The Black Sea is one of the most remarkable regional seas in the world. It is almost cut off from the rest of the world's oceans but is up to 2212 metres deep. The eutrophication of the Black Sea due to the excessive loads of nutrients via the rivers and directly from the coastal countries has led to radical changes in the ecosystem since the 1960es. This has had a major transboundary impact on biological diversity and human use of the sea, including fisheries and recreation.
Six countries border the Black Sea: Romania, Bulgaria, Turkey, Georgia, Russia and Ukraine.
The Danube is the most important river running into the Black Sea. Apart from the Danube, Europe's third and fourth largest rivers, the Dnieper and Don, flow to the Black Sea. The population of the greater Black Sea basin is more than 160 million.
The co-operation for the protection of the Black Sea environment takes place in the framework of the Convention on the Protection of the Black Sea against Pollution (Black Sea Convention). The European Union has recently been granted official observer status to the Commission work.