Floating wetlands may seem odd but are perfectly natural. They occur when mats of vegetation break free from the shore of a body of water. That got ecological engineers curious about how they affect the water they bob up and down in.A group from Saint Francis University in Pennsylvania and the University of Oklahoma, including researcher William Strosnider, has found that the floating wetlands show promise for water treatment. They engineered four different floating treatment wetlands designs using different materials and wetland plants.