The government confirmed Tuesday that plumes of dispersed oil were spreading far below the ocean surface from the leaking well in the Gulf of Mexico, raising fresh concerns about the potential impact of the spill on sea life.
Tests conducted by researchers at the University of South Florida found that the concentrations of oil-related chemicals in the water were generally low. Still, the tests confirmed that some toxic compounds that would normally be expected to evaporate from the surface in a shallow-water oil spill were instead spreading through the ocean in the Deepwater Horizon leak.
The National Oceanic and Atmospheric Administration, which helped to fund the research, said it was still working to get a better handle on the potential impact of the spill on fish, corals and other wildlife. Jane Lubchenco, the NOAA administrator, said the agency was doing its best to determine “where the oil is going, and where it is at the surface, and where it might be below the surface, and what the consequences of that oil will be to coastal communities as well as to the health of the gulf.”
The University of South Florida tests confirmed that detectable levels of petroleum compounds had traveled as far as 42 miles northeast of the leaking well in the Gulf of Mexico.
The announcement of test results appeared to confirm information first presented three weeks ago by another group of researchers, who found evidence of large plumes of dispersed oil droplets in the deep ocean, with the largest plume stretching west and southwest of the well. Their findings suggested that a significant amount of oil could be spreading through the deep ocean in plumes or layers of highly dispersed oil, rather than rising to the surface.
Those scientists have not yet completed their analysis of the water samples they collected, but one of them, Samantha Joye of the University of Georgia, held a news conference Tuesday where she presented detailed instrument readings. Those readings confirm that a large plume, probably consisting of hydrocarbons from the leak, stretches through the deep ocean for at least 15 miles west of the gushing oil well, Dr. Joye said.
Bacteria appear to be consuming the oil-related compounds at a furious pace, Dr. Joye said. That is depleting the water of oxygen, she said, though not yet to a level that would kill sea creatures.
The announcement of test results on the plumes came in a morning news conference in which the national commander of the response to the spill, Adm. Thad W. Allen of the Coast Guard, said that BP’s new containment cap had captured 14,482 barrels of oil in the most recent 24-hour period, though several of the vents on the cap remain open. The captured oil is being brought to the surface for processing, though a great deal of oil is still leaking out at the ocean floor.
The new figures bring the total collected over four days to about 42,500 barrels of oil.
Responding to a reporter’s question about why more progress has not been made, Admiral Allen responded: “I have never said this is going well. We’re throwing everything at it that we’ve got. I’ve said time and time again that nothing good happens when oil is on the water.”
Earlier Tuesday, President Obama said he would have fired BP’s chief executive, Tony Hayward, over the handling of the oil spill if Mr. Hayward worked for him. Mr. Obama’s remarks, part of an interview on NBC’s “Today” show , came as the president was defending his own response to what is being called the nation’s worst environmental disaster.
Critics have said that Mr. Obama has not displayed enough outrage over the spill, which resulted from an explosion on a drilling rig on April 20 that killed 11 workers.
“I don’t sit around just talking to experts because this is a college seminar,” Mr. Obama told the show’s host, Matt Lauer, in an interview conducted Monday in Kalamazoo, Mich. “We talk to these folks because they potentially have the best answer, so I know whose ass to kick.”
The Interior Department was preparing on Tuesday to release new safety and environmental rules that would allow shallow-water drilling in the Gulf of Mexico to resume. The step would answer concerns from the energy industry and local officials that the freeze on all drilling in the gulf is putting hundreds of people out of work and denying the industry millions of dollars in revenue.
The Obama administration declared a six-month moratorium on deep-water drilling in the aftermath of the BP spill, but said that it would allow exploration and production wells to continue operating in water less than 500 feet deep. Even so, it essentially halted shallow-water drilling operations while the new guidelines were being written. Those new rules are expected as soon as Tuesday afternoon from the Minerals Management Service, the Interior Department unit responsible for policing offshore operations.
Well operators complained that the wait for the new guidelines was causing hardship across the gulf. The president of the National Ocean Industries Association wrote in a letter on Monday, “Although as this accident shows, one accident is one too many, a lengthy shutdown of drilling will only multiply the economic and emotional stress and loss of jobs that has already devastated the region.” The trade group official, Randall Luthi, a former director of MMS, said that offshore drilling is responsible for 200,000 jobs along the gulf coast and 30 percent of the nation’s domestic oil production.
An Interior Department official said that the new rules would clarify how shallow-water drillers could meet safety and environmental regulations and resume operations. “Pulling back exploration plans and development plans and requiring them to be updated with new information is consistent with this cautious approach and will ensure that new safety standards and risk considerations are incorporated into those planning documents,” the agency said in a statement.
By JUSTIN GILLIS, CAMPBELL ROBERTSON and JOHN BRODER
Joseph Berger contributed reporting from New York.