Children play on a Nigerian oil-flow station in 2007. Nigeria, a major oil source for the United States, is riddled with ancient pipes and constant spills. That, plus the geopolitical challenges involved, is why much of Nigeria's crude is the kind of "tough oil" that author Michael Klare describes. George Osodi/AP hide caption

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Plaquemines Parish coastal zone director P.J. Hahn lifts an oil-covered pelican, which was stuck in oil at Queen Bess Island in Barataria Bay, just off the Gulf of Mexico, in early June. Gerald Herbert/AP Photo hide caption

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The efforts of Gov. Bobby Jindal to get the BP oil spill cleaned up have helped his popularity among Louisiana voters. Here, Jindal speaks on a command post boat in Barataria Bay, off Grand Isle, La. Spencer Platt/Getty Images hide caption

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Efforts to clean the beach in Elmer's Island, La., were stopped Tuesday due to bad weather created by Tropical Storm Alex. Joe Raedle/Getty Images hide caption

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Shrimp boats sit in the Pass Christian Harbor in Pass Christian, Miss. Many fishermen, seafood buyers and others in the Gulf operate with cash, which may cause problems when they cannot present the documents needed to receive government compensation. Dave Martin/AP hide caption

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The looming storm could postpone BP's plans to double the amount of oil they capture from the spill. Here, a boat uses a boom and absorbent material to soak up oil on the surface of the water near Grand Isle, La., on Monday. Joe Raedle/Getty Images hide caption

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Cleanup workers maneuver an oil boom in Bataria Bay on the coast of Louisiana. With the down economy, their are plenty of people hoping for cleanup jobs, but there are few to be found. Patrick Semansky/AP hide caption

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Oil-soaked booms sit on top of a marsh in Barataria Bay. Brian Naylor/NPR hide caption

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A shrimp-trawler gets a high-powered spray wash after spending a day skimming oil in the Gulf of Mexico. The Coast Guard has set up dozens of offshore decontamination stations like this one south of Mobile Bay. Debbie Elliot/NPR hide caption

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An image from the BP video shows oil gushing from the blown well in the Gulf of Mexico. AP hide caption

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