Abundance and biomass of phytoplankton in the Black Sea near Gelendzhik in 2002-2005

In 2004-2005 bloom of E. huxleyi was accompanied by mass development of diatom alga Chaetoceros subtilis var. abnormis f. simplex (600000-900000 cells/l). For the first time it was registered as a dominating form of Black Sea phytoplankton.

Small flagellates and picoplankton algae played a noticeable role in phytoplankton throughout the entire period of the studies. Meanwhile in the early summer period the bulk of biomass consisted of coccolithophores (50-60%), while in the late summer period diatomaceous algae dominated (50-70%). Among ecological factors that favor coccolithophore development one may note microstratification of the upper mixed layer at a high illumination level and high temperature in surface waters (18-21°C).