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Host-pathogen-environment interactions determine survival outcomes of adult sockeye salmon (Oncorhynchus nerka) released from fisheries
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  • Amy Teffer,
  • Scott Hinch,
  • Kristina Miller,
  • David Patterson,
  • Arthur Bass,
  • Steven Cooke,
  • Anthony Farrell,
  • Terry Beacham,
  • Jacqueline Chapman,
  • Francis Juanes
Amy Teffer
University of Victoria Department of Biology

Corresponding Author:[email protected]

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Scott Hinch
The University of British Columbia Faculty of Forestry
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Kristina Miller
Fisheries and Oceans Canada
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David Patterson
Fisheries and Oceans Canada
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Arthur Bass
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Steven Cooke
Carleton University
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Anthony Farrell
The University of British Columbia Department of Zoology
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Terry Beacham
Pacific Biological Station
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Jacqueline Chapman
Carleton University Department of Biology
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Francis Juanes
University of Victoria Department of Biology
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Incorporating host-pathogen(s)-environment axes into management and conservation planning is critical to preserving species in a warming climate. However, the role pathogens play in host stress resilience remains largely unexplored in wild animal populations. We experimentally characterized how independent and cumulative stressors (fisheries handling, high water temperature) and natural infections affected the health and longevity of released wild adult sockeye salmon (Oncorhynchus nerka) in British Columbia, Canada. Returning adults were collected before and after entering the Fraser River, yielding marine- and river-collected groups, respectively. Fish were exposed to a mild (seine) or severe (gill net) fishery treatment at collection, and then held in circulating freshwater tanks for up to four weeks at historical (14°C) or projected migration temperatures (18°C). Using weekly nonlethal gill biopsies and high-throughput qPCR, we quantified loads of up to 46 pathogens with host stress and immune gene expression. Marine-captured fish had less severe infections than river-captured fish, a short migration distance (100 km, 5-7 d) that produced profound infection differences. At 14°C, river-collected fish survived 1-2 weeks less than marine-collected fish. All fish held at 18°C died within 4 weeks unless they experienced minimal handling. Gene expression correlated with infections in river-collected fish, while marine-collected fish were more stressor-responsive. Cumulative stressors were detrimental regardless of infections or collection location, likely due to extreme physiological disturbance. Because river-derived infections correlated with single stressor responses, river entry likely decreases stressor resilience of adult salmon by altering both physiological status and pathogen burdens, which redirect host responses toward disease resistance.
04 May 2021Submitted to Molecular Ecology
05 May 2021Submission Checks Completed
05 May 2021Assigned to Editor
13 May 2021Reviewer(s) Assigned
03 Jul 2021Review(s) Completed, Editorial Evaluation Pending
12 Jul 2021Editorial Decision: Revise Minor
25 Aug 2021Review(s) Completed, Editorial Evaluation Pending
25 Aug 20211st Revision Received
13 Sep 2021Editorial Decision: Revise Minor
22 Sep 20212nd Revision Received
22 Sep 2021Review(s) Completed, Editorial Evaluation Pending
30 Sep 2021Editorial Decision: Accept