O and C isotope variation gradient of planktonic foraminifera is rather sharp in Dongsha and Zhongsha areas, which can be related to seawater circulation caused by Kuroshiro invasion.

• 浮游有孔虫氧碳同位素等值线在东沙和中沙海域变化梯度较大，与黑湖入侵引起的海水环流有关。