南海南部上层水体浮游有孔虫的组成与分布特征

通过分析2012年4月在南海南部获取的浮游生物拖网样品，对水体中浮游有孔虫的区域分布特征及其影响因素进行了初步探讨。南海南部上层水体中共鉴定出现代浮游有孔虫19种，其中优势种为Globigerinoides sacculifer、Globigerinoides ruber、Globigerinella calida、Globigerinella siphonifera、Globorotalia menardii、Orbulina universa、Neogloboquadrina dutertrei。浮游有孔虫种属组成整体上呈现为热带-亚热带群落特征，浮游有孔虫生物丰度与西太平洋北赤道流区域的生物丰度相当。南海南部春季上层水体中浮游有孔虫整体表现为西高东低的区域分布特征，在垂直分布上浮游有孔虫集中分布在上部0~50m水层中，50m以深水体中浮游有孔虫生物丰度迅速降低。认为浮游有孔虫的分布受到温度、水体层化、初级生产力等多方面环境因子的综合作用。个别深水种(如Globorotalia menardii)出现了主要分布在0~50 m水深的特殊现象。

Assemblage and distribution of planktonic foraminifera in the upper water layer of southern South China Sea

Modern planktonic foraminifera are quantitatively analyzed for 30 stratified towing samples collected from 6 sites in the southern South China Sea (SCS) in April, 2012. 19 planktonic foraminifera species ae identified from the upper 250m of water column, and most of them are tropical and subtropical warm water species. The faunal assemblage is dominated by Globigerinoides sacculifer, Globigerinoides ruber, Globigerinella calida, Globigerinella siphonifera , Globorotalia menardii , Orbulina universa, Neogloboquadrina dutertrei. The foraminiferal abundance is higher in the west part of area than that in the east region. High abundance value occurs in the upper 0~50 m of water column, and then quickly decrease with water depth. Some subsurface dwellers, such as Globorotalia menardii, are also found in high abundance in the upper 0~50 m water column. This distribution pattern is believed to be influenced by various factors, such as temperature, water stratification and primary production.