WASHINGTON — More than a week since a second university research cruise found oil on the bottom of the Gulf of Mexico, the head of the National Oceanic and Atmospheric Administration said Wednesday that teams of academic and federal scientists would make an aggressive effort to search for oil "from the surface to the sea floor."
The remarks by NOAA administrator Jane Lubchenco stand in contrast to the rosy report the government issued shortly after the spill was capped.
In early August, Lubchenco said that the vast majority of the oil had evaporated or been burned, skimmed, recovered at the wellhead or dispersed so that it could degrade naturally. She defended that estimate on Wednesday, saying that even more oil had degraded since then, but stressed that more scientific work still needs to be done.
Retired Coast Guard Adm. Thad Allen, speaking with Lubchenco at a news conference in Kenner, La., said months of drilling of a relief well are almost over. The relief well is expected to intersect the broken BP well in 24 hours, and then mud and cement will be pumped in.
No oil has flowed from the well since July 15, and last week, Allen pronounced it no longer a threat to the Gulf. Still, Allen has said completing the relief well is the only permanent way to kill the well. Allen said that's now expected to happen within 96 hours, or by 11 a.m. EDT Sunday, five months after the April 20 explosion that caused the disaster.
Lubchenco, meanwhile, promised that scientists would do "everything it takes for as long as it takes" to find the oil and restore habitat.
She also said that "we really do need the best scientists in the country" to account for the oil, learn what its impact would be on marine life, and guide actions to restore the region.
Recent findings of oil on the bottom were important, and looking for oil in the sediment would be a key part of future research cruises, Lubchenco said.
University of Georgia marine sciences professor Samantha Joye reported on her Gulf Oil Blog on Sept. 6 that her research team on the vessel Oceanus had taken sediment samples that showed fresh oil that was clearly not from natural seeps. In at least one sample the oil was about two inches thick.
A University of South Florida research cruise in August was the first to find oil on the sediment of the Gulf floor.
Joye's findings "confirm what we initially suggested, which was that there's oil on the sediment and it's widely distributed to the northeast of the wellhead," said David Hollander, a USF chemical oceanographer who was the lead scientist, in an interview.
The area is in a "dead spot in the circulation," where there are low amounts of currents and so sediments tend to settle, Hollander said. It's also one of the areas where the scientists earlier found oil plumes.
A major flaw of NOAA's August account of what happened to the oil was that it didn't take into account what might have settled to the bottom, he said.
Hollander said one of the intriguing things about his team's finding in August was that the oil was on the edge of the continental shelf.
The area is near the underwater DeSoto Canyon. The canyon serves as a ramp, with water running up it into the shallower water of the continental shelf.
"But now these waters may not only carry nutrients but they may carry all this stuff too," Hollander said.
Hollander's team took water samples and fed them to marine plankton in experiments onboard the research vessel in August. Even in greatly diluted form, a lower concentration than what the EPA considers acute toxicity, the oil in the water caused a toxic effect — the photosynthesis in the plankton was reduced.
The results mean that less plankton will be available at the bottom of the food chain, Hollander said.
The findings raised new questions about what concentrations and what compounds federal scientists should be concerned about, he said. "In spite of the low concentrations, something is in there."
Lubchenco said that the oil in the water, mostly in a layer between 3,000 and 4,300 feet deep, was in the form of microscopic droplets, but added: "Diluted and dispersed does not necessarily mean benign."
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