 The UN Environment Programme warns that the Caspian "suffers from an enormous burden of pollution from oil extraction and refining, offshore oil fields, radioactive wastes from nuclear power plants and huge volumes of untreated sewage and industrial waste introduced mainly by the Volga River".The magnitude of fossil fuel extraction and transport activity in the Caspian also poses a risk to the environment.The island of Vulf off Baku, for example, has suffered ecological damage as a result of the petrochemical industry; this has significantly decreased the number of species of marine birds in the area.