cost, permitting challenges, or other constraints.