Upper Columbia River Steelhead Capture-Recapture-Recovery data (2008-2018)

In the Columbia River basin, USA, predation by Caspian terns (Hydroprogne caspia) on U.S. Endangered Species Act (ESA)-listed juvenile salmonids (smolts; Oncorhynchus spp.) has led to predator management actions to reduce predation; however, the assumption that reduced predation translates into greater salmonid survival, either within the life stage where predation occurs or across their lifetime, has remained untested. To address this critical uncertainty, we analyzed a long-term (2008-2018) mark-recapture-recovery dataset of ESA-listed steelhead trout (O. mykiss) that were tagged (n = 78,409) and subsequently exposed to predation during smolt out-migration through multiple river reaches (spatial-scales), jointly estimating weekly probabilities of steelhead survival, mortality due to bird predation, and mortality due to other causes. This concurrent estimation across time-stratified cohorts allowed for the direct measurement of the strength, magnitude, and direction of relationships be...

在美国哥伦比亚河流域，里海燕鸥（Hydroprogne caspia）对列入《美国濒危物种法》（Endangered Species Act, ESA）的幼年鲑形目降海洄游幼体（smolts；Oncorhynchus属）的捕食行为，促使相关方采取捕食者管理措施以降低捕食压力；然而，“降低捕食压力可提升鲑形目鱼类存活率——无论是在捕食发生的生命阶段还是其整个生命周期”这一核心假设，迄今尚未得到实证检验。为厘清这一关键科学不确定性，本研究分析了2008-2018年的长期标记-重捕-回收（mark-recapture-recovery）数据集，研究对象为列入ESA的钢头鳟（O. mykiss）：共计78409尾个体被标记，随后在降海洄游途经多个河段（空间尺度）的过程中暴露于捕食风险。研究同步估算了钢头鳟的周度存活率、鸟类捕食致死率及其他原因致死率。基于时间分层种群的同步估算，可直接量化相关关系的强度、量级与方向……