How to clean up a lake? Floating islands might be the answer.
Man-made islands can remove ammonia, heavy metals, and other chemicals from the water.
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Holes are cut into the mesh and filled with plants. Grasses and flowers grow above the water, while their roots grow down through the mesh and into the water. Insects and minnows hide and forage in the roots underneath the islands, and bigger fish are attracted to the smaller fish. The islands expand over time.Skip to next paragraph
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The floating islands allow water to circulate, and they provide surface area for nutrient-hungry microbes, which form a film that is loosely connected to the islands. As the plants use more nitrogen and phosphorus to grow, there is less available in the water for algae blooms, which give off an unpleasant odor and form a suffocating shadow on top of the water.
“We’re taking a big enough bite out of the nutrient load that we’re not getting algae,” says Damien Austin, Kania’s staff biologist.
Evidence is mounting that the islands can remove ammonia, heavy metals, and other chemicals from the water, too. They act as a sponge on a wet countertop: Water is drawn in, and the bad stuff sticks. “It looks like a good idea, and I’m kind of surprised no one else has thought of this before, at least in a marketable way,” says Joe Gathman, a biology professor at the University of Wisconsin at River Falls.
“Ideally, problems like [excess nutrients] should be stopped at their source: Mop it up before it gets into the lake. But these islands could be helpful little mops,” he says.
The main office for Floating Islands International is just a few feet from Kania’s house. A shop and laboratory are a mile down a dirt road. Twice a week, Kania and his staff – which includes his wife, Anne – meet for lunch at the Feedlot Steakhouse outside Shepherd. They talk floating islands, from buoyancy calculations to which type of soil works best.
Floating islands are being used from downtown Chicago to Singapore. In Billings, Mont., a city of 100,000, city engineers are using floating islands to filter storm water. The local zoo uses an island in its otter habitat and no longer has to chemically treat the water, says Tim Mulholland, an engineer and one of eight license-holders who build the islands.
Kania’s licensees recently built a 22,000-square-foot island for the US Army Corps of Engineers, which launched it in a lake in Oregon. The island provides habitat for the Caspian tern. The shore birds are being relocated away from the Columbia River estuary, where they eat 5 million salmon fry a year.
“It’s floating great,” says Kitia Chambers, an Army Corps engineer. “We’ll definitely monitor this one, and if all goes well, we’d like to use this design again.”
Ideally, the licenses will fund other inventions. Kania is planning to launch an island this summer with a wind turbine on it, and he’s trying shredded carpet in the islands.
“We’re not a marketing company, and we’re not a manufacturing company,” he says. “My job as CEO is to maintain the perspective of an inventor.”