【作者】 李欣；

【导师】 汪岷； 孙军；

【作者基本信息】 中国海洋大学 ， 生物工程， 2011， 硕士

【摘要】 南海是中国最大的边缘海,地处热带与亚热带,且沿岸江河密布,珠江,湄公河等河流将陆源营养物质不断向南海输入,因其面积之广,深度之大,陆源营养盐的输入远远不能满足浮游植物大面积暴发的需要,所以南海是一个相对营养贫乏,生产力较低的海域,南海复杂的地理气候环境对浮游植物的生长影响显著。浮游植物群落是南海调查的重要指标之一,对了解南海生产力,水团海流具有重要作用。颗石藻因其显著的有机碳无机碳生产效应,对全球碳循环具有重要作用,其生长分布,丰度,生理生化机制日益受到人们的广泛关注。本研究基于CHOICE-C(973)南海夏冬季航次以及09年8月份南海北部的另外一个航次的调查,对南海颗石藻及相关浮游植物群落进行了研究。本文对09年中国南海北部(17°-24°N,108°-122°E)夏季和冬季的颗石藻和相关的其他浮游植物群落结构进行了研究,以对南海颗石藻及浮游植物的细胞丰度,物种组成,多样性,均匀度等相关系数进行统计。颗石藻的镜检工作以偏光显微镜为主,扫描电镜辅助的方法进行物种的鉴定与计数,相关浮游植物的统计工作采用国际标准的Utermohl分析方法。其中颗石藻夏季调查站位21个,冬季23个,共镜检样品273个,鉴定物种11属13种,细胞丰度在夏季介于2.6～718.1cells/L之间,平均细胞丰度59.5cells/L；冬季保持在3.021～644.1 cells/L之间,平均细胞丰度66.8cells/L。多样性指数夏季介于0.30～1.98之间,冬季介于0.51～2.25；均匀度指数夏季介于0.30-0.99之间,冬季在0.33～0.99的范围内。总体来说,冬季的颗石藻细胞丰度明显高于夏季。水平分布上,因夏季颗石藻细胞丰度整体较低,表层丰度分布规律不显著,而冬季颗石藻水平分布的高值区位于珠江口的外海站位；垂直分布上,颗石藻细胞丰度高值通常出现于次表层的样品中。调查期间颗石藻类群出现的优势种为纤细伞球藻(Umbellosphaera tenuis (Kamptner) Paasche)、赫胥黎艾米里亚藻(Emiliania huxleyi (Lohmann) Hay et Mohler)以及大洋桥石藻(Gephyrocapsa oceanica Kamptner)。浮游植物调查站位33个(分南海北部和北部湾两部分海域),取水样159个,借以分析夏季调查区浮游植物的群落结构特征。通过Utermohl方法共鉴定出浮游植物5门68属145种(包括未定种),细胞丰度介于0.009～125.6×103cells/L,平均细胞丰度为7.245×103cells/L。群落组成以硅藻为主,其次是甲藻,还有少量的蓝藻,绿藻和金藻,生态类群以广温广布型种为主,调查区的优势种为菱形海线藻(Thalassionema nitzschioides Grunow)、柔弱伪菱形藻(Pseudo-nitzschia delicatissma (Cleve) Heiden)、尖刺伪菱形藻(Pseudo-nitzschia pungens (Grunow et Cleve)Hasle)、角毛藻(Chaetoceros sp.)、矮小短棘藻(Detonula pumila (Castra) Schutt).颗粒直链藻(Melosira grannulata Ehrenberg)以及蓝藻门的铁氏束毛藻(Trichodesmium thiebaultii Gomont)也作为优势种出现。南海北部表层浮游植物细胞丰度由近岸站位向外海逐渐降低,高值区位于珠江口附近以及南部水域,而北部湾海域的表层浮游植物丰度由近岸区向湾中部逐渐降低,甲藻在调查区的西北部广东沿岸附近出现高值区。调查区浮游植物丰度在垂直方向上由表层水体向深层水体逐渐降低。Shannon-Wiener多样性指数和Pielou均匀度指数在珠江口南部和广东沿岸站位出现低值区。更多还原

