Electronic Thesis and Dissertation Repository


Master of Science




Dr. Bryan Neff


With global temperatures projected to surpass the limits of thermal tolerance for many species, evaluating the capacity for evolutionary and phenotypically plastic changes in thermal tolerance is key to our understanding of the biological consequences of climate change. Within quantitative genetic breeding designs and multiple rearing environments, I measured the thermal performance of cardiac function among families of two populations of chinook salmon (Oncorhynchus tshawytscha). I found significant indirect genetic, plastic, and additive genetic effects contributing to cardiac performance and thermal tolerance, representing a variety of adaptive mechanisms available to salmon populations faced with climate change. These results enhance our understanding of the mechanisms of thermal adaptation in fish and suggest a resiliency to rising temperatures among these ecologically, economically, and culturally important fish.