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Oil spill imperils an unseen world at the bottom of the gulf

Cleanup and containment efforts continue at the Gulf of Mexico site of the oil spill following the Deepwater Horizon explosion.

"You can go one place and it would be like quicksand. You can move over another ways, and it would be as hard as a sidewalk," said Rich Camilli, an oceanographer at Woods Hole who in 2006 made a series of dives to the gulf floor eight miles northwest of the blown-out well. His journey about 3,000 feet below the surface took place right after an earthquake.

"It looked like all hell had broken loose on the seafloor," Camilli said.

Embedded in the mud are structures made of methane hydrates, the slushy ice that forms when pressurized gas mixes with very cold water at depth. These are the hydrates that accumulated inside a huge steel containment dome that had been lowered over the major leak from a collapsed pipe. Because of the hydrates, BP engineers had to abandon that strategy for capturing the leaking oil.

When Camilli observed hydrates after the earthquake, they "had broken away from the seafloor and had floated up and away. They're buoyant. One site, called Sleeping Dragon, a massive hydrate block was working its way out of the seafloor -- about the size of a school bus. There were pockmarks where the hydrates come out of the sea floor."

This region of the gulf is fertilized by organic matter from the Mississippi River. It is rich in plankton and other organisms. The result is what is called marine snow, which is easily seen in the brief snippets of video released by BP that show the leaking pipe.

"There's this particulate matter that's falling like rain, or like snow, through the ocean, all the way from the surface to the bottom," said Peter Etnoyer, a marine biologist with the National Oceanic and Atmospheric Administration. "There's thousands of creatures in the water column. As you descend though the water column, you'll see many bioluminescent plankton."

The depths of the gulf are also a potential answer to a question that has been in the air for weeks now: Where, exactly, has all the oil gone? A partial explanation is that the slick has been bombed with more than half a million gallons of the chemical dispersant Corexit 9500, made by Nalco. More dispersants have been applied at depth, directly on the main leak. Much of the oil sinks to the bottom.

"If you apply the dispersants to the source of the oil down there, you are completely hiding the problem," said Kert Davies, research director for Greenpeace. "It looks like it's gone away, but there is no 'away' in the ocean. It's like sweeping it under the rug."

Shirley, the marine biologist, notes that oil is not a foreign substance in the gulf: "What most people haven't considered is that there's 48 million gallons of oil that's leaked naturally in the gulf every year."

Ian MacDonald, the Florida State University professor who has gained attention with his estimate, based on aerial images, that the leak is five times the official estimate of 5,000 barrels a day, said nature will ultimately have to fix the gulf mess. "BP is not going to clean up this spill," he said. "The Coast Guard is not going to clean up this spill. What's going to clean up this spill is the physical, chemical, biological process of the good ol', poor, downtrodden Gulf of Mexico."

Life is an active and improvisational agent in the deep water. Corals have found purchase on dozens of ships sunk in the gulf in 1942 when Nazi U-boats patrolled the shipping lanes. Scientists study the doomed vessels to get a better idea of coral growth rates at depth.

Less than a mile from the uncapped well, now upside down, is the hulk of the Deepwater Horizon rig. It is now, in effect, an artificial reef, destined to become another garden of the deep.

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