Weronika Patuła¹, Slawomir Kwasniewski¹, Anna Olszewska¹, Agnieszka Beszczynska-Möller², Marta Gluchowska¹, Marta Ronowicz¹, Piotr Kukliński¹ and Agata Weydmann-Zwolicka³, (1)Institute of Oceanology Polish Academy of Sciences, Department of Marine Ecology, Sopot, Poland, (2)Institute of Oceanology Polish Academy of Sciences, Department of Physical Oceanography, Sopot, Poland, (3)University of Gdańsk, Department of Marine Biology and Biotechnology, Laboratory of Plankton Biology, Gdynia, Poland