DEEP Reports Hydrilla Found In Connecticut River

Connecticut’s Department of Energy and Environmental Protection (DEEP) announced that Hydrilla (Hydrilla verticillata), a very highly invasive aquatic plant, has been found in the main stem Connecticut River in Glastonbury.

Earlier this week, DEEP staff observed several patches of hydrilla mixed in among the aquatic plants growing in the river at Glastonbury’s Riverfront Park and Boathouse. This discovery follows the identification of hydrilla in a difficult to access portion of Keeney Cove by botanists participating in a “Bioblitz” conducted around the Two Rivers Magnet School, East Hartford, in June of this year.

“Finding hydrilla in a publically accessible portion of the state’s largest water body is a matter of serious concern,” said William Hyatt, DEEP’s Chief of Natural Resources.

“The Connecticut River traverses the length of the state from north to south, supports substantial recreational use and has numerous access points,” said Hyatt. “Managing this infestation will be exceedingly difficult. Based on what we’ve seen it appears that hydrilla has been in the river for a couple of years and it is likely to be widely dispersed downstream of Hartford. As a result eradication is not practical. What we can do is educate boaters on what they need to do to reduce the risk of further spread.”

Hydrilla, which is not native to the United States, was likely first introduced to this country in the 1950’s. The source of these plants is unknown. It has since become a major problem in southeastern states and is beginning to spread into the northeast. It spreads aggressively, forms dense mats of vegetation, easily outcompetes and displaces native plants, alters aquatic habitats, and interferes with recreational activities. It is very difficult to control once established.

Hydrilla has been found in several waterbodies with public access scattered throughout the Northeast (Maine, New York, Massachusetts). Until recently, there were only a few waterbodies in Connecticut, the Silvermine River and several small ponds with no public access, known to have established hydrilla populations. In September, 2015, however, hydrilla was found in Coventry Lake (Coventry) where DEEP is currently funding ongoing eradication efforts (including surveys and herbicide treatments).

DEEP reminds users of our aquatic resources that the best method of controlling invasive species is to prevent their spread. Boaters (including kayakers, canoeists), anglers and other recreational users should follow Clean, Drain & Dry precautions to prevent the spread of invasive plants and animals, including hydrilla:

Before leaving a boat launch:

CLEAN: all visible plant, fish, and animals as well as mud or other debris. Do not transport them home.
DRAIN: all water from every space (including bilges, live wells and engine cooling systems) and item that may hold water.

At home or prior to your next launch:

DRY: anything that comes in contact with water (boats, trailers, anchors, propellers, etc).

If drying is not possible, you should take extra care to thoroughly clean your boat prior to the next launch. The techniques listed below are advised to decontaminate your vessel:

Wash your boat with hot, pressurized water, or
Dip equipment in 100% vinegar for 20 minutes prior to rinsing, or
Wash with a 1% salt solution (2/3 cup to 5 gallons water) and leave on for 24 hours prior to rinsing, or
“Wet” with bleach solution (1 oz to 1 gallon water) or soap and hot water (Lysol, boat soap, etc) for 10 minutes prior to rinsing.

When Fishing:

Do not dump your bait bucket or release live bait! Avoid introducing unwanted plants and animals. Unless your bait was obtained on site, dispose of it in a suitable trash container or give it to another angler.
Do not transport fish, other animals or plants between water bodies. Release caught fish, other animals and plants only into the waters from which they came.

Individuals wishing to report possible sightings of aquatic invasive species can contact DEEP’s Inland Fisheries Division at 860-424-3474. If you are interesting in learning how you can educate boaters on ways to prevent the spread of invasive species, contact the Boating Division at 860-447-4339. More information on aquatic invasive species can be found on the DEEP website at and in the:

2016 CT Angler’s Guide (
2016 CT Boater’s guide (