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1.
V. M. Sergeeva I. N. Sukhanova E. I. Druzhkova S. A. Mosharov V. V. Kremenetskiy A. A. Poluhin 《Oceanology》2016,56(1):107-113
The phytoplankton community and its distribution were investigated in the eastern branch of the St. Anna Trough and over the adjacent Kara Sea shelf in September 2011 and in August 2014. The spatial and seasonal differences in the phytoplankton structure were analyzed in connection with ice melting and changes in the temperature, salinity, and biogenic regime. Four 4 zones were defined: the Kara Sea shelf, the upper part of the St. Anna Trough slope, the lower part of the St. Anna Trough slope, and its deep part. It was shown that over the Kara Sea shelf where riverine runoff influence was observed, the phytoplankton community differs from the community of the St. Anna Trough in both investigated periods: in September and August. Rearrangement of the phytoplankton community was observed in the frontal zone associated with the upper part of the slope in September of 2011. The main features of this rearrangement were a change in dominant species composition and a 1.5–2-fold increase in the number and biomass of algae. Over the lower part of the slope and deep area of the St. Anna Trough in August 2014 and September 2011, the phytoplankton community was at different successive stages: in August, at the late spring and summer stage, and in September, at the summer–autumn stage. 相似文献
2.
S. A. Mosharov 《Oceanology》2010,50(6):884-892
The studies were performed from September 10 to 29 of 2007 in the Kara Sea in transects westward of the Yamal Peninsula, near
the St. Anna Trough, in the Ob River’s estuary, and on the adjacent shelf. The concentration of chlorophyll a in the euphotic layer changed from 0.02 to 4.37 mg/m3, amounting on the average to 0.76 mg/m3. The primary production in the water column varied from 10.9 to 148.0 mg C/m2 per day (the mean was 56.9 mg C/m2 per day). It was shown that frontal zones divided the Kara Sea into distinct areas with different productivities. The maximum
levels of the primary production were measured in the deep part of the Yamal transect (132.4 mg C/m2 per day) and the shallow Kara Sea shelf near the Ob River’s estuary (74.9 mg C/m2 per day). The characteristics of these regions were the low salinity of the surface water layer (19–25 psu) and the elevated
silicon content (12.8–28.1 μg-atom Si/l), which is explainable by the river water inflow. The frontal zones of the Yamal Current
in the Yamal and Ob transects displayed high values of the assimilation numbers, amounting to 2.32 and 1.49 mg C/mg of chlorophyll
per h, respectively (the maximal for the studied regions). 相似文献
3.
A. G. Zatsepin E. G. Morozov V. T. Paka A. N. Demidov A. A. Kondrashov A. O. Korzh V. V. Kremenetskiy S. G. Poyarkov D. M. Soloviev 《Oceanology》2010,50(5):643-656
During cruise 54 of the R/V Akademik Mstislav Keldysh to the southwestern Kara Sea (September 6 to October 7, 2007), a large amount of hydrophysical data with unique spatial resolution
was obtained on the basis of measurements using different instruments. The analysis of the data gave us the possibility to
study the dynamics and hydrological structure of the southwestern Kara Sea basin. The main elements of the general circulation
are the following: the Yamal Current, the Eastern Novaya Zemlya Current, and the St. Anna Trough Current. All these currents
are topographically controlled; they flow over the bottom slopes along the isobaths. The Yamal Current begins at the Kara
Gates Strait and turns to the east as part of the cyclonic circulation. Then, it turns to the north and propagates along the
Yamal coast over the 100-m isobath. The Eastern Novaya Zemlya Current (its core is located over the eastern slope of the Novaya
Zemlya Trough) flows to the northeast. Near the northern edge of Novaya Zemlya, it encounters the St. Anna Trough Current,
separates from the coast, and flows practically to the east merging with the continuation of the Yamal Current. A strong frontal
zone is formed in the region where the two currents merge above the threshold that separates the St. Anna Trough from the
Novaya Zemlya Trough and divides the warm and saline Arctic waters from the cooler and fresher waters of the southwestern
part of the Kara Sea. This threshold, whose depth does not exceed 100–150 m, is a barrier that prevents the spreading of the
Barents Sea and Arctic waters to the southwestern part of the Kara Sea basin through the St. Anna Trough. 相似文献
4.
