Against a background of extensive multi-disciplinary oceanographic investigations over a number of years, together with the long-term establishment of a Society and Institute, extensive information is available from studies undertaken in the estuarine and coastal waters of the Basque Country.The present authors gained access to unpublished literature and reports which, together with a synthesis of internationally-refereed papers, provide a series of scientific overviews of particular subject areas. Teams of researchers (from Basque Institutes and Universities) combine to present the present 'state of knowledge', within a global context, of processes ranging from sub-seabed to air-sea interaction - incorporating data on the associated biology (including fisheries) and pollutant sources and levels.