Seasonal Dynamics of the Phytoplankton Photosynthetic Apparatus Efficiency in Black Sea Coastal Regions

Abstract

A study of the fluorescence characteristics of phytoplankton in the coastal regions off the Crimean coasts of the Black Sea showed that the seasonal dynamics of the activity of the phytoplankton photosynthetic apparatus is identical both in Sevastopol Bay and inshore waters. The mean monthly values of the photochemical efficiency of photosystem II over 1 year vary within narrow limits and are close to the values of Diatoms and Dynophycea grown under optimal conditions. Phytoplankton in Black Sea coastal regions is provided with nutrients, and its developmental conditions are close to optimal. The light intensity that saturates the electron transport rate increases sevenfold from winter to summer. In summer, it coincides with the results of the phytoplankton photosynthesis rate measurements, and in winter it varies up to fivefold.