Data on the bacterial and primary production, which were obtained simultaneously for the same water samples, are presented
for three regions of the Kara Sea. The samples were collected for the transect westwards of the Yamal Peninsula, along the
St. Anna Trough, and the transect in Ob Bay. Direct counts of the DAPI-stained bacterial cells were performed. The bacterial
production and grazing rates were determined using a direct method when metabolic inhibitors vancomycin and penicillin were
added. The primary production rates were estimated using the 14C method. 相似文献
5.
Research was implemented from September 15 through October 4, 2011 in the Kara Sea along transects located southeastwards Novaya Zemlya, in the St. Anna Trough, the Yenisei River estuary, and the adjacent shelf. The concentration of chlorophyll a was the highest in the photic zone (0.05–2.30 mg/m3, on average, 0.80 ± 0.37 mg/m3). The maximal concentration of Chl a at most of the stations located in the water layer of 7–30 m. Integral primary production in the water column varied from 3.0 to 151.0 mg C/m2 per day, on average, 37.2 ± 36.6 mg C/m2 per day. The maximal rate of primary production at most of the stations has been observed for the surface layer of the water column. Within the upper mixed water layer, relative primary production was from 31 to 100% (on average, 77 ± 20%). The most productive zone was the waters along Yenisei transect. In the estuary and at the adjacent shelf, primary production was 50 mg C/m2 per day, exceeding the range observed for other areas by 1.5–2.0 times. The concentrations of silica and nitrogen together with light regime and water temperature were the major limiting factors affecting the primary production rate in the Kara Sea in autumn. 相似文献
6.
Polukhin A. A. Flint M. V. Belikov I. B. Gusak G. V. Kazakova U. A. Muravya V. O. Pankratova N. V. Pronina Yu. O. Skorokhod A. I. Chultsova A. L. Shchuka A. S. 《Oceanology》2021,61(5):625-631
Oceanology - The values and direction of carbon dioxide flux in the area of the continental slope in the north of the Kara Sea (St. Anna Trough) are calculated based on field studies in 2020 within... 相似文献
7.
The optical properties and distribution of dissolved organic matter in the surface waters of the Kara Sea and bays of Novaya Zemlya archipelago were studied during the 63th cruise of the R/V Akademik Mstislav Keldysh. The fluorescence of dissolved organic matter has been studied over wide excitation (230–550 nm) and emission (240–650 nm) wavelength ranges. Based on the results of fluorescence measurements, we propose a simple technique for estimating the relative content of humic compounds entering the Kara Sea shelf region with Ob and Yenisei river runoff. We have found that the blue shift parameters of the DOM fluorescence are Δ270–310 = 28 ± 2 nm and Δ355–310 = 29 ± 2 nm. The highest contents of humic compounds in surface waters were measured on the transect across the desalinated layer of the Kara Sea, near the continental slope on the transect along the St. Anna Trough, and in the area of Sedova, Oga and Tsivol’ki bays. Traces of labile terrigenous organic matter were found in the region of the Voronin Trough, in the bays of the Severny Island of Novaya Zemlya, as well as in some freshwater reservoirs and ice samples of the archipelago. We established a conservative distribution of dissolved organic matter, whose content in water varied from 1.25 to 8.55 mg/L. 相似文献
8.
