Understanding physiological responses of organisms to warming and ocean acidification is the first step towards predicting the potential population, community and ecological impacts of these stressors. Increasingly, physiological plasticity is being recognized as important for organisms to adapt to the changing microclimates. Here, we evaluate the importance of physiological plasticity for coping with ocean acidification and elevated temperature, and its variability among individuals from the same population, of the limpet Cellana toreuma. Heart rates (as a proxy for metabolic performance) and genes encoding heat-shock proteins were measured at different heat shock temperatures (26, 30, 34, 38 °C) in individuals acclimated under combinations of different pCO2 (400 ppm, 1000 ppm) and temperature (20 °C, 24 °C) regimes. Analysis of heart rate showed significantly higher temperature coefficients (Q10 rates) for limpets at 20 °C than at 24 °C and lower post-acclimation thermal sensitivity of limpets at 400 ppm than at 1000 ppm. hsp70 expression linearly increased with the increasing heat-shock temperatures, with the largest slope occurring in limpets under a future scenario (24 °C and 1000 ppm pCO2). These results suggested that limpets will have increased sensitivity and energy consumption under future conditions. Furthermore, the increased variation in physiological response under the future scenario indicated that some individuals were better to cope physiologically with these conditions. Therefore, while ocean acidification decreases the ability of many individuals to respond to thermal stress, physiological plasticity and variability seem to be crucial in allowing some intertidal animals to survive in a rapidly changing environment.
Wang J., Dong Y.-W., Ding M.-W. & Russell B., 2017. Ocean acidification increases the sensitivity and variability of physiological responses of an intertidal limpet to thermal stress. Biogeosciences Discussions 1-33. Article.
