莱州湾重要渔业生物种群早期补充动态及其外在驱动

Effect of marine environment change in the offsea area on the recruitment process and resources of the fishery stocks is the basic scientific issue in the frontiers of marine fisheries science. Variation in recruitment strength in early life stages of the fish population plays an essential role in determining the stability of the population structure and sustainable production. Under multiple sources of exogenous interference factors, irreversible changes have been taken place to every key link of the recruitment process in early life stages of the fish with habitat (spawning ground) loss or fragmentation. Impacts of changes in habitat factors of the spawning ground on recruitment mechanism dynamics in early life stages of the fish is one of the important basic scientific issue. Laizhou Bay which presents habitat benefits for most of the fish stocks in the Bohai Sea in terms of spawning ground would be selected as the studied area. The project aims to carry out research on relationship between long-term changes in main habitat factors and the recruitment variation in early life stages of the key fishery species (Engraulis japonicas or Pseudosciaena polyactis). Based on a pooled analysis of the historical data more than 30 years, and combined with the field survey of current fish habitat conditions, long-term changes in ichthyoplankton assemblage structure would be interpreted. Also recruitment abundance and egg quality of the key fishery species would be analyzed, their possible long time serial variation to typical climatic phenomenon and human activities would be studied. In the end, the key exogenous driving factors would be interpreted by using the Ricker stock recruitment model.

近海环境变化对渔业生物种群补充过程的影响及其资源效应是海洋渔业科学前沿领域的基础科学问题。鱼类种群早期补充状况直接决定该种群结构稳定性和资源持续生产的可能。多重外来干扰作用下，近海鱼类早期补充过程各个关键环节已随其栖息地（产卵场）生境要素发生不可逆变化或变迁。产卵场生境要素变化对鱼类早期补充机制的动态影响是海洋渔业科学前沿基础科学问题重要组成。本项目拟选择传统的渤海鱼类产卵场莱州湾为研究海域，重点对莱州湾较长时期的主要生境变化和其内重要鱼类种群早期补充动态关系开展研究。包括结合历史调查资料与现有的产卵场补充调查，了解莱州湾的渔业生物群体早期补充集群特性和结构更替；针对重要鱼类种群（鳀鱼或小黄鱼），深入阐明该种早期补充群体量和卵子质量等生物特性，探讨其长时间序列变化对典型气候环境现象或人类干扰活动可能的响应；借助Ricker亲体-补充量动态模型，解析主导重要渔业种群早期补充量变动的外在因子。

近海环境变化对渔业生物种群补充过程的影响及其资源效应是海洋渔业科学前沿领域的基础科学问题。产卵场生境要素变化对鱼类早期补充机制的动态影响是海洋渔业科学前沿基础科学问题重要组成。本项目选择传统的渤海鱼类产卵场为研究海域，重点对渤海较长时期的主要生境变化和其内重要鱼类种群早期补充动态关系开展研究。包括结合历史调查资料与现有的产卵场补充调查，了解渤海的渔业生物群体早期补充集群特性和结构更替，探讨其长时间序列变化对典型气候环境现象或人类干扰活动可能的响应；借助 GAM、引入地理加权的HSI模型、PCA分析等解析主导重要渔业种群早期补充量变动的外在因子。研究结果表明渤海各调查季节（冬季除外）鱼卵和仔稚鱼种类数和资源丰度指数呈先降后升变动趋势。当前鱼卵种类数仅为上世纪80年代二分之一左右，资源丰度不足彼时十分之一；仔稚鱼种类数和资源丰度仅为上世纪80年代的四分之三左右，但冬季仔稚鱼种类和资源丰度指数呈现上升趋势。各调查时期相同季节鱼卵优势种变化不明显，但仔稚鱼优势种变化幅度超过鱼卵；底层重要经济种类早期补充群体优势度急剧下降。鱼类早期补充群体种类更替现象明显，近年来种类更替率呈现明显加快趋势。陆架浅水中上层鱼类种数所占比例升高，中底层和底层鱼类所占比例有所下降。地理加权回归栖息地指数（HSIGWR）模型能够很好对渤海地区HSI进行模拟，为渤海鱼类早期补充动态研究提供了一种新方法。渔业种群早期补充群体的时序分布规律既决定于生物本身生理发育阶段间行为适应因素，又受制于水域温盐场势季节消长趋势等环境要素，任何一种控制机制如“上行控制”、“下行控制”或“丰腰控制”均不足以直接或清楚解释其长期变化规律，其时序变化特征是对人类活动和环境变化的综合反映。研究结果将为渤海重要渔业种群早期补充机制研究提供基础资料，也可为渤海产卵场养护与修复效果评价提供生态学基础，并为制定渤海渔业资源可持续发展利用的适应性管理策略提供科学依据。