P. N. Makkaveev A. A. Polukhin A. V. Kostyleva E. A. Protsenko S. V. Stepanova Sh. Kh. Yakubov 《Oceanology》2017,57(1):48-57
During cruise 65 of the R/V Akademik Mstislav Keldysh in the Kara Sea, three transects were executed: one eastwards from the Novaya Zemlya Archipelago and two in the St. Anna and Voronin troughs. It was noted that the continental runoff affected the entire surveyed aquatic area, even at the northern extremity of the Novaya Zemlya Archipelago. The transect along the St. Anna Trough showed the presence of a slope frontal zone overlaid at the surface by a desalinated layer. The Voronin Trough was characterized by sliding of slope waters. The hydrochemical parameters show that the surveys were carried out during a recession of biological activity of the waters and that the peak bloom was over by that time. The hydrochemical structure of waters conformed to early autumn conditions, but before the beginning of intense cooling of surface waters. 相似文献
9.
The distribution of bacterioplankton with active electron transport chains, as well as bacteria with intact cell membranes, was investigated for the first time in the region of St. Anna Trough in the Kara Sea. The average number of bacteria with active electron transport chains in the waters of the St. Anna Trough was 15.55 × 103 cells mL–1 (the limits of variation were 1.06–92.17 × 103 cells mL–1). The average number of bacteria with intact membranes was 33.46 × 103 cells mL–1 (the limits of variation were 6.78 to 103.18 × 103 cells mL–1). Almost all bacterioplankton microorganisms in the studied area were potentially viable, and the average share of bacteria with intact membranes was 92.1% of the total number of bacterioplankton (TNB) (the limits of variation were 76.2 to 98.4%). The share of bacteria with active metabolisms was 38.2% of the TNB (the limits of variation were 5.6–93.4%). The shares of the bacteria with active metabolisms were maximum in areas with the most stable environmental conditions (on the shelf and in deep water), whereas on the slope, where the gradients of water temperature and salinity were maximum, these values were lower. 相似文献
10.
M. V. Flint T. N. Semenova E. G. Arashkevich I. N. Sukhanova V. I. Gagarin V. V. Kremenetskiy M. A. Pivovarov K. A. Soloviev 《Oceanology》2010,50(5):766-779
The studies were carried out on September 27–30, 2007, in the area of the Ob estuarine frontal zone and over the adjacent
inner Kara Sea shelf. Based upon the latitudinal changes in the salinity, the 100 nautical mile wide estuarine frontal zone
was marked out. The frontal zone was inhabited by a specific zooplankton community dominated by species that occurred outside
the frontal zone in only minor amounts. The biomass of the mesozooplankton averaging 984 mg/m3 in the frontal zone exceeded by 1.5 and 6 times the corresponding values in the inner desalinated area of the estuary and
the adjacent areas of the Kara Sea shelf. At the inner southern periphery of the frontal zone, at maximal latitudinal salinity
gradients (>2 psu per mile), the maximal development of the mesoplankton with the mean biomass for the water column of 3.1
g/m3 (37 g/m2) and up to 5.8 g/m3 in the subpycnocline layer was observed. The latitudinal extension of the biomass in the maximum zone did not exceed 10 miles.
More than 90% of the maximum was composed of herbivorous zooplankton with the strong domination of the copepod Limnocalanus macrurus. The daily consumption within the zooplankton maximum area was estimated at 820 mgC/m2 per day. This value exceeds by two orders of magnitude the local primary production. At that level of consumption, the available
phytoplankton biomass was consumed by grazers in less than 8 hours (!). A zooplankton aggregation at the southern periphery
of the estuarine front exists due to the advection of phytoplankton from the adjacent river zone. The aggregation forms a
natural pelagic biofilter where new allochthonous organic matter delivered by the river flow is accumulated and high secondary
production is formed on its basis. An anomalously high concentration of planktic predatory Parasagitta elegans with biomass of over 1 g/m3 (46% of the total zooplankton biomass) was associated with the outer northern periphery of the estuarine frontal zone. 相似文献
11.
Kremenetskiy V. V. Nedospasov A. A. Shchuka S. A. Shchuka A. S. Zamyatin I. A. Bondar A. V. 《Oceanology》2021,61(6):786-790
Oceanology - During cruise 81 of the R/V Akademik Mstislav Keldysh comprehensive studies of the Kara Sea were carried out over sill separating the central spur of the St. Anna Trough and the Novaya... 相似文献
12.
