The rapid pace of ocean change has prompted a need to forecast likely future species distributions. Species distribution models are often categorized as either correlative (statistical) or mechanistic, and each has limitations both for advancing understanding and for prediction. Here we sought to benefit from mechanistic understanding of how and why low dissolved oxygen affects species' distributions by applying physiologically informed statistical models to the spatial distribution of sablefish Anoplopoma fimbria, a deep-dwelling commercially important groundfish. We fit spatial models to trawl-survey data on catch rate, local temperature and dissolved oxygen, and estimated parameters of the metabolic index, which provided a way to express the temperature-dependence of oxygen tolerance. We fit generalized linear mixed effects models with Gaussian random fields to capture the latent spatially fixed variables, and included both linear and breakpoint functions for pO₂ and the metabolic index. The best fitting models all included breakpoint effects of pO₂, and the estimated threshold value of 0.05 atm is close to levels in laboratory studies where metabolism begins to decline. Models based on the metabolic index were not as well supported as those that included pO₂, likely because of the decrease in temperature and slight increase in pO₂ at deep (> 800 m) depths. These findings illustrate that statistical models of species distributions can be improved by incorporating knowledge of how physiological mechanisms operate. Furthermore, they illustrate that even species with high tolerance for low dissolved oxygen may undergo species distribution shifts in the face of growing oxygen depletion in coastal ocean ecosystems.

中文翻译：

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使用阈值和基于生理的指数推进统计模型以揭示溶解氧对海洋分类群空间分布的影响

海洋变化的迅速步伐促使需要预测未来可能的物种分布。物种分布模型通常被归类为相关（统计）模型或机械模型，每种模型在促进理解和预测方面都有局限性。在这里，我们试图通过将生理学上的统计模型应用于紫貂无瘤菌毛的空间分布，从对低溶解氧如何以及为什么影响物种分布的机械理解中受益，一种深居的具有商业重要性的底层鱼类。我们将空间模型拟合到关于捕获率、当地温度和溶解氧的拖网调查数据，以及代谢指数的估计参数，这提供了一种表达耐氧性的温度依赖性的方法。我们用高斯随机场拟合广义线性混合效应模型来捕捉潜在的空间固定变量，并包括 pO ₂和代谢指数的线性和断点函数。最佳拟合模型均包括 pO ₂的断点效应，估计阈值 0.05 atm 接近于实验室研究中代谢开始下降的水平。基于代谢指数的模型不如包含 pO _{2的模型得到很好的支持}，可能是因为在深（> 800 m）深度处温度降低和 pO ₂略有增加。这些发现表明，通过结合生理机制如何运作的知识，可以改进物种分布的统计模型。此外，他们还说明，即使是对低溶解氧具有高度耐受性的物种，面对沿海海洋生态系统中日益严重的氧气消耗，也可能会发生物种分布变化。