中文摘要：

本次工作利用2013年基金委开放航次获得的南海北部13个站位65个浮游生物拖网样品,初步鉴定出22个浮游有孔虫属种,基本以热带暖水种为主,冷水种仅零星出现.其中,浮游有孔虫表层水种Globigerinoides ruber和Globigerinoides sacculifer主要生活在0～ 50m水层;次表层水种Neogloboquadrina dutertrei生活在0～ 100m水层、Pulleniatina obliquiloculata则主要生活在50 ～ 150m水层.温跃层结构变化对G.sacculifer、N.dutertrei影响明显,当温跃层变深时,这两种浮游有孔虫生活水深随之变深;反之,其生活水深变浅.优势种G.ruber、G.sacculifer（wo）、G.sacculifer（w）、N.dutertrei和P.obliquiloculata壳体的δ18O平均值分别是-3.08‰、-2.68‰、-2.62‰、-1.86‰和-1.52‰,壳体δ18O随着其生活水深逐渐增大,指示了海洋上层水体的垂向温度梯度变化;而壳体的δ13C平均值分别是-0.06‰、0.71‰、1.02‰、0.45‰和-0.40‰,呈现先增大后减小的特征,与上层水体中的叶绿素等营养物的垂向变化相关.因此,浮游有孔虫表层水种和次表层水种之间的δ18O和δ13C差值可以用来指示温跃层和营养物跃层深度的变化.

英文摘要：

In this study, 65 plankton tow samples were collected and analyzed from 13 sites in the northern South China Sea during the 2013 open cruises of the National Natural Science Foundation of China. Totally 22 planktonic foraminiferal species were identified in the samples and most are tropical warm water species with few cold water species. Sea surface water dwelling species Globigerinoides ruber and Globigerinoides sacculifer mainly live in the upper 0 - 50m water layer, while sub-surface water dwelling species such as Neogloboquadrina dutertrei and Pulleniatina obliquiloculata live in the 0-100m and 50-150m water layer respectively. The changes of thermocline depth significantly influence the vertical distribution of G. sacculifer and N. dutertrei. When the thermocline became deeper, both of the two species migrated downward, vice versa. The average 81SO values of G. ruber, G. sacculifer （wo） , G. sacculifer （w） , N. dutertrei, P. obliquiloculata are - 3.08‰, -2.68‰, -2.62‰, - 1.86‰ and -1.52‰ respectively, which change along with the increase of living water depth and mainly reflect the vertical temperature gradient in the upper water column. The average δ13C of these species are -0.06‰, 0.71‰, 1.02‰, 0.45‰ and -0.40‰ respectively, displaying the trend that the values increase firstly with the water depth and then decrease later, which may be related to the vertical changes of nutrients such as chlorophyll in the upper ocean. Therefore, the δ18O and δ13C differences between surface water and sub-surface water dwelling planktonic foraminiferal species can be used to indicate the variations of thermocline and nutrientcline depth.