"Floating Island International constructed 1,600 BioHavens in its first two years: in lakes, in ornamental gardens, in wastewater ponds. At first, empirical evidence documenting their effectiveness was scant. Some agencies shied away; skeptics suggested that FII might be overhyping its product. “We’ve tried their technology, and it works,” Steve Patterson, founder of a company called Bio x Design that makes its own wetlands, told me. “But they’re not just something that you can use anywhere and everywhere and magically clear your water up.”
Gradually, though, data rolled in. Floating wetlands, it appeared, had a major advantage over stationary ones: When water levels fluctuated, as they often did in stormwater ponds, Kania’s creations rose and fell on the surface, their performance unfazed. A suite of islands installed behind a museum in Durham, North Carolina, improved total nitrogen removal by almost 30 percent. Another increased ammonia removal from a Billings wastewater lagoon by 38 percent. New Zealand reported similar results. When Jim Bays of CH2M Hill conducted tests in Florida, he found the islands increased nitrogen uptake by 32 percent. “At this point, there’s definitely enough information to say that islands have an important place within the toolbox,” Bays said."
https://www.hcn.org/issues/46.20/can-biomimicry-tackle-our-toughest-water-problems
Gradually, though, data rolled in. Floating wetlands, it appeared, had a major advantage over stationary ones: When water levels fluctuated, as they often did in stormwater ponds, Kania’s creations rose and fell on the surface, their performance unfazed. A suite of islands installed behind a museum in Durham, North Carolina, improved total nitrogen removal by almost 30 percent. Another increased ammonia removal from a Billings wastewater lagoon by 38 percent. New Zealand reported similar results. When Jim Bays of CH2M Hill conducted tests in Florida, he found the islands increased nitrogen uptake by 32 percent. “At this point, there’s definitely enough information to say that islands have an important place within the toolbox,” Bays said."
https://www.hcn.org/issues/46.20/can-biomimicry-tackle-our-toughest-water-problems