By Matthew Bigg
VENICE, Louisiana (Reuters) - The United States suspended fishing across a wide swath of its Gulf of Mexico waters on Sunday as a spreading oil slick gushing from a ruptured undersea well threatened an environmental catastrophe.
President Barack Obama visited Louisiana for a first-hand look at what is fast turning into the biggest oil spill in U.S. history. His administration heaped pressure on London-based BP Plc, the well owner, to halt the out-of- control flow.
Since the explosion and sinking last month of the Deepwater Horizon rig, a disaster scenario has emerged with hundreds of thousands of gallons of crude oil gushing into the Gulf and moving inexorably north to the coast, driven by winds.
The swelling black tide threatens wildlife, beaches and one of the world's most fertile fishing grounds in an area stretching across four states, from Louisiana to Florida.
"This is a terrible day. People can still fish west (of the Mississippi river) but if the oil keeps flowing the whole coast could be closed down," Roger Halphen, whose whole family is involved in commercial fishing, told Reuters in Venice, La.
The National Oceanic and Atmospheric Administration announced it was closing commercial and recreational fishing for at least 10 days in affected waters between Louisiana at the mouth of the Mississippi River to Florida's Pensacola Bay.
This area accounts for the bulk of U.S. production of oysters and shrimps and the Gulf supports a $1.8 billion (653 billion million pounds) seafood industry that is second only to Alaska.
"There are finfish, crabs, oysters and shrimp in the Gulf of Mexico near the area of the oil spill," Roy Crabtree, NOAA Fisheries Southeast Regional Administrator, said in a statement. "The Gulf is such an important biologic and economic area in terms of seafood production and recreational fishing."
NOAA Administrator Jane Lubchenco said there should be no health risk in seafood currently in the marketplace.
Mindful of public criticism of President George W. Bush's handling of the 2005 Hurricane Katrina disaster, Obama is keen to show his government is dealing decisively with an accident that could rival the 1989 Exxon Valdez catastrophe in Alaska, the worst previous U.S. oil spill to date.
"BOOT ON THE NECK" OF BP
Desperate efforts above and below the ocean surface -- using boats, planes and even an underwater robotic vehicle -- to check the oil flow and disperse and contain the spreading slick were being hampered by high winds and rough seas.
After initially stressing cooperation with BP, Obama administration officials have made clear their frustration with the London-based energy company, urging it to do more to seal the blown-out wellhead and shut off the oil.
"Our job basically is to keep the boot on the neck of British Petroleum to carry out the responsibilities they have both under the law and contractually to move forward and stop this spill," U.S. Interior Secretary Ken Salazar told CNN.
But officials from BP, which faces billions of dollars in cleanup costs and lawsuits, said shutting off the well almost one mile (1.6 km) down on the ocean floor is an extraordinarily complicated operation that could take weeks and even months.
It was like performing "open heart surgery at 5,000 feet in the dark with robot-controlled submarines," BP America Chairman and President Lamar McKay told ABC News.
Shares of BP and other companies involved in operating the lost rig plummeted last week as fears mounted of growing financial costs and legal liability -- estimated to run into billions of dollars -- from the accident.
Alarm over the looming ecological disaster has intensified as it became clear that nobody knows how much oil is gushing from the ruptured wellhead.
Salazar said that in a worst case scenario the blown-out well could leak 100,000 barrels (4.2 million gallons or 15.9 million litres) or more of oil per day -- a huge increase over existing official estimates of only 5,000 barrels per day.
RACE AGAINST TIME
"The actual amount is impossible to estimate," Doug Suttles, chief operating officer of BP's exploration and production unit, said on CBS News.
Salazar said there was "no doubt" a mechanism that should have prevented oil from blowing out of the well was defective. He said it could be 90 days before a relief well was completed that could shut off the flow.
BP was working to fit a containment mechanism over the leaking wellhead. The three containment chambers are giant box-shaped inverted funnels designed to cover the well and two other leaks and channel the oil to a drillship. McKay said a containment dome was in the final engineering phase and he expected it to be deployed in six to eight days.
The spill has forced Obama to suspend politically sensitive plans to expand offshore oil drilling, unveiled last month partly to woo Republican support for climate legislation, one of the U.S. leader's priorities.
NOAA forecasts showed the spill heading towards the Louisiana, Mississippi and Alabama coasts.
The projection indicated the possibility of some oil beaching on the Chandeleur Islands on the fringe of the Mississippi Delta. The outlying islands are the site of the Breton National Wildlife refuge, home to major bird colonies.
The Gulf Coast is home to hundreds of species of wildlife, including manatees, sea turtles, dolphins, porpoises, whales, otters, pelicans and other birds.
The disaster came as BP was still working to repair its reputation in the United States in the wake of a 2005 blast at a Texas refinery that killed 15 workers, and a major oil spill in Alaska in 2006 that was blamed on corroded pipelines.
Although the Coast Guard has laid hundreds of thousands of feet of protective booms to try to halt the encroaching oil, high winds and rough seas were badly hampering the deployment of the plastic barriers and efforts by boats and planes to spray chemical dispersant on the oil.
"The weather is very, very hard right now to contain the spill offshore. We are able to use dispersants, but we are not able to use our booms and skimmers," said BP's Suttles.
The Minerals Management Service said two U.S. offshore Gulf of Mexico production platforms had been shut down and a third was evacuated as a safety precaution. Further shutdowns were possible, it added, but the output affected so far was very small.
(Additional reporting by Caren Bohan, Paul Simao in Washington, Chris Baltimore, Anna Driver, Kristen Hays in Houston, Tom Bergin in London, Phil Stewart in Washington, Joshua Schnyer and Rebekah Kebede in New York; Writing by Pascal Fletcher; Editing by Paul Simao and Chris Wilson)
