Using a flow cytometer （FCM） onboard the R/V Xuelong during the 24th Chinese Antarctic cruise, picoplankton community structure and biomass in the surface water were examined along the latitude and around the Antarc...Using a flow cytometer （FCM） onboard the R/V Xuelong during the 24th Chinese Antarctic cruise, picoplankton community structure and biomass in the surface water were examined along the latitude and around the Antarctic Ocean. Salinity and temperature were automatically recorded and total Chl a was determined. Along the cruise, the abundance of Synechococcus, Prochlorococ- cus, pico-eukaryotes and heterotrophic bacteria ranged in 0.001-1.855~ 10s ind./L, 0.000-2.778×108 ind./L, 0.002-1.060×108 ind./L and 0.132-27.073×108 ind./L, respectively. Major oceanic distri- bution of Synechococcus and Prochlorococcus appeared between latitudes 30°N and 30°S. Prochlorococcus was mainly influenced by water temperature, water mass combination and freshwater inflow. Meanwhile, Synechococcus distribution was significantly associated with landing freshwater inflow. Pico-eukaryotes and heterotrophic bacteria were distributed all over the oceans, but with a relatively low abundance in the high latitudes of the Antarctic Ocean. Principal Component Analysis showed that at same latitude of Atlantic Ocean and Indian Ocean, picoplankton distribution and constitution were totally different, geographical location and different water masses combination would be main reasons.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
Picophytoplankton are responsible for much of the carbon fixation process in the Arctic Ocean, and they play an im- portant role in active microbial food webs. The climate of the Arctic Ocean has changed in recent yea...Picophytoplankton are responsible for much of the carbon fixation process in the Arctic Ocean, and they play an im- portant role in active microbial food webs. The climate of the Arctic Ocean has changed in recent years, and picophytoplankton, as the most vulnerable part of the high-latitude pelagic ecosystem, have been the focus of an increasing number of scientific studies. This paper reviews and summarizes research on the characteristics of picophytoplankton in the Arctic Ocean, including their abundance, biomass, spatial distribution, seasonal variation, commtmity structure, and factors influencing their growth. The impact of climate change on the Arctic Ocean picophytoplankton community is discussed, and future research directions are considered.展开更多
基金The National Natural Science Foundation of China under contract Nos 40576002 and 40006010the Key International S & T Cooperation Projects under contract No.2008DFA20420+3 种基金the Youth Scientific and Technological Innovation Foundation of Polar Research Institute of China under contract No.JDQ200802the Polar Strategic Research Foundation under contract No.2008209the LMEB Open Research Foundation under contract No.LMEB200902the PhD Program Scholarship Fund of ECNU under contract No.2010041
文摘Using a flow cytometer （FCM） onboard the R/V Xuelong during the 24th Chinese Antarctic cruise, picoplankton community structure and biomass in the surface water were examined along the latitude and around the Antarctic Ocean. Salinity and temperature were automatically recorded and total Chl a was determined. Along the cruise, the abundance of Synechococcus, Prochlorococ- cus, pico-eukaryotes and heterotrophic bacteria ranged in 0.001-1.855~ 10s ind./L, 0.000-2.778×108 ind./L, 0.002-1.060×108 ind./L and 0.132-27.073×108 ind./L, respectively. Major oceanic distri- bution of Synechococcus and Prochlorococcus appeared between latitudes 30°N and 30°S. Prochlorococcus was mainly influenced by water temperature, water mass combination and freshwater inflow. Meanwhile, Synechococcus distribution was significantly associated with landing freshwater inflow. Pico-eukaryotes and heterotrophic bacteria were distributed all over the oceans, but with a relatively low abundance in the high latitudes of the Antarctic Ocean. Principal Component Analysis showed that at same latitude of Atlantic Ocean and Indian Ocean, picoplankton distribution and constitution were totally different, geographical location and different water masses combination would be main reasons.
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.
文摘Picophytoplankton are responsible for much of the carbon fixation process in the Arctic Ocean, and they play an im- portant role in active microbial food webs. The climate of the Arctic Ocean has changed in recent years, and picophytoplankton, as the most vulnerable part of the high-latitude pelagic ecosystem, have been the focus of an increasing number of scientific studies. This paper reviews and summarizes research on the characteristics of picophytoplankton in the Arctic Ocean, including their abundance, biomass, spatial distribution, seasonal variation, commtmity structure, and factors influencing their growth. The impact of climate change on the Arctic Ocean picophytoplankton community is discussed, and future research directions are considered.
