Potential of Submerged Vegetation to Remove Nutrients from Eutrophic Fishponds

Abstract

The possibility to remove nutrients from two eutrophic fishponds in the Czech Republic through harvesting the dominant submerged species, Ceratophyllum demersum and Stuckenia pectinata, was evaluated. Both plants were sampled in three locations within the fishpond in two-week intervals from late June to late September 2016. In the biomass of both plants nitrogen and phosphorus concentrations were measured and, subsequently, standing stocks of both elements were calculated. The results revealed that the maximum biomass occurred at different times, in June for S. pectinata and in July for C. demersum. The maximum standing stocks were 3.61 and 7.44 g N m-2 and 0.13 and 0.53 g P m-2, respectively.. These values are within the range reported in the literature for the studied species, but they are about one order of magnitude lower when compared to tall emergent species. The total amount of removable nutrients in the monitored fishponds varied between 448 and 842 kg N and between 30.5 and 31.9 kg P.