These Floating Islands Aren't Real--But They Are Cleaning Up Rivers
Floating islands are designed to grow "biofilms"—collections of microbes that consume the excessive nutrients in the water. Each platform is made up of a matrix of fibers derived from post-consumer plastic bottles, then infused with a buoyant marine foam. The plants on top, mostly perennials, grow in a peat layer. The biofilms congregate on the bottom of the structure, while roots from the plants peep through, offering additional pollution control.