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Resolving the ‘opal paradox’ in the Southern Ocean

Abstract

In the Southern Ocean, high accumulation rates of opal—which forms by precipitation from silica-bearing solutions—have been found in the sediment in spite of low production rates of biogenic silica and carbon in the overlying surface waters. This so-called ‘opal paradox’ is generally attributed to a higher efficiency of opal preservation in the Southern Ocean than elsewhere1,2. Here we report biogenic silica production rates, opal rain rates in the water column and opal sediment burial rates for the Indian Ocean sector of the Southern Ocean, which show that the assumed opal paradox is a result of underestimated opal production rates and overestimated opal accumulation rates. Our data thus demonstrate that the overall preservation efficiency of biogenic opal in this region is substantially lower than previously thought2, and that it lies within a factor of two of the global mean3. The comparison of our revised opal preservation efficiencies for the Southern Ocean with existing values from the equatorial Pacific Ocean and the North Atlantic Ocean shows that spatial differences in preservation efficiencies are not the primary reason for the differences in sedimentary opal accumulation. The reconciliation of surface production rates and sedimentary accumulation rates may enable the use of biogenic opal in the reconstruction of palaeoproductivity when the factors that affect the Si/C ratio are better understood.

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Figure 1: Hydrographic properties at three ANTARES stations.
Figure 2: Latitudinal distribution of nutrients and vertically integrated nutrient depletion in the Indian sector of the Southern Ocean during summer 1994.
Figure 3: Average daily export fluxes of particulate organic Si and C in the Indian sector of the Southern Ocean.

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References

  1. Boyle, E. A. J. Pumping iron makes thinner diatoms. Nature 393, 733–734 (1998).

    Article  ADS  CAS  Google Scholar 

  2. Nelson, D. M., Tréguer, P., Brzezinski, M. A., Leynaert, A. & Quéguiner, B. Production and dissolution of biogenic silica in the ocean: revised global estimates, comparison with regional data and relationship to biogenic sedimentation. Glob. Biogeochem. Cycles 9, 359–372 (1995).

    Article  ADS  CAS  Google Scholar 

  3. Tréguer, P. et al. The silica balance in the world ocean—a reestimate. Science 268, 375–379 (1995).

    Article  ADS  Google Scholar 

  4. Jennings, J. C. Jr, Gordon, L. I. & Nelson, D. M. Nutrient depletion indicates high primary productivity in the Weddell Sea. Nature 309, 51–54 (1984).

    Article  ADS  CAS  Google Scholar 

  5. Jacques, G. Is the concept of new-regenerated production valid for the Southern Ocean? Mar. Chem. 35, 273–286 (1991).

    Article  Google Scholar 

  6. Minas, H. J. & Minas, M. Net community production in “High Nutrient-Low Chlorophyll” waters of the tropical and Antarctic Ocean: grazing vs iron hypothesis. Oceanol. Acta 15, 145–162 (1992).

    CAS  Google Scholar 

  7. Clowes, A. J. Phosphate and silicate in the Southern Ocean. Discovery Rep. XIX, 1–120 (1938).

    Google Scholar 

  8. Kamykowski, D. & Zentara, S. J. Circumpolar plant nutrient covariation in the Southern Ocean: pattern and processes. Mar. Ecol. Prog. Ser. 58, 101–111 (1989).

    Article  ADS  Google Scholar 

  9. Semeneh, M., Dehairs, F., Fiala, M., Elskens, M. & Goeyens, L. Seasonal variation of phytoplankton community structure and nitrogen uptake regime in the Indian sector of the Southern Ocean. Polar Biol. 20, 259–272 (1998).

    Article  Google Scholar 

  10. Davis, C. O. Continuous culture of marine diatoms under silicate limitation. II. Effect of light intensity on growth and nutrient uptake of Skeletonema costatum. J. Phycol. 12, 291–300 (1976).

    CAS  Google Scholar 

  11. Takeda, S. Influence of iron availability on nutrient consumption ratio of diatoms in oceanic waters. Nature 393, 774–777 (1998).

    Article  ADS  CAS  Google Scholar 

  12. Quéguiner, B., Tréguer, P., Pecken, I. & Shareck, R. Biogeochemical dynamics and the silicon cycle in the Atlantic sector of the Southern Ocean during Austral spring 1992. Deep-Sea Res. 44, 68–89 (1997).

    ADS  Google Scholar 

  13. Caubert, T. Couplage et découplage des cycles du carbone et du silicium dans le secteur Indien de l'Océan Austral. Thesis, Univ. Bretagne Occidentale (1998).

  14. Wefer, G. & Fischer, G. Annual primary production and export flux in the Southern Ocean from sediment trap data. Mar. Chem. 35, 597–613 (1991).

    Article  CAS  Google Scholar 

  15. Pondaven, P., Ruiz-Pino, D., Druon, J. N., Fravalo, C. & Tréguer, P. Factors controlling silicon and nitrogen biogeochemical cycles in high nutrient, low chlorophyll systems (the Southern Ocean and the North Pacific – Comparison with a mesotrophic system (the North Atlantic). Deep-Sea Res. 46, 1923–1968 (1999).

