Iron fertilization in the glacial ocean

the causes of the incomplete use of macronutrients by marine organisms and hence of the existence of these high-nutrient, low-chlorophyll (HNLc) regions have been subject to intense oceanographic research in the past decades. In the late eighties John H. Martin and his team reported evidence suggesting that phytoplankton growth in these regions was chronically limited by iron deficiency (Martin and Fitzwater 1988; Martin et al. 1990). Martin immediately realized that one important consequence of this discovery was that changes in the availability of Fe in HNLc regions could have large effects on marine phytoplankton productivity and organic carbon export to the subsurface ocean, and therefore could influence the efficiency of the global biological pump in sequestering atmospheric cO2 (Martin and Fitzwater 1988).