Heterotrophic Nanoflagellates in the Pelagic Zone and Sediments of the Eastern Laptev Sea

Oceanology - For the first time, the species composition of heterotrophic nanoflagellates, their quantitative characteristics, and abundance and biomass of their main food objects—bacteria...     

Microbiological Processes in the Gor'kovskoe Reservoir

The abundance of various groups of bacteria and the rate of microbiological processes of organic decay and methane cycle in the water and soils of the Gor'kovskoe Reservoir are determined, and the ecological characterization of its river reach is presented. The autochthonous and allochthonous impact on the bacterial community of the reservoir was found to be tolerable; however, some restricted areas were revealed, where the ecosystem is strongly affected by domestic and industrial wastewater, and where the abundance and activity of anaerobic methane-producing and sulfate-reducing soil bacteria increase.     

Distribution and Relationship between Heterotrophic Organisms and Viruses on the East Siberian Sea Shelf

Oceanology - The distribution of heterotrophic bacteria, viruses, and heterotrophic nanoflagellates was studied in the shelf waters of the East Siberian Sea along the meridional transect from the...     

Distribution and Activity of Bacteriobenthos in the Upper Volga Reservoirs

Regularities of bacteria distribution in the bottom sediments of the Upper Volga reservoirs are studied. Human-induced changes in the structure and activity of bacteriobenthos communities occurring in water body areas adjacent to towns and settlements are described. Reservoir zones subject to long-term human impact are distinguished.__________Translated from Vodnye Resursy, Vol. 32, No. 4, 2005, pp. 489–499.Original Russian Text Copyright © 2005 by Kosolapov, Krylova, Kopylov.     

Seasonal and Year-to-Year Variations of Phytoplankton Primary Production in the Rybinsk Reservoir: The Effect of Weather and Climate Variations

Water Resources - The seasonal and long-term dynamics of phytoplankton primary production has been studied in the Rybinsk Reservoir (Upper Volga) in 2005–2014. A positive correlation has been...     

Pollution Degree of the Don River Water

Water Resources - The formation and distribution of river flow characteristics in the Don basin have been catholically analyzed, depending on the present-day climatic conditions in the central...     

Assessing the Abundance,Biomass, and Production of Heterotrophic Bacteria in Upper Volga Reservoirs

Water Resources - Two reservoirs in the Upper Volga were studied to determine the abundance, biomass, and production of planktonic, epiphyte, and benthos bacterial communities and to assess their...     

Hydrological hazards in Russia: origin,classification, changes and risk assessment

Hydrological extreme events pose an imminent risk to society and economics. In this paper, various aspects of hydrological hazards in Russia are analysed at different scales of risk assessment. It is shown that the number of hydrological and meteorological hazards in Russia has been growing every year. The frequency of economic losses associated with extreme low flow in this century has increased by factor five compared to the last decade of the previous century. With regard to floods, an interesting spatial patter can be observed. On the one hand, the number of floods in the Asian part of the country has increased, whereas on the other hand, the number and intensity of floods in estuarine areas in the European part of Russia have significantly reduced since the middle of the twentieth century, especially in the 2000s. This decrease can be attributed to runoff flooding in the mouths of regulated rivers, with an effective system of flood and ice jam protection. The analysis shows that there is an 8–12-year periodicity in the number of flood occurrences and that flood surges have intensified over the last 110 years, especially on the European territory of Russia. An integrated index that accounts for flood hazards and socio-economic vulnerability was calculated for each region of Russia. A classification of flood risk was also developed, taking into account more than 20 hydrological and social–economic characteristics. Based on these characteristics, hazard and vulnerability maps for entire Russia were generated which can be used for water management and the development of future water resources plans.

     

Methane Formation and Consumption Processes in the Littoral Zone of the Rybinsk Reservoir

Concentrations of CH₄ and the rates of processes of its transformation and oxidation are evaluated in the littoral zone of a large polimictic reservoir in the open-water period. The production of CH₄ in bottom sediment was found to vary within 0.07 to 17.32 mmol/(m² day) and attain its maximum in the late summer. The main factors to control the activity of methanogens were found to be the temperature and the availability of substrates (acetate and H₂/CO₂). The newly formed methane was oxidized in the top soil layer with a rate of 0.09–17.15 mmol/(m² day). The rates of processes of biogenic production and consumption of CH₄ in silts of screened coast were higher than those in sands of the open coastal zone. Methanotrophs were found to consume >87% of the methane produced. These bacteria accounted for 20 and 8% of the total oxygen consumption by bottom sediment in the screened and open littoral zones, respectively.     

Microbiological Characterization of the Ivan'kovo Reservoir Water

The current state of the Ivan'kovo Reservoir bacterioplankton is assessed. Data on the total number, biomass, and production of planktonic microflora are presented. The concentrations of active bacteria and their detritus are determined. The distribution of saprophytic microflora is studied.