plankton

FREE NUCLEOTIDES AND CHLOROPHYLL CONTENTS IN THE PLANKTON OF THE UPPER VOLGA RESERVOIRS

The content and distribution of chlorophyll (CHL) and free total nucleotides (FTN) in the plankton of the Ivankovo, Uglich (August 2005), Rybinsk and Sheksna (July 2007) reservoirs were studied. With the average CHL from 7.6±1.5 to 13.1±1.4 µg/L and the average FTN content from 76±8 to 138±20 µg/L, the highest values were obtained in the eutrophic Ivankovo reservoir. The relation of CHL and FTN with environmental factors is analyzed. It has been shown that under stable external conditions, the plankton distribution over the reservoirs is characterized by moderate variability.