Cruise 81 of the R/V Akademik Mstislav Keldysh was organized by Shirshov Institute of Oceanology and took place from August 27 to September 25, 2020 under the Program “Marine Ecosystems of the Siberian Arctic.” Participants included 76 scientists from the institutes of Russian Academy of Sciences, Moscow State University, VNIRO, and the NRC Kurchatov Institute and specialists from the Emergency Situations Ministry. Coordinated hydrophysical, hydrochemical, biooceanological, geochemical, and radioecological research was carried out over the Kara Sea, on the shelf near the St. Anna Trough, the continental slope, the Novaya Zemlya depression, and bays of the eastern coast of Novaya Zemlya. The condition of disposed radioactive waste in bays of the archipelago was assessed.
相似文献13.
E. G. Arashkevich A. V. Drits A. F. Pasternak M. V. Flint A. B. Demidov A. B. Amelina M. D. Kravchishina I. N. Sukhanova S. A. Shchuka 《Oceanology》2018,58(3):381-395
Sampling was conducted along the quasi meridional transect at 130° E from the Lena River estuary to northern deep-sea regions of the Laptev Sea in September 2015. The latitudinal zonality and the impact of river runoff are manifested in the temperature and salinity distribution, concentration of particulate organic matter, and the structure of plankton communities. The differences in the chl a concentration and primary production along the transect are insignificant. The feeding rate of mesozooplankton herbivores was assessed by a fluorescence technique. The total consumption of phytoplankton biomass and primary production are estimated based on the feeding rate, abundance of zooplankton species, and their diel migrations. The daily grazing impact of zooplankton on phytoplankton biomass increases from 2% on the inner shelf to 3% on the mid-shelf, 5% on the outer shelf, and 10% in the deep-sea part of the basin. The consumption of primary production also increases: 1, 4.5, 5.7, and 13.9%, respectively. In the fall, the consumption of phytoplankton does not compensate the energy demands for respiration. The latitudinal zonality of the Laptev Sea appears not only in the hydrophysical water parameters and the structure of plankton communities, but also in their functional characteristics. 相似文献
14.
A. A. Krylov D. Weiel V. F. Sapega G. I. Ivanov R. Stein C. Vogt E. O. Rys’kova 《Oceanology》2008,48(1):85-93
This paper is devoted to the studies of clay minerals from two cores collected in the northern and central regions of the St. Anna Trough, the largest trough of the Kara Sea. The Upper Quaternary glacial, glaciomarine, and marine deposits are characterized by various contents of kaolinite, chlorite, illite, and smectite. It is established that, from older to younger deposits, the amounts of kaolinite and chlorite generally decrease, while those of illite and smectite, on the contrary, increase. A joint analysis of the distributions of clay and heavy minerals over the section allowed us to refine the position of the sources for the terrigenous matter and their temporal variability. It is shown the changes in the sources of supply were directly related to the climate changes that occurred when passing from the glacial to marine sedimentation environments. 相似文献
15.
A. V. Drits A. B. Nikishina T. N. Semenova V. M. Sergeeva K. A. Solovyev M. V. Flint 《Oceanology》2016,56(3):382-394
The distribution and feeding of dominant mesozooplankton species were studied in the estuary of the Ob River and adjacent inner Kara Sea shelf waters in September 2013. It was shown that the spatial distributions of Cyclops sp., Senecella siberica, Limnocalanus macrurus, Mysis oculata, Drepanopus bungei, Jashnovia tolli and Pseudocalanus sp. are related to the specific characteristics of the hydrographic regime in the estuarine frontal zone. The distributions of Cyclops sp., Senecella siberica, and Pseudocalanus sp. are mainly limited by salinity, while other species inhabit an area with a wide range of salinity values without clear preferences. Peaks of their abundance could be either consolidated or distanced in space. The populations of Jashnovia tolli, Drepanopus bungei, and Pseudocalanus sp. permanently inhabit the layer under the pycnohalocline; the populations of Cyclops sp. and Mysis oculata inhabit the upper mixed layer. Limnocalanus macrurus demonstrates a different vertical distribution pattern: the copepod undertakes diel vertical migrations in the southern part of the estuarine frontal zone; in its northern part, the population is concentrated below the pycnocline during day and night. The differences in the distributions of the studied species determine their feeding behavior and their role in phytoplankton grazing. The most intense utilization of biomass and production of autotrophic phytoplankton by zooplankton occur in the freshened water zone and the adjacent southern periphery of the estuarine frontal zone: the total daily phytoplankton consumption makes up 10–18% of the biomass and 60–380% of primary production. Daily zooplankton consumption of phytoplankton in the estuarine frontal zone decreases to 2–7% of the biomass and to 14% of primary production; in inner shelf waters, the values do not exceed 1% for both phytoplankton biomass and production. 相似文献
16.
