东海、南黄海浮游植物粒级结构及环境影响因素分析

Size-Fractionated Phytoplankton in the the East China and Southern Yellow Seas and Its Environmental Factors in Autumn 2000

对粒径分级叶绿素a含量进行分析,探讨了南黄海和东海海域2000年秋季表层浮游植物的粒级结构特征及其环境影响因素。在整个调查海域范围内,叶绿素a平均含量为0.72 mg.m-3,各粒级浮游植物叶绿素a含量对叶绿素a总量的贡献有显著差异,小型(Microplankton,>20μm)、微型(Nanoplankton,3～20μm)和微微型(Picoplankton,0.45～3μm)浮游植物的贡献率分别为31.2%,49.0%和19.8%。小型浮游植物主要分布在江苏沿岸和长江口附近;微型浮游植物在整个海域的分布较均匀,以浙江沿岸和南黄海东部为高值区;微微型浮游植物主要分布在南黄海中部和东海东南部。通过浮游植物粒径分级叶绿素a和环境因子的相关性分析,发现在调查海域营养盐与浮游植物叶绿素a的相关系数随着浮游植物粒径的增大而从负逐渐变正,说明高的营养盐含量区域较大粒径的浮游植物占有较大优势。依据浮游植物粒径分级叶绿素a和环境因子对调查站位进行的聚类分析结果和海域水团的分布以及卫星遥感图显示的水色差异之间有密切联系,聚类分析方法是研究浮游植物分布和环境因子之间关系的一种有效方法。

The surface distribution of size-fractioned phytoplankton in the the East China and southern Yellow Seas was discussed as well as the correlations of the size-fractionated chlorophyll a with the environmental factors. The results showed that the chlorophyll a of microplankton（ 〉20μm）, nanopl ankton（3--20μm） and picoplankton（0.45--3μm） accounted on average for 31.2%, 49.0% and 19.8 % of the total chlorophyll a in the whole investigated sea area respectively. The microplankton was mainly distributed along the coast of Jiangshu Province, and the high value areas of nanoplankton were focused along the coast of Zhejiang Province and the east of the southern Yellow Sea. The picoplankton was mainly distributed in the middle of the southern Yellow Sea and the southeast of the East China Sea. Correlation analysis of size-fracfionated chlorophyll a with environmental factors showed that the correlation coefficients of nutrients with size-fractionated chlorophyll a varied from negative to positive with the increase of the cell size in the investigated sea area, and it indicated the advantage of bigger phytoplankton in high nutrient areas. Close relationships were found among the results of cluster analysis of all stations based on size-fractionated chlorophyll a and environmental factors, the distribution of water currents and the area difference showed by the satellite ocean color remote sensing image. It showed that cluster analysis is a powerful method for studying the relationship between the distribution of phytoplankton and the environmental factors.