Why the Concern about Milfoil

(from Maine Townsman, June 2002)
By Kirsten Hebert, Legislative Advocate, MMA State & Federal Relations

Starting this year, lake and river protection stickers (aka, milfoil stickers) are required to be displayed on motorized boats and personal watercraft operating on the inland waters in the Maine.  Stickers are not required for unmotorized boats (which do not require registration), such as canoes, kayaks and sailboats.

Stickers must be purchased by both residents and nonresidents alike.  The fee is $10 for a resident and $20 for a nonresident.  However, the cost of the sticker depends on the “home” of the boat, not the home of the owner.  If a boat is registered in Maine by a non-resident that boat owner would pay the $10 fee for a milfoil sticker.  Non-residents who use a motorized boat in Maine, but do not register their boat here, would be subject to the $20 fee.

Fines between $100 and $250 can be assessed any person found operating a motorized watercraft without a sticker.

As with hunting and fishing licenses, milfoil stickers will be sold by authorized agents of the Department of Inland Fish & Wildlife (both municipal and private).   The agent retains $1 of the milfoil sticker fee and sends the rest of the money to the Commissioner of IF&W.  Milfoil stickers can also be purchased online at http://www.maine.gov/ifw/atv_snowmobile_watercraft/lake_river_sticker.htm


Revenues generated from sticker sales will be divided between two state agencies, the Department of Environmental Protection (DEP) and the Department of Inland Fisheries & Wildlife (IF&W).  DEP receives 60% of the revenue and IF&W gets 40%.  Revenues derived from sticker sales may only be used by the agencies for education, prevention, inspections, containment, eradication, and to reimburse state agencies for costs associated with enforcement.

According to John McPhedran of the DEP’s Invasive Aquatic Species Program, the revenue is used for continuing public education, printing brochures, signage, and coordinating volunteer programs and inspections.  The law also gives these state departments the authority to contract with municipalities or other entities to conduct inspections, prevention, or eradication programs. 


In an effort to grab the attention of the general public and, at the same time, have the revenue necessary to treat and contain infected waterbodies, the new law sets fines between $500 and $5000 for persons who launch watercraft that is contaminated with an invasive aquatic plant.  This same penalty structure applies to anyone caught operating a watercraft in a DEP or IF&W quarantined area. 


Maine has six variations of native milfoil, a common type of aquatic plant.  The native milfoil plants provide both food and shelter for fish and other wildlife and protect the shoreline from erosion.

Invasive aquatic plants are considered to be non-native to Maine. They arrived in our state by virtue of today’s mobile society.  Unlike native aquatic plants which can be beneficial to lakes, rivers and streams, invasive plants wreak havoc on the natural ecology of our waters.

Native plants are quickly overtaken by invasive species and wildlife habitats are edged out.  Invasive species such as Variable-leaf milfoil or Eurasian milfoil have the capacity to grow and multiply exponentially, thereby destroying the ability of native aquatic plants to survive.  These invasive species of milfoil reduce levels of oxygen in the water and diminish fish populations.  Once these plants are introduced to a water body, the cost associated with containing and eradicating the plants is phenomenal, and is often spent with very little abatement results. 

 Variable-leaf Milfoil

Variable-leaf milfoil, a non-native species, was spotted in Maine in the 1940’s.  It is an invasive aquatic plant.  However, it is not as damaging to water bodies as its sinister cousin, Eurasian milfoil, because it does not grow as deep and spreads less rapidly.

Variable-leaf milfoil is believed to have migrated to New England from southern and eastern parts of the country via boats and other human activities. Today, Variable-leaf milfoil can be found throughout the United States and in at least six Canadian provinces.

Variable-leaf milfoil grows uncontrollably and forms dense mats up to 10-12 feet deep.  What is even more astonishing is that a single seed or a one-inch plant fragment introduced to a lake on a boat or a boat trailer can initiate the infestation of an entire lake.  Milfoil spreads to new areas of a water body as plant fragments are created by passing boats or swimmers.  These fragments break apart and are then carried by the water’s current. Once the plant is introduced to the water, infestation is capable of doubling, even tripling in size every year.  This plant is adaptive that it is even able to survive outside of the water for days and is hardy enough to withstand icy winters.  

At the present time, Variable-leaf milfoil has been identified in 10 Maine water bodies, including Lake Auburn (Auburn), Thompson Lake (Oxford), Sebago Lake/Songo River, Cushman Pond (Lovell), Messalonskee Lake and Belgrade Stream (Belgrade), Little Androscoggin River (Welshville area), the stream between Pleasant and Parker Pond (Casco), Pleasant Pond (Richmond), Lake Arrowhead (Waterboro), and the Presumpscot River (between Dundee and Newhall, NH).  It is suspected, but not confirmed, that two additional lakes, Middle Range Pond and Little Sebago, have become infected as well. 

