夏季长江口浮游细菌和浮游病毒的分布特征及环境制约因素

应用荧光显微直接计数法,研究了2006年夏季长江口及邻近海域浮游细菌、浮游病毒数量的分布特征,探讨了它们与环境因子之间的关系.结果表明:(1)浮游细菌数量为(6.92×105～5.54×106)个/mL,浮游病毒数量为(2.22×106～9.97×107)个/mL.浮游细菌和浮游病毒数量的平面分布特征较一致,均为近海过...

Distribution of bacterioplankton and virioplankton and their relationship with the environmental factors insummer in Changjiang River Estuary and its adjacent East China Sea

Distribution of virioplankton and bacterioplankton and the relationships between their abundance and the impacting environmental factors of temperature,salinity,nutrients and chlorophyll-a concentration in summer of 2006 in Changjiang River Estuary and its adjacent East China Sea are studied using fluorescence microscopic count method.The results show that bacterioplankton abundance ranged from 6.92×105 to 5.54×106 individuals/mL with an average of(2.10±0.98)×106 individuals/mL and the virioplankton abundance ranged from 2.22×106 to 9.97×107 individuals/mL with an average of(1.06±1.23)×107 individuals/mL.The mean bcterioplankton and virioplankton abundances varied in the sequence of Area B>Area A > Area C.The results of correlation analysis show that the bacterioplankton abundance had significantly positive correlation with the chlorophyll-a concentration in the surface water(r=0.798,P<0.01),and negative correlation with the water temperature at 10 m depth(r=-0.619,P<0.01);the virioplankton abundance had a significantly positive correlation with the chlorophyll-a concentration in the surface water(r=0.674,P<0.01),and with the nitrate concentration in the bottom layer(r=0.526,P<0.01);there was a significant positive relationship between virioplankton abundance and bacterioplankton abundance in the surface water(r=0.720,P<0.01),in the water at 10 m(r=0.754,P<0.01) and in the bottom water(r=0.777,P<0.01).The virioplankton abundance in our studied area is similar to the results from many other sea areas,and the bacterioplankton abundance is about an order of magnitude lower than that of virioplankton and similar to those from the past studies for Bohai Sea,Yellow Sea and East China Sea.The distribution of virioplankton,growth of planktonic algae in the surface water and the temperature at 10 m water are important impacting factors for the bacterioplankton distribution,and the nitrate concentration in surface water in Area C may also affect the bacterioplankton distribution.As for the virioplankton abundance,water temperature and salinity are not major impacting factors,while the supply of nutrients and growth of host baterioplankton and planktonic algae are.