Montpelier, Vt. – After several seasons of thorough sampling, Vermont Department of Environmental Conservation (DEC) scientists, consultants, and local partners have detected zebra mussels in United States (US) waters at Lake Memphremagog.  

Native to eastern Europe, zebra mussels (Dreissena polymorpha) are a small, invasive shellfish that can quickly form large populations and outcompete native species for food and habitat. Currently, zebra mussels are found only in Lake Champlain and Lake Bomoseen in Vermont. 

“Aquatic invasive species like zebra mussels pose a serious threat to our environment, economy, and health,” said DEC Commissioner Jason Batchelder. “Strong local partnerships and robust monitoring programs are critical to stopping the spread of zebra mussels and other aquatic invasive species.” 

The first detection of zebra mussel at Lake Memphremagog took place in Canadian waters in 2018. Since then, DEC scientists and partners have monitored US waters to inform how Vermont might manage this new introduction. During the past few years, DEC used various methods like physical surveys and water samples to monitor the spread of zebra mussels from Canada and along the border.  

Arrowwood Environmental, LLC completed targeted surveys at places where adult zebra mussels might attach and grow, such as rocky shores, docks, cement blocks, and other hard surfaces. Last summer, each of these surveys found the presence of adult zebra mussels. DEC also collected and analyzed water samples to detect the larvae of the zebra mussel, which were in all but one of the samples taken.  

“This confirmation of zebra mussels in US waters of Lake Memphremagog renews our concerns about the spread of aquatic invasive species in Vermont,” said Kimberly Jensen, DEC Environmental Scientist. “As the original population of zebra mussels spread from the northern region of Lake Memphremagog, we expect to see more in the southern region over time. We urge people to follow the Clean, Drain, Dry initiative, especially when coming and going from waterbodies with invasive species.”  

To follow the Clean, Drain, Dry initiative, remember these three steps: 

1. CLEAN off any mud, plants, and animals from boats, trailers, motors, and other equipment. Discard removed material in the trash or on high, dry ground where there is no danger of them washing into any water body.
2. DRAIN all water from boats, boat engines, and other equipment away from the water.
3. DRY anything that touches the water. If rinsing with hot, high-pressure water is not an option, dry equipment in the sun for at least five days. 

To learn more or volunteer, visit the Aquatic Invasive Species Program webpage or contact Kimberly Jensen at 802-490-6120 or Kimberly.Jensen@Vermont.gov.  

### 

The Department of Environmental Conservation is responsible for protecting Vermont's natural resources and safeguarding human health for the benefit of this and future generations. Visit dec.vermont.gov and follow the Department of Environmental Conservation on Facebook and Instagram.

This institution is an equal opportunity provider. To file a discrimination complaint, for questions, free language services, or requests for reasonable accommodations, please contact ANR’s Nondiscrimination Coordinator at ANR.CivilRights@vermont.gov or visit ANR’s online Notice of Nondiscrimination.