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Large-scale distribution of Atlantic nitrogen fixation controlled by iron availability

Nature Geoscience volume 2, pages 867–871 (2009)Cite this article

Abstract

Oceanic fixed-nitrogen concentrations are controlled by the balance between nitrogen fixation and denitrification1,2,3,4. A number of factors, including iron limitation5,6,7, can restrict nitrogen fixation, introducing the potential for decoupling of nitrogen inputs and losses2,5,8. Such decoupling could significantly affect the oceanic fixed-nitrogen inventory and consequently the biological component of ocean carbon storage and hence air–sea partitioning of carbon dioxide2,5,8,9. However, the extent to which nutrients limit nitrogen fixation in the global ocean is uncertain. Here, we examined rates of nitrogen fixation and nutrient concentrations in the surface waters of the Atlantic Ocean along a north–south 10,000 km transect during October and November 2005. We show that rates of nitrogen fixation were markedly higher in the North Atlantic compared with the South Atlantic Ocean. Across the two basins, nitrogen fixation was positively correlated with dissolved iron and negatively correlated with dissolved phosphorus concentrations. We conclude that inter-basin differences in nitrogen fixation are controlled by iron supply rather than phosphorus availability. Analysis of the nutrient content of deep waters suggests that the fixed nitrogen enters North Atlantic Deep Water. Our study thus supports the suggestion that iron significantly influences nitrogen fixation5, and that subsequent interactions with ocean circulation patterns contribute to the decoupling of nitrogen fixation and loss2,4,8.

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Figure 1: Cruise tracks and maps of annual mean excess nutrient distributions.
Figure 2: Transect data from the AMT-17 cruise.
Figure 3: Deep water N* distribution and fluxes in the Atlantic.

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References

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

    Google Scholar 

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

    Google Scholar 

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

    Article  Google Scholar 

  4. Deutsch, C., Sarmiento, J. L., Sigman, D. M., Gruber, N. & Dunne, J. P. Spatial coupling of nitrogen inputs and losses in the ocean. Nature 445, 163–167 (2007).

    Article  Google Scholar 

  5. Falkowski, P. G. Evolution of the nitrogen cycle and its influence on the biological sequestration of CO2 in the ocean. Nature 387, 272–275 (1997).

    Article  Google Scholar 

  6. Mills, M. M., Ridame, C., Davey, M., La Roche, J. & Geider, R. J. Iron and phosphorus co-limit nitrogen fixation in the eastern tropical North Atlantic. Nature 429, 292–294 (2004).

    Article  Google Scholar 

  7. Berman-Frank, I., Quigg, A., Finkel, Z. V., Irwin, A. J. & Haramaty, L. Nitrogen-fixation strategies and Fe requirements in cyanobacteria. Limnol. Oceanogr. 52, 2260–2269 (2007).

    Article  Google Scholar 

  8. Moore, J. K. & Doney, S. C. Iron availability limits the ocean nitrogen inventory stabilizing feedbacks between marine denitrification and nitrogen fixation. Glob. Biogeochem. Cycles 21, GB20001 (2007).

    Article  Google Scholar 

  9. Broecker, W. S. & Henderson, G. M. The sequence of events surrounding Termination II and their implications for the cause of glacial-interglacial CO2 changes. Paleoceanography 13, 352–364 (1998).

    Article  Google Scholar 

  10. Li, Y. H. & Peng, T. H. Latitudinal change of remineralization ratios in the oceans and its implication for nutrient cycles. Glob. Biogeochem. Cycles 16, 1130 (2002).

    Article  Google Scholar 

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

    Article  Google Scholar 

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

    Article  Google Scholar 

  13. Hood, R. R., Coles, V. J. & Capone, D. G. Modeling the distribution of Trichodesmium and nitrogen fixation in the Atlantic Ocean. J. Geophys. Res. 109, CO6006 (2004).

    Article  Google Scholar 

  14. Capone, D. G. et al. Nitrogen fixation by Trichodesmium spp.: An important source of new nitrogen to the tropical and subtropical North Atlantic Ocean. Glob. Biogeochem. Cycles 19, GB2024 (2005).

    Article  Google Scholar 

  15. Galbraith, E. D., Kienast, M., Pedersen, T. F. & Calvert, S. E. Glacial–interglacial modulation of the marine nitrogen cycle by high-latitude O2 supply to the global thermocline. Paleoceanography 19, PA4007 (2004).

    Article  Google Scholar 

  16. Mahaffey, C. et al. Biogeochemical signatures of nitrogen fixation in the eastern North Atlantic. Geophys. Res. Lett. 30, 1300 (2003).

    Article  Google Scholar 

  17. Tyrrell, T. et al. Large-scale latitudinal distribution of Trichodesmium spp. in the Atlantic Ocean. J. Plankton Res. 25, 405–416 (2003).

    Article  Google Scholar 

  18. Voss, M., Croot, P., Lochte, K., Mills, M. M. & Peeken, I. Patterns of nitrogen fixation along 10∘ N in the tropical North Atlantic. Geophys. Res. Lett. 31, L23S09 (2004).

