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
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
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. …