Crews were putting the finishing touches on a 100-ton containment dome that BP hopes will bottle up the disastrous spill threatening species and livelihoods along the Gulf Coast. BP says it has already capped one of three wellhead leaks, which may make it easier to plug the gusher.
One of three leaks has been capped at a deepwater well in the Gulf of Mexico, but that development is not expected to reduce the estimated 5,000 barrels of crude oil a day flowing from the site.
The best short-term solution to bottling up a disastrous oil spill threatening sealife and livelihoods along the Gulf Coast should be headed out to sea Wednesday, in the form of a specially built giant concrete-and-steel box designed to siphon the oil away.
Oil company BP used remotely operated vehicles a mile below the surface of the water to cut off a section of pipe that used to lead from the well up to an oil rig that exploded last month, killing 11 workers. After cutting off the section of pipe, BP capped it with a valve.
The National Oceanic and Atmospheric Administration says that while this stopped one of three leaks, oil is still flowing into the gulf at a rate of 210,000 gallons a day.
BP is trying to reduce the number of leak points as it deploys the 100-ton box nearly a mile deep to the accident site. It's designed to collect the oil at the seafloor and funnel it to a tanker on the surface.
About midday Wednesday, a barge will haul the box to the spill site. BP spokesman John Curry said it would be deployed on the seabed by Thursday.
Meanwhile, the effort to protect Louisiana coastal wetlands was expected to pick up.
In Plaquemines Parish, officials loaded absorbent boom shortly after dawn to take out to the mouth of the Mississippi River. The barge will be used as a distribution point for local fishermen to lay the boom around sensitive marshes.
At a nearby marina, local shrimpers planned to use their boats to put down boom as part of a program BP is running.
Also Wednesday, federal fisheries officials are investigating whether aggressive shrimpers are causing the deaths of endangered sea turtles that have been washing up on Gulf Coast beaches with no signs of oil, an official told the Associated Press.
Investigators will look at whether some shrimp boats taking part in an emergency shrimping season ahead of the Gulf oil spill removed devices from their nets that are intended to allow turtles to escape, said Sheryan Epperly, sea turtle team leader for the National Marine Fisheries Service.
Wildlife officials say at least 35 endangered sea turtles have washed up on Gulf coast beaches, but it's not clear what's killing them. Necropsies have shown no signs of oil.
In all, about 7,900 people are working to protect the shoreline and wildlife, and some 170 boats are also helping with the cleanup.
A rainbow sheen of oil has reached land in parts of Louisiana, but forecasts showed that the oil wasn't expected to come ashore for at least a couple more days.
"It's a gift of a little bit of time. I'm not resting," U.S. Coast Guard Rear Adm. Mary Landry said.
In their worst-case scenario, BP executives told members of a congressional committee that up to 2.5 million gallons a day could spill if the leaks worsened, though it would be more like 1.7 million gallons. In an exploration plan filed with the government in February 2009, BP said it could handle a "worst-case scenario" it described as a leak of 6.8 million gallons per day from an uncontrolled blowout.
Containment boxes have never been tried at this depth -- about 5,000 feet -- because of the extreme water pressure. If all goes well, the contraption could be fired up early next week to start funneling the oil into a tanker.
"We don't know for sure" whether the equipment will work, Salvin said. "What we do know is that we have done extensive engineering and modeling, and we believe this gives us the best chance to contain the oil, and that's very important to us."
The seas calmed Tuesday, allowing more conventional methods to contain the spill to get back on track as businesses and residents kept an eye on the ocean currents, wondering when the sheen washing ashore in places might turn into a heavier coating of oil. Crews put out more containment equipment and repaired some booms damaged in rough weather over the weekend. They also hoped to again try to burn some of the oil on the water's surface, possibly Wednesday.
Chemical dispersants piped 5,000 feet to the main leak have significantly reduced the amount of oil coming to the surface, BP said.
From the air Tuesday, the site of the Deepwater Horizon explosion looked similar to a week ago except for the appearance of a massive rig brought in to drill a relief well to shut off the spewing oil. That will take months.
People along the Gulf Coast have spent weeks living with uncertainty, wondering where and when the huge slick might come ashore, ruining their beaches -- and their livelihoods.
The anxiety is so acute that some are seeing and smelling oil where there is none. And even though the dead turtles and jellyfish washing ashore along the Gulf of Mexico are clean, and scientists have yet to determine what killed them, many are just sure the flow of crude unleashed by the explosion is the culprit.
The Deepwater Horizon rig was owned by Transocean Ltd. Some of the 115 surviving workers who were aboard when it exploded are suing that company and BP PLC. In lawsuits filed Tuesday, three workers say they were kept floating at sea for more than 10 hours while the rig burned uncontrollably. They are seeking damages.
Guy Cantwell, a spokesman for Transocean Ltd., defended the company's response, saying 115 workers did get off alive. Two wrongful death suits also have been filed.
While officials work on cleanup, the long wait is taking its toll on nerves and incomes.
In Gulf Shores, Ala., the real estate firm Brett/Robinson Vacations sent a note to those renting vacation properties that they would not be penalized for any spill-related cancellations but urged them not to jump the gun.
"There are many questions and many 'what ifs' regarding this event," the message read. "Because changes come about hourly and 30 days is a long way away, we are asking you to wait before canceling your vacation, especially those of you who are scheduled to arrive more than 30 days from today."
There are legitimate concerns, experts say. A brown pelican found in the slick is recovering at a bird rescue center in Louisiana. National Wildlife Federation president and CEO Larry Schweiger says there's no way to know how many birds have been oiled because the slick is so big and so far offshore.
Perdido Key, a barrier island between Pensacola and the Alabama state line with sugar-white sand studded with condominiums, likely would be the first place in Florida affected by the oil spill. Perdido -- Spanish for "Lost" -- got a sniff Tuesday morning of what may be in store.
"You could smell the smell of it, real heavy petroleum base," said Steve Owensby, 54, a maintenance man at the Flora-Bama Lounge abutting the state line on the Florida side.
The air cleared later, but Owensby's 28-year-old daughter, Stephanie, who tends bar at the lounge, said some visitors have complained of feeling ill from the fumes.
"It's very sad because I grew up out here," she said. "I remember growing up seeing the white beaches my whole life. Every day I've been going to the beach ... a lot of people are out watching and crying."
Contributing: NPR's Jeff Brady and Debbie Elliott; The Associated Press Copyright 2010 National Public Radio. To see more, visit http://www.npr.org/.