| 摘要: |
| 南海是一个半封闭的边缘海，与中国和东南亚大陆相毗连。以往对南海海域物理海洋学的研究较多，对浮游植物生物量和生产力的研究较少，且大多研究均集中于西沙和南沙群岛(杨嘉东，1993；陈兴群等，1989)，对南海北部海域的研究较少(黄良民，1992)。目前，尚未见有关南海北部海域粒度分级的研究报道。
南海北部湾是中国的第四大渔场，除1994年对北部湾全海域进行过生物资源调查外(刘子琳等，1998)，其他仅见小范围的调查，如在菜州湾邻近海区(昌瑞华等，1995)，但未见其他有关浮游植物现存量和初级生产力的研究报道。
海洋光能自养浮游植物作为海洋食物网结构中的基础环节，在海洋生态系的物质循环和能量转化过程中起着重要作用。叶绿素a(Chl a)浓度是表征光能自养生物量和反映海水肥瘠程度的重要指标；初级生产力(PP)反映海域自养浮游生物生产有机碳的能力，是海洋生态系研究的重要内容，也是海域生物资源评估的重要依据。
本文报道了南海北部海域和北部湾海域粒度分级叶绿素a和初级生产力的分布特征，可为渔业资源评估和海区环境质量评价提供科学依据。而且调查中对叶绿素a和初级生产力分三级(Net级份，>20μm；Nano级份，2~20μm；Pico级份，<2μm)进行粒度分析测定，从更深层次上来研究该海区浮游植物群落生物量和生产力的粒度结构及其环境调控。 |
| 关键词: 叶绿素a 初级生产力 粒度结构 |
| DOI： |
| 分类号: |
| 基金项目:国家自然科学基金资助项目，49776309和40176035号。 |
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| DISTRIBUTION CHARACTERISTICS OF SIZE-FRACTIONATED CHLOROPHYLL A AND PRODUCTIVITY OF PHYTOPLANKTON IN THE NORTHERN SOUTH CHINA SEA AND BEIBU GULF DURING AUGUST 1999 |
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Cai Yuming1, Ning Xiuren2, Liu Chenggang1
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1.Second Institute of Oceanography, State Oceanic Administation;2.Key Laboratory of Ocean Dynamic Processes & Satellite Oceanography, SOA
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| Abstract: |
| The distribution of the abundance of phytoplankton, chlorophyll a concentration and primary productivity in the northern South China Sea and the Beibu Gulf were observed in August,1999. The results showed that there were marked features of spatial zonation in the surveyed area due to the differences between the geographic environment and the hydrological conditions. Chlorophyll a value were higher near the Zhujiang (Pearl) River and lower near the eastern Hainan Island and southeastern Hong Kong at the northern South China Sea. Chlorophyll a in the surface decreased from nearshore to the mouth of the Beibu Gulf and the mean value in the water column were low at the center and mouth of the Beibu Gulf. The average concentration of chlorophyll a, primary productivity, and abundance of phytoplankton in the northern South China Sea and the Beibu Gulf were (2.03±1.18) and (0.69±0.39) mg/m3, 88.7 and 233.7 mgC/(m2·d), 0.38×106~1233.18×106 and 2.10×106~47.88×106cel/m3, respectively. The results of the size- fractionation showed that the contribution of picoplankton (<2μm) to total chlorophyll a and total primary productivity were in dominant position in phytoplankton community biomass and production of the northern South China Sea and Beibu Gulf. Nanoplankton (2-20 μm) were less, and netplankton (>20μm) the least. |
| Key words: chlorophyll a primary productivity |
