Abstract
Climate change is leading to altered temperature regimes which are impacting aquatic life, particularly for ectothermic fish. The impacts of environmental stress can be translated across generations through maternally derived glucocorticoids, leading to altered offspring phenotypes. Although these maternal stress effects are often considered negative, recent studies suggest this maternal stress signal may prepare offspring for a similarly stressful environment (environmental match). We applied the environmental match hypothesis to examine whether a prenatal stress signal can dampen the effects of elevated water temperatures on body size, condition, and survival during early development in Chinook salmon Oncorhynchus tshawytscha from Lake Ontario, Canada. We exposed fertilized eggs to prenatal exogenous egg cortisol (1,000 ng/ml cortisol or 0 ng/ml control) and then reared these dosed groups at temperatures indicative of current (+0°C) and future (+3°C) temperature conditions. Offspring reared in elevated temperatures were smaller and had a lower survival at the hatchling developmental stage. Overall, we found that our exogenous cortisol dose did not dampen effects of elevated rearing temperatures (environmental match) on body size or early survival. Instead, our eyed stage survival indicates that our prenatal cortisol dose may be detrimental, as cortisol‐dosed offspring raised in elevated temperatures had lower survival than cortisol‐dosed and control reared in current temperatures. Our results suggest that a maternal stress signal may not be able to ameliorate the effects of thermal stress during early development. However, we highlight the importance of interpreting the fitness impacts of maternal stress within an environmentally relevant context.
Highlights
Climate change is altering habitats across the globe, introducing environmental stressors such as elevated mean temperatures (Stocker et al, 2013), increased frequency of extreme weather events, and novel competitor and predator interactions
Since preparatory responses following exposure to a maternal stress signal may dampen the effects of an environmental stressor, we predicted that prenatal exposure to exogenous cortisol would help to buffer these negative impacts, resulting in relative increases in survival and body size at emergence for fish raised under elevated water temperatures
Based on predictions from the environmental matching hypothesis, we aimed to test whether prenatal exposure to elevated egg cortisol buffers these temperature effects
Summary
Climate change is altering habitats across the globe, introducing environmental stressors such as elevated mean temperatures (Stocker et al, 2013), increased frequency of extreme weather events (e.g., floods, droughts; Easterling et al, 2000; Fischer & Knutti, 2015), and novel competitor and predator interactions (e.g., via species range expansions toward the poles; Parmesan & Yohe, 2003). Maternally derived GCs may be involved in modulating the responses of ectothermic offspring to multiple environmental stressors due to climate change, by better-preparing offspring for managing harsher environmental conditions such as elevated temperatures during development (Sopinka et al, 2017). We apply the concept of environmental matching (Sheriff & Love, 2013) to examine whether exposure to maternally derived GCs can generate phenotypes that better buffer the negative phenotypic effects of developing in elevated water temperatures using Chinook salmon Oncorhynchus tshawytscha (Figure 1). Since preparatory responses following exposure to a maternal stress signal may dampen the effects of an environmental stressor (i.e., environmental matching hypothesis; Sheriff et al, 2017), we predicted that prenatal exposure to exogenous cortisol would help to buffer these negative impacts, resulting in relative increases in survival and body size at emergence (fry stage) for fish raised under elevated water temperatures
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
