The Hydrilla Threat

The Hydrilla Threat

Hydrilla represents a new and potentially devastating risk to the Twin Lakes. It is believed to have come to East Twin on a visiting boat and so far has been spotted only near the marina and north of the state boat launch. This plant is most commonly found in southern states but by 2016 had found its way to the Connecticut River, which is being choked in large sections. The video below details the impact of unchecked hydrilla spread. To read more about it click here and here. Hydrilla Verticillata, a non-native species also known as water thyme, has now been found in six Connecticut lakes and also was intercepted by boat launch monitors at Lake Champlain and Lake George. The Connecticut Federation of Lakes calls for “educating lake users about invasive species and following the clean, drain, dry procedure” to prevent the further spread of hydrilla. In July 2024 the TLA received approvals to begin applying the plant with Sonar, widely seen as the most effective treatment.

A 2024 article in the science journal Invasive Plant Science and Management explains the danger of hydrilla and how it took root in Connecticut.

The Twin Lakes Association board is acting with urgency. We applied for emergency treatment in August 2023 and upon request for more information from the Connecticut Natural Diversity Data Base replied with details you can find here

On Oct. 3, a coalition of state agencies and state and state and local officials toured the areas of East Twin where hydrilla has a toehold. Here is where you can read about that tour and the discussion that preceded and followed. Read our February 2024 newsletter for details on the steps the TLA is taking.

The New York Times reports that humans have introduced more than 37,000 species to places outside their natural ranges globally. More than 3,500 of those are harmful to their new ecosystems. Here is the study that is the basis for the Times report.  The Lakeville Journal published this report. A subscription is needed.

At left, Mark Hellman of TK displays hydrilla verticillata like that found in the Connecticut River and pulled near the marina. Above, how to tell the difference between the invasive Connecticut River strain and the native Elodea. The most obvious distinguishing feature is five or more leafs on the invasive strain and only three leafs on the native plant.

Red triangles mark confirmed locations where hydrilla was found and removed. More growth has been found north of the marina since this report.