Living in a high CO2 world: a global meta-analysis shows multiple trait-mediated responses of fish to ocean acidification

Understanding how marine organisms will be affected by global change is of primary importance to ensure ecosystem functioning and nature contributions to people. This study meets the call for addressing how life-history traits mediate effects of ocean acidification on fish. We built a database of overall and trait-mediated responses of teleost fish to future CO2 levels by searching the scientific literature. Using a meta-analytical approach, we investigated the effects of projected CO2 levels by IPCC for 2050-2070 and 2100 on fish eco-physiology and behavior from 320 contrasts on 42 species, stemming from polar to tropical regions. Moreover, since organisms may experience a mosaic of carbonate chemistry in coastal environments (e.g. in estuaries, upwelling zones and intertidal habitats), which may have higher pCO2 values than open ocean waters, we assessed responses from additional 103 contrasts on 21 fish species using pCO2 levels well above IPCC projections. Under mid- and end-of-cent...