Recent investigations have shown that Fe may limit phytoplankton growth in oceanic regions, and thus may be a key factor linking marine biological production to climate. Quantitative analysis of this iron hypothesis requires assessing the Fe-demand in oceanic phytoplankton. The iron demand of oceanic phytoplankton can be estimated only if the Fe-nutritional requirement of the population is known a priori. Dr. Welschmeyer will relate an organism's Fe-compositional ratio with its Fe-nutritional status. The results will shed additional light on the factors controlling primary productivity in the ocean.
