根据2007年底至2008年初珠江河口咸潮入侵期间大潮和小潮的两次调查资料, 对浮游植物的种类组成、种数和细胞密度的分布等群落特征进行了分析, 并探讨环境因素对浮游植物群落的影响。共鉴定浮游植物76种, 包括38种硅藻、18种绿藻、14种甲藻、4种蓝藻和2种裸藻。浮游植物种数分布有明显的空间变化, 一般从河口上段至下段种数减少; 大潮时浮游植物的种数低于小潮时, 并且各水层之间浮游植物种数分布不均匀。优势种以淡水硅藻为主, 如颗粒直链藻Melosira granulata、颗粒直链藻最窄变种 Melosira granulata v. angustissima、小环藻 Cyclotella sp.和海链藻Thalassiosira sp.等; 河口上段的站优势种突出, 密度分布不均匀, 均匀度值比较低。大潮和小潮期间浮游植物细胞密度的平均值分别为53.80×104个.L-1和62.21×104个.L-1, 变化范围为(1.48— 290.41)×104个-L-1和(1.52—283.62)×104个.L-1; 二者的平面分布趋势基本相同, 由河口上段至下段呈递减的格局; 硅藻类的细胞密度占明显优势。浮游植物的种类组成、种数和细胞密度的分布受盐度、营养盐等环境因子的影响, 并且具有明显的潮周期性。

The authors analyzed species composition, distribution of species richness and phytoplankton density based on the data collected from two cruises carried out during saline water intrusion period from the end of 2007 to the beginning of 2008 at both spring and neap tides in the Pearl River Estuary. In addition, influence of environmental factors on phytoplankton community was discussed. Seventy-six species in total were identified, including 38 diatoms, 18 green algae, 14 dinoflagel-lates, 4 cyanobacteria and 2 euglenas. In general, the distribution of species richness decreased from inner section to outer section of the Pearl River Estuary. The species richness of phytoplankton was higher at neap tide than at spring tide, and it distributed unevenly among different water layers. The dominant species were mainly freshwater diatoms, such as Melosira granulate, Melosira granulata v. angustissima, Cyclotella sp. and Thalassiosira sp. The dominant species were very out-standing in the inner section of the Pearl River Estuary with the characteristics of uneven density distribution and low even-ness index value. The mean phytoplankton densities at spring and neap tides were 53.80×104 and 62.21×104ind.L-1, and the ranges of cell density were from 1.48×104 to 290.41×104 and from 1.52×104 to 283.62×104ind.L-1, respectively. Phyto-plankton density decreased from the inner to outer sections of the Pearl River Estuary, and the density of diatom was the highest among different groups during both spring and neap tides. The community of phytoplankton presented clear tidal pe-riodicity. Environmental factors such as salinity and nutrients played an important role in the composition and distribution of phytoplankton during saline water intrusion period in the Pearl River Estuary.

中科院创新方向项目(KZCX2-YW-213, SQ200704, KZCX2-YW-Q07, KZCX2-YW-JS206); 广东省重大科技专项规划项目
(2007A032600002);  NSFC-GD联合基金重点项目(U0633007); 中国近海海洋综合调查与评价项目专项(908-01-ST08)

[1] 殷建平, 王友绍, 徐继荣, 等. 特大咸潮对珠江入海河段环境要素的影响[J]. 热带海洋学报, 2006, 25(4): 79-84.
[2] 朱三华, 沈汉堃, 林焕新, 等. 珠江三角洲咸潮活动规律研究[J]. 珠江现代建设, 2007, (6): 1-7.
[3] 陈燕群. 应对珠江口咸潮的对策初探[J]. 广西水利水电, 2005, (3): 81-83.
[4] 莫思平, 李越, 卢素兰. 广州水道咸潮影响因素分析[J]. 水利水运工程学报, 2007, (4): 36-42.
[5] 郭沛涌, 沈焕庭. 河口浮游植物生态学研究进展[J]. 应用生态学报, 2003, 14(1): 139-142.
[6] 林永水, 袁文彬. 珠江口浮游植物种类组成及群落结构[G]//珠江口海岸带和海涂资源综合调查研究文集(三). 广东省海岸带和海涂资源综合调查领导小组办公室. 广州: 广东科技出版社, 1985: 1-5.
[7] 黄良民, 陈清潮, 陈东娇, 等. 珠江虎门附近水域基础生物量与环境关系初步研究[G]//珠江及沿岸环境研究. 广州: 广东高等教育出版社, 1995: 5-12.
[8] HUANG L M, JIAN W J, SONG X Y, et al. Species diversity and distribution for phytoplankton of the Pearl River estuary during rainy and dry seasons [J]. Marine Pollution Bulletin, 2004, 49: 588-596.
[9] 冯洁娉, 姜胜, 冯佳和, 等. 广州海域浮游植物群落结构特征[J]. 生态科学, 2006, 25(3): 210-212.
[10] 雷光英, 杨宇峰, 王庆. 珠江广州河段水质和浮游植物群落特征[J]. 暨南大学学报: 自然科学版, 2007, 28(3): 302-307.
[11] 戴娟, 王超, 赖子尼, 等. 2006年夏季珠江口5大口门   网 采浮游植物群落的调查[J]. 淡水渔业, 2007, 37(3): 63-66.
[12] 国家技术监督局. GB 12763.6—1991海洋调查规范——海洋生物调查[S]. 北京: 中国标准出版社. 1991.
[13] 国家技术监督局. GB 12763.46—1991海洋调查规范——海水化学要素调查[S]. 北京: 中国标准出版社. 1991.
[14] 马克平. 生物多样性研究的原理与方法[M]. 北京: 中国科技出版社, 1994: 141-165.
[15] MING W W, TOWNSEND D W. Phytoplankton and hydrography of the Kennebec estuary, Marine, USA[J]. Marine Ecology Progress Series, 1999, 178: 133-144.
[16] PILKAITYTË R, SCHOOR A, SCHUBERT H. Response of phytoplankton communities to salinity changes–a mesocosm approach[J]. Hydrobiologia, 2004, 513: 27-38.
[17] 顾新根, 袁骐, 沈焕庭, 等. 长江口最大浑浊带浮游植物的生态研究[J]. 中国水产科学, 1995, 2(1): 16-27.
[18] 徐兆礼, 陈亚瞿.东黄海秋季浮游动物优势种聚集强度与鲐鯵渔场的关系[J]. 生态学杂志, 1989, 8(4): 13-15.
[19] REDFIELD A C, KETCHUM B H, RICHARDS F A. The influence of organisms on the composition of seawater[M]//HILL M N. The Sea: Vol. 2. New York: John Wiley, 1963. 26-77.
[20] ZHANG J, YU Z G, WANG J, et al. The subtropical Zhujiang (Pearl River) estuary: nutrient, trace species and their relationship to photosynthesis[J]. Estuarine, Coastal and Shelf Science, 1999, 49(3): 385-400.
[21] TILMAND D, KILHAM S S, KILHAMP P. Phytoplankton community ecology: the role of limiting nutrients[J]. Annual Review of Ecology and Systematics, 1982, 13: 349-372.
[22] 林祖亨, 梁舜华. 珠江口水域的潮流分析[J]. 海洋通报, 1996, 15(2): 11-22.