Influences of Temperature on the Mortality and Physiological
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INFLUENCES OF TEMPERATURE ON THE MORTALITY AND PHYSIOLOGICAL IMPAIRMENT OF SOCKEYE SALMON AFTER SIMULATED CAPTURE AND RELEASE by Marika Kirstin Gale B.Sc., The University of British Columbia, 2008 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE in THE FACULTY OF GRADUATE STUDIES (Forestry) THE UNIVERSITY OF BRITISH COLUMBIA (Vancouver) November 2011 © Marika Kirstin Gale, 2011 Abstract Pacific salmon experience intense fishing pressure as they commence their freshwater spawning migration, frequently encountering commercial net fisheries and recreational hook and line gear. Untold numbers of fish escape by their own volition or are released by fishers at a range of water temperatures, including those above metabolic and physiological optimums. This thesis focuses on the mortality and sublethal consequences of escape or release from fishing gears by migrating adult Pacific salmon, with a specific focus on how temperature mediates those effects. The role of temperature in the capture and release of fish was investigated in a comprehensive literature review. This revealed that 70% of studies examining mortality or sublethal effects at various temperatures found both to be magnified at warmer temperatures. Collectively, the results suggest that capture-release mortality increases at temperatures within, rather than above, species-specific thermal preferenda. Notably, there were no studies examining temperature effects on capture-release for adult migrating Pacific salmon. In two experiments, migrating adult sockeye salmon were intercepted during the early part of their freshwater migration held in a laboratory at three temperatures corresponding with the range of temperatures spanning the historic, current and predicted future migration conditions experienced by their run-timing group (13ºC, 19ºC, 21ºC for summer-run fish in 2009, and 13ºC, 16ºC, 19ºC for late-run fish in 2008). Fish were exposed to a simulated capture treatment including three minutes of burst exercise ± 60 seconds of air exposure. In both experiments, simulated capture treatments resulted in elevations of plasma lactate concentrations, most markedly after air exposure. The highest mortality was seen in the late-run females at 19ºC. Late-run fish who died within 24 hours of capture treatment were characterized by higher ii hematocrit, plasma lactate and cortisol, and lower glucose, sodium and chloride concentrations than survivors. Air exposure and warm temperatures were associated with longer equilibrium loss and slower ventilation rates post-treatment, which significantly predicted 24-hour survival in late-run fish. Collectively, these results indicate that released or escaped sockeye salmon may be at higher mortality risk when river temperatures are exceedingly high, and that reducing or eliminating air exposure may result in greater survival. iii Preface This research was carried out as a component of a multi-disciplinary research program investigating the effects of climate change on Pacific salmon. I held primary responsibility for research design and experimental protocols, collection and analysis of data, and preparation of manuscripts. I received considerable logistical support from my colleagues and guidance from my supervisors Scott G. Hinch and Steven J. Cooke. Collaborators on individual projects who were instrumental in development, experimentation or manuscript preparation were listed as co- authors on manuscripts submitted for publication. All experimental procedures were conducted with approval from the University of British Columbia Animal Care Committee (#A08-0388) and in accordance with guidelines set forth by the Canadian Committee on Animal Care. Chapter 2: The role of temperature in the capture and release of fish Published: Gale, M.K., S.G. Hinch, and M.R. Donaldson. In press. The role of temperature in the capture and release of fish. Fish and Fisheries. DOI: 10.1111/j.1467- 2979.2011.00441.x. Acceptance: Accepted August 15, 2011, available online September 19, 2011. Comments: This review was conducted and written by MKG with the assistance of MRD under the supervision and guidance of SGH, who helped to conceptualize the study and contributed to preparation of the manuscript. iv Chapter 3: Physiological impairment of adult sockeye salmon in fresh water after simulated capture-and-release across a range of temperatures Published: Gale, M.K., S.G. Hinch, E.J. Eliason, S.J. Cooke, and D.A. Patterson. 2011. Physiological impairment of adult sockeye salmon in fresh water after simulated capture-and-release across a range of temperatures. Fisheries Research, 112: 85- 95. Acceptance: Accepted August 16, 2011, available online September 3, 2011. Comments: This study was conducted and written by MKG with assistance from EJE, DAP, and SJC and under the supervision and guidance of SGH, who helped to conceptualize the study and contributed to preparation of the manuscript. Chapter 4: Predicting mortality of captured and released sockeye salmon at various temperatures using observational and physiological indices Comments: This study was conducted and written by MKG with assistance from Michael R. Donaldson, Ken M. Jeffries, EJE, and DAP, under the supervision and guidance of SGH and SJC, who helped to conceptualize the study and contributed to preparation of the manuscript. Thus, these contributors will be co-authors on the published manuscript. v Table of Contents Abstract(..................................................................................................................................................(ii! Preface(...................................................................................................................................................(iv! Table(of(Contents(................................................................................................................................(vi! List(of(Tables(.....................................................................................................................................(viii! List(of(Figures(......................................................................................................................................(ix! Acknowledgements(...........................................................................................................................(xi! Dedication(..........................................................................................................................................(xiii! Chapter((1:(Introduction(....................................................................................................................(1! Chapter((2:(The(role(of(temperature(in(the(capture(and(release(of(fish(............................(7! 2.1! Introduction(..........................................................................................................................................(7! 2.2! Methods(..................................................................................................................................................(9! 2.2.1! Literature!search!............................................................................................................................................!9! 2.2.2! Literature!review!.........................................................................................................................................!11! 2.3! Results(..................................................................................................................................................(14! 2.4! Discussion(...........................................................................................................................................(17! Chapter((3:(Physiological(impairment(of(adult(sockeye(salmon(in(fresh(water(after( simulated(captureKandKrelease(across(a(range(of(temperatures(.....................................(49! 3.1! Introduction(.......................................................................................................................................(49! 3.2! Methods(...............................................................................................................................................(53! 3.2.1! Study!site!and!animals!...............................................................................................................................!53! 3.2.2! Thermal!and!simulated!capture!treatments!....................................................................................!54! vi 3.2.3! Blood!sampling,!processing!and!analysis!..........................................................................................!55! 3.2.4! Assays!...............................................................................................................................................................!57! 3.2.5! Statistical!analysis!.......................................................................................................................................!57! 3.3! Results(..................................................................................................................................................(58! 3.3.1! Immediate!responses!to!treatment!......................................................................................................!58! 3.3.2! PostFcapture!samples!–!30!minutes!postFtreatment!....................................................................!59! 3.3.3! Terminal!samples!–!72!hours!aFter!treatment!................................................................................!59!