Fears are mounting that the US Gulf coast could face an environmental catastrophe of a whole new dimension as the best short-term fix for a massive oil spill failed to work.
British energy giant BP, which owns the lion's share of the leaking oil and has accepted responsibility for the clean-up, has tried to nix the idea that a massive containment box called a dome is a "silver bullet" to solve the crisis.
The BP-leased Deepwater Horizon rig sank some 80 km (50 miles) southeast of Venice, Louisiana April 22, two days after an explosion that killed 11 workers.
The riser pipe that had connected the rig to the wellhead now lies fractured on the seabed a mile below, spewing out oil at a rate at some 5,000 barrels, or 210,000 gallons, a day.
Sheen from the leading edge of the slick has surrounded island nature reserves off the coast of Louisiana and tar balls have reached as far as the Alabama coast, threatening tourist beaches further east.
|Coastal residents Thursday anxiously awaited the outcome of efforts to contain the Gulf of Mexico oil spill with a giant domelike structure|
Sea life is being affected in a low-lying region that contains vital spawning grounds for fish, shrimp and crabs and is a major migratory stop for many species of rare birds.
The 2.4-billion-dollar Louisiana fishing industry has been slapped with a temporary ban in certain areas due to health concerns about polluted fish.
But officials with the Louisiana departments of Environmental Quality (DEQ), Health and Hospitals (DHH), and Wildlife and Fisheries (LDWF) said they were working with federal agencies to protect public health and guarantee Gulf Coast-harvested seafood products are safe.
"Our primary concerns (are) the health and safety of residents near the oil spill, and the safety of anyone who enjoys Louisiana seafood," said DHH Secretary Alan Levine. "We believe this enhanced monitoring will give us the proper baseline of information we need to keep the public safe."
BP, facing a barrage of lawsuits and clean-up costs soaring above 10 million dollars a day, had pinned its hopes on a 98-ton concrete and steel containment box that it successfully lowered 5,000 feet (1,500 meters) down over the main leak.
But the contraption lay idle on the seabed as engineers furiously tried to figure out how to stop it clogging with ice crystals.
"I wouldn't say it's failed yet," BP chief operating officer Doug Suttles said on Saturday. "What we attempted to do last night didn't work because these (ice crystal) hydrates plugged up the top of the dome."
Still, if efforts fail to make the giant funnel system effective, there is no solid plan B to prevent potentially tens of millions of gallons of crude from causing one of the worst ever environmental catastrophes.
Untold damage is already being done by the 3.5 million gallons estimated to be in the sea so far, but the extent of that harm will rise exponentially if the only solution is a relief well that takes months to drill.
Admiral Thad Allen, head of the US Coast Guard, suggested they were considering what he called a "junk shot" to plug the main leak.
"They're actually going to take a bunch of debris, shredded up tires, golf balls and things like that and under very high pressure shoot it into the preventer itself and see if they can clog it up and stop the leak," Allen, who is leading the US government's response, told CBS television.
This could be risky as experts have warned that excessive tinkering with the blowout preventer -- a huge 450-ton valve system that should have shut off the oil -- could see crude shoot out unchecked at 12 times the current rate.
There are also fears the slick, which covers an area of about 2,000 square miles (5,200 square kilometers), could be carried around the Florida peninsula if it spreads far enough south to be picked up by a special Gulf current.
"If this gusher continues for several months, it's going to cover up the Gulf coast and it's going to get down into the loop current and that's going to take it down the Florida Keys and up the east coast of Florida," warned Florida Senator Bill Nelson.
"You are talking about massive economic loss to our tourism, our beaches, to our fisheries, very possibly disruption of our military testing and training, which is in the Gulf of Mexico," he told CNN.
On the dome front, clearing out the slushy crystals is easy -- the chamber just has to be raised to warmer levels, Suttles told reporters. Keeping the crystals out so that a pipe can be lowered into the dome to suck the oil to a waiting barge is another matter.
BP began drilling a first relief well one week ago, but that will take up to three months to drill -- by which time some 20 million gallons of crude could have streamed into the sea and ruined the fragile ecology of the Gulf.