A pilot project in Aitkin County is underway on Fleming Lake near Palisade, in hopes of reducing the green tint in the water of the 300-acre lake.
Steve Hughes, Aitkin County Soil and Water Conservation District (SWCD), described Fleming Lake as the perfect location for the project, as the body of water is shallow (15 feet at its deepest point) and is rich in nutrients. Those nutrients, however, are allowing for the algae in the lake to create a green-shaded water quality.
In partnership with the University of Minnesota, Midwest Floating Islands and an Enbridge Ecofootprint grant, Aitkin County SWCD launched 16 islands from the public access on Fleming Lake Aug. 23.
Floating islands, planted with aquatic vegetation which grow roots down below the islands, are now floating on the northern fringes of Fleming Lake. According to Autumn Boos, director of sales and marketing for Midwest Floating Islands, the plant roots and the matrix material create an ideal growing surface for microbes to attract pollutants, such as phosphorus and nitrogen, that cause serious odor and algae issues.
The matrix material is made of 100 percent recycled BPA-free PET plastic. The project will keep 25,000 water bottles out of the landfill.
Boos said the islands will create a floating ecosystem.
“The plants will attract pollinators, and fish will congregate under the islands in the root system,” explained Boos.
Jake Duffner, a graduate student at the University of Minnesota next spring, worked with Hughes, Enbridge and Midwest Floating Islands to bring the parties together at Fleming Lake. Duffner contacted Hughes eight months ago with the project idea, and it’s being completed with a $100,000 grant from Enbridge.
Joe Magner, professor in BioProducts and BioSystems Engineering at the university, had Duffner write the grant and contact Hughes to get the project started. Magner said three key results will come from the project: 1) improvement of water quality; 2) provide wetland habitat; and 3) provide a learning experience for university students. Dozens of volunteer students were at Fleming Lake preparing the islands.
Magner said many of the volunteer students are freshmen coming into the environmental and ecological program at the university.
Monitoring of the project will be done by the university for the following year, and plant growth will be monitored this fall, added Magner.
Duffner said the plants on the island create a biofilm with the root system below the island. The biofilm allows for microbes (bacteria) that feed on the nutrients in the water, but the microbes need somewhere to attach. The root system and the plastic matrix give the microbes the opportunity to go to work.
Each of the islands is anchored by 60-pound concrete buckets, and the cables attaching the anchors to the island are made from stainless steel to prevent rusting and additional water quality issues.
Boos said this is one of the first lake projects being tested by the company, as islands have been used mostly in small stormwater ponds. The islands will be in the lake year-round.
“One of the biggest questions about the product is how they hold up to the ice,” said Boos.
Nineteen different species of plants were planted by university students on the 16 islands; each small island features two different types of plant. There are 12 islands 5 feet by 10 feet in area; one 10 feet by 7 feet, one kidney-shaped island and two 7.5 feet by 20 feet big islands. The varying species of plants on the islands will allow the university to see which plants flourish in Fleming Lake.
Rod Bengtson, a resident on Fleming Lake, helped pull the islands from the public access with his pontoon.
“The water clarity could always use improvement,” said Bengtson. “There’s learning involved here, too. It may not mean it’s a solution, but they’re gathering the appropriate data. I fully understand what they’re doing. We can understand why this lake is so green and maybe apply it to other lakes.”
Nineteen different native aquatic plants were used on the floating islands on Fleming Lake:
• Bottle Brush Sedge
• Common Rush
• Swamp Milk Weed
• Fowl Manna Grass
• New England Aster
• Great Blue Lobelia
• Bebb’s Oval Sedge
• Sweet Flag
• Flat Top Aster
• Woolly Sedge
• Iron Weed
• Green Bulrush
• Riddell’s Goldenrod
• Wool Grass
• Obedient Plant
• Monkey Plant
• Cardinal Plant
• Fringed Loosestrife