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Importance of stirring in the development of an iron-fertilized phytoplankton bloom

Abstract

The growth of populations is known to be influenced by dispersal, which has often been described as purely diffusive1,2. In the open ocean, however, the tendrils and filaments of phytoplankton populations provide evidence for dispersal by stirring3,4. Despite the apparent importance of horizontal stirring for plankton ecology, this process remains poorly characterized. Here we investigate the development of a discrete phytoplankton bloom, which was initiated by the iron fertilization of a patch of water (7 km in diameter) in the Southern Ocean5. Satellite images show a striking, 150-km-long bloom near the experimental site, six weeks after the initial fertilization. We argue that the ribbon-like bloom was produced from the fertilized patch through stirring, growth and diffusion, and we derive an estimate of the stirring rate. In this case, stirring acts as an important control on bloom development, mixing phytoplankton and iron out of the patch, but also entraining silicate. This may have prevented the onset of silicate limitation, and so allowed the bloom to continue for as long as there was sufficient iron. Stirring in the ocean is likely to be variable, so blooms that are initially similar may develop very differently.

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Figure 1: Images of the SOIREE bloom from the SeaWiFS ocean colour satellite.
Figure 2: Changes in the size and shape of the fertilized patch following the initial infusion.

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References

  1. Kierstead, H. & Slobodkin, L. B. The size of water masses containing plankton blooms. J. Mar. Res. 12, 141– 147 (1953).

    Google Scholar 

  2. Okubo, A. Biomathematics Vol. 10, Diffusion and Ecological Problems (Springer, Berlin, 1980).

    Google Scholar 

  3. Gower, J. F. R., Denman, K. L. & Holyer, R. J. Phytoplankton patchiness indicates the fluctuation spectrum of mesoscale oceanic structure. Nature 288 , 157–159 (1980).

    Article  ADS  Google Scholar 

  4. Holligan, P. et al. A biogeochemical study of the coccolithophore, Emiliania Huxleyi, in the North Atlantic. Glob. Biogeochem. Cycles 7, 879–900 (1993).

    Article  ADS  CAS  Google Scholar 

  5. Boyd, P. W. et al. A mesoscale phytoplankton bloom in the polar Southern Ocean stimulated by iron fertilization. Nature 407, 695–701 (2000).

    Article  ADS  CAS  Google Scholar 

  6. Comiso, J. C., McClain, C. R., Sullivan, C. W., Ryan, J. P. & Leonard, C. L. Coastal Zone Color Scanner pigment concentrations in the southern ocean and relationships to geophysical surface features. J. Geophys. Res. C 2, 2419 –2451 (1993).

    Article  ADS  Google Scholar 

  7. Sullivan, C. W. et al. Distributions of phytoplankton blooms in the southern ocean. Science 262, 1832–1837 (1993).

    Article  ADS  CAS  Google Scholar 

  8. Haidvogel, D. B. & Keffer, T. Tracer dispersal by mid-ocean mesoscale eddies. Part I. Ensemble statistics. Dyn. Atmos. Oceans 8, 1–40 ( 1984).

    Article  ADS  Google Scholar 

  9. Ledwell, J. R., Watson, A. J. & Law, C. S. Mixing of a tracer in the pycnocline. J. Geophys. Res. C 103, 21499–21529 (1998).

    Article  ADS  Google Scholar 

  10. Martin, A. P., Richards, K. J., Law, C.-S. & Liddicoat, M. I. Horizontal dispersion within an anticyclonic mesoscale eddy. Deep-Sea Res. (in the press).

  11. Stanton, T. P., Law, C. S. & Watson, A. J. Physical evolution of the IronEx-I open ocean tracer patch. Deep-sea Res. II 45, 947– 975 (1998).

    Article  ADS  CAS  Google Scholar 

  12. Okubo, A. Oceanic diffusion diagrams. Deep-Sea Res. 18, 789–802 (1971).

    Google Scholar 

  13. Martin, A. P. On filament width in oceanic plankton populations. J. Plank. Res. 22, 597–602 ( 2000).

    Article  ADS  Google Scholar 

  14. Charette, M. A. & Buessler, K. O. Does iron fertilization lead to rapid carbon export in the Southern Ocean? Geochem. Geophys. Geosyst. [online] 1, Paper number 2000GC000069 〈http://www.g-cubed.org〉 (2000).

  15. Sundermeyer, M. A. & Price, J. F. Lateral mixing and the North Atlantic Tracer Release Experiment: observations and simulations of lagrangian particles and a passive tracer. J. Geophys. Res. 103, 21481–21497 ( 1998).

    Article  ADS  Google Scholar 

  16. Jackson, G. A. A model of the formation of marine algal flocs by physical coagulation processes. Deep-Sea Res. 37, 1197– 1211 (1990).

