PHYTOPLANKTON OF THE HRUSOV-RESERVOIR ON THE RIVER DANUBE

In order to assess the possible changes in the abundance of phytoplank ton in the Hrusov Reservoir a predictive model of phytoplankton biomas s was modified. The was model formerly developed for the Hrusov-Dunaki liti Reservoir on the River Danube. The original concept of model was later applied for the building up Hrusov Reservoir (variant C). The re tention time, depth and optical properties of water, together with sea sonal changes of temperature, illumination, and inflow concentration o f phytoplankton were considered as the most important factors influenc ing the growth of algae in the reservoir. Diatoms are expected to domi nate but the share of green coccal algae may increase, especially in t he shallow parts of the reservoir with restricted water exchange. Our results of qualitative and quantitative phytoplankton analyses are in a rather good accordance with our prognoses. Both previous and present states of the phytoplankton development are the topics of a detailed comparison.