Will it work?
There's no consensus about the effectiveness of the Coast Guard’s plan to burn an oil slick from a spill in the Gulf of Mexico to prevent it from reaching shore.
Greg Pollock, head of the oil spill division of the Texas General Land Office, which is providing equipment for crews in the gulf, said he is not aware of a similar burn ever being done off the U.S. coast. The last time crews with his agency used fire booms to burn oil was a 1995 spill on the San Jacinto River.
"When you can get oil ignited, it is an absolutely effective way of getting rid of a huge percentage of the oil," he said. "I can't overstate how important it is to get the oil off the surface of the water."
He said the oil will likely be ignited using jelled gasoline and lit rags soaked in oil. What's left afterward is something he described as a kind of hardened tar ball that can be removed from the water with nets or skimmers.
"I would say there is little threat to the environment because it won't coat an animal, and because all the volatiles have been consumed if it gets on a shore it can be simply picked up," he said.
Still, an expert at Louisiana State University says he's "not super optimistic" about the idea. Ed Overton says the oil samples he has seen are sticky, similar to roofing tar. He calls it "tarry crude that lies down in the water." He also says it's a technique that works better in calm, enclosed areas than in open waters.
"It can be effective in calm water, not much wind, in a protected area," he said. "When you're out in the middle of the ocean, with wave actions, and currents, pushing you around, it's not easy."
But Overton says burning is something that has to be tried.
A 500-foot boom will be used to corral several thousand gallons of the thickest oil on the surface, which will then be towed to a more remote area, set on fire, and allowed to burn for about an hour, the Coast Guard said. Such burns will continue throughout the day if they are working.
“It’s not something we do very often, so we want to make sure we do it right,” Petty Officer Steve Lehmann told the New York Times. “You need to herd it up and group it a certain way, and then there’s the whole lighting of it.”
The National Oceanic and Atmospheric Administration said birds and mammals were more likely to escape a burning area of the ocean than an oil slick. Birds might be disoriented by smoke plumes, but would be at much greater risk from oil in the water.
Authorities also said they expect no impact on sea turtles and marine mammals in the burn area. The slick was about 20 miles east of the mouth of the Mississippi River.
On the downside, burning the oil creates air pollution and some experts say the effect on marine life is unclear.
A similar burn off the coast of Newfoundland in 1993 eliminated at least half the captured oil.
The Associated Press and Reuters contributed to this report.