RAY SUAREZ: And for more about those questions, we turn to one of the administration's leading voices on the environmental impact. Jane Lubchenco, is head of the National Oceanic and Atmospheric Administration, or NOAA.
Welcome back to the program.
JANE LUBCHENCO, head, NOAA: Thank you, Ray.
RAY SUAREZ: When the well was finally capped, the two big unknowns were, where is the oil and what is it going to do now that it's just sitting there out in the Gulf of Mexico? These months on, do we know -- have a better answer to those questions?
JANE LUBCHENCO: We have a lot better idea, but not all the answers that we would want.
We do know that of the nearly five million barrels of oil that was spilled, about a quarter of it was removed by the federal effort, burned, skimmed, or captured directly. Another quarter of it evaporated. The remaining half of that, which is actually equivalent to about nine Exxon Valdez oil spills, to put it in context, about one half of that total of five million barrels was, in early August, either in the water column as dispersed oil, or on beaches, or as tar mats, or floating on the surface.
Of that, much of that is now gone. There remains oil that is on beaches, in isolated patches, and buried beneath the sediments along the shoreline. And the cleanup efforts for that continue.
There remains to be residue of oil, especially right around the wellhead. The sampling that we have done suggests that within about two miles of the wellhead, there is a fair amount of oil that is still seeped into the sediments, which is not surprising. But both the natural process of biodegradation and the cleanup efforts are ongoing, and will continue until all that oil is completely gone.
RAY SUAREZ: When you're talking about close to the broken well itself, the bottom of the Gulf is cold, and whatever is down there is under tremendous amounts of pressure.
Will it just sit there inert for some time to come, that oil?
JANE LUBCHENCO: Oil is a very complex substance. It's composed of a lot of different types of hydrocarbons. Some of them volatilize easily, some of them break down, are easily biodegraded very quickly.
Others biodegrade only very, very slowly.
And so in that environment that you describe, deep in the ocean, it's quite likely that some of that residue will remain for years, if not decades.
RAY SUAREZ: Is the Gulf of Mexico different from the open ocean in that there is not as much water exchange, not as much flushing out that goes on because it's in some parts closed?
JANE LUBCHENCO: The Gulf is a huge area. And the area in which the oil was spilled is just a very large volume.
There is circulation into and out of the Gulf, but it is fairly self-contained. We did not have any major hurricanes that came into the Gulf, and the loop current which can act to transport water and potentially oil away from the Gulf was in a form where it didn't do that. So much of the oil that was spilled, if it wasn't collected and recaptured, it did remain in the Gulf and is in the process of being degraded, or the cleanup effort has got it.
RAY SUAREZ: A lot of attention was paid to the dispersants, the chemicals that were dropped into the water to break up that oil. This time on, do we have any common wisdom about whether too much, not enough was used, whether it was the right approach chemically, whether it can be safely used in a body of water from which we also eat millions of pounds of food a year?
JANE LUBCHENCO: We know, Ray, that the use of the dispersants was intended to do two things. One, to keep the oil off the beaches and in the estuaries, where we knew it would do a lot of damage. And two, to break up the oil into smaller and smaller pieces so that it could naturally biodegrade much faster. It was successful in doing both of those.
We also know that the dispersants break down relatively rapidly between four and six days. It breaks down and is gone. And so there is no threat to seafood safety, for example.
And whether on balance the use of dispersants was appropriate is part of the ongoing questions that will be asked. It certainly did what we expected it to do, what it was intended to do. But this is a question of environmental tradeoffs. And, you know, you're faced with things that are bad on both sides. And the choice that was made I think was the right choice.
RAY SUAREZ: Early on, did the United States government misunderstand or misstate the magnitude of what was going on at the bottom of the Gulf of Mexico? And had there been a greater understanding earlier, would we as a people have done anything differently?
JANE LUBCHENCO: I think early on it was hard to tell exactly how serious the situation was. For that very reason, the president ordered all of the agencies to mount a very aggressive response and to assume the worst possible scenario. That, in fact, characterized the federal effort.
I think it's important to recognize that the magnitude of the spill was unprecedented in U.S. history. Five million barrels, that's 18 Exxon Valdez oil spills. And it just kept coming and coming and coming.
Early on, there was no way to know how long it would take to cap the well and to stop the flow. And so this very aggressive response, in fact, I believe was as much as we could have done, and, in fact, did accomplish a phenomenal amount. The sheer magnitude of the spill was one that has resulted in a lot of the damage that has been done, and we will continue to discover as time goes on.
RAY SUAREZ: Dr. Lubchenco, thanks for joining us.
JANE LUBCHENCO: Thank you, Ray.