Herbicide May Be Used for Milfoil at Beaver Lake Meadow

An herbicide treatment of the meadow area of Beaver Lake is under consideration, with a decision set for later this spring.

Beaver Lake dealt with the invasive weed milfoil for the first time a couple of summers ago, and since then the Beaver Lake Improvement Association (BLIA) has been working with Amy Smagula, limnologist/exotic species program coordinator at the New Hampshire Department of Environmental Services (DES). They have worked to control and eradicate the invasive, and it has been eradicated in areas around the lake through the efforts of DES divers.

However, one area remains – the meadow, south of Beaver Lake – where divers are unable to pull the milfoil.

According to BLIA President Rob Tompkins, “The Beaver Lake Improvement Association has worked to protect Beaver Lake for more than 50 years. Our only goal is to do what is best for the lake. (DES) has also been involved in the protection of the lake for more than 40 years.

“We have to weigh treatment of the exotic invasive weed milfoil with the concerns of the abutters,” Tompkins said, noting information about treatment can be found at beaver-lake.org/lakenews and on the BLIA Facebook page, or by emailing [email protected].

Smagula said a decision was made by the Exotic Species Program of DES “to seek a permit for a possible herbicide treatment for variable milfoil control, should one be needed in the 2016 growing season.”

She explained that variable milfoil is an invasive aquatic plant that can affect the ecological, biological, recreational, aesthetic and economic values of waterbodies.

She said variable milfoil growths in the meadow are still relatively sparse, “however the hardship lies in the fact that native plant growth is dense, and water depths are shallow, making diving or other non-chemical means of control a challenge in this type of wetland system. A no-control option would result in milfoil expansion in the wetland, and increased risk for further infestation to both upstream and downstream waterbodies.”

She said the herbicide treatment is proposed for early June, and added it is aimed to be selective for milfoil, with few to no non-target impacts. Smagula said the herbicide proposed is Navigate, a 2,4-D ester formulation.

“This product has been used in a number of waterbodies in New Hampshire and beyond, with a good safety record, and good control of the targeted invasive species,” she said. “It does not persist in water or in sediment, based on data collected by DES biologists in similar sites.”

She said later this spring, DES will survey the area to assess milfoil distribution, and will decide whether to treat with the herbicide based on site conditions.