9530961 Measures Antarctic waters are generally characterised by low standing stocks of phytoplankton and low rates of primary production despite the abundance of inorganic nutrients in the water column. Many researchers have speculated on the deficiency of iron in these waters to explain this paradox but no conclusive evidence of the importance of iron or its mechanisms in stimulating productivity have been presented. The major goals of the JGOFS Southern Ocean Process Study are, in part, to unravel the factors and processes that regulate the magnitude and variability of primary productivity and use this knowledge to determine the response of the Southern Ocean to naturally occurring climate changes both in the past and in the future. In this study, the principal investigation will measure iron and other reactive trace metals in the water column of various productivity regimes of the Polar frontal region of the Southern Ocean. These measurements will be used to further our understanding of the supply and distribution of iron in Antarctic waters and, in concert with the measurements of other P.I.'s its importance in affecting the structure of the microbial food web and the dynamics of the various biogeochemical cycles in the water column. As the complex role that iron plays in the magnitude and sequence of biological processes becomes better understood, these measurements will grow in importance in modelling the interaction of iron and its biological effects and indirectly, its impact in global biogeochemical cycles.
