Morell Alaia, Shin Yunne-Jai, Barrier Nicolas, Travers-Trolet Morgane, Ernande Bruno
IFREMER, Unité halieutique Manche Mer du Nord Ifremer, HMMN, Boulogne sur mer, France.
MARBEC, Univ. Montpellier, Ifremer, CNRS, IRD, Sète/Montpellier, France.
Ecol Lett. 2024 Nov;27(11):e70017. doi: 10.1111/ele.70017.
Understanding the response of marine organisms to temperature is crucial for predicting climate change impacts. Fundamental physiological thermal performance curves (TPCs), determined under controlled conditions, are commonly used to project future species spatial distributions or physiological performances. Yet, real-world performances may deviate due to extrinsic factors covarying with temperature (food, oxygen, etc.). Using a bioenergetic marine ecosystem model, we evaluate the differences between fundamental and realised TPCs for fish species with contrasted ecology and thermal preferences. Food limitation is the primary cause of differences, decreasing throughout ontogeny and across trophic levels due to spatio-temporal variability of low-trophic level prey availability with temperature. Deoxygenation has moderate impact, despite increasing during ontogeny. This highlights the lower sensitivity of early life stages to hypoxia, which is mechanistically explained by lower mass-specific ingestion at older stages. Understanding the emergence of realised thermal niches offers crucial insights to better determine population's persistence under climate warming.
了解海洋生物对温度的反应对于预测气候变化影响至关重要。在受控条件下确定的基本生理热性能曲线（TPCs）通常用于预测未来物种的空间分布或生理性能。然而，由于与温度共同变化的外在因素（食物、氧气等），实际性能可能会有所偏差。我们使用一个生物能量海洋生态系统模型，评估了具有不同生态和热偏好的鱼类物种的基本TPCs和实际TPCs之间的差异。食物限制是差异的主要原因，由于低营养级猎物可获得性随温度的时空变化，食物限制在个体发育过程中和跨营养级中都在降低。脱氧有中等影响，尽管在个体发育过程中有所增加。这突出了早期生命阶段对缺氧的较低敏感性，这在机制上可以通过较老阶段较低的质量比摄食来解释。了解实际热生态位的出现为更好地确定气候变暖下种群的持久性提供了关键见解。