Eurasian Milfoil

While Variable-leaf milfoil grows uncontrollably throughout New England, Maine is the only state east of the Mississippi River to have been spared the rampage of Eurasian milfoil.  Eurasian milfoil can grow to depths of 20 feet and, like Variable-leaf milfoil, it forms large dense mats of vegetation that disrupt swimming, boating and other recreational activities. 

Because of its ability to grow to deeper depths, Eurasian milfoil can overtake a larger percentage of the waterbody.  If both Eurasian and Variable-leaf milfoil occurred in the same water body, Eurasian milfoil is known to be the more aggressive plant and would edge out the Variable-leaf milfoil. Because Eurasian milfoil typically begins its growing season before other native species it frequently shades out native vegetation.  In addition to the obvious detrimental impact to the aesthetic and recreational value of the lake, the thick mat of Eurasian milfoil vegetation is also capable of disrupting the natural pH of the lake, restricting the amount of oxygen under the surface and raising the temperature of the water.

To the naked eye, it is difficult to distinguish Variable-leaf milfoil from Eurasian milfoil.  Typically, the distinction is made through the use of DNA analysis.  Eurasian milfoil has been described by biologists as having “feathery” underwater foliage.  Milfoil blooms into a tiny pink flower typically in July. 

While Maine has been fortunate to avoid the ravages of Eurasian milfoil, some residents along Crystal Lake in Gray spotted a boat last July that had strands of plant matter still attached.  New York residents had used the boat in Saratoga Lake just one-day prior to launching the boat in Crystal Lake.  After analysis of the plant, the Department of Environmental Protection confirmed that it was indeed Eurasian milfoil.  According to Roy Bouchard of the Maine Department of Environmental Protection (DEP), it could take up to two years to determine whether Crystal Lake will become infected. 

Is the Attempt to Prevent Milfoil a Waste of Time?

In states such as Vermont or New Hampshire, Eurasian milfoil has reduced both the quality of the water as well as its recreational value.  Mats are often so thick and entangled that the presence of plants impedes if not prohibits swimming.  Washington State has had such difficulty controlling Eurasian Milfoil that the plants have actually been blamed for several drownings.

Eurasian milfoil has also wreaked havoc on recreational fishing activities such as the bass tournaments that are popular in New Hampshire and Vermont.  These dense plants have been known to snag fishing lures to the point where organized fishing events have had to be shut down. Moreover, Eurasian milfoil can starve a water body of oxygen, thus diminishing the fish population. 

In addition to impairing recreational activities, it has been documented that the infestation of milfoil diminishes the lakefront property values.  A study in 2000 analyzing three lake regions in Vermont infected with Eurasian milfoil found that the degradation of water quality lowered values by $9,000 to $12,000 for an average lakefront property.

Local tax assessors in Maine have expressed concern about the potential degradation in waterfront property values related to milfoil infestation.  Freeport Assessor Jim Thomas believes milfoil has created hysteria just like that associated with lead or radon in a home.  It is difficult to enumerate the true reduction of value because these lakefront properties will still be desirable.  Speaking generally, Ken Allen, tax assessor in Casco, noted that weedy shallow frontage is not as desirable as large sandy shorelines.  The diminution in value becomes more complex the more variables are added to the assessment. 

Tax assessment is a reactive business and cannot predict a future trend until it happens.  One of the variables that must be considered is the average depths of Maine lakes.  Lakefront owners that live along a shallow cove infested with milfoil may see a substantial reduction in value, but at the same time property owners along deeper parts of the same lake may experience an increase in property values due to a preference for that part of the lake.  Any generalizations about the correlation between milfoil and property values are difficult to make since assessments are based on individual properties. 

The will of the buyer is what truly drives the market.   For instance, property owners from other states that have been impacted by Milfoil may perceive Maine’s waters as pristine when compared to the lakes and rivers of their home states.  This may occur regardless of whether an entire lake becomes infested with Milfoil or only a shallow cove.

Preventing the Spread of Milfoil

In an attempt to make headway in an ongoing battle with Variable-leaf milfoil, officials in Maine have created a series of management practices.  For instance, the Portland Water District has proposed surface use restrictions for Sebago Lake State Park in an effort to prevent the spread of the plant population.  Navigation channels are strategically designed to keep boaters away from beds of milfoil. 

The Auburn Water District has also taken measures to prevent the spread of Variable-leaf milfoil.  In order to prevent boaters from coming in contact with the plant, district officials have  restricted access in the northwest corner of the lake.  District officials are also considering placing containment barriers and redirecting the access channels.

One of the only ways that Maine will be able to keep up with the spread of the Variable-leaf milfoil is through the use of volunteer organizations.  Groups such as the Lakes Environmental Association (LEA) and Maine Volunteer Lake Monitoring (VLMP) have been in the forefront of training and educating the public about milfoil. 

