Populations of Chinook Salmon Oncorhynchus tshawytscha in California are in decline due to the combined effects of habitat degradation, water diversions, and climate change. Reduced life history diversity within these populations inhibits their ability to respond to these stressors. Putah Creek, a small creek in California’s Central Valley that once supported Chinook Salmon, is undergoing restoration to provide spawning habitats for this imperiled species. Beginning in 2014, increasing numbers of Chinook Salmon spawned throughout the creek, and emigrating juveniles were observed in the following months. Here we used otolith annual growth bands and microchemistry to investigate the age structure and natal origins of the adult spawners. Most individuals were 2 or 3 years old, and they originated from at least seven different natal sources, overwhelmingly from Central Valley hatcheries (~88%). These findings highlight that straying fall‐run Central Valley Chinook Salmon can rapidly utilize restored habitats, potentially establishing new populations. However, to facilitate local adaptations, straying rates and gene flow will have to be managed over time. Reconnecting migratory pathways and restoring many small and diverse streams, like Putah Creek, provides an opportunity to increase life history diversity, strengthening the recovery and resilience of Chinook Salmon.

中文翻译：

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地球化学工具确定奇努克鲑鱼返回还原河的起源

奇努克鲑鱼Oncorhynchus tshawytscha的种群由于栖息地退化，水源转移和气候变化的综合影响，加利福尼亚州的动物数量在下降。这些人群中减少的生活史多样性会抑制他们应对这些压力源的能力。加利福尼亚中央谷地的一条小河Putah Creek曾经为奇努克鲑鱼提供过支持，目前正在对其进行修复，以为该濒危物种提供产卵的栖息地。从2014年开始，整个小溪产卵的奇努克鲑鱼数量增加，在随后的几个月中观察到了移居的少年。在这里，我们使用了耳石年生长带和微观化学研究成年产卵者的年龄结构和出生起源。大多数个体为2或3岁，他们至少来自七个不同的出生来源，绝大多数来自中央山谷孵化场（约88％）。这些发现突出表明，迷失于秋天的中部奇努克鲑鱼可以迅速利用恢复的栖息地，从而有可能建立新的种群。但是，为了促进局部适应，必须随着时间的流逝管理流浪率和基因流。重新连接迁移途径并恢复许多小而多样的河流，例如Putah Creek，提供了增加生活史多样性，增强奇努克鲑鱼恢复能力和复原力的机会。