Aalto University researchers designed floating wetlands made from oyster mushroom (Pleurotus ostreatus) mycelium grown on common reed (Phragmites australis). These biodegradable structures filter polluted shoreline waters through mycofiltration, binding heavy metals and breaking down toxins while also creating habitat for wildlife. The wetlands double as seasonal food-producing systems and decompose naturally after use, leaving behind cleaner water and ecological benefits.