What Happened to Gulf Oil Spill? Rosy Portrait Was Hasty, Study Says
Spotts, Pete, The Christian Science Monitor
The new estimate from marine scientists comes two weeks after a report that prompted rosy conclusions from some Obama administration officials about the Gulf oil spill.
Seventy to 79 percent of the oil that the Deepwater Horizon blowout spewed into the Gulf of Mexico between late April and July 15 was probably still lurking in some form in Gulf waters in early August.
That estimate comes from marine scientists from two institutions affililiated with the Georgia Sea Grant program. It comes two weeks after the unified command (UC) took a first cut at figuring out the oil's fate. The UC report prompted some Obama administration officials to announce that anywhere from half to 75 percent of the Gulf oil spill was gone.
Indeed, natural weathering and biodegradation are slowly taking their toll on remaining oil, notes the team producing the new estimate. And Florida's Keys and East Coast have been spared, thanks to a large ocean eddy spinning in the Gulf and blocking oil from slipping through the Straits of Florida.
Still, the researchers who developed this latest estimate find that "not only is there a lot of oil remaining in the system, but there's a tremendous amount of gas in the system that's not being counted for in the budgeting process," says Samantha Joye, a University of Georgia marine scientist who was a co-author of the report.
The gas she refers to is methane, which accounted for about one- third of the hydrocarbons jetting out of the damaged undersea well.
Even though some officials drew rosy conclusions from the UC report two weeks ago, the data didn't support those conclusions. There were uncertainties surrounding important pieces of information - such as the rates at which microbes were eating oil and the rates at which oil has fallen to the bottom.
Another question mark had to do with the report's lumping of dissolved and evaporated oil into one category. Moreover, researchers have long shown that dispersed and dissolved do not equal "gone," from an ecological perspective.
On one level, the two studies represent a high-profile example of science at work - different teams using different approaches to address the same issue. But when the issue involves the aftermath of the largest offshore oil spill in US history, dueling studies take on enormous political, financial, and even legal implications.
The Sea Grant team started with the UC's total figure for the amount of oil coming from the blowout. …