Influence of trophic status on zooplankton structure in Chelyabinsk region lakes (Russia)

Abstract

Abstract Eutrophication of water-bodies, as well as lakes, is currently one of the crucial problems of both theoretical and applied ecology. Zooplankton is sensitive to changes in the ecological state of different types of reservoirs. The article analyses differences and similarities of zooplankton communities in 10 lakes of Kisegach - Miassovo hydrological system of Chelyabinsk region (Russia). The current research aims at identifying taxonomic structure of zooplankton communities of the lakes in Chelyabinsk region (Russia) and stating the influence of some abiotic factors on its formation. Integrated samples were gathered in summer 2015 - 2019. The given paper studied the correlation of the main taxonomic groups of zooplankton, marked a regular decrease in the number of zooplankton species under adverse environment. When the trophic level of water in natural fresh lakes changes in the direction of oligotrophic-mesotrophic-eutrophic, the total number of zooplankton decreases from 400.90 individuals per L−1 to 106.06 individuals per L−1. In the same direction, the number of Cladocera representatives decreases (from 362.03 individuals per L−1 to 66.34 individuals per L−1) and the number of Copepoda representatives decreases (from 34.01 individuals per L 12.67 individuals per L−1), and the number of Rotifera representatives increases (from 6.97 individuals per L−1 to 26.60 individuals per L−1).