Development of phytoplankton communities in various ecotopes of the Sumka River (Republic of Tatarstan, Russia)

Abstract

In summer, phytoplankton community of the small river Sumka located in the Republic of Tatarstan Russia, comprised 119 alga taxa, with a rank below the genus. Chlorophyta were the most diverse group. There were no significant differences in the structure of microalgae communities in different ecotopes of the small river; Sørensen similarity index was 67%. The dominant complex of algal species was mainly represented by Cyanophyta, belonging to the M- and H1-types. However, in August, the dominant complex included the S1-type representatives. The degree of organic pollution of the watercourse may be estimated as transitional from oligo- to mezotrophic type considering the phytoplankton biomass and the composition of the dominant complex of algal species.