The sea around the Ebre constitutes the largest continental shelf on the Catalan coast. The shelf has the third largest delta in the Mediterranean and the only state-run oilfield.
The coast accommodates a broad gamut of ecosystems: the large deltaic bays, the rocky seabeds to the north and south of the Delta, the meadows of phanerogamae--with some of the best preserved in Catalonia-- and open water environments that do not reach significant depths. Together they constitute one of the most biodiverse areas on the coast of Spain.
The presence of the River Ebre and the fresh water it provides endows the area with a number of special characteristics. The abundance of nutrients and the moderate water temperature together foster major breeding grounds for many species of fish, crustaceans and molluscs. In the case of commercial species, such as king prawns, this is of great value to the local fishing industry.
The Delta is also one of the most important habitats for sea birds in the Mediterranean, for both breeding and feeding. This explains why much of the sea around the Delta has been included in the Natura 2000network and designated a ZEPA (Zona de Especial Protección para las Aves – Special Protection Area for Birds).