Contribution of Fish to the Marine Inorganic Carbon Cycle

• Published in: Science (American Association for the Advancement of Science) Vol. 323; no. 5912; pp. 359 - 362
• Main Authors: Wilson, R.W, Millero, F.J, Taylor, J.R, Walsh, P.J, Christensen, V, Jennings, S, Grosell, M
• Format: Journal Article
• Language: English
• Published: United States American Association for the Advancement of Science 16.01.2009; The American Association for the Advancement of Science
• Subjects: Animals; Biomass; Calcification, Physiologic; Calcite; Calcium Carbonate - chemistry; Calcium Carbonate - metabolism; Carbon - chemistry; Carbon cycle; Carbon dioxide; Carbon Dioxide - blood; Carbonates; Chemical Precipitation; Ecosystem; Fishes - metabolism; Hydrogen-Ion Concentration; Intestines; Intestines - metabolism; Marine; Marine fishes; Oceans; Oceans and Seas; Plankton - physiology; Precipitation; Production estimates; Sea water; Seawater - chemistry; Solubility; Temperature
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.1157972

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.