琼东海域今生颗石藻群落研究

Study on modern coccolithophores in coastal region along the east Hainan Island

通过2012年7、8月在南海北部陆架琼东上升流区域的水文、化学和生物的现场综合采样调查,对采集过滤的今生颗石藻膜样在偏振光显微镜下鉴种并统计细胞丰度,分析了夏季该海域的颗石藻群落结构特征及分布规律。结果表明,夏季琼东上升流区共检出今生颗石藻34种,优势物种有赫氏艾密里藻（Emiliania huxleyi）、大洋桥石藻（Gephyrocapsa oceanica）、纤细伞球藻（Umbellosphaera tenuis）、卡特螺旋球藻（Helicosphaera carteri）、地中海花冠球藻（Coronosphaera mediterranea）等,颗石粒细胞丰度介于0~2 040.23×103粒/L,平均值8.10×103粒/L,颗石球丰度介于0~68.90×103cells/L,平均值5.01×103 cells/L。大多数颗石藻集中分布在上升流信号强的水体中。琼东中部水域的生物多样性指数H′较雷州半岛以东水域高,颗石粒群落的均匀度指数J分布与H′呈镶嵌模式。聚类Cluster和多维定标MDS结果,将颗石粒和颗石球群落各分成4个和5个组群,经相似性分析（ANOSIM）检验证明此种划分是显著的。将生物与海区环境因子进行冗余分析（Redundancy analysis,RDA）结果表明,N/P、PO3-4、NO-2和SiO2-3是影响本次调查的今生颗石藻生物群落的主控因子。

Multidisciplinary investigations of modern coccolithophores community in the Qiongdong upwelling water of the northern South China Sea（SCS）were performed during the summer cruise of the year 2012.The present study reported the coccolithophores community structure and distribution feature.Total 34 species were identified under polarizing microscope by the filtered membrane samples.The preponderant species were Emiliania huxleyi,Gephyrocapsa oceanica,Umbellosphaera tenuis,Helicosphaera carteri,Coronosphaera mediterranea.Coccolith abundance ranged within 0-2 040.23×103 cells/L,with an average value of 8.10×103 cells/L;and coccosphere abundance was 0-68.90×103 cells/L,with an average value of 5.01×103 cells/L.majority of species distributed in the strongly upwelled water.The central area of Qiongdong had larger H′value than that of east of Leizhou Peninsula.The H′and Jvalue of coccolith exhibited mosaic pattern.The results of cluster and MDS showed that coccolith and coccosphere were classified into four groups and five groups respectively,and ANOSIM test proved it to be significant.The redundancy analysis（RDA）indicated that N/P,PO3-4,NO-2and SiO2-3are the major controlling factors influencing the modern coccolithophore community.