春季东海产卵场及其邻近海域的束毛藻与网采浮游植物群落

The Trichodesmium and Netz-phytoplankton community of the spawning ground in the East China Sea and its adjacent waters in spring

对2007年5月东海产卵场及其邻近海域32个采样站位的蓝藻及其网样浮游植物群落进行了初步研究,共发现浮游植物3门33属90种(不包括未定名物种),物种以硅藻为主,甲藻在群落中也较显著,由于气象和水文因素的影响,蓝藻在个别站位成为优势群体。优势种为中肋骨条藻Skeletonema costatum、琼氏圆筛藻Coscinodiscus jonesianus、辐射圆筛藻Coscinodiscus radiatus、三角角藻Ceratium tripos、铁氏束毛藻Trichodesmium thiebautii、夜光藻Noctiluca scientillans和布氏双尾藻Ditylum brightwellii。细胞丰度以硅藻为优势,其平面分布主要由硅藻和甲藻所刻画,浮游植物高值区在调查区西北部海域,硅藻高值区与浮游植物的高值区相一致,甲藻高值区主要在调查区中部偏北海域和东部外海海域。浮游植物的Margalef物种丰富度在调查区东部和南部较高,Shannon-Wiener多样性指数和均匀度指数在在调查区中部和东部较高。

Phytoplankton community structure were studied based on the data of netz-phy- toplankton by a 32 station grid survey, which was carried out in the spawning ground of the East China Sea and its adjacent waters from 4th to 18th May 2000. Three phyla including 33 genera and 90 species （not including unidentified taxa） were found in the survey area. The ma- jor phytoplankton group was Bacillariophyta, but the Dinophyta and Cyanophyta are also signif- icant at some stations. The dominant species were Skeletonerna costaturn, Coscinodiscus jones- ianus , Coscinodiscus radiatus , Ceratium tripos , Trichodesrniurn thiebautii , Noctiluca scientillans and Ditylum brightwellii. The horizontal patterns of phytoplankton cell abundance were mainly dominated by diatoms and dinoflagellates. Abundance of diatom and total phytoplankton was high in the northwestern part of the surveyed area, and abundance of dinoflagellates was high in the central and northern part of the surveyed area. The species richness was high in the eastern and southern spawning ground, and the Shannon-Wiener index and the evenness of phy- toplankton were relatively high in the central and eastern spawning ground.