Particles Size Distribution in the Main Groups of Phytoplankton in the Baltic Sea Preliminary Results.
Pawlik, Magdalena; Cieslucinski, Marek; Ficek, Dariusz
Pomeranian University in Slupsk, POLAND

The phytoplankton size distribution plays a main role in understanding many facets of the aquatic ecosystem. Information about species composition and size-structure is important in the analysis of the optical properties of suspended matter. In this study, size and biovolume distributions of diverse phytoplankton species were measured using an inverted microscope (Utermohl 1931).
Phytoplankton samples were collected in different seasons in the South Baltic Sea (Baltic Proper, Gdansk Bay and coastal zone) in the years 2011-2012. The samples were collected in the upper 1-4 m deep layer. Total examined samples was 54. The proportion of each groups of phytoplankton in the total abundance is 30% for Cyanobacteria, 30% for Chrysophyta, 4% for Dinophyta, 16% for Cryptophyta, 10% for Chlorophyta, 1% for Euglenophyta, 10% for others.
The average value of equivalent spherical diameter in the main groups of phytoplankton in this study is 8 µm for Cyanobacteria, 13 µm for Chrysophyta, 16 µm for Dinophyta, 5 µm for Cryptophyta, 5 µm for Chlorophyta, 8 µm for Euglenophyta, 7 µm for others cells.
This research needs to be continued and developed.