Influence of some forms of nitrogen on the development of phytoplankton of ponds in the catchment area of the Kalmius River (Donetsk, DPR)

The influence of concentration of different forms of nitrogen (ammonia, nitrates) on phytoplankton composition in water bodies of Donetsk city is determined. Ponds of the catchment area of the Kalmius River were studied, and seasonal fluctuations of ammonium and nitrate nitrogen levels were analyzed. The results showed that ammonium ions, especially during the period of moderate pollution, play a key role in maintaining phytoplankton growth. Nitrates, in turn, show seasonal dynamics, including their maximum concentrations in spring and autumn periods. The algal flora of the studied ponds was dominated by algae of Heterokontophyta and Chlorophyta departments, as well as some amount of cyanobacteria, which reflected their relationship between nitrogen pollution and changes in phytoplankton composition. The work also revealed the significance of these nitrogen forms as indicators of the ecological state of water bodies. The obtained data can be used to develop measures for monitoring aquatic ecosystems and preventing pollution of water bodies.