粤东柘林湾中肋骨条藻(Skeletonema costatum)种群生态学  

Population dynamics of Skeletonema costatum in Zhelin Bay of Eastern Guangdong

作　　者：黄长江[1] 王超[2] 董巧香[1] 林小苹[2] 

机构地区：[1]浙江温州医学院环境与公共卫生学院,温州325035 [2]广东汕头大学海洋生物重点实验室,汕头515063

出　　处：《生态学报》2007年第1期142-151,共10页Acta Ecologica Sinica

基　　金：广东省自然科学基金资助项目(021260);广东省重大科技兴海资助项目(A200005F02)~~

摘　　要：于2000年5月～2004年12月对粤东大规模养殖区柘林湾的赤潮藻中肋骨条藻（Skeletonema costatum）种群的时空分布进行了长达5a的调查。结果表明，中肋骨条藻种群密度的周年变动模式基本为双峰型，平面分布没有显著的空间差异。调查期间，中肋骨条藻种群密度的站位实测值为0～1．4×10^7cells／dm^3，总均值为3．3×10^5cells／dm^3，占浮游植物总细胞数的67．1％，为调查海区第1优势种。在总共1045份样品中，有中肋骨条藻出现的样品数为1020份。其中，种群密度大于10^6cells／dm^3的样品有65份，大于10^7cells／dm。则有4份。以大于10^6cells／dm^3为中肋骨条藻的赤潮密度标准，在调查期间至少于2000年、2003年发生4次赤潮。运用灰关联理论对中肋骨条藻种群密度与13个环境因子的关系进行排序分析发现，水温、pH值和浮游动物是影响柘林湾中肋骨条藻种群时空分布的关键因子。水温还与中肋骨条藻种群密度的对数值具极显著意义的线性关系，而达到赤潮密度的样品均落在24．5～32．0℃区间，即每年的5～9月份高温季节。由于柘林湾浮游动物的年高峰期也出现在高温季节，说明浮游动物摄食压力的存在可能是柘林湾中肋骨条藻赤潮发生的重要抑制因子。2004年调查海区中肋骨条藻种群密度和在浮游植物群落中的优势度骤然降低，可能与水体营养盐结构和Fe含量的变化有关。因此，长期调查与监测对于研究海湾生态学和赤潮发生机制是极为重要的。Zhelin Bay is characterized by intensive aquaculture along the coast of Southeast China, with approximately half of the water area occupied by either cultured oysters or caged-fish farms. As one of the most important bays for large-scale mariculture in Guangdong Province, aquaculture production in Zhelin Bay has made significant contributions to the local economy. However, development of intensified caged-fish farms during the last decade has accelerated eutrophication process of the bay, and massive fish kills due to harmful algal blooms such as Phaeocystis pouchetii were reported in 1997 and 1999. Diatom blooms such as Skeletonema costatum and Thalassiosira diporocyclus have also been reported in the recent years. Since May 2000, our research group has initiated an ecological investigation around Zhelin Bay, where samples were collected monthly or quarterly for analysis of phytoplankton, zooplankton, microorganism, water temperature, salinity,nutrients and other environmental parameters. In the present study, we described the population dynamics of S. costatum in 9 sampling stations from May 2000 to November 2004. Samples were collected at high tide （ 1.5 h） weekly （March to November） or biweekly （December to February） at eight stations （ except for S3 ） between May 2000 and June 2001, and monthly at all nine stations between July 2001 and December 2003, and quarterly at all stations in 2004. For quantitative phytoplankton analysis, one liter of water samples were collected with 5 L HQM-1 sampling bottles 0.5 m under the surface and 0.5 m above the bottom at each station. Immediately after collection, the water samples were fixed with Lugol＇s iodine solution with a final concentration of 15‰. Water samples were then transferred to graduated glass cylinders and concentrated to 30 -- 100 ml gradually through sedimentation over a period of 3 days. Species identification and density counting was performed with an inverted microscope （Zeiss Axiovert25, magnification 400 ） using a 1 ml Sedgew

关 键 词：柘林湾 中肋骨条藻 种群动力学 赤潮 

分 类 号：Q948[生物学—植物学]