Canadian Journal of Fisheries and Aquatic Sciences, Ahead of Print.
Recovery of anadromous salmonid populations is complicated by their complex life histories. We examined the spatiotemporal interplay of stream temperature, geomorphic features, and a species’ thermal sensitivity mediated by biological interactions in a case study of steelhead trout (Oncorhynchus mykiss) and Chinook salmon (Oncorhynchus tshawytscha) in California’s Eel River watershed. We estimated habitat suitability and fish capacity for each salmonid run and freshwater life stage during average, cool, and warm years in each of the watershed’s subbasins, including a historically occupied high-elevation subbasin upstream of an impassable dam. Our estimates varied depending on whether we accounted for exposure to the Sacramento pikeminnow (Ptychocheilus grandis), an introduced predator and competitor. Our results indicate that the dammed subbasin has substantial salmonid capacity relative to the rest of the watershed and could provide an important cool-water refuge during warm years and from pikeminnow, potentially improving the productivity and resilience of multiple anadromous salmonid populations. Our approach can be applied in any setting where spatially explicit habitat metrics can be estimated and population-specific and life-stage-specific habitat criteria can be specified.

中文翻译：

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溯河鲑鱼生活史表达能力的物理和生物学限制：加利福尼亚州鳗鱼河案例研究

加拿大渔业和水生科学杂志，印刷前。
溯河鲑鱼种群的恢复因其复杂的生活史而变得复杂。我们以加利福尼亚鳗鱼河流域的虹鳟 (Oncorhynchus mykiss) 和奇努克鲑鱼 (Oncorhynchus tshawytscha) 为例，研究了河流温度、地貌特征和生物相互作用介导的物种热敏感性的时空相互作用。我们估计了流域每个子流域的平均、凉爽和温暖年份中每个鲑鱼流域和淡水生命阶段的栖息地适宜性和鱼类容量，包括无法通行的大坝上游历史上占据的高海拔子流域。我们的估计因我们是否考虑到引入的捕食者和竞争对手萨克拉门托梭子鱼 (Ptychocheilus grandis) 而有所不同。我们的研究结果表明，相对于流域的其他部分，筑坝子流域具有大量的鲑鱼容量，并且可以在温暖的年份和 pikeminnow 提供重要的冷水避难所，从而可能提高多种溯河鲑鱼种群的生产力和恢复力。我们的方法可以应用于任何可以估计空间明确的栖息地指标并且可以指定特定于人口和特定生命阶段的栖息地标准的环境。