Natural Highlights: Floating Wetland Islands
In celebration of American Wetlands Month, we spotlight floating wetland islands, a creative way to bring the benefits of wetlands into urban lakes and ponds.
In the lakes along the Wolf River Greenway, the water is often too deep or the banks too steep to support natural wetlands. Floating wetland islands - rafts constructed of dense PET fibers recycled from plastic trash which can support wetland plants – can provide many of the same ecosystem services, especially the reduction of some kinds of water pollution.
Volunteers recently helped us install a new Biohaven floating wetland island in the lake at the Shady Grove trailhead of the Wolf River Greenway, the site of our Earth Day service project. The 5x6 ft. island was made to accommodate numerous wetland plants with holes which were filled with coconut coir planting medium, then Blue Flag Iris, Pickerel Weed, Lizard Tail, Fringed Sedge, and Soft Rush plants – all natives. Once launched into the lake and towed out to the middle by Jim Gafford and his canoe, the island was anchored with a concrete block. As the plants grow, their roots can easily penetrate the raft fibers and extend down into the water; both the raft fibers and the plant roots will be colonized by millions of water-cleansing microorganisms which form a biofilm capable of absorbing nutrient pollution and breaking down contaminants.
Floating wetland islands, or floating treatment wetlands, were originally developed specifically to mitigate stormwater pollution, especially in stormwater detention ponds, but their benefits extend beyond water cleansing properties. Once established, the island plants provide food, shelter, and shade for birds, insects, frogs, and turtles, and fish take refuge in the intertwined roots below. A wetland island installed last year at Epping Way was used this spring as a nesting site by a pair of Canada Geese, who shared the island with a lone male Mallard. What better place than an island to find protection from land-based predators? Besides wildlife habitat, wetland islands can also become beautiful and educational landscape features.
The Wolf River Conservancy focuses its conservation efforts on protecting wetlands because of the vital ecosystem services they provide, including aquifer recharge, pollution reduction, carbon storage, and flood protection. They are critical habitats for wildlife and reservoirs of biodiversity. Along the urban Wolf River, unfortunately, many of our natural wetlands have been damaged or destroyed. Installing floating wetland islands is one creative way to bring the benefits of wetlands back to our communities. With the help of our great volunteers, we hope to add more islands in the future and expand those we have already installed.
For more information on floating wetland islands, please explore these links:
https://e360.yale.edu/features/floating-wetlands-cities-pollution
During American Wetlands Month, Wolf River Conservancy spotlights floating wetland islands, eco-friendly rafts that reduce pollution and support urban wildlife.
