Numerical Model Approaches to Address Recent Problems on Pelagic Ecosystems

A review of ecosystem modeling is presented, classifying the models on the basis of the problems they address. The problems are chosen mainly from those concerning the North Pacific and encompass: limiting factors in high-nutrient/low-chlorophyll (HNLC) regions; nutrient supply to the subtropical gyre; long-term variation; parameter optimization; oceanic provinces. A future research direction should be to sort out priorities of various biogeochemical and ecological processes with the long-term variation problem being the axis, while keeping the model complexity at a minimum and invoking the parameter optimization technique. This revised version was published online in August 2006 with corrections to the Cover Date.