Canadian Journal of Fisheries and Aquatic Sciences, Ahead of Print.
The Pacific cod (Gadus macrocephalus) fishery recently collapsed in the Gulf of Alaska after a series of marine heatwaves that began in 2014. To gauge the likelihood of population recovery following these extreme warming events, we investigate potential thermal stress on age-0 cohorts through a comprehensive analysis of juvenile cod abundance, condition, growth, and survival data collected from 15 years of beach seine surveys. Abundance was strongly negatively related to ocean temperature during the egg and larval phase (winter–spring), but age-0 cod were larger in the early summer following warm winter–spring temperatures. Body condition indices suggest that warm summers may improve energetic reserves prior to the first winter; however, there was no summer temperature effect on post-settlement growth or survival. Spatial differences in abundance, condition, or growth were not detected, and density-dependent effects were either weak or positive. While the positive effects of increased summer temperatures on juvenile condition may benefit overwintering survival, they cannot compensate for high pre-settlement mortality from warming winter–spring temperatures. We conclude the critical thermal bottleneck for juvenile abundance occurs pre-settlement.

中文翻译：

---

气候紧张的太平洋鳕鱼种群的定居后丰度、状况和生存

加拿大渔业和水生科学杂志，印刷前。
在 2014 年开始的一系列海洋热浪之后，太平洋鳕鱼 (Gadus macrocephalus) 渔业最近在阿拉斯加湾崩溃。为了衡量这些极端变暖事件后种群恢复的可能性，我们通过以下方式调查了 0 岁人群的潜在热压力对从 15 年的海滩围网调查中收集的幼鱼丰度、状况、生长和生存数据进行综合分析。在卵和幼虫阶段（冬季 - 春季），丰度与海洋温度呈强烈负相关，但在温暖的冬季 - 春季温度之后的初夏，0龄鳕鱼更大。身体状况指数表明，温暖的夏季可能会在第一个冬季之前提高能量储备；然而，夏季温度对定居后的生长或生存没有影响。丰度的空间差异，条件，或未检测到生长，并且密度依赖性效应弱或正。虽然夏季气温升高对幼体状况的积极影响可能有利于越冬生存，但它们无法弥补冬春季气温升高导致的高定居前死亡率。我们得出结论，幼鱼丰度的关键热瓶颈发生在定居前。