Global contribution of echinoderms to the marine carbon cycle: CaCO 3 budget and benthic compartments

• Published in: Ecological Monographs
• Main Authors: Lebrato, Mario, Iglesias-Rodríguez, Debora, Feely, Richard A., Greeley, Dana, Jones, Daniel O.B., Suarez-Bosche, Nadia, Lampitt, Richard S., Cartes, Joan Enric, Green, Darryl R.H., Alker, Belinda
• Format: Article in Journal/Newspaper
• Language: English
• Published: Ecological Society of America 2010
• Subjects: Benthic compartments; CaCO3 budget; Carbon cycle; Carbonate production; Echinoderms; Ocean acidification; Standing stock
• Online Access: http://hdl.handle.net/10261/79231; https://doi.org/10.1890/09-0553.1

27 pages, 6 figures, 6 tables The contribution of carbonate-producing benthic organisms to the global marine carbon budget has been overlooked, the prevailing view being that calcium carbonate (CaCO3) is predominantly produced and exported by marine plankton in the >biological pump.> Here, we provide the first estimation of the global contribution of echinoderms to the marine inorganic and organic carbon cycle, based on organism-level measurements from species of the five echinoderm classes. Echinoderms' global CaCO3 contribution amounts to ∼0.861 Pg CaCO3/yr (0.102 Pg C/yr of inorganic carbon) as a production rate, and ∼2.11 Pg CaCO3 (0.25 Pg C of inorganic carbon) as a standing stock from the shelves, slopes, and abyssal depths. Echinoderm inorganic carbon production (0.102 Pg C/yr) is less than the global pelagic production (0.4-1.8 Pg C/yr) and similar to the estimates for carbonate shelves globally (0.024-0.120 Pg C/yr). Echinoderm CaCO3 production per unit area is ∼27.01 g CaCO3.m-2.yr-1 (3.24 g C.m-2.yr-1 as inorganic carbon) on a global scale for all areas, with a standing stock of ∼63.34 g CaCO3/m 2 (7.60 g C/m2 as inorganic carbon), and ∼7.97 g C/m2 as organic carbon. The shelf production alone is 77.91 g CaCO3.m-2.yr-1 (9.35 g C.m-2.yr -1 as inorganic carbon) in contrast to 2.05 g CaCO3.m -2.yr-1 (0.24 g C.m-2.yr-1 as inorganic carbon) for the slope on a global scale. The biogeography of the CaCO3 standing stocks of echinoderms showed strong latitudinal variability. More than 80% of the global CaCO3 production from echinoderms occurs between 0 and 800 m, with the highest contribution attributed to the shelf and upper slope. We provide a global distribution of echinoderm populations in the context of global calcite saturation horizons, since undersaturated waters with respect to mineral phases are surfacing. This shallowing is a direct consequence of ocean acidification, and in some places it may reach the shelf and upper slope permanently, where the highest CaCO 3 standing stocks from ...