Oil spill off the coast of Nigeria.

On 20 December 2011 a routine transfer between a floating oil production, storage and off-loading vessel and a waiting oil tanker in the Bonga Field, off the coast of Nigeria, developed a problem resulting in the discharge of a large amount of oil into the sea. The operators, The Shell Exploration and Production Company (SNEPCo), a local subsidiary of the Shell global oil group, estimated the loss at under 40 000 barrels, roughly one-fifth of the Bonga Field's daily output, and the worst offshore oil spill in the Bight of Benin since 1998. SNEPCo has responded by closing down production at the Bonga Field, and deploying five ships and two aircraft to spray the spill with dispersants, chemicals which break down oil in seawater.

Satellite image of the oil spill released by the environmental group SkyTruth.

Oil spreads very thinly over the surface of the water very thinly, so a spill of 40 000 barrels ought to cover about 600 km² of ocean. However satellite images taken by the European Space Agency Envisat Satellite and released by the SkyTruth environmental group on 21 December appear to show a slick covering about 923 km², suggesting that Shell may have lost slightly more oil than they thought, and Peter Ibador of Nigeria's National National Oil Spill Detection and Response Agency (NOSDRA)has suggested that the spill could be three times as large as Shell has admitted, presenting a severe threat to wildlife and the local population. Senator Bukola Saraki, chairman of the Nigerian Senate Committee on Environment and Ecology expressed concern that NOSDRA lacks the equipment and manpower to monitor the situation, let alone combat a spill on this scale, making Nigeria dependent on the 'grace and benevolence' of the oil companies to deal with incidents of this nature.

Nevertheless by the 24th Shell appeared to be confident that they had dispersed about 50% of the oil, without calling on assistance from waiting Nigerian Navy vessels, and have been inviting senior Nigerian government officials to visit the area.

Shell has been the biggest player in the Nigerian oil industry since the 1950s, but has long suffered from a poor reputation in the area, both for weak environmental management and links to several military regimes with bad records on human rights. In August this year the United Nations Environment Program produced a detailed report into oil pollution in the Ogoniland area of the Niger Delta, as a result of which traditional leaders of the Ogoni People have lodged a court action against Shell in the US, seeking a billion dollars in compensation for past environmental damage.

See also The UN reports on oil pollution in Ogoniland, Nigeria.