排序方式： 共有70条查询结果，搜索用时 265 毫秒
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A. V. Drits M. D. Kravchishina A. F. Pasternak A. N. Novigatsky O. M. Dara M. V. Flint 《Oceanology》2017,57(6):841-854
The role of zooplankton in the vertical mass flux in the Kara and Laptev seas was studied during cruise 63 of the R/V Akademik Mstislav Keldysh in August–October 2015. Mass fluxes were estimated using sediment trap samples. The maximum values of the total vertical flux (19600 mg m?2 day?1) and particulate organic carbon (POC) flux (464 mg C m?2 day?1) were measured close to the Lena River Delta in the Laptev Sea. In the Kara Sea, the total flux (80–2700 mg m?2 day?1) and the POC flux (17–130 mg C m?2 day?1) were substantially higher than the estimates published earlier. The fecal pellet flux varied from 2 to 92 mg C m?2 day?1 and made up 4–190% of the total organic carbon flux. The mineral composition of fecal pellets largely mirrored that of suspended particulate matter. Clay minerals in the fecal pellets were more abundant than in particulate matter in the areas with noticeable freshwater impact. The flux of zooplankton carcasses varied from 0.1 to 66.4 mg C m?2 day?1 and made up 0.2–72% of total POC flux. The results are discussed in relation to the abundance and composition of zooplankton, the concentration and composition of suspended particulate matter, hydrophysical conditions, and methods of sample preparation for analysis. 相似文献
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Pautova L. A. Silkin V. A. Kravchishina M. D. Chultsova A. L. Lisitzin A. P. 《Doklady Earth Sciences》2020,490(1):46-50
Doklady Earth Sciences - This paper reports on a study of the phytoplankton calcium carbonate pump in the Norwegian and Barents seas in July–August 2017. Coccolithophores, a unique marine... 相似文献
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A. P. Lisitzin A. N. Novigatsky R. A. Aliev V. P. Shevchenko A. A. Klyuvitkin M. D. Kravchishina 《Doklady Earth Sciences》2015,465(2):1253-1256
A new approach using dispersed organic matter of the water column in sedimentation traps in comparison with the surface layer of the bottom sediments is applied for the study of marine sedimentation. This approach provides the opportunity for an in situ (by fluxes of sedimentary matter in the water column) study of modern sedimentation in the surface layers of the bottom sediments and tracing the changes in the environment and climate at a new technological level. This also allows us to choose the reverse task: to reconstruct the fluxes of the matter and chemical elements in ancient seas by the rates (or absolute masses) of sedimentation. 相似文献
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The biogeochemistry of some heavy metals and metalloids in the Ob River estuary-Kara Sea section 总被引：1，自引：0，他引：1
L. L. Demina V. V. Gordeev S. V. Galkin M. D. Kravchishina S. P. Aleksankina 《Oceanology》2010,50(5):729-742
The biogeochemical behavior of the group of heavy metals and metalloids in the water (including their dissolved and suspended
particulate forms), bottom sediments, and zoobenthos was studied in the Ob River estuary-Kara Sea section on the basis of
the data obtained during cruise 54 of the R/V Akademik Mstislav Keldysh in September–October 2007. The changes in the ratios of the dissolved and suspended particulate forms of Fe, Mn, Zn, Cu,
Pb, Cd, and As were shown, as well as the growth of the fraction of adsorbed forms in the near-bottom suspended particulate
matter under the mixing of the riverine and marine waters. The features of the metals’ accumulation in the typical benthic
organisms of the Ob River estuary and the Kara Sea were revealed, and their concentrating factors were calculated based on
the specific conditions of the environment. It was shown that the shells of the bivalves possessing a higher biomass compared
to the other groups of organisms in the Ob River estuary play an important role in the deposition of heavy metals. The mollusks
of the Ob River estuary accumulate Cd and Pb at the background level, whereas the Cu and Zn contents appear to be over the
background level. 相似文献
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M. D. Kravchishina I. N. Mitzkevich E. F. Veslopolova V. P. Shevchenko A. P. Lisitzin 《Oceanology》2008,48(6):837-854
During the summer periods of 2003–2005, the spatial and vertical distributions of the suspended particulate matter and bacteria in stratified and homogeneous waters of the White Sea was studied. The results of the study of various quantitative characteristics of the suspended particulate matter (first of all, the area of the surface and the volumetric and mass concentrations) and the abundance of microorganisms in the water are discussed. A direct correlation between the value of the surface area of the suspended particulate matter and the total number of bacteria in the water is revealed. However, it was manifested only during the early summer period of the observations and was not expressed at the end of the summer. The enhanced surface area of the suspended particulate matter can indicate the higher biochemical activity of its particles. The influence of the pelitic fraction on the bacteria abundance in different parts of the sea during the summer is estimated. 相似文献
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