It has been predicted that rates of coral calcification, as well as the photosynthetic rates of their symbiotic algae, will dramatically decline in response to what is typically referred to as an acidification of the world’s oceans, as the atmosphere’s CO2 concentration continues to rise in the years, decades, and centuries to come. As ever more pertinent evidence accumulates, however, the true story appears to be just the opposite. This summary examines such evidence obtained from field-based studies conducted in the natural ocean.
CO2 Science and SPPI, 9 April 2014. Summary.
The goal of the OA-ICC news stream being to provide an unbiased view of the topic of ocean acidification, it is legitimate to post the news above. However, the readership must be aware of problems associated with the work reported.
This report is anonymous and not peered-reviewed. Unfortunately, these are usual attributes of documents produced by the so-called SPPI and CO2 Science, leading to poor scientific quality and credibility.
Readers interested in the effects of global environmental changes (mostly ocean warming and acidification) on coral reefs will find thoroughly reviewed syntheses in chapters 5, 6 and 30 of the Contribution of WGII to the IPCC report (additional coverage can be found in other regional chapters). These chapters can be downloaded here:
http://ipcc-wg2.gov/AR5/report/final-drafts/
There is also a cross-chapter box covering coral reefs:
Gattuso J.-P., Hoegh-Guldberg O. & Pörtner H.-O., in press. Coral Reefs. In: Field C. et al. (Eds.), Climate Change 2014: Impacts, Adaptation and Vulnerability. Contribution of Working Group II to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge: Cambridge University Press.
which is included in the three chapters above and which can be also downloaded here:
https://dl.dropboxusercontent.com/u/3098160/Gattuso_etal_2014%208019.pdf
Finally, coral reefs are mentioned in the Technical Summary and twice in the Summary for Policy Makers (same link as the one above for the individual chapters):
– Unique and threatened systems: Some unique and threatened systems, including ecosystems and cultures, are already at risk from climate change (high confidence). The number of such systems at risk of severe consequences is higher with additional warming of around 1°C. Many species and systems with limited adaptive capacity are subject to very high risks with additional warming of 2°C, particularly Arctic-sea-ice and coral-reef systems.
– For medium- to high-emission scenarios (RCP4.5, 6.0, and 8.5), ocean acidification poses substantial risks to marine ecosystems, especially polar ecosystems and coral reefs, associated with impacts on the physiology, behavior, and population dynamics of individual species from phytoplankton to animals (medium to high confidence). Highly calcified mollusks, echinoderms, and reef-building corals are more sensitive than crustaceans (high confidence) and fishes (low confidence), with potentially detrimental consequences for fisheries and livelihoods. See Figure SPM.6B. Ocean acidification acts together with other global changes (e.g., warming, decreasing oxygen levels) and with local changes (e.g., pollution, eutrophication) (high confidence). Simultaneous drivers, such as warming and ocean acidification, can lead to interactive, complex, and amplified impacts for species and ecosystems.
Jean-Pierre Gattuso
INSU-CNRS-UPMC
Laboratoire d’Océanographie de Villefranche
06230 Villefranche-sur-mer
France