拖网选择性捕捞与鱼类生长和性成熟关系的数值模拟研究

Over the past few decades, extreme changes have occurred in the characters of exploited fish population. The majority of these changes have affected growth traits, such as a smaller size-at-age and an earlier age-at-maturation. Currently, the causes of these characters changes still require systematic analysis and empirical study. The explanations that have been cited are merely expressed in terms of fish phenotypic adaptation, and it is claimed that the original characters of fish can be recovered if the intensity of exploitation of the fish is controlled. Fishing gears have directional selectivity, and long-term directional selectivity can become the important factors induced the changes of fish phenotypic traits.In our research, we set up a fishing genetic modle according to trwal fishing model and Eco-genetic evolution model, and research on fishing stress effects the changes of fish phenotypic traits. At the same time,our research gives the basic theory about fishing induced the changes of fish phenotypic traits, and gives the references of fishery fishing managenement.

近年来，许多海洋渔业开发种群的表型性状发生了很大的变化，这些变化主要表现在种群生长特征方面，例如个体小型化、低龄化和性早熟等。目前，引起鱼类个体表型性状发生变化的原因和机制尚缺乏系统的分析和实证性研究，仅仅以鱼类自适应等相关概念来解释，并且认为只要限制捕捞强度，渔业开发种群的表型性状就可以得到恢复。但实际上，捕捞网具在捕捞渔业开发种群时具有定向的选择性，这种定向选择的长期作用很可能是导致鱼类种群个体表型性状发生变化的重要因素，故本研究拟将拖网渔具捕捞模型和生态遗传模型相结合，构建捕捞遗传模型，探究捕捞压力和鱼类种群表型性状变化的关系，以期为捕捞引起鱼类表型性状的变化提供理论依据，进而为渔业捕捞管理提供参考依据。

本课题针对近年来许多海洋渔业开发种群的表型性状发生的变化，这些变化主要表现在种群生长特征方面，例如个体小型化、低龄化和性早熟等。找寻和分析引起鱼类个体表型性状发生变化的原因和机制，本课题试图从渔具选择性角度入手，捕捞网具在捕捞渔业开发种群时具有定向的选择性，这种定向选择的长期作用很可能是导致鱼类种群个体表型性状发生变化的重要因素，故本课题将拖网渔具捕捞模型和生态遗传模型相结合，构建捕捞遗传模型，模型结果得出长期的捕捞压力导致鱼类表型性状的变化在年龄结构上具有可逆性，年龄体长上体现出不可逆性，从而得出捕捞引起鱼类进化的证据之一，进而为渔业捕捞管理提供参考依据。