Hydrobiological Journal

Chlorophyll α Content in the Near-Bottom Layer of Water of the Rybinsk Reservoir (the Upper Reaches of the Volga River, Russian Federation)

RESUMO

Long-term data on the spatial and temporal dynamics of chlorophyll α (Chl α) content in the near-bottom layer of water of the Rybinsk Reservoir obtained using the fluorometric method are given in the paper. Relationship between the content of Chl α in the near-bottom layer of water and that in the photosynthesizing zone and bottom sediments was analyzed. It has been shown that in terms of the average and prevailing values, the photosynthesizing zone is assigned to eutrophic category, whereas the near-bottom zone - to mesotrophic one. The obtained results supplement the present view on the processes of production in large water bodies. They suggest that the newly formed organic matter is of considerable importance in the formation of productivity of various biotopes. It has been shown that even under dynamic conditions the pattern of ecosystem functioning remains almost unchanged. Some specific features are observed in the years significantly differing in their hydrometeorological conditions.