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Aug 17, 2010 8:45 PM by Chris Welty

Gulf Surface Looks Cleaner, but Woes Lurk Below

WASHINGTON (AP) - Researchers are warning that the Gulf of
Mexico oil spill is a bigger mess than the government claims and
that a lot of crude is lurking deep below the surface, some of it
settling perhaps in a critical undersea canyon off the Florida
Panhandle.
The evidence of microscopic amounts of oil mixing into the soil
of the canyon was gathered by scientists at the University of South
Florida, who also found poisoned plant plankton - the vital base of
the ocean food web - which they blamed on a toxic brew of oil and
dispersants.
Their work is preliminary, hasn't been reviewed by other
scientists, requires more tests to confirm it is BP's oil they
found, and is based on a 10-day research cruise that ended late
Monday night. Scientists who were not involved said they were
uncomfortable drawing conclusions based on such a brief look.
But those early findings follow a report on Monday from Georgia
researchers that said as much as 80 percent of the oil from the
spill remains in the Gulf. Both groups' findings have already been
incorporated into lawsuits filed against BP.
Both groups paint a darker scenario than that of federal
officials, who two weeks ago announced that most of the oil had
dissolved, dispersed or been removed, leaving just a bit more than
a quarter of the amount that spewed from the well that exploded in
April.
At the White House on Aug. 4, National Oceanic and Atmospheric
Administration chief Jane Lubchenco said: "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."
That's not what the scientists from South Florida and Georgia
found.
"The oil is not gone, that's for sure," University of South
Florida's David Hollander said Tuesday. "There is oil and we need
to deal with it."
University of Georgia's Samantha Joye said: "It's a tremendous
amount of oil that's in the system. ... It's very difficult for me
to imagine that 50 percent of it has been degraded."
Marine scientist Chuck Hopkinson, also with the University of
Georgia, raised the obvious question: "Where has all the oil gone?
It hasn't gone anywhere. It still lurks in the deep."
NOAA spokesman Justin Kenney defended his agency's calculations,
saying they are "based on direct measurements whenever possible
and the best available scientific estimates where direct
measurements were not possible." But the vast majority of it is
based on "educated scientific guesses," because unless the oil
was being burned or skimmed, measurements weren't possible, NOAA
response scientist Bill Lehr said earlier this month.
What is happening in the Gulf is the outcome of a decision made
early on in the fighting of the spill: to use dispersants to keep
the surface and beaches as clean as possible, at the expense of
keeping oil stuck below the surface, said Monty Graham, a
researcher at the Dauphin Island Sea Lab in Alabama who was not
part of the latest work. Oil degrades far more slowly in cooler,
deeper waters than it would at the surface.
At the surface and the top 100 feet or so, it is obvious why oil
is harmful, fouling marshes and hampering sea turtles, fish, birds
and other life. Deep down, the effects are subtler, less direct.
Oil at that depth can chip away at the base of the food web - plant
plankton - and that could cause animals to go hungry. Reduced
oxygen levels from natural gas and oil could also starve creatures
of oxygen.
At depths of 900 to 3,300 feet, the University of South Florida
researchers found problems with plant plankton. About two-fifths of
the samples showed "some degree of toxicity."
"We found general phytoplankton health to be poor," Hollander
said. By comparison, in non-oiled southern parts of the Gulf, the
plant plankton were healthy, researchers said.
That makes sense because past research has shown that when oil
when gets into the cell membranes of plankton, it causes all sorts
of problems, said Paul Falkowski, a marine scientist at Rutgers
University who was not part of the research. However, he said plant
plankton don't live long anyway. They have about a week's lifespan,
he said, and in a few months this insult to the base of the food
web could be history.
Still, the brew that is poisoning the plankton may linger and no
one knows for how long, Hollander said.
The Florida researchers used ultraviolet light to illuminate
micro-droplets of oil deep underwater. When they did that, "it
looked like a constellation of stars," Hollander said.
He also found the oil deposited in the sea bottom near the edges
of the significant DeSoto Canyon, about 40 miles southwest of
Panama City, Fla., suggesting oil may have settled into that
canyon. The canyon is an important mixing area for cold,
nutrient-laden water and warmer surface water. It is also key for
currents and an important fisheries area.
"Clearly the oil down in the abyss, there's nothing we can do
about it," said Ed Overton of Louisiana State University. He said
the environment at the surface or down to 100 feet or so is
"rapidly going back to normal," with shrimpers starting their
harvest. But oil below 1,000 feet degrades much more slowly, he
said.
Joye has measured how fast natural gas, which also spewed from
the BP well, can degrade in water, and it may take as much as 500
days for large pools to disappear at 3,000 feet below the sea. That
natural gas starves oxygen from the water, she said.
"You're talking about a best-case situation of a year's
turnover time," Joye said.

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