An Unaccounted Fraction of Marine Biogenic CaCO3 Particles
Biogenic production and sedimentation of calcium carbonate in the ocean, referred to as the carbonate pump, has profound implications for the ocean carbon cycle, and relate both to global climate, ocean acidification and the geological past. In marine pelagic environments coccolithophores, foraminif...
| Main Authors: | , , , , |
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| Other Authors: | |
| Format: | Text |
| Language: | English |
| Published: |
2012
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| Subjects: | |
| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.668.2018 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3479124/pdf/pone.0047887.pdf |
| Summary: | Biogenic production and sedimentation of calcium carbonate in the ocean, referred to as the carbonate pump, has profound implications for the ocean carbon cycle, and relate both to global climate, ocean acidification and the geological past. In marine pelagic environments coccolithophores, foraminifera and pteropods have been considered the main calcifying organisms. Here, we document the presence of an abundant, previously unaccounted fraction of marine calcium carbonate particles in seawater, presumably formed by bacteria or in relation to extracellular polymeric substances. The particles occur in a variety of different morphologies, in a size range from,1 to.100 mm, and in a typical concentration of 104–105 particles L21 (size range counted 1–100 mm). Quantitative estimates of annual averages suggests that the pure calcium particles we counted in the 1–100 mm size range account for 2–4 times more CaCO3 than the dominating coccolithophoride Emiliania huxleyi and for 21 % of the total concentration of particulate calcium. Due to their high density, we hypothesize that the particles sediment rapidly, and therefore contribute significantly to the export of carbon and alkalinity from surface waters. The biological and environmental factors affecting the formation of these particles and possible impact of this process on global atmospheric CO2 remains to be investigated. |
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