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You are here: Home / Manager's Tool Kit / Early Detection and Rapid Response / The Early Detectives / Weed Watchers - New Hampshire: Aquatic Species
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The Early Detectives: How to Use Volunteers Against Invasive Species, Case Studies of Volunteer Early Detection Programs in the U.S.

Weed Watchers - New Hampshire: Aquatic Species

Contacts: Amy P. Smagula, Exotic Aquatic Species Coordinator, New Hampshire Department of Environmental Services
Address: NHDES, 6 Hazen Drive, Concord, NH 03301
E-mail: asmagula@des.state.nh.us
Phone: (603) 271-2248

Overview (From the NHDES Exotic Aquatic Species Program Report: 1999-2001)

The goal of this program is to promote a volunteer or grass-roots effort to monitor lakes, ponds, and rivers for exotic aquatic plants. Because eradication of established exotic plant infestations is rarely possible, early detection is of utmost importance. Trained Weed Watchers provide an important service and function to New Hampshire by monitoring waterbodies for potential new infestations. This allows NHDES biologists to respond rapidly to new infestations.

Weed Watcher volunteers are trained by the Exotic Aquatic Species Coordinator to identify plants that are common in their waterbody. Typically, training involves accompanying volunteers in the field to identify plants within their chosen waterbody. If no exotics are present, the Coordinator will provide specimens of exotic aquatic plants for the volunteers to become familiar with. Volunteers are also supplied with existing vegetation maps for their waterbody, a Weed Watcher Kit, and instructions to report any new infestations immediately.

Weed Watcher volunteers survey their waterbody once each month from late May through September for any new plant growth, patrolling the shallow zones of their lakes and mapping the vegetation they observe. The volunteers provide survey information to NHDES for entry into a database, and they are encouraged to collect specimens of any unfamiliar plants and deliver them to NHDES to confirm identification. In 2001, there were over 160 trained Weed Watchers monitoring approximately 80 waterbodies for early detection of exotics. This does not include a number of volunteers from the Volunteer Lake Assessment Program that participate on an "unofficial" basis.

Events during summer 2001 on Dublin Lake are a prime example of the success of the Weed Watcher Program. During the June Weed Watcher survey by volunteers from the Dublin Lake Association, one volunteer found a new small patch of variable milfoil in a cove of the lake. Because of early detection by Weed Watchers, NHDES divers were able to hand pull a large number of the plants and then cover the remaining area with bottom barriers. The infestation is now contained. Similar success stories are occurring more often as awareness of the plants increases.

NHDES has received requests for advanced monitoring methodologies, including establishing a 'launch watch' program for the public access ramps on their waterbodies. Due to staffing limitations, NHDES has not been able to provide staff for these launches. With the passage of a new piece of legislation on January 1, 2003, NHDES is now able to make grants to lake associations that wish to engage in prevention activities, like those associated with Launch Watch activities. The new grant program will be piloted during the summer of 2003. Launch monitoring provides one more tool to help prevent new infestations. For example, during the summer of 2001, volunteers with the Lake Sunapee Protective Association found a stem of Eurasian milfoil attached to a boat trailer that was launching into Lake Sunapee. The Launch Monitors removed the plant from the boat trailer before it made its way into the lake.

Fortunately, many of the plants that were logged over the 1999-2001 seasons were native plants. Table 1 (appendix) lists the exotic aquatic plants that were found during the surveys. These infestations would have spread rapidly if not for the early detection by the Volunteer Weed Watchers.


The Weed Watchers program was started in 1988, but really got up and running in 1998 when the program's enacting legislation went into effect. The program makes use of more than 160 volunteers, who visit sites in groups about once a month, performing visual surveys, often by boat, watching for new plant growth. To date, Weed Watcher volunteers have detected a number of exotic invasions, all of which have been met with successful eradication. Once an exotic infestation is identified, a NHDES team is sent in. Divers lay down matting to cover the lake bottom and eliminate plant growth. If the infested area is small, divers will pull plants by hand before laying down matting.

