中文摘要：

通过2011年4月和8月利用“科学三号”考察船在黄、东海海域开展的春、夏季综合调查。研究了黄、东海浮游植物粒级结构的分布格局及其时空变动规律，探讨重要环境因子的变动对浮游植物粒级结构的影响。结果表明，春季表层水体中小型、微型和微微型粒级叶绿素口浓度的范围分别为0～4．36、0．02—2．27、0—2．66mg／m3，平均叶绿素a的浓度分别为0．56、0-31和0．14mg／m0，对叶绿素a总量的贡献率分别为55．4％、30．8％和13．8％。夏季表层由大至小3个粒级浮游植物叶绿素a浓度范围分别为：0—6．78、0—2．59、0—0．86mg／m3，平均叶绿素a含量依次为0．50、0．24和0．07mg／m3，对叶绿素a总量的贡献率分别为61．8％、30．1％和8．1％。春季小型浮游植物叶绿素a浓度的垂直分布较为均匀，微型和微微型浮游植物浓度随深度增加呈现逐渐下降趋势。夏季叶绿素a浓度出现明显分层现象，lOm层以上小型和微型浮游植物浓度较高，10m层之下浓度迅速降低。微微型浮游植物浓度在不同水层都保持较低水平。受黄、东海不同季节水团影响而引起的温、盐以及营养盐分布格局的变化是影响黄、东海浮游植物粒级结构组成的重要因素。

英文摘要：

To understand the phytoplankton size structure in the Yellow Sea and East China Sea, two cruises were car- ried out in the spring （April） and summer （August） of 2011. In the spring, concentrations of micro-, nano- and pico-phytoplankton, ranged between 0---4.36, 0.02--2.27, and 0--2.66mg/m3, with the average concentrations, being 0.56, 0.31 and 0.14mg/m3 and contributing to 55.4%, 30.8% and 13.8% of the total Chl.a concentration, respectively. In the summer, concentrations of micro-, nano- and pico-phytoplankton, ranged between 0--6.78, 0--2.59, and 0--0.86mg/m3, with the average concentrations, being 0.50, 0.24 and 0.07mg/m3 and contributing to 61.8%, 30.1% and 8.1% of the total Chl.a concentration respectively. The vertical distribution of micro-phytoplankton was homogeneous, whereas the concen- trations of nano- and pico-phytoplankton decreased with the depth in the spring. In summer, there was abrupt change at the depth of 10m. The concentrations of micro- and nano-phytoplankton were much higher on the layer shallower than 10m. The concentration of pico-phytoplankton was low at all layers in summer. The changes on the pattern of temperatures, sa- linities and nutrients affected by different water masses in spring and summer were the major factors leading to the change of the phytoplankton size structure in the Yellow Sea and East China Sea.