三门湾沉积记录中长链烯酮不饱和指数-海表温度和浮游动物群落对厄尔尼诺/拉尼娜的响应

Responses of long-chain alkenone unsaturation index-sea sarface temperatare in stratigraphic record and zooplankton community in the Sanmen Bay to El Nio/La Nia phenomina

应用沉积地层记录中长链烯酮不饱和指数（U3K7）估算1916—2003年三门湾表层海水温度（SST）与变化。SST波动范围为15.97~18.00℃,年平均为17.03℃。该值比当年实测海水全年平均温度低3.52℃,同时应用长链烯醇不饱和指数与SST的关系重建历史上的厄尔尼诺现象。研究显示三门湾的厄尔尼诺气候事件在大尺度上与东太平洋一样均受制于气候影响,在变化尺度上又受到地理位置和地方性气候（季风）的影响,厄尔尼诺事件在形式和年代上相互对应,但是其涛动幅度不如东太平洋的强烈。通过比较厄尔尼诺期间（2003/2002年）和非厄尔尼诺期间（2006/2005年）的浮游动物群落结构变动信号、生物量、密度以及物种多样性等,在厄尔尼诺时期浮游动物种类数、生物量和丰度呈现偏高的趋势,三门湾的暖水性浮游动物类群、数量变化与台湾暖流活动过程中携带的浮游性动物有密切的联系。

The sea surface temperature（SST） was estimated by the record of long-chain alkenone unsaturation index in the Sanmen Bay sediment.The calculated result shows that SST fluctuation ranges from 15.97 to 18.00 ℃,and average is 17.03 ℃.The calculated value is lower than the annual measured value 3.52 ℃ in the same year.At one time,the stratigraphic record history of El Nio in the Sanmen Bay sediment was reescablished using the relatimship of long-chain alkenone unsaturation index with SST.The research indicates that change of climate event of large scale in the Sanmen Bay is same to that of the Pacific Ocean,both are major influenced by the climate factor.The event corresponds with each other in form and age,but its range of fluctuation is inferior to the Pacific Ocean because of the effect of location and monsoon.A series of characteristics of macrobenthos including the signal of community structure change,biomass,density of inhabit and biodiversity was compared both in the periods of El Nio and non-El Nio.The research indicates that zooplankton species,the biomass and the abundance have the high tendency in the period of El Nio.That was because the intensity of the warm current invasion increased,and warm-water zooplankton was carried into the Samen Bay.