Satellite remote sensing of ocean color is a powerful tool for large-scale investigations on water properties. In particular, ocean color is directly connected to the pigment concentration. This latter, in turn, is related to the presence of phytoplankton which plays a major role in the biogenic flux of carbon dioxide in the oceans. Thanks to this process, oceans represent an important sink for atmospheric carbon dioxide, thus influencing the climate equilibrium. This explains the renewed interest in space missions and oceanographic researches focused on ocean color. In this paper we review the Sea-viewing Wide Field- of-view Sensor (SeaWiFS), carried by the OrbView-2 satellite, and we compare its imagery with the measurements performed by the ENEA Lidar Fluorosensor (ELF). In particular, lidar measurements can be very useful for calibrating the satellite imagery of chlorophyll-a in a region where seasonal and spatial distributions of phytoplankton require further investigations. Actually, the present imagery processing algorithms are not exempt from uncertainties, especially because the water-leaving radiance must be separated from the atmospheric radiance, which typically represents about 80% of the 'at sensor' radiance. Moreover, such algorithms nowadays are tuned for biota very different from that of the Souther Ocean.