Traditional methods of studying phytoplankton were used in the Sea of Azov, Black Sea, and the Caspian Sea . Data was gathered on species composition, abundance and biomass of microplankton organisms (Morozova-Vodyanitskaya, 1954). Sampling was by bathometer and fixed either by formalin or Lugol’s solution. Samples were obtained from the surface (the Sea of Azov), by standard horizons (0, 10, 25, 50, 100 m), or by the location of seasonal thermocline (the Black and Caspian Seas). In the latter case, three bathometric samples were collected above, inside, and below the thermocline using operational CTD-probing data (Guidelines, 1980).
Samples were concentrated by a settling method to a final volume of 50–100 ml. To quantify the phytoplankton, concentrated samples were examined with the help of the light microscope in the Nageotte chamber (0.1 ml) with magnification of 400x (Abakumov, 1983). Large forms of microalgae are registered in the Nageotte chamber, in two-three repeated fillings. Other species are calculated in several lines of the chamber (up to 400 cells). The biomass calculation is by actual size of cells applying the geometric similarity method to calculate the volume of cell. These methods were used to obtain information on micro-phytoplankton during2005 – 2011, and were included into the database.
Results from processing of 184 micro plankton samples from the Sea of Azov have been added to the database. Results from 80 samples from the Black Sea were also added. Only fragmented data from the Volga Delta area were included (Figure 1, Table 1).
|Sea of Azov|
|Total by seas||8||28||0||68||13||53||42||17||13||19||0||8||269|