Microzooplankton grazing on the coccolithophore Emiliania huxleyi and its role in the global calcium carbonate cycle
- PMID: 39514667
- PMCID: PMC11546808
- DOI: 10.1126/sciadv.adr5453
Microzooplankton grazing on the coccolithophore Emiliania huxleyi and its role in the global calcium carbonate cycle
Abstract
Identifying mechanisms driving the substantial dissolution of biogenic CaCO3 (60 to 80%) in surface and mesopelagic waters of the global ocean is critical for constraining the surface ocean's alkalinity and inorganic carbon budgets. We examine microzooplankton grazing on coccolithophores, photosynthetic calcifying algae responsible for a majority of open-ocean CaCO3 production, as a mechanism driving shallow dissolution. We show that microzooplankton grazing dissolves 92 ± 7% of ingested coccolith calcite, which may explain 50 to 100% of the observed CaCO3 dissolution in supersaturated surface waters. Microzooplankton grazing on coccolithophores is thus a substantial, previously unrecognized biological mechanism affecting the ballasting of organic carbon to deeper waters, the ecology and fitness of microzooplankton themselves due to buffering of food vacuole pH, and ultimately the continued ability of the surface ocean to take up atmospheric carbon dioxide.
Figures



References
-
- Milliman J. D., Production and accumulation of calcium carbonate in the ocean: Budget of a nonsteady state. Global Biogeochem. Cy. 7, 927–957 (1993).
-
- Berelson W. M., Balch W. M., Najjar R., Feely R. A., Sabine C., Lee K., Relating estimates of CaCO3 production, export, and dissolution in the water column to measurements of CaCO3 rain into sediment traps and dissolution on the sea floor: A revised global carbonate budget. Global Biogeochem. Cy. 21, doi.org/10.1029/2006GB002803 (2007).
-
- Iglesias-Rodríguez M. D., Brown C. W., Doney S. C., Kleypas J., Kolber D., Kolber Z., Hayes P. K., Falkowski P. G., Representing key phytoplankton functional groups in ocean carbon cycle models: Coccolithophorids. Global Biogeochem. Cy. 16, 47-1–47-20 (2002).
-
- Gangstø R., Gehlen M., Schneider B., Bopp L., Aumont O., Joos F., Modeling the marine aragonite cycle: Changes under rising carbon dioxide and its role in shallow water CaCO3 dissolution. Biogeosciences 5, 1057–1072 (2008).
-
- Subhas A. V., Dong S., Naviaux J. D., Rollins N. E., Ziveri P., Gray W., Rae J. W. B., Liu X., Byrne R. H., Chen S., Moore C., Martell-Bonet L., Steiner Z., Antler G., Hu H., Lunstrum A., Hou Y., Kemnitz N., Stutsman J., Pallacks S., Dugenne M., Quay P., Berelson W. M., Adkins J. F., Shallow calcium carbonate cycling in the North Pacific Ocean. Global Biogeochem. Cy. 36, e2022GB007388 (2022).
MeSH terms
Substances
LinkOut - more resources
Full Text Sources