Ocean Iron Fertilization (OIF) is one of the techniques under discussion for CO2 sequestering as organic carbon in deep oceans. The role of iron in promoting algal blooms in oceans was studied by John Martin of the Woodshole Oceanographic Institute in the nineties of last century.
An article appearing in the Nature (19 July 2012) authored by Victor Smetacek and others, presents results of a geoengineering experiment (European Iron Fertilization Experiment – EIFEX) carried out in a chosen spot in the Southern Ocean, Antarctica. The experiment indicates that the carbon mopped up by the algal blooms (generated by iron fertilization) reaches great depths (below 1000m) and possibly the sea-floor. This implies that the organic carbon gets eventually embedded in the sediments of the ocean bottom and thus remains locked up for long periods. The experiment validates the ideas of John Martin, though its application on a larger scale in open oceans as a geoengineering technique to combat global warming/climate change needs perhaps a lot more of experimentation and studies.
MSR/31 July 2012
Source: “Deep Carbon Export from a Southern Ocean Iron-Fertilization Diatom Bloom” by Victor Smetacek and others, Nature, 19 July 2012, v.487, pp.313-319.