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The areas that we studied in the North Atlantic (53 and 60°N) and in the Labrador Sea in the summer were characterized by a wide variability of the concentrations of dissolved and particulate organic matter and its elemental composition both in the surface and in the deep waters. The concentrations of dissolved and particulate Corg varied within 69–360 μM and 0.7–25.6 μM, respectively; the Norg and Porg contents varied within 1.4–22.2 μM and 0.02–0.86 μM, respectively. The maximal concentrations were registered in the photic layer and in the zones of mixing between the waters of different genesis. The particulate matter contribution to the total organic matter (OM) content varied from 0.5 to 15.4%. The waters of the photic layer contained more particulate Corg than those of the near-bottom layer. The values of the C/N molar ratios from the surface to the bottom over the entire aquatic area surveyed varied 5-to 6-fold; at that, the values of the C/P molar ratios varied more than tenfold. In the most productive waters, the values of the C/N ratios were close to the Redfield ratios (6–10). The values of the C/P molar ratios varied from 160 in the photic layer to 4831 in the deep waters. The pronounced non-uniformity in the spatial distribution of the OM and its elemental composition is caused not only by the penetration of the waters of different origins but also by the changes in the microplankton metabolism under mixing of these waters. 相似文献
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The expedition for studying the Volga R. was organized by the Institute of Oceanology, Russian Academy of Sciences and the Institute of Inland Water Biology, Russian Academy of Sciences, with the participation of the Institute of Geochemistry and Analytical Chemistry on the r/v Akademik Topchiev (June 2–18, 2016). The main objective of the expedition studies of the Institute of Oceanology, Russian Academy of Sciences, was to examine the sedimentation and biogeochemical processes in the mixing zone of the Volga and its tributaries with the aim to assess the present-day water quality and trends in its changes in the recent years. In this context, the study was focused on the aerosols of near-water layer, surface water, and bottom sediments along the route the Rybinsk Reservoir (Borok Settl.)–Lower Volga (Astrakhan C.). The methodology was based on a multidisciplinary study of dissolved compounds and suspended particles (<1 μm). The main attention was focused on studying the spatial variations of biogenic substances, organic compounds (Corg in suspension and solution), the suspension itself, and hydrcarbons. 相似文献
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The spatial-temporal variations in the amount and biochemical composition of organic matter and the rates of its transformations in the ecosystems of the Russian part of the Sea of Azov are analyzed. Maximum OM concentrations are typical for Taganrog Bay. A characteristic feature of the Sea of Azov is a large proportion of particulate organic matter, which in summer in Taganrog Bay exceeded 35%. It is shown that not only the concentration of organic matter changes from season to season, but also its elementary (Corg, Norg, and Porg) and biochemical composition (proteins, carbohydrates, and lipids). The major biochemical compound of dissolved organic matter is shown to be carbohydrates (13–28%), and that of particulate matter is protein (44–51%). The hydrolytic (phosphatase and protease) and oxidation-reduction enzymes of electron-transport system demonstrate a high activity in summer. The estimated short turnover times of phosphates and protein suggest the rapid and complete utilization of organic matter in the Sea of Azov. 相似文献
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Sapozhnikov V. V. Arzhanova N. V. Titov O. V. Torgunova N. I. Rusanov I. I. 《Water Resources》2001,28(1):54-62
A comprehensive hydrochemical and microbiological study was conducted in Lake Mogil'noe. The vertical hysrochemical structure of the lake was analyzed. Large amounts of mineral compounds containing biogenic elements and their organic forms are shown to accumulate in the anaerobic zone of the lake. An abrupt increase in the concentration of Corg is recorded in the near-bottom layer, where it is almost an order of magnitude higher than that in the anaerobic zone of the Black Sea at a depth of 2000 m. All the processes are found to be most rapid in the boundary layer between the aerobic and anaerobic zones (8.25–9.25 m), where the primary production attains its maximum, the concentration of sulfates abruptly increases relative to the aerobic and anaerobic zones, microorganism population is maximum, as are the rates of sulfate reduction and glucose consumption by heterotrophic organisms. 相似文献
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The intensity of the processes of organic matter (OM) destruction in the deep-water part of the Arctic Basin is considered
in terms of the activities of hydrolytic enzymes (alkaline phosphatase and proteases) and of redox enzymes of the electron
transport system (ETS). High concentrations of mineral phosphorus are shown to cause low phosphatase activity (0.000–0.005
μM P/l h). The average time of the phosphate recycling amounted to about 240 h. The ranges of the total and specific activity
of protease are 0.000–0.192 mg of azocasein/(l h) and 0.00–3.57 mg of azocasein/h mg of protein, respectively. It is found
that the microplankton production of exo- and endopeptidase in the Arctic Basin is controlled by the concentration of nitrates
in the water. The values of the total and the specific activities of the ETS enzymes vary within 0.27–8.96 μl O2/(l h) and 8.4–583 μl O2/mg of protein h, respectively. It is shown that the maximum values of the total activities of the hydrolytic and redox enzymes
are characteristic for the photic layer. The vertical fluxes of organic carbon from the photic layer, being calculated by
the activity of the ETS enzymes, amounted to 220–600 g of Corg/year m2. The presence of ice intensifies the redox processes by factors of 2–15. 相似文献
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The considered area of the Russian sector of the Arctic Basin was characterized in August–September of 2008 by the wide horizontal
and vertical variability of the concentrations of dissolved and particulate organic matter (OM), as well as of its elemental
and biochemical composition. The concentration ranges amounted to 51.6–434 and 2.2–18.6 μM, respectively, for the dissolved
and particulate Corg; up to 1.9–30.2 μM for Norg; and up to 0.08–1.53 μM for Porg. The maximum values were characteristic for the Russian Arctic shelf. The analysis of the authors’ and published data showed
that a pronounced accumulation of OM, mainly in the dissolved form, took place in the Arctic Basin within the past 12 years.
The concentrations of dissolved OM were higher in the western sector of the Russian Arctic than those in the eastern sector.
The main biochemical components in all the waters constituting the Arctic Ocean are carbohydrates and lipids for dissolved
OM and proteins and carbohydrates for particulate matter. 相似文献
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A. I. Agatova N. V. Arzhanova N. M. Zozulya N. M. Lapina N. I. Torgunova Yu. A. Golovina 《Water Resources》2014,41(1):65-77
Data on biochemical ecosystem monitoring of Kiziltashskie Limans are given. The limans are the only natural water bodies in the Russian Black Sea where pascual breeding of very valuable commercial fish is implemented. The presented concentrations of dissolved and particulate organic matter are 2–5 times greater than the values typical of the coastal zone of the Black Sea (from 7.9 to 27.7 mg/L and from 0.3 to 1.5 mg/L, respectively). The main biochemical component of the dissolved organic matter is carbohydrates, and that of particulate matter is protein. The share of particulate organic matter in the Kiziltashskie Limans never exceeds 7%. The elemental (C, N, P) and biochemical composition of organic matter is studied (carbohydrates, proteins, lipids). The rates of enzymatic reactions vary from season to season. Thus, processes of hydrolytic splitting of phosphor-organic compounds during primary production are very intensive in the spring, while processes of organic matter oxidation, catalyzed by enzymes of electron-transport system, are intensive in the summer. 相似文献