2010年10月26日—11月24日在南海北部进行了浮游植物群落结构的调查,共鉴定浮游植物4门70属204种(包括未定种12种),浮游植物以硅藻为主,其物种数为146种,其细胞丰度占总浮游植物细胞丰度的93.17%;甲藻次之,其物种数为51种,占总浮游植物细胞丰度的0.63%;金藻门3属4种及蓝藻门2属3种;蓝藻门中以红海束毛藻(Trichodesmium erythraeum)为主。调查区浮游植物的细胞丰度介于0.06×103~107.50×103 cells/L之间,平均值为5.00×103 cells/L。海南岛东北部和粤东近岸表层浮游植物丰度较高。垂直分布上,表层和25m层的浮游植物细胞丰度较高。浮游植物主要优势种类有菱形海线藻(Thalassionema nitzschioides)、舟形藻(Navicula spp.)、中肋骨条藻(Skeletonema costatum)、旋链角毛藻(Chaetoceros curvisetus)、斯氏几内亚藻(Guinardia stolterforthii)、具槽帕拉藻(Paralia sulcata)等。调查区表层和5m层Shannon-Wiener多样性指数平均值分别为3.14和2.83,Pielou均匀度指数平均值分别为0.73和0.77;两种指数在表层和5m层均表现出较高的一致性。环境分析表明除硅酸盐外,浮游植物细胞丰度与其他环境因子均呈极显著性的相关性,主要受到氮元素及磷酸盐的共同限制作用。The abundance and species composition of phytoplankton community in the northern South China Sea(nSCS)(18°00′-23°30′N,110°30′-118°00′E)were investigated from 26 th October to 24 th November 2010.A total of 204taxa(12uncertain species included)belonging to 70 genera of 4phyla were identified.The main phytoplankton group was Bacillariophyta with 146 species,which accounted 93.17% of the total phytoplankton cell abundance,followed by Pyrrophyta with 51 species,which accounted for 0.63% of the total phytoplankton cell abundance.Chrysophyta(3genera and 4species)and Cyanophyta(2genera and 3species,where Trichodesmium erythraeum was the dominant specie)also had been found.The cell abundance of phytoplankton ranged from 0.06×103 cells/L to 107.50×103 cells/L and the average was 5.00×103 cells/L.The phytoplankton cell abundance in the surface water was high in northeast of Hainan Island and the coasts of east of Guangdong.The vertical profiles of phytoplankton showed that the maximum cell abundance was found in the surface water and 25 mlayer.The dominant species were Thalassionema nitzschioides,Naviculaspp.,Skeletonema costatum,Chaetoceros curvisetus,Guinardia stolterforthii and Paralia sulcata etc.The Shannon-Wiener diversity index and Pielou evenness index were high in the southeast of survey area and relatively low in other area,the average were 3.14 and 0.73 in surface,2.83 and 0.77 in 5mlayer,respectively.These two diversity indices showed a similar distribution.Environmental analysis showed that phytoplankton cells abundance had significant correlation with environmental factors except silicate,and the main dominant factors were the common restriction of nitrogen and phosphate.国家重点基础研究发展计划(2015CB954002);; 教育部新世纪优秀人才计划(NCET-12-1065);; 国家自然科学基金(41176136,41276124
