Academic scientists are challenging the Obama administration’s assertion that most of BP’s oil in the Gulf of Mexico is either gone or rapidly disappearing — with one group Thursday announcing the discovery of a 22-mile “plume” of oil that shows little sign of vanishing.
That plume was measured in late June and was described Thursday by scientists from Woods Hole Oceanographic Institution in Massachusetts. The biggest news was not the plume itself: For weeks, government and university scientists have said that oil from BP’s damaged well is still underwater.
The news was what is happening — or not happening — to it.
The scientists said that when they studied it, they saw little evidence that the oil was being rapidly consumed by the gulf’s petroleum-eating microbes. The plume was in a deep, cold region where microbes tend to work slowly.
“Our data would predict that the plume would still be there now,” said Benjamin Van Mooy, a Woods Hole researcher.
Their research came after a week in which other scientists had taken issue with the government’s portrait of where all the oil went. On Thursday afternoon, Jane Lubchenco, the Oceanic and Atmospheric Administration’s administrator, defended the government’s work, saying it was done by the “best scientific minds” and reviewed by outsiders.
“We remain confident in our assessment,” she said.
The Woods Hole research, published in the peer-reviewed journal Science, provided one of the most detailed pictures yet of what this oil is doing under the surface.
The scientists said that, using a robot submarine that zigzagged across the deep gulf, they found a plume of oil droplets that was as tall as a 65-story building and more than a mile wide. The plume, whose droplets were so small that the water appeared clear, extended off to the southwest of the well, 3,600 feet deep.
They said they were puzzled about how, exactly, the oil got there: Despite the conventional wisdom that oil floats, this crude seemed to have stopped rising less than halfway through its journey from the well to the surface. They thought that perhaps icelike hydrate crystals played a role, or that the dispersant chemicals squirted into the oil as it escaped.
What was certain, at least at that time, was that it wasn’t disappearing. Scientists tested the levels of dissolved oxygen to find out whether they were unusually low, which would indicate that microbes were at work. But they weren’t.
The researchers declined to speculate about how their findings should alter the government’s official “budget” of what became of BP’s oil. Their inquiry, they said, was limited to finding the plume — and, for now, they couldn’t say what percent of the spilled oil it contained.
In the future, “we may be able to say whether [this plume] is a penny in a very large checkbook,” said Christopher M. Reddy of Woods Hole. “Or whether it’s bigger.”
The federal government’s initial estimate of the oil’s fate, announced Aug. 4, provided a major shift in the narrative of the spill. Suddenly, a historic disaster looked manageable — its mysteries distilled into a pie chart.
“More than three-quarters of the oil is gone. The vast majority of the oil is gone,” White House climate and energy czar Carol M. Browner said on NBC’s “Today” show that day.
The report did not go that far, but it did portray a spill that was rapidly losing its punch. The report said that of the 4.9 million barrels (205.8 million gallons) that escaped BP’s well, about half had been cleaned up, evaporated or dissolved.
The other half might still be in the gulf, the report said. But the government said that half of it had been dispersed by chemicals and natural processes, and that preliminary indications showed the remaining oil was “biodegrading quickly.”
Since then, the government has begun a new effort to track the location and environmental effects of oil underwater. But Lubchenco defended the decision to release the first assessment publicly.
“What do you think would have happened if folks learned that we were studying where the oil was but we refused to tell people what we knew?” she said.
Lubchenco, in her afternoon news conference, said that microbes could have begun eating much more of the oil in the two months since. The study “tells us what was happening in June,” she said. “It doesn’t tell us what was happening now.”
It is still true that the gulf spill has not caused the kind of apocalyptic damage to marshes and coastal ecosystems that scientists had feared. But this week, scientists have criticized the government, saying it has made the situation seem far rosier than it is.
Testifying before a House subcommittee Thursday, Florida State University professor Ian R. MacDonald called the administration’s account “misleading.” He said that the government’s assumptions about how much oil is breaking down underwater were too optimistic and that its report didn’t mention the natural gas that gushed out of BP’s Macondo well along with the oil.
“This oil is going to be in the environment for a long time. I think that the imprint of the BP release, the discharge, will be detectable in the Gulf of Mexico for the rest of my life,” said MacDonald, who is 58.
In that hearing, Rep. Edward J. Markey (D-Mass.) criticized a NOAA scientist for saying that the agency might wait two months before releasing the full details of the methodology it used to calculate what happened to the oil. “That is, to me, unacceptable. We need to have that information,” he said.
The report was also challenged this week by a group of Georgia academics. They questioned the government’s inclusion in its pie chart of the 17 percent of the oil that emerged from the well but never entered the gulf. It was, instead, siphoned directly to the surface. By including the amount in the official chart, they said, the government seemed to take credit for cleaning up oil that never spilled.
In addition, the Georgia group said the government was overly optimistic in reporting that about 25 percent of the oil either evaporated or dissolved.
“The vast majority of this oil never got to the surface, so it couldn’t have evaporated,” said Charles S. Hopkinson, a professor in the department of marine sciences at the University of Georgia. Federal officials disagree, estimating that four-fifths of the oil rose to the surface.
The Georgia group’s conclusions were built largely on assumptions and calculations — not direct measurements from the gulf.
To gauge what’s really happening underwater, scientists must find tiny droplets in a vast ocean, then wait for lab tests to verify that it’s oil from the BP well. In some cases, it’s not even oil: One Louisiana scientist said his lab has tested several samples and found that they were an apparently natural substance, now nicknamed “sea snot.”
University of South Florida research was an attempt to gather real-world evidence in the gulf. Scientists shone ultraviolet light on sediment from the bottom of the DeSoto Canyon, a deep notch in the edge of the continental shelf, full of sea life. If oil were there, it would reflect the light.
“It flashes back at you as sort of a constellation of bright stars,” said David Hollander, a professor who worked on the seafloor study.
Other tests, he said, showed that the water samples near the canyon’s rim were toxic to plankton, key creatures at the base of the food chain. But Hollander said that other things reflect UV light, and that further tests are needed to confirm that what they found was BP oil.
