How have Dnieper River reservoirs affected plankton in the lower river?

The construction of reservoirs along the Dnieper River has significantly altered its natural ecology and hydrology. Specifically, in the lower course of the river, the amount of plankton decreases sharply under the influence of these reservoirs.1

The damming of the river has led to several broader environmental changes, including reduced seasonal flow variations, a decline in the annual outflow of the river by approximately 20 percent, and increased pollution from industrial, urban, and agricultural runoff. These modifications have also hindered the upstream movement of anadromous fish and caused damage to the wetlands surrounding the river's estuary.2