Exposure to high temperature influences the behaviour, physiology, and survival of sockeye salmon during spawning migration

• Published in: Canadian journal of zoology Vol. 86; no. 2; pp. 127 - 140
• Main Authors: Crossin, G. T, Hinch, S. G, Cooke, S. J, Welch, D. W, Patterson, D. A, Jones, S. R.M, Lotto, A. G, Leggatt, R. A, Mathes, M. T, Shrimpton, J. M, Van Der Kraak, G, Farrell, A. P
• Format: Journal Article
• Language: English
• Published: Ottawa, ON National Research Council of Canada 01.02.2008; NRC Research Press; Canadian Science Publishing NRC Research Press
• Subjects: Agnatha. Pisces; Animal and plant ecology; Animal migration; Animal, plant and microbial ecology; Animals; Behavior; Biochemistry; Biological and medical sciences; Correlation analysis; Demecology; Fundamental and applied biological sciences. Psychology; High temperature; Influence; Mortality; Oncorhynchus nerka; Parvicapsula minibicornis; Physiological aspects; Physiology; Rivers; Salmon; Sockeye salmon; Spawning; Spawning migrations; Survival analysis; Temperature; Temperature effects; Vertebrata; Zoology; Canada, British Columbia, Fraser R; Oncorhynchus nerka; Temperature; Spawning; Environmental factor; Animal migration; Experimental study; Survival; Freshwater environment; Vertebrata; Pisces; Population dynamics; Stream; Physiology
• ISSN: 0008-4301; 1480-3283; 1480-3283; 0008-4301
• DOI: 10.1139/Z07-122

Since 1996, some populations of Fraser River sockeye salmon ( Oncorhynchus nerka Walbaum in Artedi, 1792) have begun spawning migrations weeks earlier than normal, and most perish en route as a result. We suspect that a high midsummer river temperature is the principal cause of mortality. We intercepted 100 sockeye during normal migration near a spawning stream and measured somatic energy and aspects of plasma biochemistry. Fish were then held at either 10 or 18 °C for 24 days. Before release, fish were biopsied again and implanted with acoustic transmitters. A group of biopsied but untreated control salmon were released at the same time. Sixty-two percent (8 of 13) of control salmon and 68% (21 of 31) of 10 °C salmon reached spawning areas. The 18 °C-treated fish were half as successful (35%;; 6 of 17). During the holding period, mortality was 2 times higher and levels of Parvicapsula minibicornis (Kent, Whitaker and Dawe, 1997) infection were higher in the 18 °C-treated group than in the 10 °C-treated group. The only physiological difference between treatments was a change in gill Na + ,K + -ATPase activity. This drop correlated negatively with travel times for the 18 °C-treated males. Reproductive-hormone levels and stress measures did not differ between treatments but showed significant correlations with individual travel times.