南海深海区的现代放射虫及其对水团的指示意义

To learn the modern process in the deep South China Sea (SCS) may provide important information for revealing the history of paleoenvironmental evolutions. This project is aimed to obtain samples of radiolarian living forms and empty skeletons of different layers from sea surface to 2500 m in the deep SCS by using a closing-type plankton net and stained with Rose Bengal, combined with the observed hydrography data of CTD, for studying systematically modern radiolarian community composition, species diversity, depth-zonation and their relations with the ecology and sedimentology in the deep sea. Based on analysing the environment factors of radiolarian ecological depth and temporal and spatial distributions and comparing their depositional differences in surface sediments, the main purpose is to discuss how different water masses or currents effect on the present radiolarian distribution in the deep sea, to find and establish new radiolarian proxies for indicating special mid-deep waters in the tropical marginal sea environment. It will also be evidenced for the appearance of SCS throughflow, by comparatively analysing the distribution changes of tropic west Pacific radiolarian fauna in the SCS and their related circulations. Results from this study will achieve especially some new information of radiolarian deep ecological knowledge, which provide important experiment data and judge gist for further recovering high resolution histories of paleoceanography and paleo-waters, and even the modern current supplementary evidence.

认识南海深海现代过程特征对揭示区域古环境演变历史具有重要科学价值与意义。本项目拟通过浮游拖网封闭式分层取样和染色处理方法，定量获取南海从表层到2500米水柱中放射虫活体和非活体的不同区域与深度标本，结合同步CTD水文观测资料，较为系统地研究现代放射虫在南海深海区的群落结构、多样性和特殊属种分布深度等生态特征与沉积过程；通过分析造成放射虫生态深度及其时空分布格局的环境因素，对比其在海底沉积物中的分布差异，重点探讨不同水团与海流如何影响放射虫在深海的现代分布特征，提取和建立放射虫属种对热带边缘海环境尤其是中深层水团的新替代性指标与组合特征；并比较分析北太平洋热带放射虫种群进入南海后的变化状况，提供南海贯穿流的微体生物学新证据。研究结果将填补热带深海现代放射虫生态及其与沉积关系的研究空白，为深入研究与恢复南海深海的高分辨率古海洋和古水团演变过程、以及现代水团的分布特征提供实验资料和判别依据。

认识南海深海现代过程特征对揭示区域古环境演变历史具有重要科学价值与意义。本项目通过浮游拖网封闭式分层取样、沉积物捕获器取样、虎红染色和DAPI染色等处理方法，首次研究了南海深海区现代放射虫的活体群和死壳群的组成结构和多样性及其空间分布特征；首次揭示了南海北部0-3000m水体中的放射虫壳体的深度分布和季节变化；通过分析造成现代放射虫生活深度和沉降过程的环境影响因子，并对比海底沉积物中放射虫的组成分布特征和现代放射虫在西北太平洋的组成分布特征，揭示出不同水团或海流（如中尺度涡旋、侧向流、径向翻转流和贯穿流）对现代放射虫的区域分布和深度分布起着重要的影响控制作用。研究结果不仅填补了南海深海区活体放射虫的空间分布和放射虫死壳的沉降过程的研究空白，而且为深入研究现代生态环境与水团分布和重建南海深海的古海洋和古水团提供判别依据和可靠资料。. 目前，已在国内外研究领域主流期刊上发表学术论文12篇（含SCI 6篇），另有两篇英文稿在审改中和1本放射虫专著待刊印中。部分数据结果仍在进一步整理分析中。培养或协助培养研究生3名。积极参加国内外学术交流活动超过26人次。依据本项目研究发现的新问题和新思路，研究人员获得1次中科院公派留学机会和2项新的国家科学自然基金项目。