Southern Ocean iron fertilization experiment

Verity PG, Villareal TA, Smayda TJ (1988) Ecological investigations of blooms of colonial Phaeocystis pouchetti - 1. Abundance, biochemical composition, and metabolic rates. J Plankton Res 10(2) 219-248 Watson SW, Novitsky TJ, Quinby HL, Valois FW (1977) Determination of bacterial number and biomass in the marine environment. Appl Environ Microbiol 33 940-946 Weaver RS, Kirchman DL, Hutchins DA (2003) Utilization of iron/organic ligand complexes by marine bacterioplank-ton. Aquat Microb Ecol 31 227-239 Weinbauer MG, Arrieta JM, Hemdl GJ (2003) Stimulation of viral infection of bacterioplankton during a mesoscale iron fertilization experiment in the Southern ocean. Geo-phys Res abstracts 5 12280... 

Krishnamurthy, A, Moore, J. K., and Doney, S. C. (2008). The effects of dilution and mixed layer depth on deliberate ocean iron fertilization 1-D simulations of the Southern Ocean iron experiment (SOFeX).J. Mar. Sys. 71, 112-130. 

Criticism that such small-scale, enclosed experiments may not accurately reflect the response of the HNLC system at the level of the community has led to several large-scale iron fertilization experiments in the equatorial Pacific and Southern Ocean. These have been some of the most dramatic... 

Figure 38.6 Effects of Fe enrichment on N03 drawdown in the South Patch (66.45° S, 171.8° W) during the SOFeX Southern Ocean mesoscale iron addition experiment. Shown are N03 concentrations versus time in the iron-fertilized patch (closed circles) compared to nearby unfertilized control waters (open circles). Coale et al. (2004), Science 304 408—414.

The role that DMS plays in producing more clouds has offered the possibility for humans to control climate. In the Southern Ocean where iron is a limiting nutrient it would be possible to add large quantities of iron to fertilize the ocean and thus increase DMS emissions and hence cloudiness thus inducing lower temperatures (Watson and Liss, 1998). Experiments show that iron can indeed fertilize the ocean and increase phytoplanktonic activity, but it would be risky to undertake such an experiment with our only planet. 

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