This research is aimed at understanding phosphorus fluxes in the mixed layer of the ocean. Radioisotopes of phosphorus (P-32 and P-33) will be used as short-lived tracers of the biodynamics of this nutrient. Data have been obtained to show the technique is feasible and methods to measure dissolved inorganic phosphorus (DIP), dissolved organic phosphorus (DOP) and particulate organic phosphorus (POP) are fully developed. This is a two-year study in the Pacific and Atlantic oceans at places and times to be determined on an opportunity basis. Biologists have long attempted to define phosphorus cycling in the mixed layer of the ocean and have faced the difficulties of multiple rates of exchange among several compartments, such as dissolved inorganic phosphorus, dissolved organic phosphorus and particulate organic phosphorus. Through new techniques using short-lived radioactive isotopes of phosphorus as tracers, the movement of this nutrient through the various compartments can be defined. This is a two-year study involving ships of opportunity to sample and analyze the upper layer of open ocean water in the Pacific and the Atlantic.
