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Gulf oil spill: NOAA skeptical of oil-plume reports [updated]

May 17, 2010 |  2:01 pm

Pelican

Jane Lubchenco, head of the National Oceanic and Atmospheric Administration, called media reports of large underwater oil plumes "premature," adding that research conducted by an academic ocean institute was inconclusive.

"Media reports related to the research work conducted aboard the R/V Pelican included information that was misleading, premature and, in some cases, inaccurate," Lubchenco said in a statement. She was referring to research, including water sampling, done by the National Institute for Undersea Science and Technology.

Lubchenco said those scientists have clarified that they have not reached "definitive conclusions ... about the composition of the undersea layers they discovered. Characterization of these layers will require analysis of samples and calibration of key instruments. The hypothesis that the layers consist of oil remains to be verified."

The NOAA chief also made these clarifications:

"While oxygen levels detected in the layers were somewhat below normal, they are not low enough to be a source of concern at this time.... Although their initial interest in searching for subsurface oil was motivated by consideration of subsurface use of dispersants, there is no information to connect use of dispersants to the subsurface layers they discovered."

Lubchenco thanked the scientists for "repurposing their previously scheduled mission to gather information about possible impacts of the BP oil spill."

"We eagerly await results from their analyses and share with them the goal of disseminating accurate information," the statement continued.

She defended the decision to apply dispersants under the water surface, close to the gushing pipe from BP's well.

"As we have emphasized, dispersants are not a silver bullet. They are used to move us towards the lesser of two environmental outcomes. Until the flow of oil is stemmed, we must take every responsible action to reduce the impact of the oil.”

There was no immediate word from the scientists involved.

[Update: 4:52 p.m.: One of the researchers, Vernon Asper, a professor of marine science at the University of Southern Mississippi, appeared to stick to his assessment during a taping of PBS NewsHour, with Gwen Ifill.

"It's not only the size of Manhattan in area, but it's also several hundred meters' depth," Asper said. 

"That information has not been analyzed," said Charlie Henry, a NOAA official. "None of the quantitative analysis has been done on that. We don't even know what for sure is in those samples."  

In a one-on-one interview later with Lubchenco, Ifill pressed the question:

"What else would it be?" she asked.

"But the samples have not been analyzed," Lubchenco said. "They have taken good samples.  And we need to make sure that we're not jumping to conclusions.... And that's part of the -- the normal process that science has. We want to make sure that we have good information. It..."

Ifill:  "So, in short -- pardon me -- they have seen something irregular." 

Lubchenco:  "We have seen something irregular."

Ifill: "They think it's oil and that it's at a great depth and has great -- could have great impact, but you're not certain for sure. You cannot...confirm that."

Lubchenco: "That's right. And we eagerly await the results of their analyses and the calibration of their instruments, which will give us better information."

Asper later e-mailed Los Angeles Times staff writer Raja Abdulrahim, who had interviewed him Sunday in Cocodrie, La.:

1) We are not 100% sure that the plumes are oil. We have NOT analyzed the samples yet and won’t know what’s in them until we do. That will take at least a few days or even a week or more and we don’t want to rush these results.  The sensor we used is not definitive for oil and other compounds do respond in a manner that is similar to oil and could be confusing us.

2) I NEVER said that these “plumes” could cause a dead zone! It’s really important that you correct that!  Consider:

a. We don’t even know if there is any oil in the plumes so the oxygen signal we’re seeing could be due to something else that is going on near the well and, if so, it could disappear overnight (we just don’t know)

b. The oxygen levels we saw are lower than “normal” but are no where near the danger zone! For the most part, they are not even as low as the layer above them that we call the “oxygen minimum zone.”  This is a totally natural layer caused by normal oceanographic process and it is found essentially everywhere in the world with very few exceptions. The oxygen levels in these “plumes” are not as low as they are in this natural layer that is found at this site, between about 150 and 400m.

c.   Even if the levels were dangerously low (which they are not), this plume does not have the potential to create a dead zone because it cannot be brought to the surface. That water is cold and heavy; it would take far more energy than is available to bring it to the surface anywhere in the Gulf, any time soon.

3) Yes, we’re concerned about low oxygen and yes these numbers are lower than normal but we don’t see signs of anything suffocating for lack of oxygen down there.  It’s something to consider but it is very far down on the list of concerns.]

Reports of the plumes were in Sunday's New York Times and in Associated Press stories.

Sunday's Los Angeles Times story about the growing concern about the effect the underwater oil may have on marine life said:

Last week, researchers from the National Institute for Undersea Science and Technology reported on their website that they had found what they believe are large plumes of oil far beneath the surface.

Monday's story in the Los Angeles Times said:

Vernon Asper, an oceanographer and marine professor at the University of Southern Mississippi, was part of a group that landed at Cocodrie, La., on Sunday, after completing a two-week research trip in the gulf. Asper said they documented plumes of oil 2,000 to 6,000 feet below the water's surface, covering an area 4 miles wide and 15 miles long.

Bacteria in the water naturally break down oil, but that process sucks up large amounts of oxygen. Such a scenario could cause dead zones similar to a seasonal one caused by nitrogen-rich runoff down the Mississippi River.

-- Geoff Mohan

Photo: Researchers aboard the research vessel Pelican clean up after taking a water sample. Credit: National Institute for Undersea Science and Technology

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