Ocean nutrient ratios governed by plankton biogeography

Abstract

The major nutrients nitrate and phosphate have one of the strongest correlations in the sea, with a slope similar to the average nitrogen (N) to phosphorus (P) content of plankton biomass (N/P = 16:1). The processes through which this global relationship emerges despite the wide range of N/P ratios at the organism level are not known. Here we use an ocean circulation model and observed nutrient distributions to show that the N/P ratio of biological nutrient removal varies across latitude in Southern Ocean surface waters, from 12:1 in the polar ocean to 20:1 in the sub-Antarctic zone. These variations are governed by regional differences in the species composition of the plankton community. The covariation of dissolved nitrate and phosphate is maintained by ocean circulation, which mixes the shallow subsurface nutrients between distinct biogeographic provinces. Climate-driven shifts in these marine biomes may alter the mean N/P ratio and the associated carbon export by Southern Ocean ecosystems.

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Figure 1: Observed N* distribution in the Southern Ocean.
Figure 2: Redfield N* prediction.
Figure 3: Diagnosed nutrient export ratios.
Figure 4: Circulation averaging of remineralized nutrients.

References

  1. 1

    Redfield, A. C. The biological control of chemical factors in the environment. Am. Sci. 46, 205–221 (1958)

    CAS  Google Scholar 

  2. 2

    Sterner, R. W. & Elser, J. J. Ecological Stoichiometry: The Biology of Elements from Molecules to the Biosphere 80–134 (Princeton Univ. Press, 2002)

    Google Scholar 

  3. 3

    Falkowski, P. G. Rationalizing elemental ratios in unicellular algae. J. Phycol. 36, 3–6 (2000)

    CAS  Article  Google Scholar 

  4. 4

    Anderson, L. A. & Sarmiento, J. L. Redfield ratios of remineralization determined by nutrient data analysis. Glob. Biogeochem. Cycles 8, 65–80 (1994)

    ADS  CAS  Article  Google Scholar 

  5. 5

    Takahashi, T., Broecker, W. S. & Langer, S. Redfield ratio based on chemical data from isopycnal surfaces. J. Geophys. Res. 90, 6907–6924 (1985)

    ADS  CAS  Article  Google Scholar 

  6. 6

    Codispoti, L. A. in Productivity of the Ocean: Past and Present (eds Berger, W. H., Smetacek, V. S. & Wefer, G.) 377–394 (Wiley, 1989)

    Google Scholar 

  7. 7

    Broecker, W. S. Glacial to interglacial changes in ocean chemistry. Prog. Oceanogr. 2, 151–197 (1982)

    ADS  Article  Google Scholar 

  8. 8

    Tyrrell, T. The relative influences of nitrogen and phosphorus on oceanic primary production. Nature 400, 525–531 (1999)

    ADS  CAS  Article  Google Scholar 

  9. 9

    Geider, R. J. & La Roche, J. Redfield revisited: variability of C:N:P in marine microalgae and its biochemical basis. Eur. J. Phycol. 37, 1–17 (2002)

    Article  Google Scholar 

  10. 10

    Quigg, A. et al. The evolutionary inheritance of elemental stoichiometry in marine phytoplankton. Nature 425, 291–294 (2003)

    ADS  CAS  Article  Google Scholar 

  11. 11

    Finkel, Z. V. et al. Irradiance and the elemental stoichiometry of marine phytoplankton. Limnol. Oceanogr. 51, 2690–2701 (2006)

    ADS  CAS  Article  Google Scholar 

  12. 12

    Klausmeier, C. A., Litchman, E., Daufresne, T. & Levin, S. A. Optimal nitrogen-to-phosphorus stoichiometry of phytoplankton. Nature 429, 171–174 (2004)

    ADS  CAS  Article  Google Scholar 

  13. 13

    Gruber, N. & Sarmiento, J. L. Global patterns of marine nitrogen fixation and denitrification. Glob. Biogeochem. Cycles 11, 235–266 (1997)

    ADS  CAS  Article  Google Scholar 

  14. 14

    Karl, D. M. & Michaels, A. F. in Encyclopedia of Ocean Sciences Vol. 4 (eds Steele, J. H., Turekian, K. K. & Thorpe, S. A.) 1876–1884 (Academic, 2001)

    Google Scholar 

  15. 15

    Dentener, F. et al. Nitrogen and sulfur deposition on regional and global scales: a multimodel evaluation. Glob. Biogeochem. Cycles 20, GB4003 (2006)

    ADS  Article  Google Scholar 

  16. 16

    Codispoti, L. A. & Christensen, J. P. Nitrification, denitrification, and nitrous oxide cycling in the eastern tropical Pacific Ocean. Mar. Chem. 16, 277–300 (1985)

    CAS  Article  Google Scholar 

  17. 17

    Garcia, H. E., Locarni, R. A., Boyer, T. P. & Antonov, J. I. World Ocean Atlas 2005 Vol. 4 Nutrients (Phosphate, Nitrate, Silicate) (US Government Printing Office, 2006)

