气候变化对日本鳀早期补充过程的影响机制研究

Japanese anchovy, Engraulis japonicusis, is a key prey fish in the western part of the North Pacific Ocean with enormous quantitative variations linked to the structure and function of Chinese ocean ecosystem. It is known that quantitative changes of anchovy are induced mainly by early recruitment success fluctuations related to climate change. However, the mechanism of recruitment success determination for Japanese anchovy is not well realized in the Chinese waters by scientists. In order to investigate the impact of climate change on the early recruitment of Japanese anchovy, egg and larval transport, environments experience and recruitment success would be analyzed. Mechanism of growth and death determination for egg and larvae would be studied based on larval otolith examination, NEMURO-anchovy Model, and some other methods in coastal zones of the middle Yellow Sea in China. The purpose of the program is to: (1) analyze the annual and inter-seasonal variation in the egg distribution and larvae transport off Haizhou Bay spawning ground; (2) discover the environmental impact on egg, larva growth and mortality; (3) realize the mechanism of recruitment success determination of Japanese anchovy. The program is a typical case study of marine fish quantitative variation with the influence of environmental changes related to climate background, high fishing, and habitat fragmentation in Chinese waters, and would help to enrich the theory and practice of the anchovy quantitative change studies.

日本鳀是西北太平洋海域饵料关键种,其数量变动巨大，对中国近海生态系统的结构与功能影响深刻。一般认为，气候与环境变化对早期补充过程的影响是造成鳀鱼类资源巨幅变动的主要原因，但对中国海域日本鳀的具体影响机制未明。本项目以黄海中部海州湾产卵场为典型海域，利用耳石日龄分析、水动力-生态-鳀鱼耦合模型等前沿实验方法, 追踪日本鳀卵仔鱼从产卵场向育幼场的海洋学输运过程、环境履历与季节变动，研究日本鳀早期补充过程中两个关键生物学参数：生长和死亡的环境影响机制，以实现以下目标:(1)查明日本鳀产卵场选择、仔鱼输运路径与变动机制;(2)查明卵仔鱼的生长、存活及环境的影响;(3)揭示气候引起的海洋环境变迁对早期补充过程的影响机制。项目将为全球变暖、过度捕捞及生境破坏多重影响下的中国鱼类资源动态研究提供典型范例，并有助于丰富世界鳀鱼类资源变动的理论与研究实践。

气候与环境变化对早期补充过程的影响是造成鳀鱼类资源巨幅变动的主要原因，具有重要的研究意义。本项目以黄海中部海州湾及邻近产卵场为典型海域，利用耳石日龄分析、海洋水动力模型模拟、数值模型预测等前沿实验方法, 系统研究了日本鳀卵仔鱼分布、栖息地的选择机制及幼体从产卵场向育幼场的海洋学输运过程，探索了日本鳀早期补充过程中幼体的生长和死亡特征、亲鱼产卵策略及环境的影响机理，以揭示气候引起的海洋环境变动对鱼类早期补充过程的影响机制。结果表明，日本鳀在黄海海域产卵高峰位于5-6月，海州湾是其在黄海的主要产卵场，其最适产卵温度是13-18°C。海洋潮汐动力学过程是影响其产卵选择的重要因素。基于Tweedie分布的GAM模型分析结果表明，海水表面温度（SST）、海水表面盐度（SSS）和海水深度（Depth）对鳀鱼卵和仔鱼分布存在显著影响。基于拉格朗日粒子追踪模型解析了日本鳀卵仔鱼在黄渤海的幼体输运过程，发现其在黄渤海共有4个主要的育幼场，其中两个位于南黄海水域。海表温度、离岸距离和盐度是影响日本鳀卵子自然死亡的主要因素，而海水温度和母系效应是影响鳀鱼仔鱼生长的重要内外环境因子。项目将为全球变暖、过度捕捞及生境破坏多重影响下的中国鱼类资源动态研究提供典型范例，并有助于丰富世界鳀鱼类资源变动的理论与研究实践。