Nitrogen dynamics of sediment-water interface in shallow eutrophic Mogan lake

In this study, the nitrogen dynamics at the sediment-water interface in Lake Mogan, which is a shallow and eutrophic lake; the study was carried out in order to investigate the changes in two periods of the year with different climatic conditions, characterized as wet and dry periods. Six stations, which are thought to have high pollution input, were determined in the lake. In the laboratory environment; analyzes were made in sedimentary water, sediment and sediment pore water. In addition, the effect of oxygen on nitrogen fractions in the sediment was also found to be binding. Within the scope of the phD thesis, unlike the previous eutrophication and sediment related studies in the lake, it was aimed to quantitatively estimate the nitrogen dynamics (positive and/or negative aspects of ammonium and nitrate release or uptake) at the sedimet-water interface. Ammonium and nitrate release valus from the sediment changed between -9,16 – 0,36 µ/m2.dayfor ammonium release, respectively while the lowest value was at the 2nd station in July 2019, and the highest value was at the 6th station in October 2018; for nitrate release, it changed between -67,2 – 35,16 µ/m2.day, and had the lowest value in October 2018 at the 3rd station and the highest value in the 5th station in the same month. Nitrogen release estimates in the Lake Mogan sediment did not show a regular seasonal or local veriation. Although the level of nitrogen release in the lake is not high enough to affect the nutrient level of the lake, it has been determined the rate of nitrogen retention is seriously high. With this reseach, it was determined that the nitrogen fractions in the sediment of Lake Mogan should be monitored regularly and external pollution inputs should be reduced by considering climate change.