Coastal and estuarine habitats are essential for both growth and survival at juvenile stages for a large proportion of marine fish but are exposed to a variety of threats. However, the quantitative impacts of anthropic-mediated nursery degradation on exploited population dynamics and productivity are rarely addressed. We developed a comprehensive steepness-based parameterization of the stock–recruitment relationship that directly depends upon juvenile habitat quality and surface area and used a generic age- and stage-structured model to simulate exploited population dynamics under nursery degradation/restoration scenarios. Population responses to juvenile habitat modification were estimated for three species with contrasting life histories. Modifying the surface area of nursery habitat has a predictable direct scaling effect on population size and affects biomass and fishing yield, with identical responses observed for various life histories. Modification of habitat quality affects both the population size and the shape of the productivity curve, leading to more complex responses of biomass and fishing yields that depend upon combinations of life history traits. Populations with low steepness and hence lower resiliency to fishing are the most sensitive to the degradation of habitat quality. Our study emphasizes the critical impact of juvenile habitat modification on population dynamics and productivity and the need to integrate habitat consideration into the management of exploited marine species. Our modelling framework is generalizable and can be extended to handle many diverse life histories and case studies to quantify the consequences of coastal habitat degradation/restoration for the dynamics of exploited marine fish populations.

中文翻译：

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海洋鱼类种群生产力对幼鱼栖息地改变的反应取决于生活史

沿海和河口栖息地对于大部分海洋鱼类的幼鱼生长和生存至关重要，但也面临着各种威胁。然而，人为介导的苗圃退化对被利用的种群动态和生产力的定量影响很少得到解决。我们开发了一种基于陡度的种群-招募关系的全面参数化，该参数直接取决于幼鱼栖息地质量和表面积，并使用通用的年龄和阶段结构模型来模拟苗圃退化/恢复情景下的被开发种群动态。针对具有对比生活史的三个物种，估计了种群对幼年栖息地改变的反应。改变苗圃栖息地的表面积对种群规模具有可预测的直接规模效应，并影响生物量和捕捞产量，在不同的生活史中观察到相同的反应。栖息地质量的改变会影响种群规模和生产力曲线的形状，导致生物量和捕捞产量的更加复杂的响应，这取决于生活史特征的组合。陡度低、捕捞弹性较低的种群对栖息地质量的退化最敏感。我们的研究强调了幼年栖息地改变对种群动态和生产力的关键影响，以及将栖息地考虑纳入被开发海洋物种管理的必要性。我们的建模框架是可推广的，可以扩展到处理许多不同的生活史和案例研究，以量化沿海栖息地退化/恢复对被开发的海洋鱼类种群动态的影响。