Much Oil Remains in Gulf, Researchers Estimate
The federal National Incident Command, which has been coordinating clean-up efforts, reported earlier this month that the damaged well had spewed about 4.9 million barrels of oil into the Gulf before it was capped. Half of that oil had been safely burned off, skimmed, or directly recovered and another 25% had evaporated or dissolved, the federal researchers said.
Both the UGA assessment and the federal calculations it contradicts are estimates based on incomplete information. Federal researchers cautioned that their results would be refined as better information became available.
Moreover, it might easily be years before these petrochemicals disappear.
"One major misconception is that oil that has dissolved into water is gone and, therefore, harmless," said UGA marine scientist Charles Hopkinson, the senior investigator in the effort. "The oil is still out there, and it will likely take years to completely degrade."
Federal researchers involved in preparing the earlier estimate couldn't be reached for comment late Monday. Officials at the National Oceanic and Atmospheric Administration in Washington and New Orleans also couldn't be reached for comment.
In a statement, Dr. Hopkinson said most of the oil classified by the government as dispersed, dissolved or residual was actually still in the water. Using a range of likely evaporation and degradation estimates, the group calculated that 70% to 79% of oil spilled into the Gulf still remains.
The group said it was impossible for all the dissolved oil to have evaporated because only oil at the surface of the ocean can evaporate into the atmosphere and large plumes of oil are trapped in deep water.
The UGA study hasn't yet been published, nor has it been peer-reviewed by independent researchers.
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