Anlauf-Dunn Kara, Kraskura Krista, Eliason Erika J
Oregon Department of Fish and Wildlife, 28655 Highway 34, Corvallis, OR 97333, USA.
Department of Ecology, Evolution, and Marine Biology, University of California Santa Barbara, Santa Barbara, CA 93106, USA.
Conserv Physiol. 2022 May 12;10(1):coac029. doi: 10.1093/conphys/coac029. eCollection 2022.
Fish physiological performance is directly regulated by their thermal environment. Intraspecific comparisons are essential to ascertain the vulnerability of fish populations to climate change and to identify which populations may be more susceptible to extirpation and which may be more resilient to continued warming. In this study, we sought to evaluate how thermal performance varies in coastal cutthroat trout () across four distinct watersheds in OR, USA. Specifically, we measured oxygen consumption rates in trout from the four watersheds with variable hydrologic and thermal regimes, comparing three ecologically relevant temperature treatments (ambient, annual maximum and novel warm). Coastal cutthroat trout displayed considerable intraspecific variability in physiological performance and thermal tolerance across the four watersheds. Thermal tolerance matched the historical experience: the coastal watersheds experiencing warmer ambient temperatures had higher critical thermal tolerance compared with the interior, cooler Willamette watersheds. Physiological performance varied across all four watersheds and there was evidence of a trade-off between high aerobic performance and broad thermal tolerance. Given the evidence of climate regime shifts across the globe, the uncertainty in both the rate and extent of warming and species responses in the near and long term, a more nuanced approach to the management and conservation of native fish species must be considered.
鱼类的生理表现直接受其热环境的调节。种内比较对于确定鱼类种群对气候变化的脆弱性以及识别哪些种群可能更容易灭绝、哪些种群可能对持续变暖更具恢复力至关重要。在本研究中，我们试图评估美国俄勒冈州四个不同流域的沿海割喉鳟（）的热性能如何变化。具体而言，我们测量了来自四个具有不同水文和热状况流域的鳟鱼的耗氧率，比较了三种具有生态相关性的温度处理（环境温度、年度最高温度和新出现的温暖温度）。沿海割喉鳟在四个流域的生理表现和热耐受性方面表现出相当大的种内变异性。热耐受性与历史经验相符：与内陆较凉爽的威拉米特河流域相比，经历较高环境温度的沿海流域具有更高的临界热耐受性。所有四个流域的生理表现都有所不同，并且有证据表明在高有氧性能和广泛的热耐受性之间存在权衡。鉴于全球气候模式转变的证据、变暖速率和程度的不确定性以及物种在近期和长期的反应，必须考虑采用更细致入微的方法来管理和保护本地鱼类物种。
