Gulf focus shifts, but where is all the oil?

Andrew Gully Yahoo News 27 Jul 10;

WASHINGTON (AFP) – With BP's broken well in the Gulf of Mexico finally capped, the focus shifts to the surface clean-up and the question on everyone's lips is: where is all the oil?

For three long months a massive slick threatened the shorelines of Louisiana and other southern US Gulf Coast states as BP tried everything from top hats to junk shots and giant domes to stanch the toxic sludge.

A cap stopped the flow on July 15 after between three and 5.2 million barrels (117.6 million and 189 million gallons) had gushed out. Roughly one quarter of that was picked up by BP's various collection and containment systems.

After frantic efforts to skim and burn the crude on the surface -- some 34.7 million gallons of oil-water mix have been recovered and 411 burns have been conducted -- the real difficulty now is finding any oil to clean up.

Dozens of reconnaissance planes fly constant sorties from Florida to Texas noting any oil sightings, while flat-bottomed boats trawl the marshes for lumps of tar too large to biodegrade.

"What we're trying to figure out is where is all the oil at and what can we do about it," said US spill response chief Thad Allen. "What we're seeing are mats, patties, small concentrations, very hard to detect, but they're out there."

The figures speak for themselves. Before the cap went on, some 25,000 barrels of oil a day were being skimmed from the thickest part of the slick near the well site.

By the time Tropical Storm Bonnie arrived last week, the take was down to a pitiful 56 barrels, begging the question of what to do with the fleet of 800 skimmers, many of them run by disgruntled fishermen.

Jane Lubchenco, the head of the US government's National Oceanic and Atmospheric Administration (NOAA), said Tuesday that a lot of the oil had been broken down naturally.

"We know that a significant amount of the oil has dispersed and been biodegraded by naturally occurring bacteria," she said.

"Bacteria that break down oil are naturally abundant in the Gulf of Mexico, in large part because of the warm water there and the conditions afforded by nutrients and oxygen availability."

"We are currently doing a very careful analysis to better understand where the oil has gone," she added.

Another concern is the dispersant used by BP to break up the oil. Some 1.8 million gallons of the controversial chemical Corexit were poured into the Gulf from a short time after the spill began until early July.

"Less oil on the surface does not mean that there isn't oil beneath the surface however or that our beaches and marshes aren't still at risk. We are extremely concerned about the ongoing short-term and long-term impacts to the Gulf eco-system," said Lubchenco.

"We are working with the best scientific minds in the government as well as the independent scientific community to produce an estimate of just how much oil has been skimmed, burned, contained, evaporated, and dispersed, so stay tuned on that front."

Only weeks ago, the slick was an unstoppable force that couldn't be prevented from swamping shorelines and slowly choking helpless pelicans; now the oil is an elusive enemy, one that has to be tracked down.

The latest "Nearshore Surface Oil Forecast" from the US government's National Oceanic and Atmospheric Administration (NOAA) indicated only seven sizeable patches of surface oil, all light sheen.

An overflight Sunday identified one thicker patch of emulsified crude. A flotilla of skimmers was immediately dispatched and made short work of mopping it up.

With hopes high that the well will be sealed for good next week, Allen was conscious of the need to plan for the next phase, admitting, "we are going to have to figure out how we make a transition in our resources."

Sophisticated underwater operations involving fleets of robotic submarines at brain-crunching depths will make way for the less glamorous but equally complex work of Shoreline Clean-up Assessment Teams, SCATs for short.

"They will sign off literally mile by mile where we've had oil impact," said Rear Admiral Paul Zukunft, a government on-scene coordinator. "And that is the very long phase of this operation where you ultimately determine how clean is clean."

Approximately 638 miles (1,027 kilometers) of Gulf Coast is officially listed as "oiled," 362 miles in Louisiana, 109 miles in Mississippi, 70 miles in Alabama, and 97 miles in Florida.

The beaches should be relatively painless to mop up, but cleaning up the maze of marshes, where there is nothing to stand on and shallow-bottomed boats are needed to navigate the narrow channels, is a logistical nightmare.