Floating wetlands act as floating littoral shelves, providing a platform for plants to grow.
Aquatic plants then absorb pollutants and toxins in the stormwater and sequester the toxins, nitrogen, carbon and phosphorous in their biomass.
Plants on floating platforms can sequester up almost ten percent of their dry weight in the form of nitrogen and phosphorous and much more in the form of carbon.
Acres of floating wetlands could easily help to resolve total maximum daily limit (TMDL) issues and in fact could offer an opportunity to create TMDL credits if the appropriate biomass harvesting program were initiated.
The above slideshow shows a mature floating wetland field trial having the above surface biomass harvested for composting.
Floating wetlands provide habitat, sequester carbon, nitrogen and other pollutants, pump oxygen into the air, clean CO2 from the air, offer beauty, clean stormwater, create economic opportunities and more.
12 days into the pond the 100 plus water fowl have adopted the floating wetland platform as 'home'. The platform is a 'trial' to see just how the resident ducks and geese would affect the system. Presently the pond has a sandy island with trees but no herbaceous or other vegetation. Concern was expressed the large contingency of ducks would devour the biomass quickly, rendering the plant-nutrient uptake platform useless. Twelve days into the process the plants are a little trampled but growing vigorously in the duck matter nutrient enriched waters. Plans are to begin harvesting the biomass on a periodic basis to remove sequestered nitrogen and phosphorous from the system.
Listed below are several photographs of a pond where the existence of Nutrients In-Nutrients Out is of balance. Due to the large waterfowl population and the local resident's feeding the ducks, the waterbody constantly accumulates nutrients. However the water body possesses no capability or mechanism for removing those nutrients. Algae blooms are perennial and the water quality poor. Floating Wetlands are in the process of being added to the pond to provide the Nutrient Out Component. We will be posting data and photographs of the results.
The pickerel weed, canna and bullrush are growing well - filling out the 2" thick polypropylene platform, and providing a two-tiered platform for removing Nitrogen and Phosphorous. Firstly, the dense root system allows for microbe activity and digestion to occur just below the surface. Secondly, the plants ingest Nitrogen and Phosphorous as part of their required nutrients, sequestering both in the biomass.
These floating platforms of wetland plants function on a Nutrient In - Nutrient Out basis as described below - perfect for a TMDL nutrient removal program.