Weed Watchers Target Milfoil

Freedom — June 3, 2004 — Ossipee Lake Alliance is looking for a few good sets of eyes to keep an eye out for variable milfoil and other exotic plant species that could take hold in the lake and spread around its shoreline.

David Smith, president of the association, said the group hopes getting people to participate in the Weed Watchers program will raise awareness of the problems of exotic plants and to help stop their spread.

The state has targeted a number of exotic aquatic plants that have already been found in lakes and ponds in New Hampshire and neighboring states. These invasive species include Variable and Eurasian Milfoil, Water Chestnut, Hydrilla, Brazilian Elodea, and Fanwort. They pose a threat because they can proliferate in the absence of natural predators, and choke out native vegetation. They can also be nusance to boaters, swimmers and other people who want to enjoy the lake because they can grow thickly and so, can cause such problems as clogged boat engines.

The Ossipee Lake Alliance hosted a presentation on the Weed Watchers program by Amy Smagula, clean lakes and exotic species coordinator for the Water Management Bureau at N.H. Department of Enivironmental Services, Saturday morning at Freedom Town Hall. About 40 people attended the presentation to learn more about the exotic plant species and what they can do to help stop their spread.

Variable milfoil is the only invasive species yet found in Ossipee Lake. It has also been found in several locations on Lake Winnipesaukee, as well as several other locations in Carroll County: Danforth Pond in Freedom, Cresent Lake and Lake Wentworth in Wolfeboro, Balch Lake and Belleau Lake in Wakefield, and Lees Pond in Moultonboro. So far, only Variable milfoil has been found in this part of the state. But Eurasian milfoil has been found in the western part of the state, and Brazilian Elodea, Fanwort, Water Chestnut and Hydrilla have been found in the southern part of the state. Hydrilla has also been found in Limerick, Maine, just over the border from Wakefield. And zebra mussels have been found along the Connecticut River in Vermont.

Unfortunately, there is no completely effective way to eradicate exotic plants once they gain a toehold in a lake. Variable milfoil was first spotted about 10 years ago in Broad Bay, and at that time the state responded with several methods to slow the spread of the plant. They initially tried pulling the plants up by the roots, smothering some with mats and drawing down the lake one winter in order to kill the plants by freezing and drying them. The work was successful in that it did slow the spreading down, but these efforts were not enough to completely get rid of the milfoil that was there. At this point milfoil has been found on Broad Bay and some distance away on Phillips Brook, as well as on Danforth.

The problem is similar to the way in which milfoil is first established in a new location. Often it comes in by hitching a ride on the bottom of a boat. Motorboat propellers chop up the plant into small pieces, and when the boat is taken out of one body of water and put into another, it only takes one small piece to fall off into the water give the plant an opportunity to take root. That is why one method being used to stop the spread of exotic plants is to teach boaters to inspect and clean their boats before they take them to a new location.

Weed Watchers is a another method to stop the spread. It involves volunteers who check sections of shoreline once a month, looking for plants that don’t belong.

Smagula recommended that people “go slowly along the shoreline, looking particularly at places where light reaches the bottom of the lake.” “Because your lakes are very large, you can break it down into sections,” she said, adding that the group could designate an individual to be in charge of a single section or of the lake as a whole. When volunteers notice a suspicious plant they could bring it to the attention of the this individual or send a sample to her office for positive identification.

She gave out guidelines on how to conduct a weed-watching survey. She recommended that watchers have a small boat with a short shaft motor, a canoe, kayak or rowboat, with at least two people, one to operate the boat and one to look for plants.

“It’s good to have a driver and then one or more observers,” she said. Among other tools, they should bring along plant identification books or cards, and zip-lock bags to collect samples in.

The Weed Watchers program also provides outline maps of the lake, on which finds can be marked. It isn’t always easy to identify the invasive species. There are several native species of milfoil for instance, as well as plants like bladderwort and coontail that have a similar appearance to the long strands of milfoil and Fanworth, with their thin, feather-like leaves.

