Zebra Mussel Alert

 DEP Reports Zebra Mussels Discovered in
Lake Zoar and Lake Lillinonah

First New Confirmation of this Invasive Species
in Connecticut Since 1998

In October 2010, the Connecticut Department of Environmental Protection (DEP) announced that the aquatic invasive species, Zebra mussel, has been discovered in Lake Zoar and Lake Lillinonah, two large impound-ments on the Housatonic River in western Connecticut. 

Background Information
Zebra mussels (Dreissena polymorpha) have harmed, and sometimes irreversibly, impacted the ecology, recreation and other resources of some lakes across the country. Following their discovery in Laurel Lake, Laurel Brook, and the Housatonic River in western Massachusetts in 2009, small numbers of zebra mussels were found downstream in lakes Lillinonah and Zoar in October of 2010. This was the first confirmed identification of new zebra mussel populations in the Housatonic River watershed since they were first identified in East Twin Lake in 1998 and West Twin Lake in 2001. 

Lake Lillinonah and Lake Zoar are impoundments formed by large hydropower dams in the Housatonic River. Candlewood Lake, located upstream of these two lakes, is also hydrologically connected to the Housatonic River – water is both taken in from the river and released back to the river depending on the time of year for power generation.

Therefore, what flows down the Housatonic River from its headwaters in Massachusetts is likely to eventually flow into these three large lakes. In addition, there is a significant amount of traffic from boaters, fishermen, and divers between these lakes and the river. So the discovery of zebra mussels in Zoar and Lillinonah is not just an isolated concern for these two lake communities, but rather a serious threat to the entire watershed.   

The Task Force
In response to discovery of new zebra mussel populations in the watershed and elevated public concern about the issue, a Zebra Mussel Task Force was formed in December 2010. The Zebra Mussel Task Force, spearheaded by the Candlewood Lake Authority, included individuals and agencies with expertise in this issue and lake community residents and users from the three major lakes. 

HVA serves on this task force. 

The Task Force has published a final report on this issue. Click here for a copy of the report. Below is a list of Appendices to the report.

A. Signage
B. ZM Trifold
C. CT DEEP and CBFN Self Certification
D. Legislative and Regulatory
E. Sample Decontamination
F. Press Release
G. Invasive Investigators
H. Candlewood Calcium Levels
I. SCUBA Diving Sites
J. Public Comments and Task Force Responses
K. Housatonic River Water Temperatures
L. Task Force Accomplishments as of August 2011


Individuals wishing to report possible sightings of zebra mussels and other aquatic nuisance species can contact DEP’s Inland Fisheries Division at 860-424-3474
More information on zebra mussels and other aquatic nuisance species can be found on the DEP website (www.ct.gov/dep), 

Before Leaving a Boat Launch

  • Completely drain all water from the boat, including bilge water, livewells and engine cooling systems. 

  • Inspect your boat, trailer, and equipment. Remove and discard all aquatic plants and animals you may have picked up while on the water.

At Home

  • Wash your boat’s hull, trailer, equipment, and any other exposed surfaces, and the inside of your bilge area, live well, and engine cooling system with high pressure, hot water AND either household bleach, 100% vinegar, or a 1% salt bath.

  • Keep your watercraft dry for at least one week (during hot, dry weather) and at least 18 days (during cool, wet weather) before launching into any freshwater lake or pond.

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. 

  • 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 cam

2010-2011 Connecticut Zebra Mussel Task Force Members: 
Bart Conant – Echo Bay Marina
Bernie Lintzner – Lake Zoar Authority
David Santos – Conservation Director of the CT BASS Federation Nation
Dr. Mitch Wagener – WCSU Biology and Environmental Science Department
Eleanor Mariani – Director of the CT DEP Boating Division
Gary Smolen – FirstLight Power Resources
Greg Bollard – Friends of the Lake (Lake Lillinonah), Water Quality Division Chair
Larry Marsicano – Executive Director of the Candlewood Lake Authority
Linda Berger – Sherman Resident (Atchison Cove Tax District); Vice Chair IWWC
Mark Howarth – Candlewood Lake Authority Staff
Mark Propper – Candlewood Lakefront resident for 35 years; CLUB*A member
Meghan Ruta – HVA Water Protection Manager
Peter Aarrestad – Director of the CT DEP Inland Fisheries Division
Phyllis Schaer – Candlewood Lake Authority Delegate, Invasive Species Subcommittee Chair
Ray Crawford – Candlewood Lakefront Resident; Engineer & Master Diver
Tom Beecher – Chairman of the New Milford Park and Recreation Commission

Zebra Mussel Presentation
at February 2012 forum cosponsored
by HVA and Bard College
Douglas A. Jensen
Aquatic Invasive Species
Program Coordinator
University of
Minnesota Sea Grant Program

Also read the
Zebra Mussel Forum
Break-out sessions