ON THE GULF OF MEXICO — The captain of the boat hauling a box designed to capture the oil spewing into the Gulf said concerns that oil fumes could ignite were delaying operations.
Workers gathered to begin lowering the giant concrete-and-steel box over the blown-out oil well at the bottom of the sea Thursday in a risky and untested bid to capture most of the gushing crude and avert a wider environmental disaster.
But the lowering of the 100-ton containment vessel was delayed late Thursday because of dangerous fumes rising from the oily water in the windless night, the captain of the supply boat hauling the box told The Associated Press. A spark caused by the scrape of metal on metal could cause a fire, Capt. Demi Shaffer said.
"We haven't done this before. It's very complex and we can't guarantee it," BP spokesman David Nicholas warned.
Deckhands wore respirators while workers on surrounding vessels took air-quality readings. It was unclear when they would be able to proceed.
The technology has been used a few times in shallow waters, but never at such extreme depths — 5,000 feet down, where the water pressure is enough to crush a submarine.
The mission took on added urgency as oil started washing up on delicate barrier islands.
A top BP executive, meanwhile, said the leak would change the industry.
"There is no doubt that this event will change the offshore industry forever, around the globe," Robert Dudley, executive vice president for the Americas and Asia at BP, told business executives in Boston. BP will "consider the trade-offs" of new offshore exploration, he added.
Interior Secretary Ken Salazar, after meeting with BP officials Thursday, told reporters that "there were very major mistakes that were made by the companies involved."
"Its life is very much on the line here," Salazar said, referring to BP. "Are they doing everything that they can possibly do? I hope that they are."
More than 200,000 gallons of oil a day is pouring from the well, creating a massive sheen that's been floating on the Gulf for more than two weeks.
On Thursday, a pinkish oily substance was lapping at the shore of New Harbor Island, washing into thick marsh grass. It looked like soggy cornflakes, possibly because it was mixed with chemicals that it had been sprayed to break it up before it reached land.
Offshore, birds dove into the water amid lines of orange oil, but none appeared to be in distress. There were numerous dead jellyfish, some washing up on the shore. It's nesting time for sea gulls and pelicans and the danger is they may be taking contaminated food or oil on their feathers to their young.
Oil was also spotted Thursday on Freemason Island and North Island. All three islands are part of the Chandeleurs.
Video: Will cap work? Moreover, west of the mouth of the Mississippi River, an area that has received less attention, streaks of putrid, orange and rust-colored oil were visible Thursday.
Much of the oil west of the river was still miles out in the Gulf, but there appeared to be little or no effort to contain or clean it up. There were hundreds of dead jellyfish there.
If the concrete-and-steel box that crews plan to lower a mile into the ocean works, it could collect as much as 85 percent of the oil that's been leaking from the ocean floor after the Deepwater Horizon drilling rig exploded on April 20, killing 11 workers. The technique has not been tried before at that depth.
"Hopefully, it will work better than they expect," first mate Douglas Peake told The Associated Press aboard the ship that brought the cap to the site.
It won't solve the problem altogether. Crews are drilling a relief well to take the pressure off the blown-out well at the site, and that could take up to three months.
Winds to pick up over weekend
Federal maps show that the concentration of heavy oil remains much farther off the coast for now, close to the site of the leak. But the Mississippi Delta, Breton Sound, and Chandeleur Sound continue to be threatened by shoreline contacts over the next few days, NOAA said.
By late Saturday night into Sunday morning, winds in the Gulf region could pick up to 15 to 20 knots (17 to 23 mph). That may make efforts to battle the slick more difficult.
"We're coming out of a period of relatively calm weather, with light winds and flat seas. There's going to be a little bit of change here over the weekend," Tim Destri, a meteorologist with the National Weather Service office in New Orleans, said.
Putting a lid Oil has been leaking in three places since the explosion. One small leak was capped Wednesday. The containment box will be lowered over a much bigger leak in a pipe that's responsible for about 85 percent of the oil that's coming out.
The rest of the oil is coming from the blowout preventer at the well, a heavy piece of machinery designed to prevent blowouts that failed in the April 20 explosion. Crews have been trying to shut it off using robotic devices, but that hasn't worked.
