Zooplankton of Lake Tana Shore Zone (Ethiopia) at Different Periods of the Dry Season

The shore zone of Bahir Dar Gulf of Lake Tana has been studied at the beginning, peak, and the end of the dry season. A total of 145 species of zooplankton are identified, including 96 species of rotifers, 36 cladocerans, and 13 copepods. The highest species richness, abundance, and biomass of zooplankton are recorded at the peak of the dry season. A significant influence of planktivorous cyprinids on the quantitative and size characteristics of zooplankton is established. At the end of the dry season, the main prey for planktivorous Enteromius spp. is Cladocera, resulting in a decrease in abundance, biomass, and size–weight characteristics of these crustaceans. A decrease in the average individual weight of Cladocera, in turn, leads to an increase in the quantitative characteristics of Cyanobacteria, Euglenophyta, and Bacillariophyta, as well as the total abundance and biomass of phytoplankton. Interannual differences in the quantitative characteristics of zooplankton at the beginning of the dry season are determined by the total precipitation and air temperature.