No. 5 - Lagos, Nigeria

With 13.5 million inhabitants, Lagos is the fifth largest coastal city in the world. Nigeria itself is one of the world's largest oil exporters. Nigeria is a major oil supplier to Western Europe and was the 5th largest supplier of crude oil to the United States in 2000. And oil is, unsurprisingly, a major contaminator of coastal waters off Lagos.

Sporadic enforcement of environmental laws resulted in the closure of two highly polluting industrial plants in Lagos. However, there has been no incentive for plants to implement pollution abatement strategies. The Federal Government has indicated that it is no longer willing to tolerate oil companies absolving themselves of their responsibility to reduce pollution and future drilling rights will be closely determined by companies' environmental compliance, in addition to their submission of an environmental impact assessment for the proposed site.

One of the most apparent results of the numerous oil spills that have plagued Lagos is the loss of mangrove trees. Mangroves were once a source of fuel and haven for wildlife but many have been unable to survive the level of oil toxicity they are now exposed to.

Oil pollution is also an element effecting fishing success along the coast. Certain species of fish have moved into deeper portions of sea due to unfavourable environmental conditions along the coast. Fishing of these species is a central factor in the economy of people along the coast and is no longer practicable.