Faculty of Materials and Energy, Southwest University, Chongqing 400715, China; Southern Seas Ecology Laboratories, The Environment Institute, School of Biological Sciences, The University of Adelaide, South Australia, Australia.
The Swire Institute of Marine Science and School of Biological Sciences, The University of Hong Kong, Hong Kong, SAR, China.
Sci Total Environ. 2021 Jun 1;771:145208. doi: 10.1016/j.scitotenv.2021.145208. Epub 2021 Jan 22.
Ocean warming is predicted to challenge the persistence of a variety of marine organisms, especially when combined with ocean acidification. While temperature affects virtually all physiological processes, the extent to which thermal history mediates the adaptive capacity of marine organisms to climate change has been largely overlooked. Using populations of a marine gastropod (Turbo undulatus) with different thermal histories (cool vs. warm), we compared their physiological adjustments following exposure (8-week) to ocean acidification and warming. Compared to cool-acclimated counterparts, we found that warm-acclimated individuals had a higher thermal threshold (i.e. increased CT by 2 °C), which was unaffected by the exposure to ocean acidification and warming. Thermal history also strongly mediated physiological effects, where warm-acclimated individuals adjusted to warming by conserving energy, suggested by lower respiration and ingestion rates, energy budget (i.e. scope for growth) and O:N ratio. After exposure to warming, warm-acclimated individuals had higher metabolic rates and greater energy budget due to boosted ingestion rates, but such compensatory feeding disappeared when combined with ocean acidification. Overall, we suggest that thermal history can be a critical mediator of physiological performance under future climatic conditions. Given the relatively gradual rate of global warming, marine organisms may be better able to adaptively adjust their physiology to future climate than what short-term experiments currently convey.
海洋变暖预计将挑战多种海洋生物的生存能力，尤其是在与海洋酸化相结合的情况下。虽然温度几乎影响所有生理过程，但热历史在多大程度上调节海洋生物对气候变化的适应能力在很大程度上被忽视了。我们使用具有不同热历史（冷适应与暖适应）的海洋腹足纲动物（Turbo undulatus）种群，比较了它们在暴露于海洋酸化和变暖（8 周）后的生理调整。与冷适应的个体相比，我们发现暖适应的个体具有更高的热阈值（即 CT 增加 2°C），而热历史对其不受海洋酸化和变暖的影响。热历史也强烈调节生理效应，暖适应的个体通过节约能量来适应变暖，这表现在呼吸和摄食率、能量预算（即生长范围）和 O:N 比降低。在暴露于变暖后，暖适应的个体由于摄食率的提高而具有更高的代谢率和更大的能量预算，但当与海洋酸化结合时，这种补偿性摄食就消失了。总的来说，我们认为热历史可以成为未来气候条件下生理表现的关键调节因素。考虑到全球变暖的相对缓慢速度，海洋生物可能比短期实验目前所传达的更有能力适应未来的气候变化来调整其生理机能。
