Carbon isotopic record of foraminifers in surface sediments from the South China Sea and its significance

The study is based on stable carbon isotopic measurements of 112 foraminiferal samples from surface sediments at 40 sites in the South China Sea (SCS). δ¹³C of foraminifers and Δδ¹³C between planktonic and benthic foraminiferal species exhibit a low value area at the north-eastern and southern ends of the SCS. It is correlated with the nutrient distributional pattern in the SCS and circumjacent area, the influence of the northeastern and southwestern monsoons on water flow and water chemistry in the SCS. The monsoons have not only brought nutrients to the upper part of the sea but also disturbed water and decreased difference between the surface and bottom water. Its influence is most obvious at both ends, which resulted in the low value areas in δ¹³C and Δδ¹³C at the ends. The distributional pattern of the stable carbon isotope in the SCS is a reflection of the East Asian monsoons.