Sensitivities of extant animal taxa to ocean acidification

• Published in: Nature climate change Vol. 3; no. 11; pp. 995 - 1001
• Main Authors: Wittmann, Astrid C., Pörtner, Hans-O.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01-11-2013; Nature Publishing Group
• Subjects: 631/158/2455; Acidification; Animal, plant and microbial ecology; Anthropogenic factors; Applied ecology; Biological and medical sciences; Biota; Calcium carbonate; Carbon dioxide emissions; Climate Change; Climate Change/Climate Change Impacts; Conservation, protection and management of environment and wildlife; Crustaceans; Ecotoxicology, biological effects of pollution; Environment; Environmental degradation: ecosystems survey and restoration; Environmental Law/Policy/Ecojustice; Fundamental and applied biological sciences. Psychology; Inorganic carbon; Marine; Marine and brackish environment; Marine ecosystems; Mollusca; Mollusks; Ocean acidification; Oceans; Shellfish; Species composition; Taxa; Marine environment; Ecological damage; Vertebrata; Sensitivity resistance; Animal community; Pisces; Acidification; Invertebrata
• ISSN: 1758-678X; 1758-6798
• DOI: 10.1038/nclimate1982

Anthropogenic CO
2
emitted to the atmosphere is absorbed by the oceans, causing a progressive increase in ocean inorganic carbon concentrations and resulting in decreased water pH and calcium carbonate saturation. This phenomenon, called ocean acidification, is in addition to the warming effects of CO
2
emissions. Ocean acidification has been reported to affect ocean biota, but the severity of this threat to ocean ecosystems (and humans depending on these ecosystems) is poorly understood. Here we evaluate the scale of this threat in the context of widely used representative concentration pathways (RCPs) by analysing the sensitivities of five animal taxa (corals, echinoderms, molluscs, crustaceans and fishes) to a wide range of CO
2
concentrations. Corals, echinoderms and molluscs are more sensitive to RCP8.5 (936 ppm in 2100) than are crustaceans. Larval fishes may be even more sensitive than the lower invertebrates, but taxon sensitivity on evolutionary timescales remains obscure. The variety of responses within and between taxa, together with observations in mesocosms and palaeo-analogues, suggest that ocean acidification is a driver for substantial change in ocean ecosystems this century, potentially leading to long-term shifts in species composition.
The severity of the ecological threat posed by ocean acidification remains poorly understood. Now analysis of the sensitivities of five animal groups to a wide range of CO
2
concentrations finds a variety of responses within and between taxa, indicating that acidification will drive substantial changes in ocean ecosystems this century.