Diatom carbon export enhanced by silicate upwelling in the northeast Atlantic

J T Allen, L Brown, R Sanders, M Moore, A Mustard, S Fielding, M Lucas, M Rixen, G Savidge, S Henson, Daniel Justin Mayor

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118 Citations (Scopus)

Abstract

Diatoms are unicellular or chain-forming phytoplankton that use silicon ( Si) in cell wall construction. Their survival during periods of apparent nutrient exhaustion enhances carbon sequestration in frontal regions of the northern North Atlantic. These regions may therefore have a more important role in the 'biological pump' than they have previously been attributed(1), but how this is achieved is unknown. Diatom growth depends on silicate availability, in addition to nitrate and phosphate(2,3), but northern Atlantic waters are richer in nitrate than silicate(4). Following the spring stratification, diatoms are the first phytoplankton to bloom(2,5). Once silicate is exhausted, diatom blooms subside in a major export event(6,7). Here we show that, with nitrate still available for new production, the diatom bloom is prolonged where there is a periodic supply of new silicate: specifically, diatoms thrive by 'mining' deep-water silicate brought to the surface by an unstable ocean front. The mechanism we present here is not limited to silicate fertilization; similar mechanisms could support nitrate-,phosphate- or iron-limited frontal regions in oceans elsewhere.

Original languageEnglish
Pages (from-to)728-732
Number of pages5
JournalNature
Volume437
Issue number7059
DOIs
Publication statusPublished - 29 Sep 2005

Keywords

  • Iceland-Faeroes Front
  • Almeira-Oran Front
  • Mesoscale subduction
  • Spring bloom
  • Phytoplankton
  • ocean
  • nutrients
  • Pacific
  • June

Cite this

Allen, J. T., Brown, L., Sanders, R., Moore, M., Mustard, A., Fielding, S., Lucas, M., Rixen, M., Savidge, G., Henson, S., & Mayor, D. J. (2005). Diatom carbon export enhanced by silicate upwelling in the northeast Atlantic. Nature, 437(7059), 728-732. https://doi.org/10.1038/nature03948