台风过境前后南海北部水体浮游有孔虫群落变化

Influences of typhoon on planktonic foraminiferal fauna in the northern South China Sea

通过2008年8月南海北部浮游有孔虫拖网调查,对12号台风"鹦鹉"过境前后南海北部水体中的活体浮游有孔虫群落进行了对比分析,结合海洋环境参数,初步探讨了台风对水体浮游有孔虫群落分布的影响,以增加对浮游有孔虫群落的环境生态的了解,为古环境重建积累基础资料。结果显示,台风过境后的浮游有孔虫丰度较台风来临前有明显降低,优势属种Globigerinoides sacculifer的相对百分含量在台风过境后有明显的降低,而生活在次表层水体中的Globigerina calida和Globigerinella aequilateralis的相对百分含量则在台风过境后明显上升。研究认为台风过境造成的水体垂直混合增强可能是导致浮游有孔虫群落变化的主要因素。

Eight plankton tow samples were obtained from the northern South China Sea（SCS） during Typhoon ＂NURI ＂（200812） in August 2008.Through planktonic foraminiferal analysis,together with in-situ measurements of environmental parameters,the influence of typhoon on the living planktonic foraminifera was discussed.Such study can improve our understanding of the environmental and ecological communities of planktonic foraminifera,and of applying basic data for palaeoenvironmental reconstruction.Compared with pre-typhoon oceanographic conditions,the abundance of living planktonic foraminifera decreased greatly after the typhoon passed,so did the relative abundance of dominated species Globigenoides sacculifer;in contrast,subsurface-dwelling species Globigerina calida and Globigerinella aequilateralis showed increased relative abundance in the after-typhoon waters.The results suggest that the enhanced vertical mixing of upper water caused by the typhoon was the main factor that leads to the changes of planktonic foraminiferal fauna in the northern SCS.