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Mechanism driving depleted anchovy and sardine abundance and their amplitude/periodicity changes on decadal timescales during the Medieval Warm Period

中世纪温暖时期凤尾鱼和沙丁鱼丰度减少的驱动机制及其在十年时间尺度上的幅度/周期性变化

基本信息

批准号：
22340155
负责人：
KUWAE Michinobu
金额：
$ 12.15万
依托单位：
Ehime University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2010
资助国家：
日本
起止时间：
2010-04-01 至 2014-03-31
项目状态：
已结题

项目摘要

To elucidate how decadal-scale variability of Japanese sardine stock will change in relation to global ocean warming, we examined changes in amplitude of sardine decadal variability and changes in peleotemperature and paleoploductivity around Medieval Climate Anomaly as an analogue for their response to climate change. Sardine abundance was reconstructed from coastal marine sediments of Beppu Bay, Japan. The record showed centennial-scale variability (250-300 years) and no clear response of sardine to climate changes corresponding to Medieval Climate Anomaly/Little Ice Age transitions in the western North Pacific. Rather, centennial variability of sardine abundance showed a similar pattern to basin-wide climate variability found in the reconstructed PDO index in the North America and the abnormal snow index in the East Asia. It is possible that one of driving factors of the centennial variations in sardine abundance is prey abundance in the western North Pacific.

为了阐明日本沙丁鱼种群的年代际变率与全球海洋变暖的关系，我们研究了中世纪气候异常前后沙丁鱼年代际变率的幅度变化、古温度和古生产力的变化，作为它们对气候变化的响应的类比。利用日本别府湾沿海沉积物重建了沙丁鱼的丰度。记录显示了百年尺度的变率（250-300年），沙丁鱼对北太平洋西部中世纪气候异常/小冰期转变的气候变化没有明显的响应。相反，沙丁鱼丰度的百年变率与北美重建的PDO指数和东亚异常雪指数中发现的全流域气候变率相似。北太平洋西部的猎物数量可能是导致沙丁鱼数量百年变化的驱动因素之一。