Meeting Abstract
Thermal tolerance can vary widely across individuals of the same species. For example, our research has shown that thermal tolerance differs across populations, over the life history, and between sexes in Pacific salmon. We take advantage of this variation to look for the underlying mechanisms that determine thermal tolerance. Over the last decade or so, research has shown the adult female Pacific salmon have much higher mortality compared to males, particularly when they are exposed to secondary stressors (e.g. high temperature). Our most recent work has focused on trying to understand the mechanisms underlying this mysterious phenomenon. We examined several hypotheses: 1) Males have higher aerobic scope and swimming performance at elevated temperatures; 2) Females experience cardiac collapse due to reduced oxygen delivery to their hearts; 3) Females have impaired recovery from stressors at high temperature; 4) Females accumulate increased oxidative damage compared to males.
