Vertical distribution of Cyanobacteria in the marine rocky supralittoral zone of the Choban-Basty cape (Meganom Peninsula, the Black Sea)

Abstract

The vertical distribution (altitudes at 0.1; 0.3; 0.6; 0.9; 1.2 and 1,5 m above mean sea level - MSL) of Cyanobacteria in the supralittoral zone of the Cape Choban-Basty (Meganom Peninsula) was characterized. A total of 14 species of Cyanobacteria have been recorded; their number at various altitudes varied from 4 to 8 (minimal at 0.9 m above MSL). As for the systematic composition, species of the Oscillatoriophycidae subclass were found on the entire range of altitudes. The high contribution of representatives of the Synechococcophycidae subclass was noted at altitudes of 1.2 and 1.5m MSL. The orders Chroococcales and Pleurocapsales were dominant at 0.9 m MSL; and the order Nostocales - at 1.2 m and 1.5m MSL. Among the families, Hyellaceae, Rivulariaceae, Merismopediaceae и Heteroleibleiniaceae family was observed at all altitudes. The genera Gloeocapsopsis , Calothrix, Aphanocapsa и Chroococcus (with a low contribution) have been recorded at almost all altitudes. According to the substrate confinement, the noted microphytes belonged to the attached ones; benthic mesosaprobiont marine species predominated in the entire surveyed range of altitudes. Brackish-marine (except 0.9 m above sea level) and freshwater-brackish (except 0.1 m above sea level) species were noted almost all over the range, while only one freshwater species was recorded at 0.1 m MSL. Species with cosmopolitan, boreal and boreal-tropical distribution predominated at all altitudes. The share of the latter was the highest at 1.5 m MSL. The features of the vertical distribution of Cyanobacteria emphasize the specificity of the environmental conditions of the supralittoral biotope.