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VLMP Center for Invasive Aquatic Plants

The introduction of non-indigenous invasive aquatic plant and animal species to the United States has been escalating with widespread destructive consequences. The impacts of the spread of invasive aquatic plants are well known: habitat disruption, loss of native plant and animal communities, reduced property values, impaired fishing and degraded recreational experiences, and enormous and ongoing control costs.

Power Point Overview of
Invasive Aquatic Plants

Overview (pdf ~ 3.7 meg)

With over 6000 lakes and ponds, and thousands of miles of stream habitat, the task of preventing the spread of invasive aquatic species in Maine waters is one of the greatest environmental challenges of our time. Invasive plants and animals are moved about in complex and often unseen ways. The speed at which a new introduction can explode into an ecologically and economically disastrous infestation is well documented. Once an invader is well established, eradication is extremely difficult and costly, if not impossible.

No matter how comprehensive and aggressive our statewide prevention effort, chances are, some invasive organisms will slip through the cracks. In such cases, it is crucial that the invaders are detected as early as possible, before they have had an opportunity to cause significant damage or to spread to other waterbodies. Early detection provides the best (and sometimes only) hope of eradication.

If we truly want to have an effective, statewide early detection system we must act swiftly, vigorously and with unprecedented commitment to the "long haul." Not only must millions of acres of underwater habitat be screened by trained eyes, these same vast acres must be visited and revisited on a frequent and ongoing basis, indefinitely.

The critical role that volunteers will play in this effort cannot be overstated.

Milfoil Sign
Boat Launch Sign

As awareness of this new threat to Maine waters has emerged across the state, Mainers have taken swift and decisive action. In 2000, the State of Maine passed legislation that outlaws the sale, propagation, or introduction to Maine waters, eleven invasive aquatic plants. Currently, four of these “outlawed” plants are known to be established in Maine waters: variable leaf water-milfoil (and a hybrid form of this plant), Eurasian water-milfoil, curly-leaf pondweed and hydrilla. In 2001 further legislation was enacted, instituting additional regulations, programs and planning requirements. In addition to establishing a dedicated funding mechanism to support statewide efforts to address the threat of invasive aquatic species, the new law established an Interagency Task Force on Invasive Aquatic Plants and Nuisance Species. The Task Force, comprised of state agency personnel and private citizens representing diverse stakeholder interests, quickly got to work on Maine’s Action Plan for Managing Invasive Aquatic Species, a federally approved plan that provides guidance for statewide action in Maine. One of the primary goals laid out in the plan was the development of a practical and effective statewide “early detection” system.

The Center for Invasive Aquatic Plants (CIAP) was established by the Maine Volunteer Lake Monitoring Program (VLMP) in 2003 to provide a citizen-based "front-line" in the battle to protect Maine waters from the threat of invasive aquatic plants. Through the Center, the VLMP has developed the Invasive Plant Patrol, a comprehensive program providing high-quality hands-on workshops, a wide range of technical services including plant identification assistance, and a growing catalog of technical and educational resources and online tools to encourage and support active public participation in Maine’s early detection effort. CIAP has trained more than 2300 individuals in Maine to date, and has implemented what has come to be considered one of the most comprehensive and successful citizen-based invasive plant monitoring programs in the nation.

How Invaders Spread
The primary means by which invasive aquatic plants are spread is by hitching a ride on a boat, trailer or other gear that is used in the water, such as fishing gear and anchors. The following fictitious scenario provides an illustration of the process:

Joe drives his boat around a lake in New York that is infested with Eurasian Water Milfoil; some fragments of this highly invasive plant get caught on his prop; later, he pulls his boat out of the lake and puts it on the trailer. Two days later, Joe decides to drive to Maine to do some fishing. He launches his boat in his favorite Maine lake and while he is driving around, the fragments of milfoil drop off. They float around for a few days, sprouting adventitious roots (long pale hair-like roots that emerge along the stem). Eventually the sprouted fragments, each one a genetic “clone” of the original parent plant, settle to the bottom in a nice sunny spot. A few days later each plant starts showing signs of new growth. By the end of the season the Eurasian milfoil is well established in several locations in the lake. Boating activity in newly infested waterbody during the following season creates new fragments, furthering the spread of the plant within the lake.

There are other ways in which invasive plants are spread. Some species are still sold as aquarium plants, or as decorative plants for water gardens. In some cases, even non-invasive plant stock can be contaminated with invasive plant fragments. It is believed that the hydrilla infestations in the state of Washington were the result of the release of contaminated water lilies.

On patrol
Surveying for Invasives

Maine's “Early Detection" System
Case studies of infestations throughout the US indicate that once invasive plants become well established in a lake, stream or pond, they are nearly impossible to eradicate. A comprehensive, ongoing effort to prevent the introduction of aquatic invaders to Maine waters, through public education and Courtesy Boat Inspections is, and should remain, a top priority. But, Maine is a large state, with over 6000 lakes and ponds and thousands of miles of aquatic plant stream habitat. Despite our most aggressive efforts to ward off new infestations, a significant probability remains that, from time to time, an invasive plant will manage to “slip through the cracks.” Early detection of a new infestation provides the best (and perhaps only) hope of eradication. In cases where eradication is not possible, the earlier an infestation is detected the greater the chance that the invasive plants can be managed effectively using relatively low-impact methods.

Trained volunteers have an extremely important role to play in Maine’s early detection effort. To help the state meet this challenge, the VLMP has expanded the scope of its mission to include support for citizen-based invasive plant monitoring through the development of the VLMP Center for Invasive Aquatic Plants and the Invasive Plant Patrol training workshops.

Since the first IPP workshop in 2002, the VLMP has trained over 2300 individuals to screen Maine waters for aquatic invaders. The program was specifically designed to engage widespread participation by individuals with varying amounts of time and expertise to commit to the endeavor, from those who simply want to be more knowledgeable when they are out recreating on their lake, to those who are conducting and leading comprehensive lakewide surveys.

11 Most Unwanted Poster
click for printable pdf

Maine's "Eleven Most Unwanted"
There are 11 plants currently listed as imminent threats to Maine waters. These are:

European Frogbit

Water Chestnut

Yellow Floating Heart

Eurasian Water Milfoil

Variable Water Milfoil

Parrot Feather



Brazilian Elodea

European Naiad

Curly-Leaved Pondweed

Documented Infestations in Maine Waterbodies: Maine DEP Listing

MCIAP Resources


10 Tips for Improved Lakeshore Stewardship from US EPA

Maine Volunteer Lake Monitoring Program
24 Maple Hill Road, Auburn, ME 04210
(207) 783-7733
copyright 2010 Maine Volunteer Lake Monitoring Program | website comments to:

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