Invasive Species

Prevention and rapid response to exotic aquatic species that threaten New Hampshire’s freshwater systems.

NHDES recognizes the threats invasive species pose to our aquatic resources. In an effort to reduce the introduction of invasive species and manage their spread in the state’s surface waters, the Invasive Species Program has five focal areas: 1) Prevention of new infestations; 2) Monitoring for early detection of new infestations to facilitate rapid control activities; 3) Control of new and established infestations; 4) Research towards new control methods with the goal of reducing or eliminating infested areas; and 5) Regional cooperation.

Invasive Species Program

New Hampshire has been actively involved in protecting our freshwater resources from aquatic invasive species since they were first identified in the state in the 1960s. Today, nearly 100 waterbodies across the state are impacted by growths of aquatic exotic/invasive species.

 Expansive growth of variable milfoil

Aquatic invasive species are those species that are non-native to our area, and that can pose direct impacts to the ecological health and recreational opportunities of our waterbodies.

Learn more about invasive species  

Water chestnut mechanical harvest

Grants are available to local lake associations and municipalities for control and/or prevention of state-listed exotic aquatic plants, and to institutions of higher learning for in furthering research associated with exotic aquatic plant management, control, biology, ecology or prevention. 

Request a grant application  

dense variable milfoil in Pemigewasset River

NHDES tracks growths of state-listed aquatic invasive species in freshwaters of the state and maintains an overall list of infested waterbodies. Many of these waterbodies are under active management, and waterbody-specific maps and long-term management plans are also available in the NHDES Lake Mapper Application.   

View infested waterbodies  

Control Grant Cycle Calendar

September 15 of each year - Completed application form for fund request submitted to NHDES
October 15 of each year - Bids/quotes due to NHDES for review
November 30 of each year - Announcement of Grant Recipients

Prevention and Research Grant Cycle Calendar

September 15 of each year - Announced by NHDES 
November 30 of each year - Applications Due
By February 1 of each year - Announcement of Grant Recipients
By December 31 of each year - Final Report Due by Grant Applicant (unless other arrangements are made)

Report a New Infestation

If you find a suspected aquatic invasive plant in a waterbody not listed in the map of infested waters please email the program coordinator with the waterbody name, possible finding, description of the location, date/time of find, and your contact information.

Training/Volunteer Opportunities

Interested in becoming a Weed Watcher? Email the Invasive Species Program Coordinator for more information. Informational kits are provided at no charge.