The CTD “Sea Bird” (Sea-Bird Electronics, Inc.) was used for
hydrophysical measurements. Water samples of phytoplankton were
collected using 5-L bathometers. Fixation and concentration of samples
and all other procedures for counting the number of cellswere conducted
according to phytoplankton manuals (Kiselev, 1969; Moncheva and
Parr, 2010)