Living in a high CO 2 world: a global meta‐analysis shows multiple trait‐mediated fish responses to ocean acidification

• Published in: Ecological Monographs
• Main Authors: Cattano, Carlo, Claudet, Joachim, Domenici, Paolo, Milazzo, Marco
• Other Authors: Università degli Studi di Palermo
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2018
• Subjects: Ocean acidification
• Online Access: http://dx.doi.org/10.1002/ecm.1297; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fecm.1297; https://esajournals.onlinelibrary.wiley.com/doi/pdf/10.1002/ecm.1297

Abstract 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 CO 2 levels by searching the scientific literature. Using a meta‐analytical approach, we investigated the effects of projected CO 2 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 p CO 2 values than open ocean waters, we assessed responses from additional 103 contrasts on 21 fish species using p CO 2 levels well above IPCC projections. Under mid‐century and end‐of‐century CO 2 emission scenarios, we found multiple CO 2 ‐dose‐dependent effects on calcification, resting metabolic rate, yolk, and behavioral performances, along with increased predation risk and decreased foraging, particularly for larvae. Importantly, many of the traits considered will not confer fish tolerance to elevated CO 2 and far‐reaching ecological consequences on fish population replenishment and community structure will likely occur. Extreme CO 2 levels well above IPCC projections showed effects on fish mortality and calcification, while growth, metabolism, and yolk were unaffected. CO 2 exposures in short‐term experiments increased fish mortality, which in turn decreased in longer‐term exposures. Whatever the elevated CO 2 levels considered, some key biological processes (e.g., reproduction, development, habitat choice) were critically understudied. Fish are an important resource for livelihoods in coastal communities and a key component for stability of marine ecosystems. Given the multiple ...