AUBURN — Efforts to keep milfoil out of Lake Auburn continue this summer as watershed officials place more light-blocking mats underwater downstream from The Basin.
Water Quality Manager Mary Jane Dillingham of the Auburn Water District said the mats are marked with neon buoys and a sign that explains what’s happening.
“We have not, in the past, done any work with milfoil there, but this year, we’ve gone in and attacked it,” she said.
Water quality officials in Maine are on constant watch for nonnative plants, and especially for the variable leaf milfoil. The nuisance plant is perfectly suited for life in Maine’s ponds because nothing natural in Maine can keep it in check, Dillingham said.
“What the invasive plants do is just take over and push out the native plants,” she said. “The consequence is destruction of fish habitat and a potential impact on water quality. It severely impacts biodiversity.”
One solution is to blot out the sun from the lake bottom. Water quality officials have used a synthetic fabric, called a benthic barrier, across parts of the floor of The Basin at the north end of the lake since 2002, hoping to starve the plants of sunlight and stop the spread before it reaches Lake Auburn.
This year, they are moving downstream from The Basin’s dam. The barriers will remain for at least 60 days to make the stream bottom unavailable to milfoil fragments.
“We’ve gone in and attacked it basically by diving in and doing some hand-pulling and then putting these geotextile mats, weighed down by rebar,” she said.
The plant has long, skinny tendrils that tend to come apart easily. Any part of the plant can break off, float away and establish a new stand where it lands.
Water quality officials suspect the plant is spread from lake to lake in Maine via the bottoms of recreation boats and fishing equipment. Motorized boats are not allowed in The Basin because of the risk of spreading the plant.
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