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1.
The characteristic pattern of multiple colored layers in coastal stratified lakes in the process of separation from the White Sea 总被引：1，自引：1，他引：0
Krasnova Elena D. Matorin Dmitry N. Belevich Tatiana A. Efimova Ludmila E. Kharcheva Anastasiia V. Kokryatskaya Natalia M. Losyuk Galina N. Todorenko Daria A. Voronov Dmitry A. Patsaeva Svetlana V. 《中国海洋湖沼学报》2018,36(6):1962-1977
An unusual feature of the saline stratified lakes that were formed due to ongoing postglacial uplift on the White Sea coast is the presence of several differently colored thin layers in the zone with sharp gradients. Colored layers in five lakes at various stages of separation from the sea were investigated using optical microscopy, spectrophotometry, spectrofluorimetry, and photobiology. The upper greenish colored layer located in the aerobic strata of all lakes near the compensation depth of 1% light penetration contains green algae. In the chemocline, another layer, brightly green, red or pink, is dominated by mixotrophic flagellates. Despite the very low light intensities and the presence of H 2 S, active photosynthesis by these algae appears to be occurring, as indicated by high values of the maximum quantum yield of primary photochemistry, electron transport activity, photosynthetic activity of photosystem II, the fraction of active centers, and low values of heat dissipation. In the reduced zone of the chemocline, a dense green or brown suspension of anoxygenic phototrophs(green sulfur bacteria) is located. 相似文献
2.
A. G. Rozanov I. I. Volkov N. M. Kokryatskaya M. V. Yudin 《Lithology and Mineral Resources》2006,41(5):483-501
Iron and manganese in bottom sediments studied along the sublatitudinal transect from Kandalaksha to Arkhangelsk are characterized by various contents and forms depending on sedimentation environments, grain size of sediments, and diagenetic processes. The latter include redistribution of reactive forms leading to enrichment in Fe and Mn of the surface sediments, formation of films, incrustations, and ferromanganese nodules. Variations in the total Fe content (2–8%) are accompanied by changes in the concentration of its reactive forms (acid extraction) and the concentration of dissolved Fe in the interstitial water (1–14 μM). Variations in the Mn content in sediments (0.03–3.7%) and the interstitial water (up to 500 μM) correspond to a high diagenetic mobility of this element. Changes in the valence of chemical elements results in the redox stratification of sediment strata with maximum concentrations of Fe, Mn, and sulfides. Organic matter of sediments with a considerable terrestrial constituent is oxidized by bottom water oxygen mainly at the sediment surface or in anaerobic conditions within the sediment strata. The role of inorganic components in organic matter oxidation changes from surface sediments, where manganese oxyhydroxide dominates among oxidants, to deeper layers, where sulfate of interstitial water serves as the main oxidant. Differences in river runoff and hydrodynamics are responsible for geochemical asymmetry of the transect. The deep Kandalaksha Bay serves as a sediment trap for manganese (Mn content in sediments varies within 0.5–0.7%), whereas the sedimentary environment in the Dvina Bay promotes its removal from sediments (Mn 0.05%). 相似文献
3.
V. P. Shevchenko O. S. Pokrovsky A. S. Filippov A. P. Lisitsyn V. A. Bobrov A. Yu. Bogunov N. N. Zavernina E. O. Zolotykh A. B. Isaeva N. M. Kokryatskaya V. B. Korobov M. D. Kravchishina A. N. Novigatsky N. V. Politova 《Doklady Earth Sciences》2010,430(2):228-234
New data on the elemental composition of the Severnaya Dvina River, the largest one in the White Sea region, are presented. The elemental composition of the river water in May, the period of the snowmelt flood, is similar to the upper layer of the Earth’s continental crust due to the active erosion of the earth material in the catchment area. In August, the period of the summer low water, the impact of biogenic components increases and elevated concentrations of Cd, Sb, Mn, Zn, Pb, and Cu are observed. At other times, no significant pollution by heavy and rare-earth elements is registered. 相似文献
4.
E. O. Dubinina S. A. Kossova A. Yu. Miroshnikov N. M. Kokryatskaya 《Geochemistry International》2017,55(11):1022-1032
Oxygen and hydrogen isotope analysis was performed to study the processes of distribution of water masses and modification of their salinity in the Russian Arctic seas. A wealth of new isotopic data was obtained for freshwater (river runoff, Novaya Zemlya glaciers) and seawater samples collected along a set of extended 2D profiles in the Barents, Kara, and Laptev Seas. The study presents the first δD values measured for the Northeast Atlantic Deep Water NEADW dominated the water column of the Barents Sea (S = 34.90 ± 0.05, δD = +1.55 ± 0.4‰, δ18O = +0.26 ± 0.1‰, n = 44). This water mass is present in the Kara Sea and western Laptev Sea. The relationship between δD, δ18О, and salinity data was used to calculate the fractions of waters of different origin, including the fractions of continental runoff in waters of the Barents, Kara, and Laptev Seas. It was shown that the relationships between the isotopic parameters (δD, δ18О) and salinity in waters of the Kara and Laptev Seas is controlled by the intensity of continental runoff and sea ice processes. Sea ice formation is the main factor controlling the formation of the water column on the Laptev Sea shelf, whereas the surface waters of the middle Kara Sea are dominated by the contribution of river runoff. A very strong stratification in the Kara Sea is caused by the presence of a relatively fresh surface layer mostly contributed by estuarine water inputs from the Ob and Yenisei Rivers. The contribution of river waters reaches 40–60% in the surface layer in the central part of the sea and decreases to a few percent down 100 m water depth. Stratification in the western part of the Laptev Sea is controlled by the contribution of freshwater input from the Lena River and modification of salinity by sea ice formation. 相似文献
5.