But when in doubt, Smagula said, she would rather look at the samples and give a definite identification. She recommended surveying the lake once a month from May to October. She also recommended that if an invasive species is found people should not try to pick it themselves. “Have one of us from the state do it. You have to trace the root down or it won’t work,” she said.

In addition to picking, draw-downs and the use of mats, the state is also now using herbicides like diquat to target specific plant species. The state has received a $1 million federal grant to research better methods of removing the plants, includeding chemical and biological approaches.

While there is no permanent solution at this point, catching new colonies of the plant before they are well established should help. “What we’re trying to do is establish a network on the lake,” Smagula said. “The only thing we can do is try to prevent more infestation and try to control what’s already there,” Smith said.

For more information about milfoil and other invasive species, look on the web at www.des.state.nh.us/wmb/exoticspecies. For more information about Ossipee Lake Alliance look on the web at www.ossipeelake.org.


Reprinted by courtesy of the Carroll County Independent

Be On the Lookout

By Terry Leavitt, Editor

Freedom – June 3, 2004 – Editorial

New Hampshire is facing a growing threat from invasive aquatic plants. Variable milfoil has now been found in more than 50 separate bodies of water in the state, from our southern border to as far north as Danforth Pond in Freedom. Further, that figure does not take into account the multiple locations where it has been found on larger bodies of water like Lake Winnipesaukee and Ossipee Lake.

Variable milfoil is not the only new plant making its way into our waters, although it is currently the most prevalent. There are already five other species that have been found in New Hampshire lakes, streams and ponds. They include Eurasian milfoil, Fanwort, Water Chestnut, Hydrilla and Brazillian Elodea. In addition, there are other species that can be found in neighboring states and could soon potentially make their way here: yellow floating heart, frogbit, parrot feather, curly-leaf pondweed, European naiad, common reed, flowering rush, and purple loosestrife.

Such plants, mostly natives of Asia and Europe, have few if any natural enemies here to control their proliferation. When they take hold in our waters they can edge out native species, stunt the growth of fish and choke waterways. They can turn a pleasant swimming hole or clear lake into a murky, swampy area. Boat engines can become clogged by the vegetation as it becomes wrapped around propellers. How do these plants come to be invading New England?

State officials believe that the original problem came from people dumping their fish tanks into or near local ponds and streams. Many of the species listed have been popular for use in aquariums.

But once they are established in one body of water, boaters often spread them to others. In boating through an area that contains aquatic plants, a boat can easily pick up bits of the plants on the hull. Motorboats are particularly at risk, because propellers chop the plants and provide easy spaces for them to hide in. Within a single body of water, the plants can easily spread along the shoreline or with the currents if they are not kept under control.

The state of New Hampshire now lists all 14 of the above mentioned species as prohibited species, making it illegal to transport them or introduce them into New Hampshire waters. But of course the solution to the problem is more complex than simply passing a law. Education is required and to be successful it must reach all those who might play a role in spreading the plants, as well as those who can help control them. There is plenty that we can all do to help. Learn about what species are belong and keep an eye out for those that don’t. Whenever you launch or take your boat out of a waterbody, check it and the trailer and remove any plant fragments. Washing and drying boats and equipment is also recommended to kill any fragments of plants.

Fishing gear and diving gear can also carry plant material and should be checked and cleaned. Steer clear of “Restricted Use Areas” which were established to contain invasive plants, as well as avoiding areas with dense plant growth.

And for those who enjoy their fish in small containers close to home, remember to never dump an aquarium into a pond, lake or stream. The newest program in the state’s arsenal to fight the spread of these plants is the Volunteer Weed Watcher Program. This program enlists volunteers to monitor lakes, or sections of lakes, once a month throughout the summer season. Ossipee Lake Alliance is working with local associations and individuals to cover weed watching on that lake. Catching groups of invasive plants while they are small makes it easier to control their spread.

For more information contact N.H. DES at 271-2248, or look on the web at www.des.state.nh.us/wmb/exoticspecies. Ossipee Lake Alliance can also be found on the web at www.ossipeelake.org.

Leave a reply

Your email address will not be published. Required fields are marked *