title: Fishing for Effective Conservation: Context and Biotic Variation are Keys to Understanding the Survival of Pacific Salmon after Catch-and-Release.
abstract: Acute stressors are commonly experienced by wild animals but their effects on fitness rarely are studied in the natural environment. Billions of fish are captured and released annually around the globe across all fishing sectors (e.g., recreational, commercial, subsistence). Whatever the motivation, release often occurs under the assumption of post-release survival. Yet, capture by fisheries (hereafter "fisheries-capture") is likely the most severe acute stressor experienced in the animal's lifetime, which makes the problem of physiological recovery and survival of relevance to biology and conservation. Indeed, fisheries managers require accurate estimates of mortality to better account for total mortality from fishing, while fishers desire guidance on strategies for reducing mortality and maintaining the welfare of released fish, to maximize current and future opportunities for fishing. In partnership with stakeholders, our team has extensively studied the effects of catch-and-release on Pacific salmon in both marine and freshwater environments, using biotelemetry and physiological assessments in a combined laboratory-based and field-based approach. The emergent theme is that post-release rates of mortality are consistently context-specific and can be affected by a suite of interacting biotic and abiotic factors. The fishing gear used, location of a fishery, water temperature, and handling techniques employed by fishers each can dramatically affect survival of the salmon they release. Variation among individuals, co-migrating populations, and between sexes all seem to play a role in the response of fish to capture and in their subsequent survival, potentially driven by pre-capture pathogen-load, maturation states, and inter-individual variation in responsiveness to stress. Although some of these findings are fascinating from a biological perspective, they all create unresolved challenges for managers. We summarize our findings by highlighting the patterns that have emerged most consistently, and point to areas of uncertainty that require further research.
authors.affiliation: *Fish Ecology and Conservation Physiology Laboratory, Department of Biology and Institute of Environmental Science, Carleton University, Ottawa, ON K1S5B6, Canada; graham.d.raby@gmail.com.
authors.forename: Graham D
authors.initials: GD
authors.lastname: Raby
authors.affiliation: Pacific Salmon Ecology and Conservation Laboratory, Department of Forest and Conservation Sciences, University of British Columbia, Vancouver, BC V6T1Z4, Canada;
authors.forename: Michael R
authors.initials: MR
authors.lastname: Donaldson
authors.affiliation: Pacific Salmon Ecology and Conservation Laboratory, Department of Forest and Conservation Sciences, University of British Columbia, Vancouver, BC V6T1Z4, Canada;
authors.forename: Scott G
authors.initials: SG
authors.lastname: Hinch
authors.affiliation: Pacific Salmon Ecology and Conservation Laboratory, Department of Forest and Conservation Sciences, University of British Columbia, Vancouver, BC V6T1Z4, Canada; Australian Institute of Marine Science, PMB 3, Townsville MC, QLD 4810, Australia;
authors.forename: Timothy D
authors.initials: TD
authors.lastname: Clark
authors.affiliation: *Fish Ecology and Conservation Physiology Laboratory, Department of Biology and Institute of Environmental Science, Carleton University, Ottawa, ON K1S5B6, Canada; Pacific Salmon Ecology and Conservation Laboratory, Department of Forest and Conservation Sciences, University of British Columbia, Vancouver, BC V6T1Z4, Canada;
authors.forename: Erika J
authors.initials: EJ
authors.lastname: Eliason
authors.affiliation: Anatomy, Physiology & Cell Biology, School of Veterinary Medicine, University of California, Davis, CA 95616, USA;
authors.forename: Kenneth M
authors.initials: KM
authors.lastname: Jeffries
authors.affiliation: Pacific Salmon Ecology and Conservation Laboratory, Department of Forest and Conservation Sciences, University of British Columbia, Vancouver, BC V6T1Z4, Canada;
authors.forename: Katrina V
authors.initials: KV
authors.lastname: Cook
authors.affiliation: Pacific Salmon Ecology and Conservation Laboratory, Department of Forest and Conservation Sciences, University of British Columbia, Vancouver, BC V6T1Z4, Canada; Biology Department, University of Victoria, Victoria, BC V8P5C2, Canada;
authors.forename: Amy
authors.initials: A
authors.lastname: Teffer
authors.affiliation: Pacific Salmon Ecology and Conservation Laboratory, Department of Forest and Conservation Sciences, University of British Columbia, Vancouver, BC V6T1Z4, Canada;
authors.forename: Arthur L
authors.initials: AL
authors.lastname: Bass
authors.affiliation: Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, BC V9R5K6, Canada;
authors.forename: Kristina M
authors.initials: KM
authors.lastname: Miller
authors.affiliation: Fisheries and Oceans Canada, Science Branch, Pacific Region, Cooperative Resource Management Institute, School of Resource and Environmental Management, Simon Fraser University, Burnaby, BC V5A1S6, Canada;
authors.forename: David A
authors.initials: DA
authors.lastname: Patterson
authors.affiliation: **Department of Zoology and Faculty of Land and Food Systems, University of British Columbia, Vancouver, BC V6T1Z4, Canada.
authors.forename: Anthony P
authors.initials: AP
authors.lastname: Farrell
authors.affiliation: *Fish Ecology and Conservation Physiology Laboratory, Department of Biology and Institute of Environmental Science, Carleton University, Ottawa, ON K1S5B6, Canada;
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Cooke
mesh_terms: D000818:Animals; D003247:Conservation of Natural Resources / Q000379:methods*; D005398:Fisheries; D012474:Salmon / Q000502:physiology*; D013312:Stress, Physiological; D016019:Survival Analysis