N. M. Kokryatskaya I. I. Volkov T. P. Demidova T. S. Murzina 《Lithology and Mineral Resources》2003,38(6):552-563
Composition and distribution of different forms of sulfur in bottom sediments of the Severnaya Dvina River mouth and Rybinsk water reservoir are studied. The sediments are characterized by low accumulation rate of reduced sulfur compounds and high content of organic matter. Common features of the distribution of products of hydrogen sulfide in sediments of the river and water reservoir and the specificity of anthropogenic influence in each basin are established. 相似文献
6.
Seasonal biogeochemical and microbiological studies of small lakes in taiga zone of northwestern Russian (Arkhangelsk Province) 总被引：1，自引：0，他引：1
N. M. Kokryatskaya S. A. Zabelina A. S. Savvichev O. Yu. Moreva T. Ya. Vorobjeva 《Water Resources》2012,39(1):105-117
The results of biogeochemical and microbiological studies of three small lakes in southwestern Arkhangelsk province are presented.
The lakes differ in their morphometric characteristics, thermal and oxygen regimes, and the extent of anthropogenic impact
they experience. In the periods of summer and winter stratification, anaerobic water layers with higher phosphates, ammonium,
and sulfide sulfur (hydrogen sulfide) are found to form in the bottom horizon of deep-water zones of the lakes. The highest
concentrations of sulfide sulfur (150–210 μg dm−3) were recorded in the shallow Beloe Lake during winter low-water period, while in summer, sulfide concentration did not differ
from those obtained in other lakes (∼10 μg dm−3). The abundance of sulfate-reducing bacteria in lake bottom sediments varied from 10 to 100000 cell cm−3, and the rate of sulfate reduction process varied from 29 to 3746 μg S dm−3 day−1. Seasonal variations were revealed in hydrogen sulfide distribution over the water column and in the rate of sulfate reduction
process in the upper horizons of bottom sediments in the examined lakes. 相似文献
7.
O. S. Pokrovsky L. S. Shirokova S. A. Zabelina T. Ya. Vorobieva O. Yu. Moreva S. I. Klimov A. V. Chupakov N. V. Shorina N. M. Kokryatskaya S. Audry J. Viers C. Zoutien R. Freydier 《Aquatic Geochemistry》2012,18(2):115-139
The colloidal distribution and size fractionation of organic carbon and trace elements were studied in a seasonally stratified, organic-rich boreal lake, Lake Maselga, located in the European subarctic zone (NW Russia, Arkhangelsk region). This study took place over the course of 5?years in winter (glacial) and summer periods and during the spring and autumn overturn. A newly developed in situ dialysis technique (1, 10, and 50?kDa) and traditional frontal filtration and ultrafiltration (20, 10, 5, 0.22, and 0.025???m) were used to assess element concentrations at different depths. No significant changes in element concentrations occurred during filtration through sub-colloidal pore-size membranes (20?C0.22???m), suggesting a negligible amount of particulate Fe, OC, and associated trace metals. Large colloids (0.025?C0.22???m) were found to be the main carriers of poorly soluble elements (Fe, Al, Ti, Zr, REEs, Th, and U) during the summer and winter stratification. There was also a clear change in the vertical pattern of the percentage of colloidal Al, Ti, V, Cr, Fe, and Ni during different seasons, and the greatest proportion of colloidal forms was observed during the spring and autumn overturn. This pattern is most likely linked to the dominance of soil (allochthonous) organic carbon, which complexes with trace metals during these periods. During the summer seasons, autochthonous production of small exometabolites or photodegradation increases the concentration of the low-molecular weight fractions (<1?kDa) that dominate the speciation of divalent heavy metals in surface horizons. The colloidal status of As (30?C60%), which was documented in different seasons along the full depth of the water column, is most likely linked to the presence of organic complexes. The overall results of this study suggest that changes in the colloidal speciation of trace elements with depth in different seasons depend on changes in the redox conditions, the input of soil OM, the biodegradation of plankton biomass releasing dissolved organic matter in the bottom horizons, and in upward diffusion from the sediments. 相似文献
8.
The occurrence and distribution of reduced inorganic sulfur compounds in the waters of the White Sea and the Northern Dvina mouth are studied. Universal occurrence of micro-quantities of the above compounds in the oxic marine and fluvial waters is established. The White Sea water is found to be depleted of reduced sulfur, judging by the sum of reduced S forms (<0.5 mol), as compared with that in the water of the Black and Baltic seas. 相似文献
9.
Study of sediments and water column in the Black Sea has been carried out for a long time. However, issues of the formation of seawater and sediments in the geological (ancient) and Recent marine history remain debatable so far. Studies of the physical, biological, and biogeochemical settings in the northeastern part of the Black Sea carried out onboard the R/V Professor Shtokman in 2009 yielded new data on this region. The present paper reports the results of study of the chemical composition of bottom sediments and interstitial waters from the meridional profile extending from the Kerch Peninsula to the central part of the eastern deep-water depression. 相似文献
10.
Multidisciplinary studies of the separating lakes at different stage of isolation from the White Sea performed in March 2012 总被引：1，自引：0，他引：1