At the top of the image, south of the Carpathian Mountains, the Danube brings sediment-rich waters into the Black Sea. Combined with the often-intense biological activity that takes place in this sea, the resulting phytoplankton and the suspended sediments create the vivid green patches seen in the image.

Further south, Greece, and the Aegean Sea are facing the Mediterranean. The Romans used to call the Mediterranean the ‘Mare Nostrum’, meaning, ‘Our Sea’. Since centuries, the navigation on its waters has played and important role in the development of European countries. MERIS, with its 15 visible and near-infrared channels enable the retrieval of water composition data. It provides Europe with an unprecedented tool to better understand and monitor the eco-systems of our coastal waters.