Diversity of Hydrobionts of the Different Type Salt Lakes in the South-Eastern Transbaikalia in the Period of Moisture Changing

Abstract

The results of a complex hydrochemical and hydrobiological study of salt lakes in the South-Eastern Transbaikalia during the period of moisture change are presented. The studied lakes, according to the geochemical classification, belong to the chloride and soda types. The taxonomic diversity of aquatic biota decreases while the salinity increases and the hydrochemical type of lakes changes from soda oligo-mesohaline (4–16 g/L) to chloride eu-hyperhaline (33–70 g/L) and to soda hyperhaline (128–231 g/L). In soda oligo-mesohaline and chloride lakes the phytoplankton taxonomic composition is similar and is represented by green and diatom algae, as well as cyanobacteria. Submerged aquatic plants are represented by Stuckenia pectinata in soda oligo-mesohaline lakes. Ruppia maritime was found in the Dabasa-Nor chloride lake. In zooplankton and zoobenthos, rotifers and chironomids dominated respectively. Quantitative characteristics of phytoplankton in oligo-mesohaline lakes are lower than in hyperhaline soda and eu-hyperhaline chloride lakes. The phytomass of submerged aquatic plants, on the contrary, is higher in oligo-mesohaline lakes. In the hypersaline soda lake Borzinskoye, zoobenthos and zooplankton organisms are represented by planktonobenthos species, namely Anostrica, with low abundance.