Mesozooplankton was sampled by open-closing JUDAY net with a 37 cm ring diameter (0.1 m**2 mouth area) and mesh sizes of 125 µm. Depth of tow is evaluated by wire paid out and the angle of wire inclination. Samples were treated using express method: copepods were identified to genus level, other zooplankton groups - to type, class, order and family levels.