2015年春、夏季江苏近岸海域网采浮游植物群落变化

Changes of net-collected phytoplankton community in the coastal seawaters of Jiangsu in spring and summer,2015

为了解江苏近岸海域浮游植物群落变化特征,分别于2015年5月(春季)和8月(夏季)对江苏近岸海域(119°30′0″~122°30′0″E,31°30′0″~35°30′0″N)网采浮游植物样品进行了分析,并同步监测其他环境因子。浮游植物共鉴定出7门70属150种(含变型、变种及未定名种),其中硅藻46属114种、甲藻16属27种,其余门类(蓝藻、金藻、裸藻、绿藻和隐藻)9种。春、夏季浮游植物平均细胞丰度分别为33.44×104cells/m3和71.82×104cells/m3。两季浮游植物优势种均为硅藻,其中中肋骨条藻在春、夏两季均占主要优势。群落参数(种类数、细胞丰度、香浓-威纳多样性指数、物种丰富度指数、均匀度指数)均存在明显季节差异。聚类分析结果表明,江苏近岸海域浮游植物群落可分为三个类群:海州湾区域(Ⅰ区)、废黄河三角洲区域(Ⅱ区)和辐射沙洲区域(Ⅲ区)。冗余分析结果表明,春季对浮游植物群落结构有显著影响的主要环境因子分别为:氮磷比、悬浮物、硅酸盐和总氮等;夏季分别为:盐度、水温、pH、溶解无机氮和活性磷酸盐等。与历史资料对比,调查海域网采浮游植物仍以硅藻占主导,其次是甲藻,但硅藻占总种类数的百分比有下降趋势。

In this paper,we studied the community composition of net-collected phytoplankton near the sea area of Jiangsu.The net-phytoplankton were collected in April(spring)and August(summer),2015,in which a total of 7phyla,70genera and 150species were found.These phytoplankton mainly included 114diatom and 27dinoflagellate species,and rarely,for example,the species of Euglenophyta,Chrysophyta,Cryphophyta,Cyanophyta and Chlorophyta.The phytoplankton community described with the number of species,abundance,Shannon-Wiener diversity,Pielou evenness and Margalef richness index was different between two seasons.In spring and summer,the average cell abundance was 33.44and 71.82×104cells/m3,respectively.Diatoms dominated the phytoplankton community,of them,Skeletonema costatum was the first dominant.The cluster analysis showed that the phytoplankton assemblages can be divided into three groups,Haizhou Bay(Group I),radial submarine sand ridges(Group II)and Yellow River Delta(Group III).Redundancy analysis showed that N/P,SS,SiO3-Si and TN were the main factors influencing net-phytoplankton community in spring while salinity,temperature,pH,DIN and PO4-P were the main factors in summer.Besides,comparing with the historical data,we found that the diatom species in percentage declined in comparison with the total.