夏季风爆发前后南沙海区上层水体中的现代放射虫  

RADIOLARIANS IN UPPER WATERS OF NANSHA SEA AREA BEFORE AND AFTER THE SUMMER MONSOON ONSET

作　　者：张兰兰[1] 陈木宏[1] 向荣[1] 杜恕环[1] 

机构地区：[1]中国科学院边缘海重点实验室,中国科学院南海海洋研究所,广州510301

出　　处：《海洋地质与第四纪地质》2012年第4期25-32,共8页Marine Geology & Quaternary Geology

基　　金：国家自然科学基金青年项目(40906030);国家自然科学基金项目(40631007);国家重点基础研究发展规划项目(2010CB428901)

摘　　要：利用在南沙群岛及其邻近海域获取的2002和2004年两个春季航次的28个浮游拖网站位,分析了南海夏季风爆发前后南沙海区上层水体中的现代放射虫分布特征及其年际变化。研究结果显示,南沙海区春季两个航次放射虫属种组成以热带亚热带暖水种为主要优势种,但在主要属种组成及其丰度分布上具有明显的年际差异。上层水体中放射虫丰度以及主要属种相对丰度在夏季风爆发前后的分布变化也非常明显,表明南海上层水体中放射虫对夏季风爆发有响应;在夏季风爆发后放射虫总丰度明显增高,推测夏季风爆发后的海洋环境变化可能更有利于放射虫群的发育繁盛。但对造成放射虫在夏季风爆发前后分布差异特征的直接环境因素或其形成机制还有待深入分析。研究结果还进一步证实了T.octacantha和S.glacialis可以作为热带上升流的指示种。28 towing samples for plankton were collected from the upper waters of the Nansha Islands and its adjacent sea areas in the spring of 2002 and 2004 for understanding the distribution pattern of modern radiolarians and their annual changes in the upper waters of Nansha sea area before and after the summer monsoon onset. The results showed that the dominant species in the spring of 2002 and 2004 were consis- ting of the tropical-subtropical warm species; however there were obviously annual differences in abun- dance distributions of radiolarians and their typieal species. Noticeably, the radiolarian abundance and its dominant species were significantly different before and after the summer monsoon onset, suggesting that there was a response of radiolarians in upper waters to summer monsoon onset in the South China Sea; The radiolarian abundance after the summer monsoon onset was significantly higher than that before the sum- mer monsoon onset, indicating that the marine environment after the summer monsoon onset would be good for the survive of radiolarians. However, it is necessary to further study the mechanism of the change and try to find more direct environmental parameters to indicate the changes in distribution pattern before and after the summer monsoon onset. This study also confirmed that T. octacantha and S. glacialis could be proxies for upwelling processes in the tropic.

关 键 词：夏季风爆发前后 上层水体 现代放射虫 南沙海区 

分 类 号：P736.22[天文地球—海洋地质]