Kongsfjorden is a typical fjord on the edge of the ice cap of the Arctic Svalbard-Barents Sea. Its inner bay is connected with a modern glacier front along the direction of the fjord axis with a significant gradient c...Kongsfjorden is a typical fjord on the edge of the ice cap of the Arctic Svalbard-Barents Sea. Its inner bay is connected with a modern glacier front along the direction of the fjord axis with a significant gradient change in the parameters of hydrology, sedimentation, and biology. In summer, ice and snow melt-water and floating ice collapse continuously and thus transport the weathering products on the surrounding land into the sea. Thus Kongsfjorden is regards as a natural laboratory for the study of unique sedimentation in polar fjords under modern glacial-sea water conditions. In this study, fifty-two surface sediments were collected in Kongsfjorden for clay mineral analysis to study the sediment source and sediment-transport process. Our results indicate that clay minerals in the surface sediments from Kongsfjorden are mainly composed of illite, chlorite, and kaolinite, and no smectite is found. Rocks from different periods exposed extensively in the surrounding areas of Kongsfjorden provide an important material basis for clay minerals in the Kongsfjorden. Kaolinite may be mainly derived from the fluvial deposits, weathered from reddish sandstones and conglomerates during the Carboniferous Period.Illite is mainly derived from Proterozoic low-grade and medium-grade metamorphic phyllite, mica schist, and gneiss. While chlorite is mainly from Proterozoic low-grade metamorphic phyllite and mica schist. In the direction from the fluvio-glacial estuary to the sea of the glacier front of Kongsfjorden, illite increase gradually,and the content of kaolinite declines gradually. However, the change pattern of chlorite is insignificant, which may be related to the provenance. Kongsfjorden detritus is mainly transported by the fluvio-glacial streams and icebergs into the sea and deposited in the inner bay. Coarse sediments are rapidly deposited in the glacier front,estuary, and near-shore areas. Clay fraction begins to deposit significantly by 200–400 m after flowing into the sea,which due to the crystal behavior of clay minerals, hydrodynamic condition and flocculation. Kaolinite and chlorite on the south of the bay near the Blomstrandhalv？ya Island is mainly affected by ice-rafted detritus and thus can reveal the trajectory of transportation by the floating ice while entering the sea.展开更多
The basic environmental variables and adaptability ofphytoplankton communities to low light and salinity were stud- ied using incubation experiments in Kongsfjorden, a high Arctic fjord of Spitsbergen, in late summer ...The basic environmental variables and adaptability ofphytoplankton communities to low light and salinity were stud- ied using incubation experiments in Kongsfjorden, a high Arctic fjord of Spitsbergen, in late summer 2006. Chlorophyll a concentrations were steady or decreased slightly in darkness after one day or one week incubation. Chlorophyll a concentrations showed an initial decline when exposed to natural light after one week incubation in darkness, and then increased significantly. In a salinity experiment, the maximal growth rate was observed at a dilution ratio of 10%, however, higher dilution ratios （≥0%） had an obvious negative effect on phytoplankton growth. We suggest that the phytoplankton communities in fjords in late summer are dark- ness adapted, and the inflow of glacial melt water is favorable for phytoplankton growth in the outer fiords where the influence of freshwater is limited.展开更多
The 16S and 18S ribosomal ribonucleic acid genes of microbial organisms collected from the contrasting environments （temperature, salinity, silicate, phosphate and nitrate, p 〈0.05） of the inner and outer basins of...The 16S and 18S ribosomal ribonucleic acid genes of microbial organisms collected from the contrasting environments （temperature, salinity, silicate, phosphate and nitrate, p 〈0.05） of the inner and outer basins of Kongsfjorden （Spitsbergen, Arctic） were studied using polymerase chain reaction-denaturing gradient gel electrophoresis（DGGE） fingerprinting. Comparison of the microbial fingerprints and the physicochemical parameters revealed that molecular methodology exhibited a greater sensitivity. Sequences obtained from bacterial DGGE were affiliated with four main phylogenetic groups of bacteria：Proteobacteria（Alpha, Beta and Gamma）, Bacteroidetes, Verrucomicrobia and Cyanobacteria. The relationships between the genotype distribution of these microbes and associated biotic/abiotic factors, revealed by canonical correspondence analysis, showed that Station 1 at 30 m （outer fjord） was grouped separately from the other sites. This difference could be a consequence of the thermocline and base of the euphotic layer at this depth where the Atlantic and Arctic-type waters overlapped.展开更多
