权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Fluctuation in spawning behavior and larval transport of the Japanese eel associated with global oceanic change

与全球海洋变化相关的日本鳗鱼产卵行为和幼体运输的波动

基本信息

批准号：
11660179
负责人：
KIMURA Shingo
金额：
$ 2.18万
依托单位：
The University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2001
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11660179/
关键词：
Japanese eel egg and larval tranport North Equatorial Current salinity front El Nino southern oscillation index Atlantic eel North Atlantic Oscillation index 水温フロント地衡流速適水温シミュレーション回遊

项目摘要

Spawning ground of the Japanese eel is located in the North Equatorial Current (NEC) in the Pacific Ocean. However, several unanswered questions about the distribution of the eel and their larvae downstream of the NEC remain and are unlikely to be resolved by the observations alone. Three such questions are about 1) previous mis-determination of spawning ground, 2) large larval catch off the west coast of Taiwan, not off the east coast, 3) low abundance of larvae in Korean coastal waters. In this research, we have demonstrated that answers to these questions can be explained by the water circulation in the North Pacific by using numerical simulations. Movement of the salinity front associated with ENSO (El Nino and Southern Oscillation) controls abundance of larval transport from the spawning ground in the NEC to the nursery ground in the East Asia. The salinityfront has moved from 13°N to 17°N during last three decades. Since condition of larval transport north of 15°N is worse, this northward displacement of the salinity front probably can explain decadal scale linear decreasing of the Japanese glass eel catch from the 1970s. In this research, decadal scale ocean-climate change charecterized by the NAO (North Atrantic Oscillation) index was also proposed to explain decline of glass eel catch of the American and European eels. Associated with large regime shift in 1975, the Southern Oscillation Index and NAO index changed to another phase simultaneously and the decline of the glass eel catch in both the Pacific and Atlantic oceans was started in the mid 1970s. This correspondence suggests that the global ocean-climate changes afect migration behavior of the genetically close-related species in the Pacific and Atlantic Oceans through similar physical processes, and finally control their fish stocks.

日本鳗鱼的产卵场位于太平洋的北赤道流（NEC）。然而，关于NEC下游鳗鱼及其幼虫的分布仍有几个未解之谜，不太可能仅通过观察来解决。三个这样的问题是：1）以前错误的产卵场，2）大量的幼虫捕获台湾西海岸，而不是东海岸，3）在韩国沿海沃茨的低丰度的幼虫。在这项研究中，我们已经证明，这些问题的答案可以解释的水循环在北太平洋使用数值模拟。与ENSO（厄尔尼诺和南方涛动）相关的盐度锋的运动控制了从NEC产卵场到东亚育苗场的大量幼虫运输。在过去的30年中，盐度锋从13°N移动到17°N。由于15°N以北的幼鳗运输条件较差，盐度锋的北移可能解释了自20世纪70年代以来日本鳗鲡渔获量的年代际线性下降。本研究还提出了用NAO（North Atrantic Oscillation）指数表征的年代际尺度海洋气候变化来解释美洲鳗和欧洲鳗产量下降的原因。伴随着1975年的大的体制转换，南方涛动指数和NAO指数同时进入另一个阶段，太平洋和大西洋的玻璃鳗渔获量在20世纪70年代中期开始下降。这种对应关系表明，全球海洋气候变化通过类似的物理过程影响太平洋和大西洋遗传上近缘物种的迁移行为，并最终控制其鱼类种群。