| 摘要: |
| 2001年7月—2002年7月对粤东赤潮重灾区柘林湾进行的浮游植物周年调查表明, 柘林湾共有浮游植物68属183种。其中硅藻为最优势类群, 共51属143种, 占总种数的77.8%；甲藻11属34种；其它浮游植物类群6属6种。调查海区浮游植物群落的种类丰富度、细胞密度、生物多样性和均匀度的平面分布均表现为湾外高于湾内和湾内外侧高于湾内内侧的基本格局, 但黄冈河河内浮游植物群落的构成却呈现种类少而密度高的特点。调查期间浮游植物的总细胞数年均值为16.9×104cells/L, 周年变动模式为双峰型 (高峰位于8月和4月)。与上一个周年调查(2000年5月—2001年5月)的总细胞数年均值(36.0×104cells/L)和单峰型周年变动模式(最高峰位于7月)相比, 差异较大。这可能是2001—2002年厄尔尼诺现象导致粤东地区气候异常、干旱少雨, 以及调查海区无机磷剧减45%所致。中肋骨条藻(Skeletonema costatum)为该湾的全年优势种, 在群落总细胞数中的百分比年均值从上一年度的58.7%上升至本年度的71.0%, 导致Shannon-Wiener多样性指数从上一年度的1.91减少至本年度的1.75。中肋骨条藻的绝对占优已在很大程度上改变了该湾浮游植物的群落结构, 并使中肋骨条藻赤潮的发生机率大大增加。陆源排污、大规模增养殖业和水体交换对柘林湾高营养盐低浮游植物密度及浮游植物群落的时空分布具最重要的影响。
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| 关键词: 柘林湾,浮游植物,群落结构,生态学,赤潮,中肋骨条藻 |
| DOI：10.11693/hyhz200306004004 |
| 分类号: |
| 基金项目:广东省重大科技兴海项目,A200005F02号;广东省自然科学基金项目,021260号 |
附件 |
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| ECOLOGICAL STUDY ON PHYTOPLANKTON IN ZHELIN BAY, EASTERN GUANGDONG: 2001—2002 |
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DU Hong1, HUANG Chang-Jiang2, CHEN Shan-Wen2, ZHU Lin2, ZHANG Yu-Bin2, DONG Qiao-Xiang3
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1.Institute of Aquatic Ecoscience, Jinan University;2.Institute of Aquatic Technology and Environmental Resources Protection, Shantou University;3.Aquaculture Research Station, Louisiana Agricultural Experiment Station, Louisiana State University Agricultural Center
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| Abstract: |
| Phytoplankton in the Zhelin Bay, eastern Guangdong, where the harmful algal blooms most frequently occurred, was investigated from July 2001 to July 2002. The results show that there were 183 species in total, representing 68 genera. Among these, diatoms (143 species, representing 51 genera) accounted for 77.8%, followed by dinoflagellates, with 34 species representing 11 genera. The species richness, abundance, diversity and evenness of phytoplankton at the outside of the bay were higher than inside. Within the bay, higher values were observed in the outer bay than in the inner bay. However, the density of phytoplankton increased from the inside of bay to the outside of bay, and was greater in outer and eastern parts than in the inner and western parts. Such a horizontal distribution pattern was mainly due tothe low density and fewer species in the bay. The large-scale cage fish culture may explain why the high nutrients could not accommodate high density or more species of phytoplankton. Compared with previous investigations (7/2000—7/2001), the annual density of phytoplankton decreased from 36.0×104 cells/L to 16.9×104 cells/L, and the density dynamics shifted from mono-peak in July to dual-peak in August and April. The variation might relate to the El Nino event in 2001—2002, which resulted in low precipitation over eastern Guangdong and the consequent 45% decrease of PO4-P in Zhelin Bay compared with the previous investigation year. During the present investigation, Skeletonema costatum was the most dominant species, and its percentage in total cell number of phytoplankton increased from 58.7% to
71.0%, which accounted for the decrease of the diversity index from 1.91 of the previous period to 1.75. Dominance of S. costatum has largely changed the hytoplanktonic community in Zhelin Bay and may increase the occurrence of its bloom outbreak. Sewage, large-scale mariculture and water exchange are the most important factors to affect the spatial-temporal distribution of phytoplankton and driving forces for high nutrients and low phytoplankton densities in Zhelin Bay.
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| Key words: Zhelin Bay, Phytoplankton, Community, Ecology, Red-tide, Skeletonema costatum |
