ABSTRACT Chemical and biological oceanographers have long puzzled over the source of nutrients, especially nitrogen, to primary production in the central ocean gyres. In the case of the central North Pacific, some believe that nitrogen fixing bacteria may be the answer while a smaller group believes that advection of nitrogen from other parts of the basin is more likely. In this small but clever study, the principal investigator and a group of students from the University of Washington will combine spatially continuous chemical and hydrographic measurements taken underway on a cruise from Washington to Hawaii to estimate how important horizontal transport from the North American shelf to the basin interior can be expected to be. This will be the first time that a horizontal profile of sufficient resolution has been made to allow assessment of the importance of margin-to-central gyre transport of nutrients.