长江口赤潮高发区浮游植物与水动力环境因子的分布特征

报道了2002年春季长江口海域(30°50′～31°50′N，121°50′～123°00′E)的22个大面观察站和一个昼夜连续观察站的水样和网样浮游植物的种类组成、丰度分布与水动力环境因子、营养盐的关系．结果表明，长江口区共有浮游植物5门45属110种．主要赤潮生物优势种为中肋骨条藻(Skeletonema castaturn)和具齿原甲藻(Prorocentrum dentatum)等．浮游植物丰度的昼夜变化白天大于夜间，垂直分布不明显．浮游植物主要生态类型可划分为：沿岸河口低盐半咸水类群、沿岸偏低盐广布性类群、外海高盐暖水性类群等．长江口区浮游植物丰度在1．6×10^3～75．2×10^3个.dm-3．浮游植物的种类组成和丰度分布与长江冲淡水密切相关．在该区域存在三股不同性质的水，即长江河口水、长江冲淡水及外海水(台湾暖流)影响着浮游植物的分布．

Distribution of phytoplankton and water dynamical environmental factors in high red tide occurrence area of Changjiang River estuary

Species composition and cell abundance of phytoplankton, and its relations with environmental factors were investigated in the Changjiang River estuary of east China sea (30 degrees 50'-31 degrees 50'N, 121 degrees 50'-123 degrees 00'E). A total of 110 taxa belonging to 45 genera of phytoplankton in the investigation area were identified. The main species of phytoplankton resulted in red tide were Skeletonema costatum and Prorocentrum dentatum, etc. Phytoplankton abundance in the day was higher than that at night. The vertical distribution of phytoplankton in different water bodies was not obvious. The ecological groups of phytoplankton were freshwater group, estuarine and brackish water and low salinity group in the coast, high salinity and warm water group in off-sea, and widely ranging group. The abundance of phytoplankton in the Changjiang River estuary was 1.6 x 10(3)-75.2 x 10(3) ind.dm-3. The species composition and cell abundance of phytoplankton were related to the freshwater pouring into the Changjiang River estuary. The three waters in the area affecting the distribution of phytoplankton were the Changjiang River estuary water, freshwater, and warm water from outsea.