<Tr> <Td> </Td> <Td> This article has an unclear citation style . The references used may be made clearer with a different or consistent style of citation and footnoting . (September 2009) (Learn how and when to remove this template message) </Td> </Tr> <P> The Niger Delta is the delta of the Niger River sitting directly on the Gulf of Guinea on the Atlantic Ocean in Nigeria . It is typically considered to be located within nine coastal southern Nigerian states, which include: all six states from the South South geopolitical zone, one state (Ondo) from South West geopolitical zone and two states (Abia and Imo) from South East geopolitical zone . Of all the states that the region covers, only Cross River is not an oil - producing state . </P> <P> Niger Delta is a very densely populated region sometimes called the Oil Rivers because it was once a major producer of palm oil . The area was the British Oil Rivers Protectorate from 1885 until 1893, when it was expanded and became the Niger Coast Protectorate . The delta is a petroleum - rich region, and has been the centre of international controversy over pollution . </P> <P> The Niger Delta, as now defined officially by the Nigerian government, extends over about 70,000 km (27,000 sq mi) and makes up 7.5% of Nigeria's land mass . Historically and cartographically, it consists of present - day Bayelsa, Delta, and Rivers States . In 2000, however, Obasanjo's regime included Abia, Akwa - Ibom, Cross River State, Edo, Imo and Ondo States in the region . Some 31 million people of more than 40 ethnic groups including the Bini, Efik, Esan, Ibibio, Igbo, Annang, Yoruba, Oron, Ijaw, Ikwerre, Abua / Odual, Itsekiri, Isoko, Urhobo, Ukwuani, Kalabari, Okrika and Ogoni, are among the inhabitants of the political Niger Delta, speaking about 250 different dialects . </P>

What is the principal resource extracted in the niger delta
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