R. W. Wilson et al., Contribution of Fish to the Marine Inorganic Carbon Cycle

Science 16 January 2009, Vol. 323, No. 5912, pp. 359-362; DOI: 10.1126/science.1157972

Reports

Contribution of Fish to the Marine Inorganic Carbon Cycle

R. W. Wilson,^1* F. J. Millero,^2* J. R. Taylor,² P. J. Walsh,^2,3 V. Christensen,⁴ S. Jennings,⁵ and M. Grosell^2*

Oceanic production of calcium carbonate is conventionally attributed to marine plankton (coccolithophores and foraminifera). Here we report that marine fish produce precipitated carbonates within their intestines and excrete these at high rates. When combined with estimates of global fish biomass, this suggests that marine fish contribute 3 to 15% of total oceanic carbonate production. Fish carbonates have a higher magnesium content and solubility than traditional sources, yielding faster dissolution with depth. This may explain up to a quarter of the increase in titratable alkalinity within 1000 meters of the ocean surface, a controversial phenomenon that has puzzled oceanographers for decades. We also predict that fish carbonate production may rise in response to future environmental changes in carbon dioxide, and thus become an increasingly important component of the inorganic carbon cycle.

¹ School of Biosciences, University of Exeter, Exeter EX4 4PS, UK.
² Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL 33149–1098, USA.
³ University of Ottawa, Ottawa, ON K1N 6N5, Canada.
⁴ Fisheries Centre, University of British Columbia, Vancouver, BC V6T 1Z4, Canada.
⁵ Centre for Environment, Fisheries and Aquaculture Science, Lowestoft, and School of Environmental Sciences, University of East Anglia, Norwich NR4 7TJ, UK.

^* To whom correspondence should be addressed. e-mail: r.w.wilson@ex.ac.uk (R.W.W.), fmillero@rsmas.miami.edu (F.J.M.), and mgrosell@rsmas.miami.edu (M.G.)

Link to abstract: http://www.sciencemag.org/cgi/content/abstract/sci;323/5912/359