LAUSR

Abstract Studies on zooplankton in the littoral zone of Bahir Dar Gulf of Lake Tana (Ethiopia) carried out in March 2018 have revealed its high qualitative characteristics and species richness (Rotifera (61 species) Copepoda (4), Cladocera (13)). High quantitative characteristics were also recorded. The maximum abundance and biomass of zooplankton were recorded in the sites with hydatophytes (the degree of overgrowing 10–50%). These parameters are significantly lower in the sites with helophytes (the degree of overgrowing up to 100%). It is concluded that the difference between zooplankton communities in the sites with helophytes and in the sites with submerged macrophytes within particular stations is determined by the top-down effect of predators. The Shannon index increases and quantitative parameters of plankton invertebrates decrease with increasing predator press.