东海赤潮高发区春季叶绿素a和初级生产力的分布特征

2002年4-5月对东海海域进行了综合调查，分析了海区叶绿素a和初级生产力的分布特性．结果表明,大面站表层平均叶绿素a浓度为1．086mg·m-3．分级叶绿素a结果显示．春季东海浮游植物以微型和微微型(<20μm)占优势，其对海区叶绿素a的贡献为64％，超微型浮游植物(<5μm)占浮游植物生物量的27％．营养盐分布和浮游动物的摄食压力影响了叶绿素a及其粒级结构的分布．平均初级生产力为10．091mg·m-3·h-1。赤潮跟踪的R-03、RL-01、RG-01站的平均初级生产力为399．984mg·m-3·h-1．光和营养盐成为叶绿素和初级生产力平面分布的主要限制因子．表层叶绿素a和初级生产力均在调查海区的123·E纵断面冲淡区产生高值区．DC-11站浮游植物生物量异常高，表层叶绿素a达到9．082mg·m-3，初级生产力为128．79mg·m-3·h-1．但并未出现水色异常．

Distribution features of chlorophyll a and primary productivity in high frequency area of red tide in East China Sea during Spring

The distributions of chlorophyll a and primary productivity were determined during April to May 2002 in the East China Sea. The results showed that the average concentration of chlorophyll a was 1.086 mg.m-3 at surface layer, and that nano- and pico-phytoplankton (< 20 microns) dominated the phytoplankton biomass in this sea region during Spring (up to 64% of total chlorophyll a content). Ultra-phytoplankton (< 5 microns) consisted 27% of total phytoplankton biomass. Nutrients and feeding pressure of zooplankton affected the distribution of chlorophyll a and its size-fractionation. The average primary productivity was 10.091 mg.m-3.h-1, while that of red tide tracking stations R-03, RL-01 and RG-01 was 399.984 mg.m-3.h-1. Light and nutrients were the main factors affecting the distributions of chlorophyll a and primary productivity. The station DC-11 had a high concentration of phytoplankton biomass. The surface layer concentration of chlorophyll a and primary productivity were up to 9,082 mg.m-3 and 128,79 mg.m-3.h-1, respectively, but the color of the seawater was normal.