【Abstract】 South China Sea (SCS), being the deepest and biggest sea adjacent to China, lies in the western part of the Pacific Ocean. Rivers flows into South China Sea, including Pearl River, Hong Ha River, Mekong River, etc. which can supply nutrients for the south china sea. However SCS is also the deepest and the biggest sea along China, the nutrients is scarce, and they can’t support to form phytoplankton blooms. The phytoplankton community is an important index on understanding SCS, including the water masses, the productivity and so on. The living coccolithophores (LC) plays an important role in the production of Particle Inorganic Carbon (PIC) and Particle Organic Carbon (POC), so the species composition, community structure, the physiological and biochemical mechanism of LC were concerned in this thesis, menwhile the LC associated phytoplankton community was also reported in this thesis.According to the samples gottend by the cruises from the northern South China Sea(17°-24°,108°-122°E)in summer and winter 2009, the species composition, cell abundance, community structure, Shannon-Wiener index, Pielou index of LC and phytoplankton are reported here. The LC analysis via polarizing microscope, and identifying of uncertain taxa with the help of scanning electron microscope (SEM), the associated phytoplankton was analysed with Utermohl method.LC samples taken from 8 stations in summer and winter cruises respectively, and a total of 273 samples were analysed. There are 13 LC species belonging to 11 genera. The coccolithophores cell abundance ranged from 2.633 to 718.1 cells/L in the summer and the average cell abundance is 59.53 cells/L,while the cell abundence ranged from 3.021 to 644.1 cells/L in the winter, coupling with the average of 66.83cells/L. The Shannon-Wiener index of LC in summer and winter ranged from 0.3034 to 1.981 and 0.5107 to 2.249 respectively, and Pielou evenness index ranged from 0.3034 to 0.9998 and from 0.3340 to 0.9984. The LC cell abundance is greaterin winter than that of in summer. In the surface distribution of the LC abundance isn’t remarkable in summer, while the distribution of abundance appeared prevailed in the basin than on the continental shelf in winter;In the vertical distribution, the high cell abundance usually lie in tne sub-surface. Umbellosphaera tenuis (Kamptner) Paasche, Emiliania huxleyi (Lohmann) Hay et Mohler and Gephyrocapsa oceanica Kamptner were predominant in the two cruises.The associated phytoplankton community structure in this area were also studied, and a total of 145 taxa (include unidentifying species) belonging to 68 genera in 5 phyla were recorded. The phytoplankton cell abundance ranged from 0.009 to 125.6×103cells/L in summer and the average cell abundance is 7.245×103cells/L Bacillariophyta were predominant and coexisted with Dinophyta, and some species belonging to Cyanophyta, Chlorophyta and Chrysophyta, most of phytoplankton taxa is eurythermal species and cosmopolitan species. The dominant species in turn were Thalassionema nitzschioides Grunow, Pseudo-nitzschia delicatissma (Cleve) Heiden, Pseudo-nitzschia pungens (Grunow et Cleve) Hasle, Chaetoceros sp., Detonula pumila (Castra) Schiitt, Melosira grannulata Ehrenberg, Trichodesmium thiebaultii Gomont, which belonging to Cyanophyta. The high phytoplankton cell abundance region in surface layer occurred in the Pearl River Estuary and its southern part. In the Beibu Gulf, phytoplankton cell abundance decreased from coastal zone to the center of the Gulf, and cell abundance of dinoflagellates was high in the coastal seawater of Guangdong Province. Phytoplankton cell abundance was high in surface water and decreased rapidly from surface layer to the bottom. The Shannon-Wiener index and Pielou evenness index were low in the southern part of Pearl River Estuary and the coastal water of Guangdong Province.更多还原