The variability of coastal phytoplankton of the north-western Black Sea region

Goal. The inter-annual changes in the structural organization of the coastal phytoplankton of the North-Western part of the Black Sea in 2016, 2017 and 2019 were analyzed and compared with historical data in order to assess the direction of environmental processes. Methods. Samples taken in coastal waters were processed under a light microscope, and subsequently the complex of phytoplankton structural parameters was analyzed. Results. Unlike most of the Black Sea, where an increase in phytoplankton biomass was observed, the phytoplankton biomass significantly decreased in the North-Western region coastal waters in 2019. Conclusions. The data indicates that the state of phytoplankton is stable for the North-Western region of Black Sea. This confirms the current trend in the recovery ecosystem of this region that has been observed after the eutrophication of the 1970-80s.Key words: phytoplankton, structural organization, ecological status, Black Sea.