Canadian Journal of Fisheries and Aquatic Sciences, Ahead of Print.
In recent decades, the relative proportion of female sockeye salmon (Oncorhynchus nerka) on spawning grounds of several British Columbia populations has declined. Coincident with the decline has been large changes to oceanic, estuarine, and river migration environments. Over the past 30 years, numerous telemetry tracking and laboratory studies have examined mortality of adult Fraser River sockeye salmon during ocean and freshwater migrations. We reviewed 19 studies that provided 40 situations where male and female mortality could be directly compared. Female mortality averaged 2.1 times greater than that of males and up to eightfold higher. High female mortality was also evident in migrating coho salmon (Oncorhynchus kisutch) and Chinook salmon (Oncorhynchus tshawytscha) and for sockeye salmon in other systems. Female mortality was highest when migration conditions were challenging (e.g., high or turbulent flows, high temperatures, confinement, or handling) and towards end of river migration. We review mechanisms for differential mortality, including energy exhaustion, cardiac performance, physiological stress, and immune factors. Female-specific mortality will become even more pronounced in coming years as ocean and riverine conditions continue to change.

中文翻译：

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成年雌性鲑鱼死亡率极高：大规模养殖和对养护的关注

《加拿大渔业和水生科学杂志》，印刷前。
近几十年来，在不列颠哥伦比亚省的一些种群的产卵场中，雌性红鲑鱼（Oncorhynchus nerka）的相对比例下降了。与下降相吻合的是，海洋，河口和河流迁移环境发生了巨大变化。在过去的30年中，许多遥测跟踪和实验室研究已经检查了成年的弗雷泽河红鲑在海洋和淡水迁移过程中的死亡率。我们回顾了19项研究，提供了40种可以直接比较男性和女性死亡率的情况。女性死亡率平均是男性的2.1倍，高出八倍。在迁徙银大麻哈鱼（Oncorhynchus kisutch）和奇努克鲑鱼（Oncorhynchus tshawytscha）以及其他系统的红鲑鱼中，女性死亡率也很高。当迁移条件具有挑战性（例如高流量或湍流，高温，封闭或处理）以及临近河床迁移时，女性死亡率最高。我们审查了不同死亡率的机制，包括能量消耗，心脏功能，生理压力和免疫因素。随着海洋和河流条件的不断变化，未来几年女性的死亡率将变得更加明显。