Almost 75% of Oil in Gulf Now Accounted For, Government Says

BY Lea Winerman  August 4, 2010 at 2:23 PM EST

Almost three-quarters of the oil that was released into the Gulf of Mexico during the nearly three-month-long Deepwater Horizon oil leak has been vacuumed up, burned, naturally biodegraded or dispersed in the water, according to a government report released Wednesday.

The other 26 percent of the oil remains — some as a light sheen on the water or as weathered tarballs, and some as oil that has washed ashore (some of which has been collected, and some buried in sand and sediment), according to the report by the National Oceanic and Atmospheric Administration and the Department of the Interior. Earlier this week, a federal panel revised its estimate on the size of the spill, saying that approximately 205.8 million gallons of oil has been released from the gusher.

You can read the full report here. Below is a graphic released with the findings:

oilgraphic.jpg

According to the report:

  • About 25 percent of the oil has evaporated from the surface of the water or dissolved into its constituent molecules like sugar dissolving in water.
  • About 17 percent was collected directly from the wellhead and processed on surface ships, through various containment systems.
  • About 5 percent was burned off.
  • About 3 percent was skimmed from the water surface with skimmer vessels.
  • And about 24 percent has been dispersed in the water (broken up into tiny droplets that can more easily biodegrade) either using chemical dispersants or naturally through turbulence when the oil first shot out of the pipe.

“I think the bottom line here is we can account for all but about 26 percent [of the oil] and of that, much is in the process of being degraded and cleaned up on shore,” NOAA administrator Jane Lubchenco told reporters.

The White House called the report good news. Responding to a question from a reporter, spokesman Robert Gibbs said that many of the “doomsday scenarios” of oil contamination predicted earlier in the spill “have not and will not occur.”

But not all scientists are convinced that the situation is as rosy as the report indicates.

Much of the contention revolves around the oil that has been dispersed below the ocean’s surface. Government scientists say that the favorable conditions in the Gulf are allowing the dispersed oil droplets to biodegrade quickly. At a press conference, Lubchenco put it succinctly: “Mother nature is assisting.”

The report went into more detail:

Dispersed oil in the water column and oil on the surface of the water biodegrade naturally. While there is more analysis to be done to quantify the rate of biodegradation in the Gulf, early observations and preliminary research results from a number of scientists show that the oil from the BP Deepwater Horizon spill is biodegrading quickly. Scientists from NOAA, EPA, DOE and academia are working to calculate more precise estimates of this rate. It is well known that bacteria that break down the dispersed and weathered surface oil are abundant in the Gulf of Mexico in large part because of the warm water, the favorable nutrient and oxygen levels, and the fact that oil regularly enters the Gulf of Mexico through natural seeps.

But Florida State University oceanographer Ian MacDonald says that scientists don’t know enough about how quickly the dispersed oil will disappear, or what effects it might have as it does, to say that that oil is “accounted for.”

“This idea floated in this report that these natural processes are going to take care of this for us, is wishful thinking,” he says.

Lubchenco acknowledged these concerns, telling reporters in a press conference: “We remain concerned about the long-term impacts [...] beneath the surface, and are actively studying that.”

And in a statement by the Deepwater Horizon Joint Response team, officials acknowledged the limits of the estimates:

“The estimates do not make conclusions about the long-term impacts of oil on the Gulf. Fully understanding the damages and impacts of the spill on the Gulf of Mexico ecosystem is something that will take time and continued monitoring and research.”

Tune in to the NewsHour Wednesday for an interview with Carol Browner, White House senior adviser on energy and climate change.