Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biology, University of Oslo, PO Box 1066 Blindern, N-0316 Oslo, Norway.
Ecol Lett. 2012 Jul;15(7):658-65. doi: 10.1111/j.1461-0248.2012.01781.x. Epub 2012 Apr 10.
Fluctuations of fish populations abundances are shaped by the interplay between population dynamics and the stochastic forcing of the environment. Age-structured populations behave as a filter of the environment. This filter is characterised by the species-specific life cycle and life-history traits. An increased mortality of mature individuals alters these characteristics and may therefore induce changes in the variability of populations. The response of a generic age-structured model was analysed to investigate the expected changes in the fluctuations of fish populations in response to decreased adult survival. These expectations were then tested on an extensive dataset. In accordance with theory, the analyses revealed that decreased adult survival and mean age of spawners were linked to an increase in the relative importance of short-term fluctuations. It suggests that intensive exploitation can lead to a change in the variability of fish populations, an issue of central interest from both conservation and management perspectives.
鱼类种群丰度的波动是由种群动态和环境随机胁迫之间的相互作用所塑造的。年龄结构的种群表现为环境的过滤器。这个过滤器的特点是特定物种的生命周期和生活史特征。成熟个体的死亡率增加会改变这些特征，因此可能会导致种群变异性的变化。分析了一个通用的年龄结构模型的响应，以研究鱼类种群波动对成年个体存活率降低的预期变化。然后，这些预期在一个广泛的数据集上进行了测试。与理论相符的是，分析结果表明，成年个体存活率和产卵期个体平均年龄的降低与短期波动的相对重要性增加有关。这表明，密集捕捞可能会导致鱼类种群变异性的变化，这是保护和管理角度都非常关注的问题。