    Article  ADS  CAS  Google Scholar 

  17. Olson, R. J., Sosik, H. M., Chekalyuk, A. M. & Shalapyonok, A. Effects of iron enrichment on phytoplankton in the Southern Ocean during late summer: Active fluorescence and flow cytometric analyses. Deep-Sea Res. (in the press).

  18. de Baar, H. J. W. & Boyd, P. W. in The Dynamic Ocean Carbon Cycle: A Midterm Synthesis of the Joint Global Ocean Flux Study (eds Hanson, R. B., Ducklow, H. W. & Field, J. G.) 61– 140 (International Geosphere Biosphere Programme Book Series, Cambridge Univ. Press, Cambridge, 1999).

    Google Scholar 

  19. Abbott, M. R., Richman, J. G., Letelier, R. M. & Bartlett, J. S. The spring bloom in the Antarctic Polar Frontal Zone as observed from a mesoscale array of bio-optical sensors. Deep-Sea Res. (in the press).

  20. Washburn, L., Emery, B. M., Jones, B. H. & Ondercin, D. G. Eddy stirring and phytoplankton patchiness in the subarctic North Atlantic in late summer. Deep-Sea Res. I 45, 1411 –1439 (1998).

    Article  Google Scholar 

  21. Abraham, E. R. The generation of plankton patchiness by turbulent stirring. Nature 391, 577–580 ( 1998).

    Article  ADS  CAS  Google Scholar 

  22. Lavender, S. J. & Groom, S. B. The SeaWiFS Automatic Data Processing System (SeaAPS). Int. J. Remote Sensing 20, 1051–1056 (1999).

    Article  ADS  Google Scholar 

  23. O'Reilly, J. E. et al. Ocean color chlorophyll algorithms for SeaWiFS. J. Geophys. Res. C 103, 24937–24953 (1998).

    Article  ADS  CAS  Google Scholar 

  24. Moore, J. K. et al. SeaWiFS satellite ocean color data from the Southern Ocean. Geophys. Res. Lett. 26, 1465– 1468 (1999).

    Article  ADS  Google Scholar 

  25. Okubo, A. A note on horizontal diffusion from an instantaneous source in a nonuniform flow. J. Oceanogr. Soc. J. 22, 1– 6 (1966).

    Article  Google Scholar 

  26. Garrett, C. On the initial streakiness of a dispersing tracer in two- and three-dimensional turbulence. Dyn. Atmos. Oceans 7, 265– 277 (1983).

    Article  ADS  Google Scholar 

  27. Rintoul, S. R., Donguy, J. R. & Roemmich, D. H. Seasonal evolution of upper ocean thermal structure between Tasmania and Antarctica. Deep-Sea Res. I 44 , 1185–1202 (1997).

    Article  Google Scholar 

  28. Maldonado, M. T., Boyd, P. W., Harrison, P. J. & Price, N. M. Co-limitation of phytoplankton growth by light and Fe during winter in the NE subarctic Pacific Ocean. Deep-Sea Res. II 46, 2475–2485 (1999).

    Article  ADS  CAS  Google Scholar 

  29. Bowie, A. R., Achterberg, E. P., Mantoura, R. F. C. & Worsfold, P. J. Determination of sub-nanomolar levels of iron in seawater using flow injection with chemiluminescence detection. Anal. Chim. Acta 361, 189–200 (1998).

    Article  CAS  Google Scholar 

  30. Law, C. S., Watson, A. J., Liddicoat, M. I. & Stanton, T. Sulphur hexafluoride as a tracer of biogeochemical and physical processes in an open-ocean iron fertilisation experiment. Deep-Sea Res. II 45, 977–994 ( 1998).

    Article  ADS  CAS  Google Scholar 

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Acknowledgements

We thank all the SOIREE team, particularly the captain and crew of RV Tangaroa for their assistance throughout the experiment; S. Nodder, R. Murdoch, A. Watson and T. Trull for experiment planning and coordination; and G. Jameson, M. Liddicoat and R. Ling for their work on the tracer release and mapping. We also thank S. Groom for additional interpretation of the remote sensing data; P. Nightingale for ARGOS data transfer; S. Rintoul for providing the XBT data; and M. Morris, C. Stevens and A. Martin for comments on the original manuscript. The SeaWiFS data, provided by the NASA DAAC/GSF and copyright of Orbital Imaging Corps and the NASA SeaWiFS project, was processed at CCMS-PML. E.A. and P.B. acknowledge the financial assistance of the NZ Public Good Science Fund for Antarctic research; C.L. thanks the UK Natural Environment Research Council for support; M.M. was supported by the Natural Sciences and Engineering Research Council of Canada (NSERC) and the Center for Environmental Bioinorganic Chemistry, Princeton (CEBIC); A.B. was supported by the University of Plymouth and Plymouth Marine Laboratory.

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Correspondence to Edward R. Abraham.

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Abraham, E., Law, C., Boyd, P. et al. Importance of stirring in the development of an iron-fertilized phytoplankton bloom. Nature 407, 727–730 (2000). https://doi.org/10.1038/35037555

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