Effects of injury, pathogens and climate warming on migration and spawning success of Pacific salmon that have escaped from fishing gear

丰富和可持续的太平洋鲑鱼资源对加拿大的经济、文化、生态和政治都很重要。大多数太平洋鲑鱼在产卵迁徙过程中遇到了更温暖的河流。河边捕捞方法导致“逃亡者”(例如，从网中逃脱的鱼)，它们在温暖的淡水中生存的机会减少。鱼常常逃脱占主导地位的河内渔具、海滩围网和刺网。在弗雷泽河的某些年份，从产卵场采集的红眼鱼样本中，有30%-60%的红眼鱼遭受皮肤损伤，这与挣扎着摆脱渔网的情况一致。逃脱渔网会造成伤害、压力和病原体发展，在迁徙和产卵过程中可能导致疾病和死亡，但从未对成年太平洋鲑鱼进行过直接评估。如果没有我们提出的经验研究，很难预测捕捞方法、初始病原体状态、初始生理条件、逃逸相关伤害、应激、疾病发展和变暖对迁徙和产卵成功的交互影响。我们的目标是扩大我们对经历气候变暖的弗雷泽河红鲑鱼野生种群迁徙和产卵的成年鲑鱼生理和疾病的理解，并为资源管理者和利益相关者提供指导适应战略的知识。为了实现这一目标，我们将把严格的自然科学实验与有针对性的社会科学调查结合起来，因为我们认识到弗雷泽河的渔业代表着相互耦合的社会生态系统。这些综合研究将共同提供支持决策所需的证据基础，并确保有效地调动产生的科学成果。我们的工作将直接使我们的合作伙伴(加拿大渔业和海洋、太平洋三文鱼委员会和太平洋三文鱼基金会)受益，他们代表加拿大管理三文鱼资源。我们的研究成果可以导致收获政策的迅速变化，这将对经济和环境产生重大和积极的影响。

Abundant and sustainable Pacific salmon stocks are important economically, culturally, ecologically and politically to Canada. Most Pacific salmon are now encountering warmer rivers during spawning migration. Riverine harvest methods result in 'escapees' (e.g., fish that escape from nets) whose chance of survival is reduced in warm freshwater. Fish often escape from the dominant in-river fishing gears, beach seines and gillnets. In some years in the Fraser River, a remarkable 30-60% of sockeye sampled from spawning grounds suffer skin damage consistent with having struggled free of a net. Escaping from nets causes injury, stress and pathogen development which can lead to disease and mortality during the migration and while spawning but this has never been directly assessed with adult Pacific salmon. Without the empirical studies we propose, it is difficult to predict interactive effects of fishing approach, initial pathogen state, initial physiological condition, escape related injury, stress, disease development, and warming temperatures on migration and spawning success. Our objective is to broaden our understanding of migrating and spawning adult salmon physiology and disease in wild populations of Fraser River sockeye salmon experiencing climate warming and to provide resource managers and stakeholders with knowledge to guide adaptation strategies. To achieve this, we will combine rigorous natural science experimentation with targeted social science surveys given our recognition that the fisheries in the Fraser River represent coupled socio-ecological systems. These integrated studies will collectively provide the evidence base needed to support decision-making and ensure that the science generated is mobilized in an effective manner. Our work will directly benefit our partners (Fisheries and Oceans Canada, the Pacific Salmon Commission, and the Pacific Salmon Foundation) who manage the salmon resource on behalf of Canadians. Our research results can lead to rapid changes in harvest policy, which will have significant and positive economic and environmental consequences.******