For Pacific salmon captured and released by fisheries, post-release behaviour and survival may be influenced by their health and condition at time of capture. We sought to characterize the interactions between infectious agent burden, fish immune and stress physiology and fisheries stressors to investigate the potential for capture-mediated pathogen-induced mortality in adult coho salmon Oncorhynchus kisutch. We used radio-telemetry paired with high-throughput qPCR of non-lethal gill biopsies for infectious agents and host biomarkers from 200 tagged fish experimentally displaced and exposed to various experimental fisheries treatments (gill net entanglement, recreational angling and recreational angling with air exposure vs. non-sampled control). We characterized relationships among post-release behaviour and survival, infectious agent presence and loads, physiological parameters and transcription profiles of stress and immune genes. All infectious agents detected were endemic and in loads consistent with previous adult Pacific salmon monitoring. Individuals exposed to fisheries treatments were less likely to reach spawning habitat compared to controls, and handling duration independent of fisheries gear had a negative effect on survival. High infectious agent burden was associated with accelerated migration initiation post-release, revealing behavioural plasticity in response to deteriorating condition in this semelparous species. Prevalence and load of infectious agents increased post-migration as well as transcription signatures reflected changes in immune and stress profiles consistent with senescence. Results from this study further our understanding of factors associated with fisheries that increase risk of post-release mortality and characterize some physiological mechanisms that underpin migratory behaviour.

中文翻译：

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处理、传染性病原体和生理条件会影响迁移成年银鲑在实验性置换后的存活和释放后行为。

对于渔业捕获和放归的太平洋鲑鱼，放归后的行为和生存可能会受到捕获时它们的健康和状况的影响。我们试图描述传染性病原体负担、鱼类免疫和应激生理学以及渔业应激源之间的相互作用，以研究捕获介导的病原体诱导成年银鲑 Oncorhynchus kisutch 死亡的可能性。我们使用无线电遥测技术与非致命性鳃活检的高通量 qPCR 相结合，对 200 条经过实验置换并暴露于各种实验性渔业处理（刺网缠结、休闲垂钓和休闲垂钓与空气暴露与. 非抽样对照）。我们描述了释放后行为和生存之间的关系，感染因子的存在和负荷、生理参数和应激和免疫基因的转录谱。检测到的所有传染性病原体都是地方性的，并且载量与以前的成年太平洋鲑鱼监测一致。与对照组相比，接受渔业处理的个体不太可能到达产卵栖息地，并且与渔具无关的处理时间对生存有负面影响。高传染性病原体负担与释放后加速迁移开始相关，揭示了响应这种semelparous物种恶化状况的行为可塑性。感染因子的流行和负载增加了迁移后以及转录特征，反映了与衰老一致的免疫和压力特征的变化。