    Google Scholar 

  18. 18

    Orsi, A. H., Whitworth, T. W. & Nowlin, W. D. On the meridional extent and fronts of the Antarctic Circumpolar Current. Deep-Sea Res. I 42, 641–673 (1995)

    Article  Google Scholar 

  19. 19

    Schlitzer, R. Carbon export fluxes in the Southern Ocean: results from inverse modeling and comparison with satellite-based estimates. Deep-Sea Res. II 49, 1623–1644 (2002)

    ADS  CAS  Article  Google Scholar 

  20. 20

    Green, S. E. & Sambrotto, R. N. Plankton community structure and export of C, N, P and Si in the Antarctic Circumpolar Current. Deep-Sea Res. II 53, 620–643 (2006)

    ADS  CAS  Article  Google Scholar 

  21. 21

    Longhurst, A. Seasonal cycles of pelagic production and consumption. Prog. Oceanogr. 36, 77–167 (1995)

    ADS  Article  Google Scholar 

  22. 22

    Kopczynska, E. E., Weber, L. H. & El-Sayed, S. Z. Phytoplankton species composition and abundance in the Indian sector of the Antarctic Ocean. Polar Biol. 6, 161–169 (1986)

    Article  Google Scholar 

  23. 23

    Jin, X., Gruber, N., Dunne, J. P., Sarmiento, J. L. & Armstrong, R. A. Diagnosing the contribution of phytoplankton functional groups to the production and export of particulate organic carbon, CaCO3, and opal from global nutrient and alkalinity distributions. Glob. Biogeochem. Cycles 20, GB2015 (2006)

    ADS  Article  Google Scholar 

  24. 24

    Price, N. M. The elemental stoichiometry and composition of an iron-limited diatom. Limnol. Oceanogr. 50, 1159–1171 (2005)

    ADS  CAS  Article  Google Scholar 

  25. 25

    Fu, F. X., Warner, M. E., Zhang, Y. H., Feng, Y. Y. & Hutchins, D. A. Effects of increased temperature and CO2 on photosynthesis, growth, and elemental ratios in marine Synechococcus and Prochlorococcus (Cyanobacteria). J. Phycol. 43, 485–496 (2007)

    Article  Google Scholar 

  26. 26

    Arrigo, K. R. et al. Phytoplankton community structure and the drawdown of nutrients and CO2 in the Southern Ocean. Science 283, 365–367 (1999)

    ADS  CAS  Article  Google Scholar 

  27. 27

    Karl, D. et al. The role of nitrogen fixation in biogeochemical cycling in the subtropical North Pacific Ocean. Nature 388, 533–538 (1997)

    ADS  CAS  Article  Google Scholar 

  28. 28

    Wu, J. F., Sunda, W., Boyle, E. A. & Karl, D. M. Phosphate depletion in the western North Atlantic Ocean. Science 289, 759–762 (2000)

    ADS  CAS  Article  Google Scholar 

  29. 29

    Anderson, R. F. et al. Wind-driven upwelling in the Southern Ocean and the deglacial rise in atmospheric CO2 . Science 323, 1443–1448 (2009)

    ADS  CAS  Article  Google Scholar 

  30. 30

    Elderfield, H. & Rickaby, R. E. M. Oceanic Cd/P ratio and nutrient utilization in the glacial Southern Ocean. Nature 405, 305–310 (2000)

    ADS  CAS  Article  Google Scholar 

  31. 31

    Sarmiento, J. L. & Toggweiler, J. R. A new model for the role of the oceans in determining atmospheric PCO2 . Nature 308, 621–624 (1984)

    ADS  CAS  Article  Google Scholar 

  32. 32

    Le Quere, C. et al. Saturation of the Southern Ocean CO2 sink due to recent climate change. Science 316, 1735–1738 (2007)

    ADS  CAS  Article  Google Scholar 

  33. 33

    Sarmiento, J. L. et al. Response of ocean ecosystems to climate warming. Glob. Biogeochem. Cycles 18, GB3003 (2004)

    ADS  Article  Google Scholar 

  34. 34

    Khatiwala, S., Visbeck, M. & Cane, M. A. Accelerated simulation of passive tracers in ocean circulation models. Ocean Model. 9, 51–69 (2005)

    ADS  Article  Google Scholar 

  35. 35

    Brzezinski, M. A. et al. A switch from Si(OH)4 to NO3 depletion in the glacial Southern Ocean. Geophys. Res. Lett. 29, 1564 (2002)

    ADS  Article  Google Scholar 

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Acknowledgements

We thank S. Khatiwala for providing the transport matrix. This work was funded by grants from the National Science Foundation and the Gordon and Betty Moore Foundation. Additional support for T.S.W. was provided by a Pauley Fellowship from UCLA.

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T.S.W. conducted the simulations and analysed the results. C.D. designed the study. Both authors wrote the paper.

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Correspondence to Thomas S. Weber.

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This file contains Supplementary Methods, Supplementary Tables 1-3, Supplementary Notes on sensitivity testing, Supplementary Figures 1-6 with legends and additional references. (PDF 4248 kb)

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Weber, T., Deutsch, C. Ocean nutrient ratios governed by plankton biogeography. Nature 467, 550–554 (2010). https://doi.org/10.1038/nature09403

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