Efforts to close a well spewing oil in the Gulf of Mexico are failing so the Coast Guard is considering lighting the mess on fire.
Crews have been unable to stop thousands of barrels of oil from fouling gulf waters since an April 20 explosion sank the Deepwater Horizon, which was drilling 50 miles off the Louisiana coast. Eleven workers are missing and presumed dead, and the cause of the blast has not been determined.
Coast Guard Rear Adm. Mary Landry said the controlled burns would be done during the day far from shore. Crews would make sure marine life and people were protected and that work on other oil rigs would not be interrupted.
The burning could start as early as Wednesday afternoon, but whether it will work is unclear.
Ed Overton, a professor emeritus of environmental sciences at Louisiana State University, questioned the method.
"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."
He has another concern: The oil samples from the spill he's looked at shows it to be a sticky substance similar to roofing tar.
"I'm not super optimistic. This is tarry crude that lies down in the water," he said. "But it's something that has got to be tried."
According to the National Oceanic and Atmospheric Administration, birds and mammals are more likely to escape a burning area of the ocean than escape from an oil slick. The agency said birds might be disoriented by the plumes of smoke, but they would be at much greater risk from exposure to oil in the water.
A similar burn off the coast of Newfoundland in 1993 eliminated 50 to 99 percent of captured oil. However, burning the oil also creates air pollution, and the effect on marine life is unclear.
Crews from the Texas General Land Office Oil Spill Prevention and Response Program are bringing in equipment to help corral the oil and burn the slick.
Texas Land Commissioner Jerry Patterson said burning surface oil is one of the best ways to deal with so large a slick.
The last time crews with the agency used fire booms to burn oil was a 1995 spill on the San Jacinto River, Patterson said.
"When you burn it, the plume from the fire is the biggest environmental concern, but this far out to sea it will not be as big of a problem," Patterson said.
Oil from the Deepwater Horizon is not expected to reach the coast until late in the week, if at all. But longer-term forecasts show the winds and ocean currents veering toward the coast. The glistening sheen of sweet crude is forming long reddish-orange ribbons of oil that, if they wash up on shore, could cover birds, white sand beaches and marsh grasses.
"As the days progress, the (oil) plume will migrate north, northeast," said Gregory W. Stone, an oceanographer and head of the Coastal Studies Institute at Louisiana State University. "That plume will push onshore."
Hotel owners, fishermen and restaurateurs are keeping anxious watch.
Louis Skrmetta, 54, runs a company called Ship Island Excursions that takes tourists to the Gulf Islands National Seashore, where white-sand beaches and green water create an idyllic landscape.
"This is the worst possible thing that could happen to the Mississippi Gulf Coast," he said. "It will wipe out the oyster industry. Shrimping wouldn't recover for years. It would kill family tourism. That's our livelihood."
The last major spill in the Gulf was in June 1979, when an offshore drilling rig in Mexican waters — the Ixtoc I — blew up, releasing 140 million gallons. It took until March 1980 to cap the well, and the oil contaminated U.S. waters and Texas shores.
As of Tuesday, the spill was about 20 miles offshore, south of Venice, La. It covered an expanding area about 48 miles long and 80 miles wide, but with uneven borders, making it difficult to calculate its area in square miles.
"I understand there's got to be industry, but it's so sad for our kids. We don't have a lot of beaches left," Bonnie Bethel, 66, said as she watched her grandchildren splash in the water on a Mississippi beach. "Can you imagine these poor birds in oil?"
Thousands of birds such as egrets and brown pelicans are nesting on barrier islands close to the rig's wreckage. If the oil gets to them, rescuers would need to reach their remote islands, wash them down and release them back into the wild.
Michael Ziccardi, director of the Oiled Wildlife Care Network affiliated with the University of California at Davis, said he is standing by to clean up Gulf Coast birds.
"Just about any petroleum can cause problems for birds because they lose their waterproofing, and that's what keeps them dry and warm," Ziccardi said. "It's a really difficult time, and we're close to the peak of migration."
The spill also threatens billions of fish eggs and larvae coating the Gulf's surface this time of year.
If the well cannot be closed, almost 100,000 barrels of oil, or 4.2 million gallons, could spill into the Gulf before crews can drill a relief well to alleviate the pressure. By comparison, the Exxon Valdez, the worst oil spill in U.S. history, leaked 11 million gallons into Alaska's Prince William Sound in 1989.
BP said Tuesday that it planned to begin drilling a relief well to redirect the leaking oil in a $100 million effort to take the pressure off the blown-out well.
The company said it would begin the drilling by Thursday even if crews can shut off oil leaking from the pipe 5,000 feet underground. Robot subs have tried to activate a shut-off device, but so far that has not worked.
Louisiana-based BP spokesman Neil Chapman said 49 vessels — oil skimmers, tugboats barges and special recovery boats that separate oil from water — are working to round up oil.
In Washington, meanwhile, the Obama administration launched a full investigation of the explosion, promising every available resource.
Mohr reported from Biloxi, Miss. Associated Press writers Alan Sayre and Kevin McGill in New Orleans, Melissa Nelson in Pensacola, Fla., and Ramit Plushnick-Masti in Houston contributed to this report.
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