Cold Ocean Acidification

A new study by an international team of oceanographers published in Nature on September 29, 2005 reports that ocean acidification could result in corrosive chemical conditions that would be reached much sooner than previously thought. Within 50 to 100 years, there could be severe consequences for marine calcifying organisms, which build their external skeletal material out of calcium carbonate, the basic building block of limestone. Most threatened are cold-water calcifying organisms, including sea urchins, cold-water corals, coralline algae, and plankton known as pteropods--winged snails that swim through surface waters. Below you will find photographs of some of these organisms.

Chemical Saturation State:

Projections for the "chemical state" of the surface ocean for years 2000 (top) and 2099 (bottom) given as the median of 10 ocean models. The magenta colored line (seen only in 2099) separates saturated waters (orange colors) from undersaturated waters (blue colors).

Movie of this surface saturation state (with respect to aragonite) during the 21st century

Pteropods:

Limacina helicina, the dominant pteropod in polar waters

[Credits: AWI (left); Russ Hopcroft, NOAA (right)]

More images of Limacina helicina

Clio pyramidata, an important pteropod in subpolar waters

The pteropod Clio pyramidata, a common planktonic mollusk (pteropods) with a shell made out of aragonite, a metastable form of calcium carbonate. [Photo: R. W. Gilmer and G. R. Harbison]. This photo appeared on the cover of Science magazine, accompanying the article by Feely et al. (Science 305, 362366, 16 July 2004)

More images of Clio pyrimidata

Cold-water corals:

Lophelia pertusa, the dominant stony cold-water coral

[Credits: IFREMER (left); Andre Freiwald (right)]

Lophelia pertusa, the heart of a thriving ecosystem

Living cold-water coral (Lophelia pertusa) with a large red crabs (Eumunida picta), sea urchins (Echinus tylodes), and a Conger eel (Conger oceanicus). Photo taken from Johson Sea Link, Dive 3431 off North Carolina at 384 m. Photo by S.W. Ross, K. Sulak, M. Nizinski with partial support for their deep-coral research from NOAA Ocean Exploration and US Geological Survey.

More images of Lophelia pertusa

Reference

Orr, J. C., V. J. Fabry, O. Aumont, Laurent Bopp, S. C. Doney, R. A. Feely, A. Gnanadesikan, N. Gruber, A. Ishida, F. Joos, R. M. Key, K. Lindsay, E. Maier-Reimer, R. Matear, P. Monfray, A. Mouchet, R. G. Najjar, G.-K. Plattner, K. B. Rodgers, C. L. Sabine, J. L. Sarmiento, R. Schlitzer, R. D. Slater, I. J. Totterdell, M.-F. Weirig, Y. Yamanaka, and A. Yool, Anthropogenic ocean acidification over the twenty-first century and its impact on calcifying organisms, Nature, Vol 437, doi:10.1038/nature04095, 681--686, 29 Sept. 2005.
PDF of paper
PDF of Supplementary information

Recent press reports about this paper

Links to recent related documents

The Ocean in a High CO2 World (JGR Oceans Special Section [Sept 2005]
- Expands upon ocean chemistry predictions beyond 21st century while also including calcite:
  Caldeira, K., and M. E. Wickett (2005), Ocean model predictions of chemistry changes from carbon dioxide emissions to the atmosphere and ocean, J. Geophys. Res., 110, C09S04, doi:10.1029/2004JC002671. (PDF)
- Introduces this JGR special section:
  Orr, J. C., S. Pantoja, and H.-O. Poertner (2005), Introduction to special section: The Ocean in a High-CO2 World, J. Geophys. Res., 110, C09S01, doi:10.1029/2005JC003086. (PDF)
Royal Society report on ocean acidification [July 2005]
UNEP Report: Cold-water Coral Reefs: Out of Sight - No Longer Out of Mind [Revised June 2005]
Workshop on the Impacts of Increasing Atmospheric CO2 on Coral Reefs and Other Marine Calcifiers [April 2005]