VENICE, La. – VENICE, La. (AP) — The surface area of a catastrophic Gulf of Mexico oil spill quickly tripled in size amid growing fears among experts that the slick could become vastly more devastating than it seemed just two days ago.
Frustrated fishermen eager to help contain the spill from a ruptured underwater well had to keep their boats idle Saturday as another day of rough seas kept crews away from the slick, and President Barack Obama planned a Sunday trip to the Gulf Coast.
Documents also emerged showing British Petroleum downplayed the possibility of a catastrophic accident at the offshore rig that exploded.
How far the spill will reach is unknown, but the sheen already has reached into precious shoreline habitat and remains unstopped, raising fears that the ruptured well could be pouring more oil into the Gulf than estimated.
The Coast Guard estimates now that at least 1.6 million gallons of oil have spilled since the April 20 explosion that killed 11 workers. The environmental mess could eclipse the Exxon Valdez disaster, when an oil tanker spilled 11 million gallons off Alaska's shores in 1989.
The slick nearly tripled in just a day or so, growing from a spill the size of Rhode Island to something closer to the size of Puerto Rico, according to images collected from mostly European satellites and analyzed by the University of Miami.
On Thursday, the size of the slick was about 1,150 square miles, but by Friday's end it was in the range of 3,850 square miles, said Hans Graber, executive director of the university's Center for Southeastern Tropical Advanced Remote Sensing. That suggests the oil has started spilling from the well more quickly, Graber said.
"The spill and the spreading is getting so much faster and expanding much quicker than they estimated," Graber told The Associated Press on Saturday.
Louisiana State University professor Ed Overton, who heads a federal chemical hazard assessment team for oil spills, cautioned that the satellite imagery could be deceiving.
He said satellites can't measure the thickness of the sheen and makes it difficult to judge how much oil is on the water.
Another issue is that the oil slicks are not one giant uniform spill the size of an island. Instead, they are "little globs of oil in an area of big water," Overton said.
Ian R. MacDonald, an oceanography professor at Florida State University, said his examination of Coast Guard charts and satellite images indicated that 8 million to 9 million gallons had already spilled by April 28.
"I hope I'm wrong. I hope there's less oil out there than that. But that's what I get when I apply the numbers," he said.
Alabama's governor said his state was preparing for a worst-case scenario of 150,000 barrels, or more than 6 million gallons per day. At that rate the spill would amount to a Valdez-sized spill every two days, and the situation could last for months.
"I hope they can cap this and we talk about 'remember back when,'" Gov. Bob Riley said late Friday, "but we are taking that worst-case and building barriers against it."
Coast Guard Rear Adm. Mary Landry brushed off such fears, saying "I would caution you not to get fixated on an estimate of how much is out there."
"This is highly imprecise, highly imprecise," agreed Doug Suttles, BP's chief operating officer for exploration and production. "We continue to respond to a much more significant case so that we're prepared for that in the eventuality that the rate is higher."
BP suggested in a 2009 exploration plan and environmental impact analysis for the well that an accident leading to a giant crude oil spill — and serious damage to beaches, fish and mammals — was unlikely, or virtually impossible.
The plan for the Deepwater Horizon well, filed with the federal Minerals Management Service, said repeatedly that it was "unlikely that an accidental surface or subsurface oil spill would occur from the proposed activities."
The company conceded a spill would impact beaches, wildlife refuges and wilderness areas, but argued that "due to the distance to shore (48 miles) and the response capabilities that would be implemented, no significant adverse impacts are expected."
The spill — a slick more than 130 miles long and 70 miles wide — threatens hundreds of species of wildlife, including birds, dolphins, and the fish, shrimp, oysters and crabs that make the Gulf Coast one of the nation's most abundant sources of seafood.
Although the cause of the explosion was under investigation, many of the more than two dozen lawsuits filed in the wake of the explosion claim it was caused when workers for oil services contractor Halliburton Inc. improperly capped the well — a process known as cementing. Halliburton denied it.
The Coast Guard said Saturday it had shut down two offshore platforms and evacuated one of them near the spill as a safety precaution.
A sheen of oil from the edges of the slick was washing up at Venice, La., and other extreme southeastern portions of Louisiana. Animal rescue operations ramped up as crews found the first oiled bird offshore.
Several miles out, the normally blue-green gulf waters were dotted with sticky, pea- to quarter-sized brown beads the consistency of tar. High seas were forecast through Sunday and could push oil deep into the inlets, ponds, creeks and lakes that line the boot of southeastern Louisiana. With the wind blowing from the south, the mess could reach the Mississippi, Alabama and Florida coasts by Monday.
Amid increased fingerpointing, the government desperately cast about for new ideas for dealing with the growing environmental crisis. Obama halted any new offshore drilling projects unless rigs have new safeguards to prevent another disaster.
Officials have said stemming the flow of oil is their top priority, but the seas have been too rough and the winds too strong to burn off the oil, suck it up effectively with skimmer vessels, or hold it in check with the miles of orange and yellow inflatable booms strung along the coast.
The floating barriers broke loose in the choppy water, and waves sent oily water lapping over them.
BP also sought ideas from some of its rivals and was using at least one of them Friday — applying chemicals underwater to break up the oil before it reaches the surface. That had never before been attempted at such depths.
BP and federal authorities said the dispersant was released overnight at the site of the leak, nearly 5,000 feet underwater, and they were evaluating the effort Saturday.
As dawn broke Saturday over Venice, many of the oil-cleaning boats began another day tied to the docks. A few fishermen loaded gear and prepared to head to the marshes to try their luck one last time before the water becomes too oily to fish.
"I feel sorry for the local people down here," said sport fisherman Ted Boddie, 67, of Shreveport, as he prepared to head out with his two sons and a few friends. "Sad deal. If all that stuff reaches shore, there's going to be a lot of people out of work."
A few boats made their way out in St. Bernard parish in eastern Louisiana, loaded with boom that would be wrapped around the coastal marshlands there. Back in Venice, local officials were meeting in hopes of activating a plan to allow shrimpers and other locals to lay booms, but the weather is a factor in those plans, too.
"It's just the weather holding them up right now," said Coast Guard spokesman Cory Mendenhall. "They're looking at six- to nine-foot seas. Once they can, they'll resume."
Associated Press writers Seth Borenstein, Melissa Nelson, Michael Kunzelman, Chris Kahn, Allen G. Breed, Vicki Smith, Janet McConnaughey, Alan Sayre, Tamara Lush and Brian Skoloff contributed to this report.