ISSN 0026-2617, Microbiology, 2015, Vol. 84, No. 6, pp. 811–821. © Pleiades Publishing, Ltd., 2015. Original Russian Text © I.V. Mosharova, V.V. Il’inskii, D.N. Matorin, S.A. Mosharov, A.Yu. Akulova, F.F. Protopopov, 2015, published in Mikrobiologiya, 2015, Vol. 84, No. 6, pp. 712–724. 811 The first quantitative study of bacterial population in Moskva River water was carried by Stroganov et al. in 1911 (Stroganov, 1913). The next detailed study was carried out in 1944. Since 1950, the river was surveyed regularly in different seasons (Il’inskii et al., 1998; Popova, 1972; Shchegolkova et al., 2012). Investiga- tion of the state and productivity of aquatic ecosys- tems affected by the megalopolis remain important in view of considerable expansion of its borders. Assess- ment of the informativeness of the major hydrobiolog- ical parameters, including the microbiological ones, is therefore required. Bacterio- and phytoplankton are the main groups responsible for the basic processes of degradation and production of organic matter (OM). Such parameters as total bacterioplankton abundance, numbers of metabolically active cells, and numbers of saprotrophic microorganisms reflect the processes of OM decomposition in an ecosystem. The content of chlorophyll a, the major photosynthetic pigment, determines the patterns of phytoplankton develop- ment and spatial distribution, while the parameters of chlorophyll a fluorescence may be used for rapid assessment of its photosynthetic activity (Matorin et al., 2004; Matorin and Rubin, 2012; Shchegolkova et al., 2012). Such comprehensive studies using up-to- date methods have not been carried out in the Moskva River in recent years. The goal of the present work was to carry out com- prehensive investigation of the yearly dynamics of microbiological parameters, as well as of chlorophyll a content and fluorescence in the surface layer of three sites of the Moskva River affected to a different degree by a megalopolis and to assess the informativeness of selected hydrobiological parameters. MATERIALS AND METHODS The study was carried out at three stations along the Moskva River flow: in Tushino (st. Tushino) where river waters enter the city boundaries, in the central part of Moscow (st. Vorob’evy Gory), and beyond Moscow border, in the town of Dzerzhinskii (st. Dzerzhinskii). The samples were collected monthly (except for February 2010) from October 2009 to December 2010. The sampling locations were 3 to 5 m from the shore at Monitoring of the Moskva River Water Using Microbiological Parameters and Chlorophyll a Fluorescence I. V. Mosharova a, 1 , V. V. Il’inskii a , D. N. Matorin a , S. A. Mosharov b , A. Yu. Akulova a , and F. F. Protopopov a a Biological Faculty, Lomonosov Moscow State University, Moscow, Russia b Shirshov Institute of Oceanology, Russian Academy of Sciences, Moscow, Russia Received May 18, 2015 Abstract—The results of investigations of three Moskva River sites with different degrees of pollution using a complex of microbiological characteristics and the parameters of chlorophyll a fluorescence are presented. We determined that the bacterioplankton seasonal dynamics at less polluted waters (Tushino and Vorob’evy Gory) were similar but differed significantly from one in more polluted waters (Dzerzhinskii). The number of bacteria with active electron transport chain, as well as their share in the bacterioplankton structure, was higher in the water of Dzerzhinskii (average annual values of 0.23 × 10 6 cells/mL and 14%) than that in the less polluted water of Tushino and Vorob’evy Gory (0.14 × 10 6 cells/mL; 6% and 0.15 × 10 6 cells/mL; 7%, respectively). From April to October, the content of chlorophyll a and its photosynthetic activity were the highest in Tushino. In Dzerzhinskii, during spring the increase in photosynthetic activity commenced earlier and was more intensive that the increase in chlorophyll a content; i.e., the increase in phytoplankton biomass was temporarily suppressed. We suggest association of this phenomenon with suppression of organic matter synthesis by phytoplankton due to the high water pollution in Dzerzhinskii. The second autumn peak of chlo- rophyll a content, which was typical of clear water and was observed in Tushino, did not occur in Dzerzhin- skii. We recommend combined application of these microbiological parameters and characteristics of chlo- rophyll a fluorescence for further monitoring. Keywords: monitoring of water pollution, bacterioplankton, active bacteria, chlorophyll a fluorescence, Moskva River DOI: 10.1134/S0026261715060065 1 Corresponding author; e-mail: ivmpost@mail.ru EXPERIMENTAL ARTICLES