ABSTRACT: The natural variability of fish populations is increased by exploitation, but the specific mechanisms driving this variability are still debated. We propose a macroscopic approach combining the size-density relationship and Taylor’s law to predict the temporal variance of exploited and unexploited fish populations. Using information from 11 years of fishery-independent abundance surveys, we showed that the body-size dependence of the variance of exploited (targeted) and unexploited (non-targeted or bycatch) fish populations can be accurately predicted. Targeted fish populations showed a variability that was 2 orders of magnitude greater than that of non-targeted fish populations. Such variability was explained solely by the higher relative abundance of the former, regardless of their specific trophic position, while aggregated community fluctuation was lower in a high trophic position group. This study showed the usefulness of the macroscopic approach to predict fish variability and fishing effect in the whole community. This approach is complementary to other modeling strategies and seems to be useful in tackling the problem of variability in population fluctuations of exploited fish, particularly in cases where specific details of the interacting species are lacking.

中文翻译：

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鱼类被剥削种群波动的宏观生态学观点

摘要：鱼类种群的自然变异性因开采而增加，但驱动这种变异性的具体机制仍在争论中。我们提出了一种将尺寸-密度关系和泰勒定律相结合的宏观方法，以预测已开发和未开发鱼类种群的时间变化。使用11年与渔业无关的丰度调查提供的信息，我们表明，可以准确地预测开发（目标）和未开发（非目标或兼捕）鱼类种群方差的体型依赖性。目标鱼类种群的变异性比非目标鱼类种群大2个数量级。这种可变性仅是由于前者的相对丰度较高，而不论其具体的营养位置如何，在较高营养级别的群体中，总体社区波动较小。这项研究表明，宏观方法可用于预测整个社区的鱼类变异性和捕捞效果。这种方法是其他建模策略的补充，在解决被开发鱼类种群波动的可变性问题方面尤其有用，特别是在缺少相互作用物种的具体细节的情况下。