冲绳海槽中南部不同环境表层沉积物质来源 总被引：1，自引：0，他引：1
对冲绳海槽中南部3种不同沉积环境(东海外陆架、东海陆坡和冲绳海槽)表层沉积物进行了稀土等元素地球化学分析,结果显示,冲绳海槽和陆坡表层沉积物具有与台湾物质来源类似的稀土元素配分模式,La/Sm-Gd/Yb散点图也显示海槽和陆坡沉积物主要分布在台湾物源端元区,表明冲绳海槽中南部海槽和陆坡表层沉积物主要来源于台湾,而外陆架... 相似文献
17.
The problem of the dynamics of surface and internal waves M 2 in the Kara Sea is solved within the QUODDY-4 3D finite-element hydrostatic model. It is shown that the conventional concept of surface-tide wave generation due to the interaction of two tidal waves (one arrives from the Barents Sea and the other is generated in the Arctic Ocean (AO) and propagates southward along the west coasts of Severnaya Zemlya) is only partially valid: the east branch of the tidal wave generated in the AO actually exists, but there is also a west branch that propagates along the St. Anna trough and another tidal wave that penetrates in the Kara Sea from the Laptev Sea through the Vilkitsky Strait. Simulated spatial distributions of the tidal velocities, amplitudes of internal tidal waves at the pycnocline depth, and some components of the budgets of barotropic and baroclinic tidal energy are discussed. 相似文献
18.
冲绳海槽北端表层沉积物过渡元素地球化学特征 总被引：4，自引：0，他引：4
利用原子吸收和等离子发射光谱等方法,对冲绳海槽北端184个表层沉积物中的Al和过渡元素(Ti、Cr、Mn、Fe、Co、Ni、Cu、Zn和Zr)进行了化学分析。结果表明,由于受生源碎屑稀释作用的影响,过渡元素在陆架砂质区含量较低,其分布呈北西-南东向舌状延伸;由于细粒组分的增加,在陆架细粒沉积区和海槽区过渡元素含量较高。Mn主要在海槽区富集,在陆架和陆坡区变化不大。除了Mn之外,Al和其他过渡元素均呈明显正相关。Al/Ti比值与陆壳平均值接近,说明二者主要来源于陆源碎屑。Mn/Fe比值与邻近海区沉积物类似,但在陆架区CaO含量大于20%的沉积物和海槽区沉积物中相对较高,这分别是生物富集作用和自生沉积的结果。过渡元素富集因子分析结果表明,研究区过渡元素部分来自于黄河、部分来自于长江物质。 相似文献
19.
Oceanology - The material was obtained on July 18–24, 2016 in the area comprising the Ob River estuary and the adjacent shelf of the Kara Sea (71°28.3′–74°38.8′... 相似文献
20.
Sukhanova I. N. Flint M. V. Sakharova E. G. Fedorov A. V. Makkaveev P. N. Nedospasov A. A. 《Oceanology》2018,58(6):802-816
Oceanology - Based on the material obtained in the spring–summer season of 2016, the composition and quantitative distribution of phytoplankton in the Ob estuary and over the Kara Sea shelf... 相似文献