Science New Series, Vol. 304, No. 5669, pp. 414-417 (2004)

Research by Ken Buesseler, John Andrews, Steven Pike, and Matthew Charette from the Department of Marine Chemistry and Geochemistry at the Woods Hole Oceanographic Institution suggests that iron fertilization could help reduce anthropogenic carbon dioxide in the ocean (though the reduction would be relatively small). Using Thorium 234 (a naturally occurring radionuclide) as a tracer, the researchers observed an increased flux of marine snow (falling organic matter/detritus composed mostly of dead plankton), in the Southern Ocean after injecting iron into the surface layer, demonstrating successful export of particulate organic carbon. Injecting iron into the ocean induces algal blooms (because iron is a limiting nutrient for phytoplankton), resulting in increased uptake of carbon dioxide by phytoplankton in the process of photosynthesis. This results in the increased amounts of marine snow, some of which falls all the way to the ocean floor; storing carbon dioxide in detritus at the bottom of the ocean is a potential method for counteracting ocean acidification.