Keyword: «toxic cyanobacteria»

The main issues of biosafety of eutrophicated water reservoirs, which are used as drinking-water sources, are related with the risk of mass development of toxic cyanobacteria. The factor of this risk is, in particular, a character of feedbacks in zooplankton, some species of which in the course of their nutrition eliminate repre-sentatives of phytoplankton. In turn, these representatives are the competitors to cyanobacteria and saturate water with the products of their metabolism – nutrients for phytoplankton. The authors describe the relations for these species, which open the new approaches to the prediction of the risk of mass development of cyanobacteria in eutrophicated hydrobiocoenoses.