台湾海峡生态系统对海洋环境年际变动的响应分析

Evidence of ecosystem response to the interannual environmental variability in the Taiwan Strait

通过比较1985～2001年的海表温度与其间收集的现场营养盐、浮游植物和浮游动物丰度及群落结构变动信号，以及1971～1998年的中上层鱼类渔获量变动信息，发现了台湾海峡生态系统对物理环境年际变动产生的响应迹象．1997年夏季台湾海峡处于偏冷状态，南部近岸上升流强度减弱；1997年冬季正值一个较强的暖事件发展到顶峰，北上入侵暖水强度增强、浙闽沿岸冷水强度减弱．导致这两个时期营养盐分布特征改变，发生了一系列从浮游植物到浮游动物，从生物量到群落结构的异常响应，暖水性中上层鱼类渔获量则似乎呈现出El Nino年偏高的趋势．根据有限的辅助证据推测，El Nino很可能不是控制台湾海峡海洋环境年际变动的强信号，而台湾海峡的气候一海洋一生态长期低频变动可能更多地受到东亚季风一中国边缘海系统的控制．

By comparing remote sensing sea surface temperature and in situ chemical and biological data collected since 1985, some evidences of ecosystem variation responding to interannual environmental variability were found in the Taiwan Strait. Owing to incomplete extensive and serial biological observations, the eco-system responses were mainly illustrated by two specific cases. Coastal upwelling weakened in the summer of 1997, when the Taiwan Strait was during a cold phase. Cold Zhe-Min coastal water weakened and northward intrusion of warm water was strengthened in the winter of 1997, while it was the peak of a strong warm episode of the Taiwan Strait and the South China Sea. During these two periods, nutrient distribution, phytoplankton and zooplankton abundance and community structure altered and showed anomaly. El Nino seemed weakly linking to the Taiwan Strait. It was hypothesized that forcing within the East Asia monsoon-China marginal sea system might the dominant mechanism. To achieve better understanding of how the Taiwan Strait ecosystem responds to climate variations, supporting the long-term physical evidences and serial biotic variation signals observation are especially needed.