Scientists question government team's report of shrinking gulf oil spill

By David A. Fahrenthold
Washington Post Staff Writer
Thursday, August 5, 2010; A05

The "greatest environmental disaster" in U.S. history -- which has appeared at times to leave a high-control White House powerless -- seemed to have lost its power to scare.

A few hours after BP's well was declared virtually dead, the Obama administration announced Wednesday that only about 26 percent of the oil spilled in the Gulf of Mexico was unaccounted for.

"A significant amount of this," said Jane Lubchenco, head of the National Oceanic and Atmospheric Administration, "is a direct result of the very robust federal response efforts."

But, in interviews, scientists who worked on the report said the figures were based in large part on assumptions and estimates with a significant margin of error.

Some outside scientists went further: In a situation in which many facts remain murky, they said, the government seemed to have used interpretations that made the gulf -- and the federal efforts to save it -- look as good as possible.

"There's a lot of . . . smoke and mirrors in this report," said Ian MacDonald, a professor of biological oceanography at Florida State University. "It seems very reassuring, but the data aren't there to actually bear out the assurances that were made."

The government's accounting of the spilled oil, called an "oil budget," was announced Wednesday at the White House. It appeared to answer the most troubling question: Of the 4.9 million barrels (205.8 million gallons) that poured out of the well, only 827,000 barrels were siphoned to vessels on the surface. Where did the rest of it go? Where there had been mystery, now there was a pie chart.

It showed that 5 percent of the total oil had been burned and that 3 percent had been skimmed off the surface. An additional 25 percent had evaporated or dissolved. About another quarter had been "dispersed" -- broken into tiny droplets by chemicals or by the force of being blasted out of the well.

The dispersed oil, Lubchenco said, "is in the process of being very rapidly degraded naturally, and so Mother Nature is assisting here considerably." She said, however, that "diluted and out of sight doesn't necessarily mean benign."

Those facts did not seem to support a statement that White House climate and energy czar Carol M. Browner made Wednesday on NBC's "Today" show. An initial assessment showed that "more than three-quarters of the oil is gone. The vast majority of the oil is gone," she said. At best, the report shows that three-quarters of the oil could be on its way out: It does not say that it has vanished.

The remaining 26 percent or so of the oil was still unaccounted for, although Lubchenco said that did not necessarily mean it is still causing ecological harm.

Asked how much of the success of the cleanup should be attributable to BP, White House press secretary Robert Gibbs said the cleanup "would have been different" if federal officials had not pushed the company to work faster.

But scientists who worked on the report said many of the numbers on the White House's pie chart had significant margins of error. The estimate of how much oil evaporated was calculated using a formula designed for spills near the surface, not 5,000 feet underwater. The calculation of how much oil would be "dispersed" as it flowed from the well was a new one, extrapolated from data about the way oil is broken by waves.

And, as for Lubchenco's assertion that the oil that has been dispersed is "rapidly degrading," Bill Lehr, a NOAA scientist and an author of the report, said the analysis did not include an actual calculation or measurement of what's happening in the gulf. "We haven't attempted yet to calculate that rate," he said, and instead relied on assumptions based on past spills in the gulf.

Given such uncertainties, one researcher who collaborated on the report said he would not have given out exact figures. "We don't have the foggiest idea [about how to measure the oil] with that precision," said Ed Overton, a professor at Louisiana State University.

Some outside researchers said that, given the uncertainty about what's happening in the gulf, the administration's assertion that 74 percent of the oil had been accounted for seemed too optimistic. They saw it another way: About half of the oil is probably gone for certain: skimmed, burned, siphoned or evaporated.

They said the other half, including the 24 percent that has been "dispersed" but is underwater, is the real total of what's missing. Despite the largest oil-spill response in history, these 2.5 million barrels of oil will be cleaned up by the Gulf of Mexico, if at all.

The situation is "being portrayed as 'the oil is out of the environment; it's gone,' " said Michael J. Blum, a professor at Tulane University in New Orleans. But, he said, all that's certain is that "the form of the oil has shifted. Dispersed oil is still oil. It's just in a different form."

Even if the government is right, and only 26 percent of the oil is left? That would still be 1.3 million barrels, five times the oil spilled from the Exxon Valdez in 1989.

Federal officials said they were unsure what kind of damage the gulf oil had done, or will do, to fish and other species.

"In terms of the environmental impacts, the story is really not written yet," said Steve Murawski, a NOAA senior scientist.

He said Wednesday's analysis indicates "where the oil is. But you know, what did the oil do when it was there?"

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