The urgency of this work is due to the catastrophic increase in overgrowth of reservoirs with higher aquatic plants (HAP) compared to previous decades and, as a result, the strengthening of negative impact on aquatic organisms living in the overgrown areas. For example, the analysis of space images in 2019 conducted at the Institute of Hydrobiology, showed that there was an increase in floating leaves vegetation area from 42 km2 to 121 km2. The negative impact on aquatic organisms, particularly fish, is that the overgrowth of HAP leads to the loss of spawning and feeding areas and, as a result, to a decrease in fish productivity. It is estimated that the damage to the biodiversity of native fish species is directly proportional to the increase in overgrown area of these aquatic plants. On the other hand, some authors (Sakevych, Usenko, 2003; Romanenko et al., 2005; Kirpenko, Usenko, 2012) note a decrease in the intensity of algal bloom due to the consumption of excess nutrients by HAP and under the influence of their metabolites, and experimentally validate it. HAP can thus be used to regulate the number of phytoplankton and, accordingly, to solve the current problem of reservoirs in Ukraine related to blooming.
The main purpose of this work is to study the interrelation between higher aquatic plants and other components of hydroecosystems, including phytoplankton and fish, in the reservoirs of the Dnipro cascade (by the case of Kyiv and Kaniv reservoirs). As a result of this project, the overgrowing processes of Kyiv and Kaniv reservoirs with mass HAP species will be studied, the optimal values of projective water surface coverage will be determined, which will help to improve the situation of water blooming in the Dnipro cascade reservoirs, increase fish capacity and achieve the highest ecological potential of the Dnipro cascade reservoirs.