(Video APTN)

Oil powers the economy in the West African nation of Nigeria, but it is killing its southern shores.

While the world is transfixed by the BP disaster in the Gulf of Mexico, oil spills have become a part of everyday life during the 50 years that foreign firms have been pumping out Nigeria's easily refined fuel.

Environmentalists estimate as much as 550 (m) million gallons (2 (b) billion litres) of oil have poured into the Niger River Delta during that time - at a rate roughly comparable to one Exxon Valdez disaster per year.

Villagers here say the spillage regularly washes on to land, ruining their fishing nets and meagre livelihoods.

Colonised by the British in the late 1800s for its palm oil, Nigeria became an oil power after Royal Dutch Shell PLC struck its first working well in 1956 in the Niger Delta. Other foreign firms moved in, among them Chevron Corp., Italy's Eni SpA, Exxon Mobil Corp. and French major Total SA, all working across the delta in partnership with the state-run Nigerian National Petroleum Corp.

Much of the oil heads to the US.

OPEC figures put daily production at about 2 (m) million barrels. But the profits come at a steep ecological price.

According to government figures, Nigeria suffered more than 6,800 oil spills from 1976 through 2001, losing some 130 (m) million gallons (492 (m) million litres) - 3 (m) million barrels.

Black crude stains the coasts of the Niger Delta, a region of swamps, mangroves and creeks almost the size of South Carolina or Portugal.

In Iwuo-Okpom, an Atlantic Ocean village of 7,000, a tiny flame on the horizon marks an offshore Exxon Mobil oil platform.

On this coast, in January 1998, a pipeline of the company then known only as Mobil broke and spilled about 1.6 (m) million gallons (6 (m) million litres) into the ocean, one of Nigeria's worst spills. The slick spread as far as Lagos, a city of 14 (m) million people 200 kilometres (120 miles) northwest.

Tade Amuwa, a 35-year-old woman who smokes fish in Iwuo-Okpom, says those caught near the village cook poorly.

"All these things, they all go black," she said, sweeping her hand across oil-soaked driftwood and puny, discoloured fish.

Many of the fishermen in the area find it hard to make ends meet and children whose parents can't afford school fees end up staying at home.

In a statement, Exxon Mobil's Nigerian subsidiary said it used airplanes and boats to spray dispersants on recent slicks, though "regrettably some oil did reach shoreline areas." The subsidiary said it also offered contracts for locals to help with the cleanup. Village leaders denied receiving any such offers.

More than 4,300 miles (7,000 kilometres) of pipelines and flow stations snake through the delta, some of them decades old, corroded and prone to failure under the pressure.

Oil companies can't be blamed for all the spills. Militant groups have targeted pipelines, kidnapped oil workers and fought government troops here since 2006.

Fearing attacks and kidnappings, firms are hesitant to send staff to spill sites, and often confine employees to offshore platforms and military-protected compounds.

In Ogoniland, a swampy, oil-rich portion of the delta, villagers rebelled and drove out the oil companies in the 1990s. Still, Shell pipelines run throughout the area.

As the tide ebbs at Bodo City, a town in Ogoniland, exposed mangrove roots drip black from spilled crude. There are no birds in the sky or fish in the creeks.

"We need help from the world to come to our aid, help us out of this problem, this oil spillage that Shell doesn't want to do anything about it," said Mike K. Vipene, a youth leader in Bodo City.

Caroline Wittgen, a Shell spokeswoman, said the company wouldn't comment on individual spills.

A recent Shell environmental report said that almost all the oil spilled from company lines last year - more than 4 (m) million gallons (15.14 (m) million litres) - resulted from sabotage.

Criminal gangs often tap into pipelines in remote, unprotected areas. Government estimates suggest they steal as much as 15 percent of the delta's oil, loading some onto ships for sale on the black market.

Others run refineries in the bush, producing bootleg gasoline to sell at rickety roadside tables throughout the delta.

Though thefts continue, violence has calmed in recent months with the offer of a government amnesty. Goodluck Jonathan, Nigeria's new president, is from the delta and has promised to make peace a priority.

But the amnesty deal now appears to be faltering and demands for compensation persist. Okon Sunday, the village chief in Iwuo-Okpom, wants Exxon Mobil to pay his community (b) billions of US dollars.

"My life is not OK because of the poor water, the environment has been polluted," he said.

If compensation isn't treated seriously, militancy is inevitable, Sunday added.