Search This journal All of Nature.com Advanced search Journal home > Archive > Article > Abstract Article Nature 437, 681-686 (29 September 2005) | doi:10.1038/nature04095
Anthropogenic ocean acidification over the twenty-first century and its impact on calcifying organisms
James C. Orr1, Victoria J. Fabry2, Olivier Aumont3, Laurent Bopp1, Scott C. Doney4, Richard A. Feely5, Anand Gnanadesikan6, Nicolas Gruber7, Akio Ishida8, Fortunat Joos9, Robert M. Key10, Keith Lindsay11, Ernst Maier-Reimer12, Richard Matear13, Patrick Monfray1,19, Anne Mouchet14, Raymond G. Najjar15, Gian-Kasper Plattner7,9, Keith B. Rodgers1,16,19, Christopher L. Sabine5, Jorge L. Sarmiento10, Reiner Schlitzer17, Richard D. Slater10, Ian J. Totterdell18,19, Marie-France Weirig17, Yasuhiro Yamanaka8 and Andrew Yool18
Today's surface ocean is saturated with respect to calcium carbonate, but increasing atmospheric carbon dioxide concentrations are reducing ocean pH and carbonate ion concentrations, and thus the level of calcium carbonate saturation. Experimental evidence suggests that if these trends continue, key marine organisms—such as corals and some plankton—will have difficulty maintaining their external calcium carbonate skeletons. Here we use 13 models of the ocean–carbon cycle to assess calcium carbonate saturation under the IS92a 'business-as-usual' scenario for future emissions of anthropogenic carbon dioxide. In our projections, Southern Ocean surface waters will begin to become undersaturated with respect to aragonite, a metastable form of calcium carbonate, by the year 2050. By 2100, this undersaturation could extend throughout the entire Southern Ocean and into the subarctic Pacific Ocean. When live pteropods were exposed to our predicted level of undersaturation during a two-day shipboard experiment, their aragonite shells showed notable dissolution. Our findings indicate that conditions detrimental to high-latitude ecosystems could develop within decades, not centuries as suggested previously.
Editorial Comment: Not only will the effects of low calcification be shown in shellfish and crustaceans very soon, but the 'building blocks' (zooplankton - coral polyps) of coral reefs will be adversely impacted. Coral reefs offer the habitat for so many species of shark (white-tip, black-tip, grey reef) - - - it becomes crtically important to support all Carbon Capture and Storage measures if we are to retain any level of marine biodiversity.