by Dan Ferber
Sometimes, all a polluted lake needs is a little love from an island—a “floating treatment wetland.” Load soil or sod onto a loofah-like mesh of plastic (made from recycled carpet and water bottles, of course), float it, add seeds, and let the plants take over. Their roots become home to biofilms that gobble nitrates and phosphates, denying those nutrients to algal blooms. Small critters eat the biofilms, fish eat the critters, and the water gradually gets cleaner. Bruce Kania, CEO of Floating Island International, says he modeled the version he sells on the floating peat islands on the waters of Wisconsin’s Lake Chippewa Flowage, near where he grew up. His company has sold more than 4,000 of the plant rafts in a dozen countries. But filtration islands aren’t a cure-all. According to Bill Crumpton, a wetland expert at Iowa State University, only healthy, conventional wetlands can completely restore water systems. Still, Kania says his islands could one day revive dead zones in bays and estuaries and be solid enough for people to live on. “Nature is an incredible model,” he says. “It’s the ultimate inventor.”
Sometimes, all a polluted lake needs is a little love from an island—a “floating treatment wetland.” Load soil or sod onto a loofah-like mesh of plastic (made from recycled carpet and water bottles, of course), float it, add seeds, and let the plants take over. Their roots become home to biofilms that gobble nitrates and phosphates, denying those nutrients to algal blooms. Small critters eat the biofilms, fish eat the critters, and the water gradually gets cleaner. Bruce Kania, CEO of Floating Island International, says he modeled the version he sells on the floating peat islands on the waters of Wisconsin’s Lake Chippewa Flowage, near where he grew up. His company has sold more than 4,000 of the plant rafts in a dozen countries. But filtration islands aren’t a cure-all. According to Bill Crumpton, a wetland expert at Iowa State University, only healthy, conventional wetlands can completely restore water systems. Still, Kania says his islands could one day revive dead zones in bays and estuaries and be solid enough for people to live on. “Nature is an incredible model,” he says. “It’s the ultimate inventor.”
