Ecological Systems and Devices Annotation << Back THE EFFECT OF ZOOPLANKTON ON THE DEVELOPMENT OF ALGAE AND CYANOBACTERIA IN A POND SUBJECT TO A HIGH ANTHROPOGENIC LOAD T.N. Gerasimova, P.I. Pogozhev, A.P. Sadchikov It is shown that, in the absence of trophic press of fi sh and despite the high biogenic load, zooplankton can regulate the development of cyanobacteria. The main consumer of algae and cyanobacteria in the pond is large-size Daphnia longispina. At a high concentration of nutrients, blooming is suppressed because of the high abundance and biomass of daphnia. At a maximal biomass of cyanobacteria Aphanizomenon flexuosum, the daily consumption of edible phytoplankton fractions by D. longispina organisms can reach 42 times the biomasses recorded at the moment of sampling in the water body. Daphnia maintain cyanobacteria biomass at the level of up to 2 mg/L. They actively consume planktonic algae and clarify water mass in the pond. The excessive biomass of phytoplankton is transferred by filterers into bottom sediments and utilized by benthic fauna. This leads to the prevention of blooming of the water body and improves its water quality. Keywords: zooplankton; phytoplankton; cyanobacteria; Daphnia longispina; Aphanizomenon flexuosum; mineral phosphorus; water transparency; filterers-phytophages. DOI: 10.25791/esip.03.2021.1218 Pp. 45-52.