August 20, 2010 06:40
A team of University of Georgia scientists on Tuesday disputed the Obama administration’s claim, made two weeks ago, that most of the oil spewed from BP’s Deepwater Horizon well is either gone or widely dispersed.
Far from gone or dispersed, the scientists said, 70 to 79 percent of the
more than 4 million barrels of oil that escaped into the Gulf of Mexico
remains in the water, posing real but still undetermined risks.
“The idea that 75 percent of the oil is gone and of no concern for the
environment is just absolutely incorrect,” said Charles Hopkinson, a
director of Georgia Sea Grant and marine science professor at the
University of Georgia, who co-authored the report.
The Georgia report blamed the media for “inaccurate and misleading”
interpretation of a federal analysis released Aug. 2, but its authors,
in a teleconference, declined to address questions about whether an
upbeat spin by the Obama administration had shaped coverage.
The federal report, produced by government and independent scientists,
estimated that the “vast majority” of the 4.9 million barrels of crude
released into the Gulf had evaporated or been burned, skimmed, recovered
by BP from the wellhead, dispersed naturally or by chemicals into drops
likely to be rapidly consumed by microbes. Only 26 percent of
“residual” oil remained largely in the form of sheen or tarballs, the
federal report found – still a volume four times the amount spilled by
the Exxon Valdez.
In announcing the data, Jane Lubchenco, administrator of the National
Oceanic and Atmospheric Administration, cautioned that the vast amount
of oil would cause impacts for years but still struck a glass-half-full
tone echoed by other Obama aides.
“At least 50 percent of the oil that was released is now completely gone
from the system, and most of the remainder is degrading rapidly or is
being removed from the beaches,” she said at a White House conference.
Two calculations explain the bulk of the difference in the Georgia
report, produced by Hopkinson with four colleagues at the University of
Georgia and the Skidaway Institute of Oceanography.
The Georgia report tossed out 800,000-plus barrels BP managed to pipe
directly from the well after it had fitted a sealing cap on the gusher -
17 percent of the well’s estimated flow – arguing that oil had never
actually “spilled” into the Gulf.
More significantly, the report also dramatically reduced the amount of
oil estimated to have evaporated, to 7 to 12 percent from the federal
study’s 25 percent.
The federal government’s evaporation estimate was based on a standard
accepted by industry experts and researchers for light sweet crude in
the warm Gulf. But Hopkinson argued that the percentage is invalid
because much of the oil remains deep beneath the surface, trapped under
dense temperature and salinity layers that would dramatically limit
evaporation.
“My suspicion is that a large fraction of this oil is still in the
system,” said Samantha Joye, a UGA marine scientist who in May was the
first researcher to detect massive deep sea “plumes” of oil droplets
spreading from the well. “Whether it’s floating around or down in the
bottom, we still don’t know.”
Another report released Tuesday by University of South Florida
researchers found evidence of droplets spreading eastward up the
continental shelf and settling into the DeSoto Canyon, a much shallower
area considered a prime spawning spot for fish. The team reported
finding oil at potentially toxic concentrations for some organisms in
sediment taken from 900 feet to as shallow as 215 feet. BP’s well is
5,000 feet deep.
Most analysis and research to date, Georgia’s Joye said, also has
ignored methane, which accounted for as much as one-third of the overall
flow. Methane levels were 10,000 to 100,000 times greater than normal
in some deep sea pockets, she said. At such levels, it could take a year
for the dissolved methane to dissipate, she said.
In an e-mail statement Tuesday, NOAA spokesman Justin Kenney defended
the official analysis as “validated by federal and independent
scientific experts.” By omitting oil recovered directly from the well,
he said, the Georgia researchers had fundamentally changed the baseline
calculation, making it impossible to compare the two estimates.
He also dismissed critics who have contended the White House was eager
to put the environmental disaster in its rearview mirror. NOAA and its
contributing independent scientists, he said, “have been clear that oil
and its remnants left in the water represent a potential threat.”
The agency intended to continue to “rigorously monitor, test and assess short- and long-term ramifications,” he added.
Joye stressed that the Georgia team wasn’t implying that there were
toxic “rivers of oil” submerged in the Gulf. Oil is degrading every day,
she said.
There are, however, still vast volumes of crude oil in the water column,
widely dispersed and breaking down into multiple compounds whose impact
on the environment won’t be understood for years, she said.
Source: McClatchy Newspapers
