The effects of elevated water temperature on adult Pacific salmon gene expression, blood physiology and mortality ...

• Main Author: Jeffries, Kenneth Michael
• Format: Text
• Language: English
• Published: University of British Columbia 2012
• Subjects: Pacific; Sockeye; Pink salmon
• Online Access: https://dx.doi.org/10.14288/1.0073147; https://doi.library.ubc.ca/10.14288/1.0073147

Many populations of Pacific salmon (Oncorhynchus spp.) now encounter warmer rivers during their once-in-a-lifetime spawning migrations, which can result in premature mortality and may have contributed to some of the population declines observed in recent decades. One objective of this thesis was to determine the effects of high water temperatures on wild caught adult sockeye (O. nerka) and pink (O. gorbuscha) salmon at the level of the individual, tissue and cell through a series of temperature exposure studies. Fish held at 19°C consistently had higher mortality compared with fish held at a cooler temperature (13°C or 14°C) for both species with sockeye salmon demonstrating sex-specific mortality patterns. Sockeye salmon had higher plasma chloride levels when held at 19°C and both sockeye and pink salmon had reduced levels of plasma sex steroids at 19°C compared with fish at 13°C, which suggests an osmoregulatory disturbance and a potential reproductive consequence, respectively. Sockeye and pink salmon ...