LAUSR

The dynamics of the nitrogen, carbon, and phosphorus contents in the detrital particles suspended in the water column was examined. The study was carried out in two freshwater reservoirs of different trophic levels. Detritus was collected in natural aquatic ecosystems at various depths. The nitrogen, phosphorus, and carbon concentrations in the detrital particles were found to decrease significantly during the detritus sedimentation in the water column. This pattern was observed both for a mesotrophic reservoir and an eutrophic aquatic ecosystem. It was the phosphorus concentration that decreased especially rapidly during the sedimentation of the detrital particles in the water column. These findings were considered in the context of water quality formation. The new facts and their analysis advance our understanding of the most important functions of detritus in aquatic ecosystems; a new aspect of coupling of ecological and biogeochemical processes in aquatic ecosystems was revealed. The results were analyzed using the innovative scientific term, exometabolism, which was proposed by S.A. Ostroumov in his monograph “Aquatic Organisms in Water Self- Purification” in 2008.