Аннотация:The article gives the results of studies of the hydroecological characteristics (water temperature,dissolved oxygen, chemical characteristics, production, methane concentration and emission, and the abundance of phytoplankton and benthos) in the Ivankovo Reservoir in August 2020–2021. Data of integrated surveys were used to show that the specific weather conditions and flowage have led to difference in these closely interrelated characteristics. The hot weather and the low flowage in 2021 contributed to an increase in oxygen consumption by bed soil, intensification of exchange processes at the water–bottom sediment interface, an increase in mineral phosphorus flux, more active blooming of the water body, decay of dead organic matter at higher temperature of the bottom layer. The role of bioturbation in changes in the rate of exchange processes between bottom water layer and sediments is demonstrated. The changes in the combination of processes in the water body caused an increase in methane flux into the atmosphere in 2021 compared with the previous year.
