Condition-Dependent En Route Migration Mortality of Adult Chinook Salmon in the Willamette River Main Stem

摘要: AbstractEpisodically high adult mortality during migration and near spawning sites has hindered the recovery of threatened spring-run Chinook Salmon Oncorhynchus tshawytscha in Oregon’s Willamette River basin. In 2011–2014, we assessed for 762 radio-tagged adults along a ~260-km reach main stem River. Annual survival salmon to tributaries ranged from 0.791 (95% CI = 0.741–0.833) 0.896 (0.856–0.926), confirming concerns about corridor. series general linear models, descaling, marine mammal injuries, head injuries were linked reduced tributaries. Many minor (i.e., epidermal abrasions), which hypothesize unlikely have caused direct but may increased vulnerability pathogens or other disease processes. Mortality was not significantly associated with body size, energetic status, sex, or...