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.