Phytoplankton data collected in the Black Sea during 117 cruise of the R/V "Kovalevskiy" and processed by Lyudmila Georgieva. <br> Samples were taken with 6 liter bathometers at standard depths and in the thermocline layer. 1-3 liter of water was concentrated by inverse filtering. Organisms were counted with a Nauman camera 0.4 cm³ or 0.001-0.01 cm³ for nanophytoplankton.