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Water Chestnut

Aquatic Invasive Species

Aquatic invasive species in the Connecticut River watershed can cause significant harm to local plants, animals, and ecosystems. Their aggressive growth and spread can lower biodiversity by reducing the availability of natural resources for beneficial native species and negatively impact recreational opportunities in rivers, lakes, and ponds. Water Chestnut and Hydrilla are the two aquatic invasive species that CRC focuses on managing through community science and regional coalitions. 

Impact stats for aquatic invasive species removal. 107 partners, 125 volunteers, 33 waterbodies that Connecticut River Conservancy is restoring.
Smiling volunteers in kayaks on a lake, holding water chestnut during an event for aquatic invasive species removal.

Water Chestnut

The water chestnut is a rooted, floating aquatic plant. It is an annual plant that is not native to the United States and is categorized as an invasive species in the Connecticut River watershed. It is fast growing and quickly reproducing. If left unattended it will easily cover an entire waterbody.


Water chestnut infestations have been found in most of the watershed – in NH, VT, MA, and CT – that the Connecticut River travels through. Click below to learn more about the origins of water chestnut and removal efforts along the Connecticut River.  

A hand in the water showing hydrilla in Connecticut River.


Hydrilla (hydrilla verticillata) is an aquatic invasive species that was first identified in the Connecticut River in 2016 in Glastonbury, CT. Scientists discovered that the Connecticut River strain of hydrilla is genetically distinct from all other hydrilla. Since then, the Connecticut Agriculture Experiment Station (CAES) surveyed the Connecticut River from Agawam, MA to the Long Island Sound, reporting at least 774 acres of hydrilla.


In 2023, the Connecticut River strain was documented in several lakes and ponds in both Connecticut and Massachusetts, which indicates that it continues to spread. Hydrilla can outcompete native species and replace habitat for sensitive species, including migratory fish. In recent years, thick mats of hydrilla have crowded out boaters, anglers and those who come to recreate on the Connecticut River.

Human activity has been linked to the spread of aquatic invasive species. Boats that aren’t properly washed and dried can carry invasive species from one water body to another.  It’s easy to help prevent the spread of these species by following three easy steps: 


Clean off visible aquatic plants, animals, and mud from all equipment before leaving water access. 


Drain motor, bilge, livewell, and other water containing devices before leaving water access. 


Dry everything for at least five days OR wipe with a towel before reuse. 

Preventing the spread of aquatic invasive species starts with all of us. It’s an easy process that can help protect the important ecosystems of our watershed and keep our waterways clear for recreation for years to come. Learn more about how to stop aquatic hitchhikers.

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Volunteer for Invasive Species Removal and Monitoring 

Water chestnut can easily be identified and managed by trained volunteers pulling the plants from kayaks and canoes. CRC and partners organize weekly water chestnut pulls across the watershed! Plus, it’s a great opportunity to get on the water and have some fun… all for a good cause!


Pulling events are part of a multi-organizational collaboration united in the goal of removing this invasive plant from all parts of the Connecticut River watershed.  ​If you attend an organized pull, we will provide supplies and instruction on how to pull the plants. It’s easy to do, but the technique is important. You are welcome to bring your own boat, or borrow one of our foldable kayaks. While this is generally a paddle event, shallow motorboats, such as Jon boats, are helpful to shuttle loads of plants back to land.  ​


Our volunteer events run from June through August. Click here to find upcoming volunteer opportunities and sign up for our newsletter to get notifications for upcoming pulls!

Want to get involved with hydrilla work? CRC also organizes quarterly hydrilla stakeholder meetings – if you are interested in attending, reach out to Rhea at rdrozdenko - at - 

It's a messy job, but somebody's got to do it!

Thanks to our incredible volunteers who help with water chestnut pulls.

Our Volunteers in Action

Special Thanks to Our Partners 

Aquatic invasive species in the Connecticut River watershed have long been a priority for organizations, groups, and individuals throughout the region. We are incredibly grateful to CRC’s network of partners and funders that help to collectively address the challenge of aquatic invasive species in our waters. 

Capitol Region Council of Governments


City of East Hartford

City of Middletown 

Community Foundation of Middlesex County - Janvrin Fund

Connecticut Department of Energy and Environmental Protection

Eightmile River Wild & Scenic Watershed

Farmington River Watershed Association

Friends of Whalebone Cove

Hartford Foundation for Public Giving, Sestero Fund 

Jonah Center for Earth and Art

Laurie Callahan

Lower Connecticut River Valley

Council of Governments

MA Department of Conservation and Recreation

NH DES Aquatic Invasives Species Program


Northeast Aquatic Nuisance Species Panel

Office of Aquatic Invasive Species

Robert F. Schumann Foundation

Town of Glastonbury 

US Army Corps of Engineers

US Fish and Wildlife Service


Windham County Natural Resources Conservation District

For questions related to CRC’s Aquatic Invasive Species work, or to connect about volunteering,  contact us at volunteer - at - or 413.772.2020 x207.

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