Interannual changes in the summer zooplankton in the lakes of the Khopyor River flood plain

Abstract

By zooplankton indices, the lakes of the Khopyor River flood plain in the reserve area can be classified as eutrophic–hypertrophic reservoirs. In the years of intensive overflow of the Khopyor River, the trophic level of the flood plain lakes has been revealed to increase; the variety, numbers, biomass, and relative abundance of rotifers in the zooplankton increase. It is most evident in the coastal zone, where the total number and biomass of the zooplankton decreases. In the central parts of the lakes, the number and biomass of zooplankton increase, as does the proportion of crustaceans and the variety of rotifers. In the zooplankton of the central parts of the reservoirs with the longest term of coastal flooding after high water, the fraction of rotifers in the total number and the biomass of zooplankton communities increases. Simultaneously, the annually flooded lakes are characterized by maximum specific richness.