Rosemond R Claire, Head Melissa A, Heppell Scott A
Department of Fisheries, Wildlife, and Conservation Sciences, Oregon State University, Corvallis, Oregon, USA.
Fishery Resource Analysis and Monitoring Division, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Seattle, Washington, USA.
Ecol Appl. 2025 Jun;35(4):e70033. doi: 10.1002/eap.70033.
In the last decade, the northeast Pacific Ocean has experienced new climatic extremes with the occurrence of several marine heatwaves (MHWs), prolonged periods of warmer-than-normal ocean temperatures, likely as a result of anthropogenic climate change. The temperature-size rule is used to contextualize the impacts of climate change on fish maturity and growth, and predicts earlier maturation, faster growth of juveniles, and smaller adult body sizes with increasing temperatures. We investigated the temporal dynamics of fish reproductive development, maturity, and growth from 2014 to 2021, during intense and less intense MHW conditions. We estimated length and age at 50% maturity with histological sections of ovarian tissue samples collected from 644 female Black Rockfish (Sebastes melanops) caught off the Pacific Coast of the United States (42° N-49° N) and estimated von Bertalanffy growth function parameters with length-at-age data for a subset of 302 females. During intense MHWs, maturation was postponed, reproductive success was lower by a third, and parasite prevalence in ovaries was nominally higher. Younger females were larger at age during intense MHWs, and throughout the last decade, growth rate coefficients were higher than what is typically expected for slower-growing fishes, like rockfishes. The increase in juvenile growth during intense MHW conditions may be explained by the temperature-size rule, but our observation of postponed maturation contradicts theoretical predictions. Our work reveals that MHWs can induce shifts in fish growth and maturation, but that the temperature-size rule may not provide an adequate framework to predict how increasing temperatures associated with climate change may influence reproductive development and maturity for fishes with complex reproductive strategies. An understanding of how anomalous environmental conditions interact with fish life histories may help predict population vulnerability, which will be critical for future fisheries management under climate change.
在过去十年中，东北太平洋经历了新的气候极端事件，出现了几次海洋热浪（MHW），即海洋温度持续高于正常水平的时期，这很可能是人为气候变化的结果。温度-体型规则用于说明气候变化对鱼类成熟和生长的影响，并预测随着温度升高，鱼类会更早成熟、幼鱼生长更快，但成年鱼体型更小。我们研究了2014年至2021年期间，在强烈和不太强烈的海洋热浪条件下鱼类繁殖发育、成熟和生长的时间动态。我们通过对从美国太平洋海岸（北纬42°-49°）捕获的644条雌性黑岩鱼（Sebastes melanops）的卵巢组织样本进行组织学切片，估计了50%成熟时的体长和年龄，并利用302条雌性鱼的体长-年龄数据估计了冯·贝塔朗菲生长函数参数。在强烈的海洋热浪期间，成熟被推迟，繁殖成功率降低了三分之一，卵巢中的寄生虫患病率名义上更高。在强烈的海洋热浪期间，较年轻的雌性鱼在同龄时体型更大，并且在过去十年中，生长速率系数高于像岩鱼这样生长较慢的鱼类的典型预期。强烈的海洋热浪条件下幼鱼生长的增加可能可以用温度-体型规则来解释，但我们观察到的成熟推迟与理论预测相矛盾。我们的研究表明，海洋热浪会导致鱼类生长和成熟发生变化，但温度-体型规则可能无法提供一个充分的框架来预测与气候变化相关的温度升高如何影响具有复杂繁殖策略的鱼类的繁殖发育和成熟。了解异常环境条件如何与鱼类生活史相互作用，可能有助于预测种群的脆弱性，这对于气候变化下未来的渔业管理至关重要。
