Meeting Abstract
Climate change is a major driver of elevated water temperatures globally, altering temperature regimes, which can substantially impact aquatic life particularly for oviparous fish species whose early development is temperature-dependent. When mothers encounter stressors such as elevated temperatures during follicular recruitment (maternal stress), resulting offspring often have altered phenotypes. Although these effects were previously often considered negative, recent studies suggest that this maternal stress signal may prepare offspring if they also face a similarly stressful environment (environmental match). We applied the environmental match hypothesis to investigate whether a maternal stress signal can prepare offspring for a stressful environment under climate change. Specifically, we exposed Lake Ontario Chinook salmon (Oncorhynchus tshawytscha) eggs to a biologically relevant maternal stress signal (1000ng/mL cortisol or control). We then split these groups and incubated them at temperatures indicative of current and future climate conditions (3°C higher). We examined offspring survival in early rearing environments, and experimentally tested the ability of the offspring to metabolically cope with chronic thermal stress by exposing the offspring to temperature spikes over 3 consecutive days. We assessed their metabolic response to extreme variation in temperature through their plasma cortisol, glucose and lactate levels. By examining an ecologically and commercially important fish within the environmentally relevant context of climate change our results should facilitate predictions of how fish populations may cope with the rapid increase in water temperatures under projected climate scenarios.
