Canadian Journal of Fisheries and Aquatic Sciences, Ahead of Print.
Animals actively select the most suitable habitat in terms of fitness, much of which is mediated by temperature. We reconstructed population abundance, oxygen isotope and temperature chronologies for the Icelandic and the Northeast Arctic (NEA) cod (Gadus morhua) populations to determine if their temperature selectivity over the last 100 years was driven by rising water temperatures and (or) changes in abundance. Individual annual growth increments from immature and mature life history stages of cod collected in southern Iceland and the Lofoten area (Norway) were micromilled from adult otoliths and then assayed for stable oxygen isotopes (δ18Ootolith). Linear mixed effect models were used to identify and quantify the density-dependent temperature exposure of both cod populations. The results indicated that Icelandic cod migrated into warmer waters with increasing abundance (p < 0.05), whereas NEA cod moved into colder waters (p < 0.001). Our results suggest that thermal preferences and density-dependent effects can be used to forecast potential redistribution scenarios of fish as oceans warm.

中文翻译：

---

由丰度变化驱动的鳕鱼温度暴露

加拿大渔业和水生科学杂志，印刷前。
动物根据适应性积极选择最合适的栖息地，其中大部分是由温度调节的。我们重建了冰岛和东北北极 (NEA) 鳕鱼 (Gadus morhua) 种群的种群丰度、氧同位素和温度年表，以确定它们在过去 100 年中的温度选择性是否是由水温上升和（或）丰度变化驱动的. 在冰岛南部和罗弗敦地区（挪威）收集的鳕鱼的未成熟和成熟生活史阶段的个体年生长增量从成年耳石中进行微粉碎，然后测定稳定氧同位素（δ18Ootolith）。线性混合效应模型用于识别和量化两种鳕鱼种群的密度依赖性温度暴露。结果表明，冰岛鳕鱼迁移到温暖水域的丰度增加（p <0.05），而NEA鳕鱼迁移到较冷的水域（p <0.001）。我们的研究结果表明，随着海洋变暖，热偏好和密度相关效应可用于预测鱼类潜在的重新分布情景。