If the box being lowered Thursday can contain the bigger leak, a second box being built may be used to stop the smaller leak at the blowout preventer.
The containment box has a dome-like structure at the top that's designed to act like a funnel and siphon the oil up through 5,000 feet of pipe and onto a tanker at the surface.
First, crews need to properly position the four-story structure with the help of a remote-controlled robotic submarine. A steel pipe will then be attached to a tanker at the surface and connected to the top of the dome to move the oil.
That process presents several challenges because of the frigid water temperature — about 42 degrees Fahrenheit — and exceptionally high pressure at those depths. Those conditions could cause the pipe to clog with what are known in the drilling industry as "ice plugs." To combat that problem, crews plan to continuously pump warm water and methanol down the pipe to dissolve the clogging.
They are also worried about the volatile cocktail of oil, gas and water when it arrives on the ship above. Engineers believe the liquids can be safely separated without an explosion.
"But of course we haven't done this before, it's very complex and we can't guarantee it," BP spokesman David Nicholas said Thursday.
'Top kill' weighed
BP engineers are also examining whether the leaking well could be shut off by plugging it from the top instead of drilling a relief well to cap it from the bottom.
The technique — called a top kill — would use a tube to shoot specialized mud and concrete directly into the top of the leaking blowout preventer, BP spokesman Bill Salvin said. The process would take two to three weeks, compared with the two to three months needed to drill a relief well.
No decision has been made on whether to use the technique.
The cause of the rig explosion is still not known, but investigators from multiple federal agencies are looking into the matter. A six-member investigative panel will begin its work next week.
Globules of oil are already falling to the bottom of the sea, where they threaten virtually every link in the ocean food chain, from plankton to fish that are on dinner tables everywhere.
Hail-size gobs of oil with the consistency of tar or asphalt will roll around the bottom, while other bits will get trapped hundreds of feet below the surface and move with the current, said Robert Carney, a Louisiana State University oceanographer.
Slideshow: Images from the disaster "The threat to the deep-sea habitat is already a done deal — it is happening now," said Paul Montagna, a marine scientist at the Harte Research Institute for Gulf of Mexico Studies at Texas A&M University-Corpus Christi.
Scientists say bacteria, plankton and other tiny, bottom-feeding creatures will consume oil, and will then be eaten by small fish, crabs and shrimp. They, in turn, will be eaten by bigger fish, such as red snapper, and marine mammals like dolphins.
The petroleum substances that concentrate in the sea creatures could kill them or render them unsafe for eating, scientists say.
"If the oil settles on the bottom, it will kill the smaller organisms like the copepods and small worms," Montagna said. "When we lose the forage, then you have an impact on the larger fish."
Making matters worse for the deep sea is the leaking well's location: It is near the continental shelf of the Gulf where a string of coral reefs flourishes. Coral is a living creature that excretes a hard calcium carbonate exoskeleton, and oil globs can kill it.
In other developments:
- The Interior Department on Thursday postponed a comment period and canceled public meetings planned this month on a proposal to sell oil and gas leases off the Virginia coastline. The move was cheered by environmentalists.
- Florida's two top incoming legislative leaders say there will be no discussion of offshore oil drilling in the 2011 session and perhaps for years to come. Republicans Mike Haridopolos and Dean Cannon said a Thursday fact-finding flyover of the spill area persuaded them to take the issue off the table until they can be assured Florida won't face a similar threat.
- The rig owner, Transocean Ltd., said in a filing with regulators Wednesday that it has received a request from the Justice Department to preserve information about the blast. The cause of the rig explosion is still not known, but investigators from multiple federal agencies are looking into the matter.
- Obama administration officials were reviewing the practice of granting exemptions from environmental impact studies for oil exploration projects deemed to involve little risk. The Minerals Management Service had exempted BP from a detailed environmental review of the project. U.S. government agencies grant the so-called categorical exclusions for types of projects typically found to not have substantial environmental impacts, or in cases where the agency has past experience with a similar projects.
The Associated Press and Reuters contributed to this report.