The Obama administration’s conclusion that much of the oil released into the Gulf of Mexico from the Deepwater Horizon spill has disappeared is coming under additional fire from scientists.
Earlier this month, a team led by the Interior Department and the National Oceanographic and Atmospheric Administration said that of 4.9 million barrels released from the out-of-control well, roughly 75% had been cleaned up or had broken down. Most of the rest was a light sheen at or near the surface or had washed ashore, the government researchers said.
The findings suggested the long-term impact of the spill on the coastline and fisheries might not be as bad as once feared.
But Ian MacDonald, an oceanographer at Florida State University, is expected to tell a U.S. House Energy and Commerce subcommittee Thursday that the administration findings were misleading and that the government has made rosy forecasts about the pace at which dispersed oil will biodegrade. Only 10% of oil discharged into the ocean was “actually removed from the ocean,” according to his prepared testimony. Mr. MacDonald uses satellite imagery to measure oil slicks.
Mr. MacDonald is expected to cite research that indicates oxygen levels in the Gulf aren’t consistent with rapid degradation of oil by petroleum-eating microbes.
The government report said 17% of the oil released by the well had been collected without ever reaching the ocean and about half had dissolved or been dispersed.
NOAA chief Jane Lubchenco defended the government’s estimates Wednesday. “We stand by the calculations that we released recently,” she said. The government is going forward with additional monitoring and would change its estimates if it develops new information, she said.
BP PLC referred questions to the Obama administration’s joint command, overseeing the spill response. The company said it has donated $500 million for research into the environmental effects of the spill.
Evidence has been mounting that much of the oil from the damaged well is still in the Gulf, suspended in subsurface waters or working its way into seafloor sediments.
Moreover, at least a third of the petroleum hydrocarbons spewed from the well were released in the form of methane and other gases, which have yet to be accounted for in any government assessment of the spill.
“A third of the impact is being overlooked,’ said the University of Georgia’s Samantha Joye, who was among the first to detect evidence of the underwater clouds of oil droplets and various petroleum hydrocarbons from the damaged well.
Earlier this week, Dr. Joye and a team of marine researchers from the University of Georgia and the Georgia Sea Grant program challenged the government’s accounting of the oil cleanup, saying that as much as 79% of the oil remained in the Gulf, where it still threatened fisheries and marine life.
“We don’t know how much is on the bottom; we don’t know where it is; we don’t know what the impact will be,” said Dr. Joye.
Mr. MacDonald is also expected to testify that the gas released by the spill “should not be ignored.” Fish exposed to concentrated methane “have exhibited mortality and neurological damage,” according to his testimony.