基金The National Natural Science Foundation of China under contract Nos 41606223 and U1606401the Basic Scientific Fund for National Public Research Institutes of China under contract No.2011G27+1 种基金the Polar Strategic Research Foundation of China under contract No.20140305the Taishan Scholar Program of Shandong Province
文摘Kongsfjorden is a typical fjord on the edge of the ice cap of the Arctic Svalbard-Barents Sea. Its inner bay is connected with a modern glacier front along the direction of the fjord axis with a significant gradient change in the parameters of hydrology, sedimentation, and biology. In summer, ice and snow melt-water and floating ice collapse continuously and thus transport the weathering products on the surrounding land into the sea. Thus Kongsfjorden is regards as a natural laboratory for the study of unique sedimentation in polar fjords under modern glacial-sea water conditions. In this study, fifty-two surface sediments were collected in Kongsfjorden for clay mineral analysis to study the sediment source and sediment-transport process. Our results indicate that clay minerals in the surface sediments from Kongsfjorden are mainly composed of illite, chlorite, and kaolinite, and no smectite is found. Rocks from different periods exposed extensively in the surrounding areas of Kongsfjorden provide an important material basis for clay minerals in the Kongsfjorden. Kaolinite may be mainly derived from the fluvial deposits, weathered from reddish sandstones and conglomerates during the Carboniferous Period.Illite is mainly derived from Proterozoic low-grade and medium-grade metamorphic phyllite, mica schist, and gneiss. While chlorite is mainly from Proterozoic low-grade metamorphic phyllite and mica schist. In the direction from the fluvio-glacial estuary to the sea of the glacier front of Kongsfjorden, illite increase gradually,and the content of kaolinite declines gradually. However, the change pattern of chlorite is insignificant, which may be related to the provenance. Kongsfjorden detritus is mainly transported by the fluvio-glacial streams and icebergs into the sea and deposited in the inner bay. Coarse sediments are rapidly deposited in the glacier front,estuary, and near-shore areas. Clay fraction begins to deposit significantly by 200–400 m after flowing into the sea,which due to the crystal behavior of clay minerals, hydrodynamic condition and flocculation. Kaolinite and chlorite on the south of the bay near the Blomstrandhalv？ya Island is mainly affected by ice-rafted detritus and thus can reveal the trajectory of transportation by the floating ice while entering the sea.
基金supported by the National Natural Science Foundation of China (Grant nos. 41076130, 40576002)the Youth Marine Science Foundation of SOA (Grant no. 2010116)
文摘The basic environmental variables and adaptability ofphytoplankton communities to low light and salinity were stud- ied using incubation experiments in Kongsfjorden, a high Arctic fjord of Spitsbergen, in late summer 2006. Chlorophyll a concentrations were steady or decreased slightly in darkness after one day or one week incubation. Chlorophyll a concentrations showed an initial decline when exposed to natural light after one week incubation in darkness, and then increased significantly. In a salinity experiment, the maximal growth rate was observed at a dilution ratio of 10%, however, higher dilution ratios （≥0%） had an obvious negative effect on phytoplankton growth. We suggest that the phytoplankton communities in fjords in late summer are dark- ness adapted, and the inflow of glacial melt water is favorable for phytoplankton growth in the outer fiords where the influence of freshwater is limited.
基金supported by the National Natural Science Foundation of China (Grant Nos.41076130, 40576002)the International Cooperation Project of Science and Technology Commission of Shanghai Municipality (Grant no. 052307053)+1 种基金the Youth Marine Science Foundation of SOA (Grant no. 2010116)the Open Research Foundation of the SOA Laboratory of Marine Ecosystem and Biogeochemistry (Grant no. LMEB200902)
文摘The 16S and 18S ribosomal ribonucleic acid genes of microbial organisms collected from the contrasting environments （temperature, salinity, silicate, phosphate and nitrate, p 〈0.05） of the inner and outer basins of Kongsfjorden （Spitsbergen, Arctic） were studied using polymerase chain reaction-denaturing gradient gel electrophoresis（DGGE） fingerprinting. Comparison of the microbial fingerprints and the physicochemical parameters revealed that molecular methodology exhibited a greater sensitivity. Sequences obtained from bacterial DGGE were affiliated with four main phylogenetic groups of bacteria：Proteobacteria（Alpha, Beta and Gamma）, Bacteroidetes, Verrucomicrobia and Cyanobacteria. The relationships between the genotype distribution of these microbes and associated biotic/abiotic factors, revealed by canonical correspondence analysis, showed that Station 1 at 30 m （outer fjord） was grouped separately from the other sites. This difference could be a consequence of the thermocline and base of the euphotic layer at this depth where the Atlantic and Arctic-type waters overlapped.
