Picoplankton distribution in different water masses of the East China Sea in autumn and winter  

作　　者：赵丽 赵苑 张武昌 周锋 张翠霞 任景玲 倪晓波 DENIS Michel 肖天 

机构地区：[1]Key Laboratory of Marine Ecology and Environmental Sciences,Institute of Oceanology,Chinese Academy of Sciences [2]Graduate University of Chinese Academy of Sciences [3]Mediterranean Institute of Oceanology,Aix-Marseille University,CNRS-INSU,163 Avenue de Lumimy,Case 901,13288,Marseille Cedex 09,France [4]Key Laboratory of Marine Ecosystem and Biogeochemistry,Second Institute of Oceanography,State Oceanic Administration [5]Key Laboratory of Marine Chemistry Theory and Technology,Ministry of Education,Ocean University of China

出　　处：《Chinese Journal of Oceanology and Limnology》2013年第2期247-266,共20页中国海洋湖沼学报（英文版）

基　　金：Supported by the National Basic Research Program of China(973 Program)(No.2011CB409804);the National Natural Science Foundation of China for Creative Research Groups(No.41121064);the Knowledge Innovation Program of China(No.KZCX2-YW-Q07-02)

摘　　要：Abstract Picoplankton distribution was investigated in different water masses of the East China Sea in November, 2006 and February, 2007. The autumn and winter cruises crossed three major water masses： the coastal water mass （CWM）, the mixed water mass （MWM）, which forms on the continental shelf, and the Kuroshio water mass （KWM）. Picoplankton composition was resolved into four main groups by flow cytometry, namely Synechococcus, Prochlorococcus, picoeukaryotes, and heterotrophic bacteria. The average abundances of Synechococcus, picoeukaryotes, and heterotrophic bacteria were （0.63＋ 10.88）~ 103, （1.61＋1.16）x103, （3.39~1.27）x105 cells/mL in autumn and （6.45~8.60）x103, （3.23~2.63）x103, （3.76~1.37）x 105 cells/mL in winter, respectively. Prochlorococcus was not found in the CWM and seldom observed in surface samples in either season. However, Prochlorococcus was observed in the MWM and KWM （approximately 103 cells/mL） in both auttman and winter. Synechococcus distribution varied considerably among water masses, with the highest levels in KWM and lowest levels in CWM. The depth-averaged integrated abundance of Synechococcus was approximately 5-fold higher in KWM than in CWM, which may be due primarily to water temperature. In the MWM, Synechococcus was resolved as two subgroups; the presence of both subgroups was more common in autumn. Picoeukaryote abundance varied less among water masses than Synechococcus, and heterotrophic bacteria depth-averaged integrated abundance exhibited the smallest seasonal variations with respect to water mass. Correlation analysis showed that relationships between picoplankton abundances and environmental factors （temperature, nutrients, and chlorophyll a） differed among the three water masses, suggesting that the three water masses have different effects on picoplankton distribution （particularly Synechococcus）.Picoplankton distribution was investigated in different water masses of the East China Sea in November,2006 and February,2007.The autumn and winter cruises crossed three major water masses:the coastal water mass(CWM),the mixed water mass(MWM),which forms on the continental shelf,and the Kuroshio water mass(KWM).Picoplankton composition was resolved into four main groups by flow cytometry,namely Synechococcus,Prochlorococcus,picoeukaryotes,and heterotrophic bacteria.The average abundances of Synechococcus,picoeukaryotes,and heterotrophic bacteria were(0.63±10.88)×103,(1.61±1.16)×103,(3.39±1.27)×105 cells/mL in autumn and(6.45±8.60)×103,(3.23±2.63)×103,(3.76±1.37)×105 cells/mL in winter,respectively.Prochlorococcus was not found in the CWM and seldom observed in surface samples in either season.However,Prochlorococcus was observed in the MWM and KWM(approximately 10 3 cells/mL) in both autumn and winter.Synechococcus distribution varied considerably among water masses,with the highest levels in KWM and lowest levels in CWM.The depth-averaged integrated abundance of Synechococcus was approximately 5-fold higher in KWM than in CWM,which may be due primarily to water temperature.In the MWM,Synechococcus was resolved as two subgroups;the presence of both subgroups was more common in autumn.Picoeukaryote abundance varied less among water masses than Synechococcus,and heterotrophic bacteria depth-averaged integrated abundance exhibited the smallest seasonal variations with respect to water mass.Correlation analysis showed that relationships between picoplankton abundances and environmental factors(temperature,nutrients,and chlorophyll a) differed among the three water masses,suggesting that the three water masses have different effects on picoplankton distribution(particularly Synechococcus).

关 键 词：SYNECHOCOCCUS PROCHLOROCOCCUS PICOEUKARYOTES heterotrophic bacteria water masses East China Sea 

分 类 号：Q178.53[生物学—水生生物学]