Phytoplankton data collected by the IBSS staff near Sochi (Mamaika. Matsesta. Sochi river's mouth), Black Sea, during three surveys in 1974 and 1975. Samples were taken in the area of deep sea outfall of Sochi. This dataset contains abundance data (individuals per liter) and biomass (mg/m³) for phytoplankton taxa. Also size records are given for some of them. No additional metadata is available.