Home – Home – Jornals – Contemporary Problems of Ecology 2021 number 4

The assessment of species composition, abundance, biomass, and pigment characteristics of phytoperiphyton and phytoplankton of Lake Pyasino, its tributaries (Bezymyannyi stream, the Daldykan, Ambarnaya, and Norilskaya rivers), and the head of the Pyasina river was carried out after man-made accident - diesel fuel spill in vicinity of the city of Norilsk in May 2020. Significant decline of biomass and changes in species composition of phytoperiphyton after water contamination by fuel was revealed near the spillage site only (in the Daldykan river and in the Ambarnaya river downstream the Daldykan mouth). Downstream, in the Ambarnaya mouth zone, as a response to the release of a large amount of nutrients during the decomposition of oil products and dead organisms, as well as mechanical cleaning of the bank line, in the water column there was a massive growth of diatom and green algae ( Tabularia tabulata , Spirogyra sp.) and indicators of organic pollution (Euglenophyceae and Cryptophyceae) appeared. Significant changes in the plankton of Lake Pyasino and river Pyasina in comparison with the data obtained in the second half of the XX century (i. e., long before the accident) were not found. Species composition and quantitative features as well as amount and ratio of pigments characterized phytoplankton and phytoperiphyton of Lake Pyasino and the Pyasina river as normally functioning freshwater community of oligotrophic waters. All this indicates the absence of a negative impact of the accidental oil spillage on the ecosystem of Lake Pyasino and the Pyasina river.