(AP) -- With a startling report that some researchers call more spin than science, the government said Wednesday that the mess made by the BP oil spill in the Gulf of Mexico is mostly gone already.
On the same day they trumpeted success in plugging up the leaking well with drilling mud, federal officials announced that nearly 70 percent of the oil spilled dissolved naturally, or was burned, skimmed, dispersed or captured, with almost nothing left to see - at least on top of the water.
The National Oceanic and Atmospheric Administration and the U.S. Geological Survey announced in the five-page report that only 52.7 million gallons of oil are left in the Gulf. That is about 31 percent of the 172 million gallons that spewed into the water from the broken BP well.
Just because the oil is out of sight doesn't mean the Gulf is out of harm's way, federal scientists emphasized. And what's left in the water is still almost five times the amount spilled by the Exxon Valdez in 1989.
Nevertheless, Wednesday was a day of cautious celebration by a White House that has had little to cheer about from the oil spill.
"I think it is fairly safe to say ... that many of the doomsday scenarios that we talked about and repeated a lot have not and will not come to fruition," White House spokesman Robert Gibbs said at a briefing with NOAA's top scientist.
Much of the reasoning behind the disappearing oil has to do with the natural resilience of the Gulf, which is teeming with microbes that eat oil. On top of that is the natural tendency of oil in seawater to evaporate and dissolve to half its volume in about a week - something even critics acknowledge.
The federal calculations are based on direct measurements for only 18 million gallons of the oil spilled - the stuff burned and skimmed. The other numbers are "educated scientific guesses," said NOAA emergency response senior scientist Bill Lehr, an author of the report. That is because it is impossible to measure oil that is dispersed, he said.
That's what worries some outside scientists.
"This is a shaky report. The more I read it, the less satisfied I am with the thoroughness of the presentation," Florida State University oceanography professor Ian MacDonald told The Associated Press. "There are sweeping assumptions here."
NOAA chief Jane Lubchenco acknowledged the numbers could be off by as much as 10 percent. One of the scientists who peer-reviewed the work and is mentioned in the report, Ed Overton of Louisiana State University, said he wasn't comfortable with NOAA's putting precise percentages of how much oil is left in the Gulf. What would be more accurate would be a much broader range of, say, 40 million to 60 million gallons, he said.
Still, Overton thought the report was mostly good work. He said the Gulf itself deserves much of the credit, describing the body of water in two words: "incredibly resilient."
The White House claimed only 26 percent of the oil remained in the Gulf, but that was based on a 206-million-gallon figure for the spill that included oil that spewed from the pipe but was captured by BP and never got into the Gulf. Using the 172 million gallons that got into the Gulf, 31 percent of the oil remains.
So what happened to the oil?
Thank nature more than the federal government. Burning, skimming and chemically dispersing the spill got rid of 35 million gallons of oil, while natural processes of dispersion, evaporation and dissolving got rid of 84 million gallons, according to the report.
"Mother Nature is assisting here considerably," Lubchenco said. She cautioned that the oil that's left can harm wildlife for years or even decades to come, saying: "Diluted and out of sight doesn't necessarily mean benign."
Still, outside scientists said this was a just too-simple explanation for a complex oil that has confounded federal scientists at every turn.
"This is just way too neat," said Larry McKinney, director of the Texas A&M University research center on the Gulf of Mexico. "How can you even do this at this point? There's a lot of oil still floating out there."
McKinney said he most worried that this overly optimistic assessment would cost the government - and save BP - billions of dollars in the damage assessment process. McKinney, who has served as a state of Texas trustee in the process, said, "BP attorneys are placing this in plastic and putting this in frames."
White House energy adviser Carol Browner said, "We are going to continue to ensure BP is held accountable for damage they did."
MacDonald said the core of the idea here - that oil in water essentially has about a half-life of a week - makes sense, but what happened from there doesn't.
"There's some science here, but mostly, it's spin," he said. "And it breaks my heart to see them do it."
MacDonald pointed out that NOAA spent weeks sticking with its claim the BP well was spewing only 210,000 gallons a day. Now, after several revisions, the federal government said it really was 2.2 million gallons a day. So he has a hard time believing NOAA this time, he said.
When Lubchenco was asked about that at the Washington news conference, Gibbs stepped in to defend the agency's credibility. Gibbs and Lubchenco said NOAA provided the best information at the time and updated estimates when it had better data and tools.
"Is there uncertainty to this? Of course there is," said NOAA's Lehr. But he said there was no political interference.
That question got raised because of the coordination of the media rollout of the report. Browner was on all four morning TV shows saying "the vast majority of oil is gone," and the report was leaked to The New York Times. The version of the report sent to Congress was created by a former campaign spokesman for President Barack Obama who is now the Commerce Department's public affairs chief.
The scientific report, which has four pages of text followed by one page of credits, is small compared to other similar reports. Initially, NOAA said there was a fuller, 200-page report, but then retracted that. There is a second report that is 10 pages. The initial report cites no scientific references - those, Lehr said, are in his head.
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