Abstract
The study was conducted on a degraded Lake Długie in Olsztyn (surface area 26.8 ha, max depth 17.3 m) restored in 1987 - 2000 with the method of the artificial aeration with destratification. The aim of the study was to determine the influence of the applied method on the exchange of nitrogen compounds between the bottom sediments and overlying water. The results revealed that the applied method caused a decrease of nitrogen release from the bottom sediments and influenced the content of this component in the sediments. The observed changes may have been the effect of the intensification of the coupled nitrification-denitrification processes occurring in the aquatic conditions modified by the restoration.