Parental environment mediates impacts of increased carbon dioxide on a coral reef fish

Carbon dioxide concentrations in the surface ocean are increasing owing to rising CO2 concentrations in the atmosphere(1). Higher CO2 levels are predicted to affect essential physiological processes of many aquatic organisms(2,3), leading to widespread impacts on marine diversity and ecosystem function, especially when combined with the effects of global warming(4-6). Yet the ability for marine species to adjust to increasing CO2 levels over many generations is an unresolved issue. Here we show that ocean conditions projected for the end of the century (approximately 1,000 mu atm CO2 and a temperature rise of 1.5-3.0 degrees C) cause an increase in metabolic rate and decreases in length, weight, condition and Survival of juvenile fish. However, these effects are absent or reversed when parents also experience high CO2 concentrations. Our results show that non-genetic parental effects can dramatically alter the response of marine organisms to increasing CO2 and demonstrate that some species have more capacity to - acclimate to ocean acidification than previously thought.