The density and distribution of the dominant phytoplankton in the southern Caspian Sea

The research project was comprised of four sampling cruises, which were carried out in summer 94; spring, autumn and winter 95 in the southern part of the Caspian Sea, where Chrysophyta (Diatoms) and Pyrrophyta were found to be the dominant phytoplankton. The maximum density of phylum Chrysophyta (Diatoms) was observed mainly during the autumn in the coast line (below 20 m) and in the central part of the southern Caspian Sea, while the highest density of phylum Pyrrophyta occurred during the spring in the subcoastal zone (below 50 m.). The dominant species in the phylum Chrysophyta (Diatoms) were Rhizosolenia calcar-avis, Thalossionema nitzschiodes, Sceletonema costatum, Cyclotella meneghiniane and three members of genus Coscinodiscus, among which R. calcar-avis had the highest density. Members of phylum Pyrrophyta, i.e. Exuvialla cordata, Prorocentrum scutellum and Glenodinium penardii had the highest density during the spring in the central part of the southern Caspian Sea, where E. cordata was the most abundant