Recruitment and training

The majority of volunteers are recruited through presentations given to state and local lake associations. Many of these organizations are pro-active and actively seek out Weed Watcher training. Volunteers are also recruited on the organization's Web site. Weed Watcher volunteers are typically given one day of on-lake training on the body of water they are to be charged with. In these training sessions, volunteers learn to identify aquatic plants within their waterbody, and are shown samples of exotic weeds not found on location. Volunteers are also given a Weed Watcher Kit, consisting of a binder with pictures, facts sheets, and instructions on how to go about searching for and reporting targeted species. New Weed Watchers are also given a current vegetation map of their waterbody.

Weed Watchers are trained to recognize native plants, as well as five of the 14 species listed exotic aquatic plants in New Hampshire. Of the 14 species, 8 are currently established in the state. There is deep concern that species such as Hydrilla will enter from neighboring states such as Maine and Massachusetts, where it is prevalent around the New Hampshire border. Training stresses the fact that infestations need to be found and reported immediately (program steps for reporting a suspected exotic plant sighting are listed in the appendix). If volunteers are unsure how to classify a particular plant, they are encouraged to submit a sample to NHDES for identification.

Amy Smagula presently conducts all training for the program. She would like to add many more lakes to the program. Currently, Weed Watchers monitor around 200 of the state's 950 lakes.

For those starting new programs, Amy suggests one first work through established networks such as lake associations, retirement groups, Boy Scouts, Girl Scouts, college/high school students, etc. Such groups often send out newsletters one can advertise in, or have weekly/monthly meetings one can speak at.

Technical Work

A database containing information on Weed Watchers, and the lakes they are charged with is an invaluable tool that should be incorporated from the outset of any related program. Amy can't stress enough the importance of starting with a high quality, well thought-out database. When setting up a database, one should consider the reporting method that is to be used by volunteers. This reporting method should be taught to volunteers in training, and used consistently. The NHDES Weed Watcher program uses the data collected from its volunteers for monitoring/eradication, as well as for public education.

Motivating Volunteers

Since the majority of volunteers come from local lake associations, they have a vested interest in the program's success, as they live on/around the lake, and enjoy life on the water. Scare tactics are a definite motivating factor. Volunteers really get charged up when they hear of the problems aquatic invasives cause if not caught and controlled early.

Amy suggests that those involved in such programs send out newsletters every so often. Newsletters are an excellent way to motivate volunteers, as well as keep them informed of what is going on in lakes around the state. By reading the newsletters, Weed Watchers are able to stay up-to-date on current best management practices regarding aquatic weed monitoring.

Challenges of the Program

It is hard to make accurate vegetation maps without the use of GPS units. If funding were available, it would be beneficial to have GPS units to loan out to volunteers for accurate surveying of lakes. GPS units would allow volunteers to precisely mark infested areas, improving response times. GPS units would also allow the organization to better record the movement of vegetation over time. Currently, only one Weed Watcher uses a GPS receiver for monitoring.

Quick Facts

Staffing: The Weed Watcher program requires approximately 1/4 of a full time staff worker's time each year (mostly in the summer).

Operating Budget: The entire Exotic Species Program has roughly a $150,000 budget, raised through boat licensing fees (Program receives $1.50 from each registration fee collected). The Weed Watcher Program is not directly funded from these monies, short of roughly $8,000 each year need to supply the Weed Watcher Kit Materials, and then another portion for staff time spent training and identifying plant specimens.

Species Targeted: Aquatic Invasive Plant Species
Variable milfoil (Myriophyllum heterophyllum)
Eurasian Milfoil (Myriophyllum spicatum)
Hydrilla (Hydrilla verticillata)
Fanwort (Cabomba caroliniana)
Brazilian elodea (Egeria densa)

Habitats Patrolled: lakes and ponds in New Hampshire and surrounding waters

Location: USA, New Hampshire, Maine/Massachusetts borders

Report prepared by: Kyle Hegamyer

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Last Modified: Sep 02, 2017
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