中文摘要：

在2011年10月（代表秋季）和2012年4月（代表春季）对大亚湾海域浮游植物的种类组成、优势种和丰度进行了观测,实测数据采用Surfer 8.0软件进行绘图和插图制作,用SPSS 17.0软件进行主成分因子分析（PCA）,同时用多元逐步回归分析方法,以主成分得分为解释变量,研究环境因子对浮游植物丰度的影响,以筛选出影响该海区浮游植物丰度分布的重要环境因子,并讨论了浮游植物丰度分布特征与环境因子的相关性及影响浮游植物分布的主要因素。分析结果表明：2个航次观测获得的浮游植物有4门31属51种（包括变型与变种）,其中硅藻门的占优势,甲藻门的次之,黄藻与着色鞭毛藻门的较少。秋季浮游植物优势种有赤潮异湾藻Heterosigma akashiwo、中肋骨条藻Skeletonemacostatum、刚毛根管藻Rhizosolenia setigera、尖刺菱形藻Nitzschia pungens和菱形海线藻Thalas-sionema nitzschioides;春季浮游植物优势种有叉状角藻Ceratium furca、微小原甲藻Prorocentrumminimum、梭角藻Ceratium fusus和三角角藻Ceratium tripos。秋季浮游植物丰度为1.56×104～8.03×104个/dm3,平均值为3.95×104个/dm3;春季浮游植物丰度为1.21×104～4.70×105个/dm3,平均值为7.84×104个/dm3。水温、pH值、磷酸盐和总磷是影响大亚湾海域浮游植物分布的主要因素。

英文摘要：

This study was carried out in the Daya Bay in October 2011 and April 2012.Based on the data collected from 12 stations,phytoplankton taxonomic composition,abundance,dominance species and their impacting factors were examined.Surfer 8.0 software was used for drawing and illustrating,while SPSS 17.0 software was used for analyzing principal component factors（PCA）.At the same time,it used multiple stepwise regression analysis method,and principal component scores as explanatory variables,aiming at studying the effect of environmental factor for phytoplankton abundance and picking out the main factors which influenced the distribution of phytoplankton in the Daya Bay.Furthermore,its distribution characteristics and the correlation with environmental factors were discussed.A total of 51 species（4 phyla,31 genera） were identified.Among those species,Bacillariophyta is the dominant species,Pyrrophyta is subdominant species,and Xanthophyceae and Chromophyia are even rarely.The dominant species are Heterosigma akashiwo、Skeletonema costatum、Rhizosolenia setigera、Nitzschia pungens、Thalassionema nitzschioides in autumn,and Ceratium furca、Prorocentrum minimum、Ceratium fusus、Ceratium tripos in spring.The abundance of phytoplankton range from 1.56×104 to 8.03×104 cell/dm3 and the average value is 3.95×104 cell/dm3 in autumn and range from 1.21×104 to 4.70×105 cell/dm3 and the average value is 7.84×104 cell/dm3 in spring.Temperature、pH、PO3-4-P and TP are the main factors influencing the distribution of phytoplankton in the Daya Bay.