The Oceanic Carbonate System: A Reassessment of Biogenic Controls

• Published in: Science (American Association for the Advancement of Science) Vol. 226; no. 4678; pp. 1074 - 1077
• Main Authors: Betzer, P. R., Byrne, R. H., Acker, J. G., Lewis, C. S., Jolley, R. R., Feely, R. A.
• Format: Journal Article
• Language: English
• Published: Washington, DC The American Association for the Advancement of Science 30.11.1984; American Association for the Advancement of Science
• Subjects: Alkalinity; Aragonite; Carbonates; Deep water; Dissolution; Earth, ocean, space; Euphotic zone; Exact sciences and technology; External geophysics; Marine; Observations; Oceanographic research; Oceans; Pacific Ocean; Particulate matter; Physical and chemical properties of sea water; Physics of the oceans; Pteropoda; Sea water; Sediments; Pacific Ocean; IN, North Pacific; Aragonite; Climate; Carbon dioxide; Carbonates; Chemical properties; Seawater; North Pacific
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.226.4678.1074

Fluxes of biogenic carbonates moving out of the euphotic zone and into deeper undersaturated waters of the North Pacific were estimated with free-drifting sediment traps. Short-duration (1 to 1.5 day) sampling between 100 and 2200 meters points to a major involvement in the oceanic carbonate system by a class of organisms which had been relegated to a secondary role--aragonitic pteropods. Pteropod fluxes through the base of the euphotic zone are almost large enough to balance the alkalinity budget for the Pacific Ocean. Dissolution experiments with freshly collected materials shed considerable light on a mystery surrounding these labile organisms: although plankton collections from net tows almost always contain large numbers of pteropods, these organisms are never a major component of biogenic materials in long-duration sediment trap collections. Their low abundance in long-duration collections results from dissolution subsequent to collection. Short-duration sampling showed significant increases in the ratio of calcitic foraminifera to aragonitic pteropods in undersaturated waters, indicating the more stable mineralogic form, calcite, was preserved relative to aragonite. Approximately 90 percent of the aragonite flux is remineralized in the upper 2.2 kilometers of the water column.