Seasonal variability of phytoplankton in river Słupia of the southern Baltic Sea
In the Baltic Sea, there can be observed seasonal variations in the structure of phytoplankton. These organisms are particularly sensitive to changes in different environmental parameters. The consequence of these changes is cyclical repeated every year fluctuation of the species composition, their abundance and biomass of phytoplankton. The spatial and temporal variability of individual phytoplankton groups is not the same in different regions of the Baltic Sea, and this is why the study was conducted in the area of the central Baltic coast, since in that particular region data on phytoplankton is not available. One of the main goals was to determine the temporal and spatial structure of the occurrence of phytoplankton, as well as to study biodiversity in the area of the estuary of the Slupia river in southern Baltic for the period between November 2014 and September 2016. The results of the research confirm typical changes of phytoplankton in three studied areas depending on the given season. The average values of phytoplankton abundance and biomass were typical for this kind of coastal waters and there were no significant species differences between these stations. The only research (and available studies) on phytoplankton in central sea basin areas is being conducted by Institute of Meteorology and Water Management (IMWM) as part of the HELCOM Baltic Sea Monitoring at station P16, which is the closest location to the studied area. When comparing the results obtained in this study to the data from the IMWM annual reports for the last decade, it can be noticed that the size and fluctuations of total biomass and phytoplankton abundance in the three studied areas are typical for the coastal region of the South Baltic.