2005年秋季长江口及其邻近水域浮游植物群集

采用Utermhl分析方法，对长江口及其邻近水域（30.5° ~ 32.5° N，121.0° ~ 123.5° E）2005年秋季浮游植物进行了分析，并对其与环境之间的关系做了进一步的探讨。结果表明：调查区初步鉴定浮游植物95种（含变种和变型），硅藻是主要的浮游植物类群，其丰度比例达到93.1%；生态类型多为温带近岸种，少数为暖水种和大洋种；优势种主要为中肋骨条藻〖WTBX〗（Skeletonema costatum）、具槽帕拉藻（Paralia sulcata）、菱形海线藻（Thalassionema nitzschioides）和圆海链藻（Thalassiosira rotula）〖WTBZ〗；浮游植物平均丰度为2.04 cells/mL，高值出现在长江口门偏南水域；Margalef指数、Shannon Wiener指数以及Pielou指数的分布显示：秋季调查区离岸海域浮游植物多样性程度高，物种均一性好。Pearson相关分析结果显示：海水温度和硝酸盐含量是控制调查区浮游植物分布格局的主要环境因子；优势种中肋骨条藻与温度呈极显著负相关，与硝酸盐呈极显著正相关。

PHYTOPLANKTON ASSEMBLAGE OF THE YANGTZE RIVER ESTUARY AND ITS ADJACENT WATERS IN AUTUMN,2005

In order to illustrate the community structure of phytoplankton assemblage of the Yangtze River Estuary and its adjacent waters (30.5° ~ 32.5°N，121.0° ~ 123.5°E) in autumn 2005，besides clarifying its relationship with the nutrient pulsing of the Yangtze River.Phytoplankton samples were analyzed by using Utermhl method and their relationship with the environmental factors were further discussed meanwhile.After a total of 95 phytoplankton species were identified including species variation results were obtained.Diatom was the major phytoplankton group in survey area and accounted for 93.1% in total abundance.Most of the phytoplankton ecotypes were temperate coastal species and few were warm and oceanic species.Dominant species were Skeletonema costatum，Paralia sulcata，Coscinodiscus spp.，〖WTBX〗Thalassionema nitzschioides and Thalassiosira rotula.Averaging phytoplankton abundance was 2.04 cells/mL with the maximum appeared in the southern part of the Yangtze River mouth.The distribution of Margalef，Shannon Wiener and Pielou′ indexes indicated that relative high phytoplankton diversity and evenness appeared in the offshore pelagic water area.Pearson correlation showed that seawater temperature and nitrate content were the main environmental factors that controlling the phytoplankton distribution pattern in autumn.Dominant species S.costatum was negatively correlated with the temperature and positively correlated with the nitrate.