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The
Milfoil Battle By Peter Lowell, Director,
In October, experimental blue tarps began coming
out of the Songo River. LEA
devised this method Photo: LEA's Supersized Mainer Tarp is rolled on swim noodles so it can be floated into position. In addition to the tarps, a grant from Maine’s Libra Foundation funded full-time boat inspections at the locks and hand removal and bottom barriers at the infestation in Brandy Pond at Causeway Marina. Plants were discovered there in the fall of 2004 and through repeated work at the site by LEA divers, the situation seems manageable and diminishing in scope. A final assessment of this site will be done in November. The other marinas have been surveyed with only one plant found.
Despite the apparent success of the tarps, it will be a daunting task to eliminate Milfoil from the upper river. A sweep of the river by four divers in October revealed only a few plants had made a foothold within 1,500 feet of Brandy Pond. This is good news and those plants were removed. Below this point, it’s a different story. There, some of the plant beds rise to the surface and look dense enough to walk on. Ken Wagner, a well-known lake scientist visited the Songo this fall to assess the infestation. Following discussions with Wagner, Portland Water District staff and Maine DEP staff, LEA has made preliminary plans for a four-stage program for the Songo: 1. Attempt to draw the river down to the maximum extent in November and hope for late snow cover and minimal precipitation. Although this “freeze the plants” approach is highly weather-dependant, it is a low cost and effective way to reduce the size of the infested area. 2. Design a suction barge that would assist in the hand harvesting by suctioning the plants pulled by divers to the surface and bagging them for disposal. Little Sebago Lake has successfully built such a device. We may be able to utilize a pontoon boat donated by Naples Marina. If it is not possible to build the barge by spring, we may need to contract with a commercial harvester for one season. 3. Continue to use the tarp barriers on the sections of the river where the bottom contour is relatively flat. 4. Continue diver monitoring of the river and marinas with hand-pulling where necessary. Area-wide, Courtesy Boat Inspectors were trained
by LEA to staff a dozen boat launches with Photo: Swim noodles on the tarp's leading edge keep it afloat during application. Note floating air compressor at right; see our Interesting Websites Here and There page for the manufacturer, Hookah Systems. Milfoil continues to be a significant threat
to the Lakes Region. Most of the 26 documented infested lakes and streams
in Maine are located within an hour’s drive. Invasive plant control
and education is consuming more and more of LEA’s resources and
will still need to be intensified. Our priority is to contain the Songo
infestation, Photo: The Mainer Tarp unrolls upstream on the Songo River. |
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of covering and killing Milfoil on the river bottom. Because the infestation
in the river above the locks is extensive (perhaps as large as three
acres), we needed an affordable way to kill the plants. The tarps are
each 2,400 square feet. Four were installed this past summer to test
the technique. When the first tarp was removed, a barren sandy bottom
was revealed where there had once been dense plant growth, giving us
hope that the tarps can be used effectively on more of the river next
season.
Photo:
LEA's rolled and ready barrier floats as diver-director Peter Lowell
discusses the next step with boaters. 
financial
support from towns and the DEP. New washing stations were built at Trickey
Pond in Naples, and Moose Pond in Bridgton and Denmark. Milfoil Day
was initiated in August, offering landowners an opportunity to have
their shoreline surveyed for invasives.
eradicate
the plants in Brandy Pond and build a rapid response and prevention
program that will keep plants out of other lakes or detect them early
enough to be able to control them. Towns may need to consider centralizing
access or requiring mandatory inspections in order to prevent this problem
from getting out of control. A full blown infestation in any one of
our lakes threatens all others and would generate enormous ecological
damage and economic costs.