    Article  Google Scholar 

  19. Sohm, J. A. & Capone, D. G. Phosphorus dynamics of the tropical and subtropical North Atlantic: Trichodesmium spp. versus bulk plankton. Mar. Ecol. Progr. Ser. 317, 21–28 (2006).

    Article  Google Scholar 

  20. Hansell, D. A., Olson, D. B., Dentener, F. & Zamora, L. M. Assessment of excess nitrate development in the subtropical North Atlantic. Mar. Chem. 106, 562–579 (2007).

    Article  Google Scholar 

  21. Moore, C. M. et al. Relative influence of nitrogen and phosphorus availability on phytoplankton physiology and productivity in the oligotrophic sub-tropical North Atlantic Ocean. Limnol. Oceanogr. 53, 291–305 (2008).

    Article  Google Scholar 

  22. Sanudo-Wilhelmy, S. A. et al. Phosphorus limitation of nitrogen fixation by Trichodesmium in the central Atlantic Ocean. Nature 411, 66–69 (2001).

    Article  Google Scholar 

  23. Yamamoto-Kawai, M., Carmack, E. & McLaughlin, F. Nitrogen balance and Arctic throughflow. Nature 443, 43–43 (2006).

    Article  Google Scholar 

  24. Sarmiento, J. L., Gruber, N., Brzezinski, M. A. & Dunne, J. P. High-latitude controls of thermocline nutrients and low latitude biological productivity. Nature 427, 56–60 (2004).

    Article  Google Scholar 

  25. Williams, R. G., Roussenov, V. & Follows, M. J. Nutrient streams and their induction into the mixed layer. Glob. Biogeochem. Cycles 20, GB1016 (2006).

    Article  Google Scholar 

  26. McDonagh, E. L. & King, B. A. Oceanic fluxes in the South Atlantic. J. Phys. Oceanogr. 35, 109–122 (2005).

    Article  Google Scholar 

  27. Rahmstorf, S. Ocean circulation and climate during the past 120,000 years. Nature 419, 207–214 (2002).

    Article  Google Scholar 

  28. Deutsch, C., Gruber, N., Key, R. M., Sarmiento, J. L. & Ganachaud, A. Denitrification and N2 fixation in the Pacific Ocean. Glob. Biogeochem. Cycles 15, 483–506 (2001).

    Article  Google Scholar 

  29. Ganachaud, A. & Wunsch, C. Improved estimates of global ocean circulation, heat transport and mixing from hydrographic data. Nature 408, 453–457 (2000).

    Article  Google Scholar 

  30. Ren, H. et al. Foraminiferal isotope evidence of reduced nitrogen fixation in the ice age Atlantic Ocean. Science 323, 244–248 (2009).

    Article  Google Scholar 

Download references

Acknowledgements

We thank the scientific complement and crew of the RRS Discovery during AMT-17 for all of their assistance. P. Holligan, A. Martin, R. Sanders and T. Tyrrell are thanked for discussions and comments on the manuscript. This work was supported by EU Carboocean grants to R.J.G. and J.L.R. and the UK Natural Environment Research Council, through a fellowship to C.M.M. and the Atlantic Meridional Transect consortium. This is contribution number 172 of the AMT programme.

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Authors and Affiliations

  1. Department of Biological Sciences, University of Essex, Colchester CO4 3SQ, UK

    C. Mark Moore, Richard J. Geider & David J. Suggett

  2. National Oceanography Centre, University of Southampton, European Way, Southampton SO14 3ZH, UK

    C. Mark Moore, Eric P. Achterberg, Elaine L. McDonagh, Xi Pan, Alex J. Poulton & Micha J. A. Rijkenberg

  3. Department of Environmental Earth System Science, Stanford University, Stanford, California 94305, USA

    Matthew M. Mills

  4. Marine Biogeochemistry, Leibniz-Institut für Meereswissenschaften, D-24105 Kiel, Germany

    Julie LaRoche

  5. Department of Zoology, University of Cape Town, Rondebosch 7701, South Africa

    Mike I. Lucas

  6. School of Earth, Ocean and Environmental Sciences, University of Plymouth, Plymouth PL4 8AA, UK

    Simon J. Ussher

  7. Plymouth Marine Laboratory, Prospect Place, The Hoe, Plymouth PL1 3DH, UK

    E. Malcolm S. Woodward

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Contributions

R.J.G., J.L.R., C.M.M., M.M.M. and E.P.A. designed the research. C.M.M., M.M.M., E.P.A., M.I.L., X.P., D.J.S., S.J.U. and E.M.S.W. collected samples and carried out the work at sea. M.J.A.R. analysed iron samples. A.J.P. enumerated Trichodesmium. C.M.M. and E.L.M. analysed nutrient distributions and calculated transport data. C.M.M. wrote the first draft of the paper. C.M.M., M.M.M., R.J.G., J.L.R. and E.P.A. discussed the results and extensively edited subsequent drafts. All of the authors commented on the manuscript.

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Correspondence to C. Mark Moore.

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Mark Moore, C., Mills, M., Achterberg, E. et al. Large-scale distribution of Atlantic nitrogen fixation controlled by iron availability. Nature Geosci 2, 867–871 (2009). https://doi.org/10.1038/ngeo667

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