Virio- and Bacterioplankton of the Coastal Water of the Moscow River.

The first study on the dynamics of virioplankton abundance (VA) in the coastal waters of the Moscow River in the autumn-winter period at stations differing in the level of anthropogenic impact has been performed. The VA in the waters of the more polluted Dzerzhinsky st. (with a mean of 235.6 ± 71.5 × 106 particles/mL, varying from 167.79 to 397.39 × 106 particles/mL) was higher than in the waters of the less polluted Tushino st. (with a mean value of 129.0 ± 39.6 × 106 particles/mL, varying from 61.01 to 186.85 × 106 particles/mL) throughout the study. Positive correlation was observed (R = 0.6, p < 0.01) between the abundances of virio- and bacterioplankton in the waters of the Dzerzhinsky st. We assume that a significant proportion of the virioplankton of the coastal waters o of the Moscow River is represented by bacteriophages. Three quarters of the differences in the VA dynamics were significantly positively correlated with the content of ammonium and phosphates in the waters at the Dzerzhinsky st. Apparently, an increase in the nutrient load is the main factor responsible for the high VA in the waters of the Moscow River in the autumn-winter period.

Effect of invasive ctenophores Mnemiopsis leidyi and Beroe ovata on low trophic webs of the Black Sea ecosystem.

The study focuses on the impact of life excretion and mucus released by the "biological pollutants" invasive ctenophore Mnemiopsis leidyi and its predator Beroe ovata on the marine environment and lower trophic levels of the Black Sea ecosystem (bacteria, pico-phytoplankton, nano-autotrophic/heterotrophic flagellates, micro-phytoplankton, chlorophyll a, primary production (PP), micro-zooplankton). The chemical and biological variables were analysed in two sets of lab experiments with natural communities from mesotrophic (Gelendzhik) and eutrophic (Varna) coastal waters. While both species altered the chemical properties of experimental media, exerting structural and functional changes in the low food-web biological compartments, the results showed a stronger effect of B. ovata, most likely related to the measured higher rate of excretion and amount of released mucus. In addition the alterations in the Gelendzhik experiment were more pronounced, indicating that environmental implications on lower food-web are more conspicuous in mesotrophic than in eutrophic coastal waters.

[Monitoring of the Moskva River Water Using Microbiological Parameters and Chlorophyll a Fluorescence].

The results of investigations of three Moskva River sites with different degree 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 Vorobyovy Gory) were similar and 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 x 10(6) cells/mL and 14%), that in the less polluted water of Tushino and Vorobyovy Gory (0.14 x 10(6) cells/mL; 6% and 0.15 x 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 chlorophyll a content, that was typical of clear water and was observed in Tushino, did not occur in Dzerzhinskii. We recommend combined application of these microbiological parameters and characteristics of chlorophyll a fluorescence for a monitoring.