JEFFREY BROWN: And, even as that debate goes on, charting the magnitude of the spread of oil both at the surface and below has remained a difficult and even controversial task.
"NewsHour" correspondent Tom Bearden went out on the water with a team of researchers near Venice, Louisiana, to track their efforts.
ED OVERTON, