Spatial and temporal distribution of chlorophyll-a in the Aegean Sea according to SeaWiFS imagery. Two years of continuous operation have been completed since the launch of the SeaWiFS satellite. The Institute of Marine Biology of Crete is a NASA authorized land station and SeaWiFS user. In this work we investigate the level-3 images for the region of the Aegean Sea for the period between September 1997 and August 1999. Relatively few field studies have been undertaken in the Aegean, therefore this study provides important baseline information concerning the spatial and temporal distribution of algal biomass. We establish geographical provinces from pigment, sea surface tem¬perature (SST) and Sea Surface Salinity (SSS) climatologies. Investigating the seasonal patterns, for both subbasins the peak of pigment concentration is during winter, with concetrations being almost an order of magnitude higher in North Aegean.