    Article  CAS  Google Scholar 

  16. Arrigo, K., Worthon, D., Schnell, A. & Lizotte, M. P. Primary production in Southern Ocean waters. J. Geophys. Res. 103, 15587–15600 (1998).

    Article  ADS  Google Scholar 

  17. Blain, S., Leynaert, A., Tréguer, P., Chrétiennot-Dinet, M.-J. & Rodier, M. Biomass, growth rates and limitation of equatorial Pacific diatoms. Deep-Sea Res. 44, 1255–1275 (1997).

    Article  CAS  Google Scholar 

  18. Nelson, D. M. & Brzezinski, M. A. Diatom growth and productivity in an oligotrophic midocean gyre: a 3-yr record from the Sargasso Sea near Bermuda. Limnol. Oceanogr. 42, 473–486 (1997).

    Article  ADS  CAS  Google Scholar 

  19. Lampitt, R. & Antia, A. N. Particle flux in deep-seas: regional characteristics and temporal variability. Deep-Sea Res. 44, 1377–1403 (1997).

    Article  CAS  Google Scholar 

  20. Honjo, S., Dymond, J., Collier, R. & Manganini, S. J. Export production of particles to the interior of the Equatorial Pacific Ocean during the 1992 EqPac experiment. Deep-Sea Res. 42, 831–870 (1995).

    ADS  CAS  Google Scholar 

  21. Deuser, W. G., Jickells, T. D., King, P. & Commeau, J. A. Decadal and annual changes in biogenic opal and carbonate fluxes to the deep Sargasso Sea. Deep-Sea Res. 33, 225–246 (1995).

    Article  Google Scholar 

  22. Berger, W. H. & Wefer, G. Export production: seasonality and intermittency, and paleoceanographic implications. Paleoceanogr. Paleoclimatol. Paleoecol. 89, 245–254 (1990).

    Article  ADS  Google Scholar 

  23. Bacon, M. P. Glacial to Interglacial changes in carbonate and clay sedimentation in the Atlantic ocean estimated from 230Th measurements. Isotope Geosci. 2, 97–111 (1984).

    CAS  Google Scholar 

  24. Francois, R., Bacon, M. P., Altabet, M. A. & Labeyrie, L. D. Glacial/interglacial changes in sediment rain rate in the SW Indian sector of Subantarctic waters as recorded by 230Th, 231Pa, U, and 15N. Paleoceanography 8, 611–629 (1993).

    Article  ADS  Google Scholar 

  25. Rabouille, C., Gaillard, J. F., Tréguer, P. & Vincendeau, M. A. Biogenic silica recycling in surficial sediments across the Polar Front of the Southern Ocean (Indian Sector). Deep-Sea Res. 44, 1151–1176 (1997).

    ADS  CAS  Google Scholar 

  26. Berelson, W. M. et al. Biogenic budgets of particle rain, benthic remineralization and sediment accumulation in the Equatorial Pacific. Deep-Sea Res. 44, 2251–2282 (1997).

    ADS  CAS  Google Scholar 

  27. Sayles, F. L. et al. The benthic cycle of biogenic opal at the Bermuda Atlantic Time series site. Deep-Sea Res. 43, 383–409 (1996).

    Article  CAS  Google Scholar 

  28. Gordon, A. L., Chen, C. T. A. & Metcalf, W. G. Winter layer entrainment of the Weddell Deep Water. J. Geophys. Res. 89, 637–640 (1984).

    Article  ADS  Google Scholar 

  29. Tréguer, P., Kamatami, A., Gueneley, S. & Quéguiner, B. Kinetics of dissolution of Antarctic diatoms frustules and the biogeochemical cycle of silicon in the Southern Ocean. Polar Biol. 9, 397–403 (1989).

    Article  Google Scholar 

  30. Bianchi, M., Feliatra, F., Tréguer, P., Vincendeau, M. & Morvan, J. Nitrification rates, ammonium and nitrate distribution in upper layers of the water column and in sediments of the Indian sector of the Southern Ocean. Deep-Sea Res. 44, 1017–1032 (1997).

    ADS  CAS  Google Scholar 

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Acknowledgements

We thank J. Morvan, C. Jeandel, M. Fiala and P. Mayzaud for taking care of the moorings and sediment traps during the ANTARES programme; the officers, engineers and crew of RV Marion Dufresne for their help during the ANTARES cruises; CERSAT (IFREMER/Plouzané, France) for providing ERS1 satellite estimates of the seasonal ice-cover; R. Lampitt and A. Gooday for taking care of the moorings, sediment traps and multiple cores during the BENGAL programme in the North East Atlantic; and R. C. Dugdale for critically reading the manuscript. This work was supported by Région Bretagne (P.P.), the Institut National des Sciences de l’Univers (INSU/CNRS), and the French Polar Research Institute (IFRTP/CNRS).

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Correspondence to Philippe Pondaven.

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Pondaven, P., Ragueneau, O., Tréguer, P. et al. Resolving the ‘opal paradox’ in the Southern Ocean. Nature 405, 168–172 (2000). https://doi.org/10.1038/35012046

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