Understanding oceanic primary production on a global scale can be enhanced by methods that are able to automatically track phytoplankton blooms from color satellite images. In this paper, unsupervised clustering and rule learning are combined to track green river, a plume of discolored water that forms every March-May offshore along the edge of the west Florida Shelf, from the Sea Viewing Wide Field of View Sensor which began flying in late 1997. Spatial information and sea surface temperature can be integrated into the approach to improve performance. Using cross-validation experiments over a series of 59 multi-spectral images, it is shown that the developed system is able to reliably discriminate between images with green river from those...