During the early stages of the 2001 boating season volunteers were stationed at boat launches to conduct surveys and inspect boats and trailers for plant fragments.  According to VLMP, there were over 250 “Plant Patrollers” used last summer to assist in monitoring the water quality.  While doing the inspection, the volunteers were able to educate the public and raise the level of awareness about the dangers of the invasive aquatic plants. 

Progress Report

In its January 2002 report to the Joint Standing Committees on Natural Resources and Inland Fisheries and Wildlife, the DEP and IF&W reported on the progress made during the 2001 boating season.  The report states that the IF&W wardens and various volunteer groups conducted inspections of boats, trailers, as well as other gear such as anchors and lines in the areas with the largest threat; southern and western Maine.  

The report summarizes the number of inspections conducted at the boat launches.  Of the 2848 inspections, Maine registered boaters accounted for 1724 (60.5%) of the boaters, while boats from other New England states accounted for 491 (16.9%) of the boaters.  The remaining 22.2% were boaters from outside of New England.  According to the report, a significant number of boaters agreed to voluntary inspections.  Approximately 90.3% of Maine registered boaters proclaimed familiarity with milfoil and 86.6% of New England residents said they were familiar with the problems caused by milfoil.  Of the boats and trailers inspected, 112 were found to be carrying plant fragments, though the identification of the species was not possible at the time.

The entry points to Maine were also assessed by the state agencies.  Of the 42-plus highway entry points into Maine, the majority of the traffic, not surprisingly, comes from I-95.  In summer, 35,000-40,000 motor vehicles travel northbound on I-95 on weekdays and on weekends an additional 2,000-5,000 vehicles are on the interstate.  The agencies concluded that of the 18,000 boats counted entering Maine at these selected sites, about one-third were registered, motorized craft and the remaining two-thirds included kayaks and canoes.  Trailored outboard boats account for most of the motorized boats with personal watercraft. (i.e., jet ski, mini speedboat) making up the difference. 

State agency recommendations to legislative committees on Natural Resources and Inland Fisheries & Wildlife included doing away with “courtesy inspections.”  The report states that an estimated 3035 boats passed the courtesy inspection points and 88% of them continued without stopping.  Department officials said that mandatory inspections along I-95 would greatly increase the number of inspections and would be a more effective use of staff time.  It is estimated that these mandatory inspections would yield up to 8,000 inspections from Memorial Day to Labor Day, while a full seven days a week with an eight-hour operation would result in 15,000-18,000 inspections. 

At the current time, there are no roadside inspections scheduled for 2002 boating season because of state budget constraints.

Volunteer Efforts Important to Program

According to the aforementioned legislative committee report, DEP and IF&W officials consider volunteers to be a vital element of the prevention program.  The report provides that, without this extra assistance, state resources were spread too thin.  Volunteers were able to return phone calls of concerned citizens and respond and investigate calls of “plant” sightings.  Prevention depends upon the awareness and dedication of volunteer organizations and lake associations. 

LEA and VLMP are continually training people that are willing to give up an afternoon to volunteer at the boat launch inspecting boats and trailers for plants.  Volunteers across the state are trained according to the standards established by the Maine Warden Service.  Inspectors, armed with tally sheets and questionnaires, greet boaters and ask to do an inspection prior to putting the boat and trailer in the water.  According to an inspector at one of the launches at Long Lake in Belgrade, the majority of boaters are willing to comply with inspections.  In addition to counting the boats and trailers inspected, volunteers also tally the number of trailers parked in the lot prior to their arrival in the morning, as well as the number that have previously been inspected.  This information then goes back to LEA and VLMP in an effort to determine the “boating patterns” on Maine’s lakes. 

Since this is the first year of the sticker requirement, IF&W is taking steps to inform the public about the mandatory stickers.  Boaters that have not yet purchased a sticker are only advised of the law and encouraged to comply.  According to Don Kleiner, the Director of Public Information and Education Division at IF&W, the volunteers and wardens alike are warning boaters about the sticker requirement.  Boaters without stickers will have their registrations marked so if they are subsequently stopped, the warden will know that the boater has been warned and assess the proper monetary penalty. 

Volunteer inspectors are trained to refer enforcement issues to the proper authorities.  Boats launched without a sticker are recorded on the tally sheet along with the trailer license plate number.   Though some wardens will be available at the public launches with the organized volunteers, not all launches will have wardens present. The “milfoil” legislation authorized IF&W to hire six new warden positions.  Until the revenue for these positions is generated by the sale of stickers, these positions will not be filled.  The new wardens will not be “plant police”; however, the hiring of new wardens will enable all wardens to spend more time on the milfoil protection program.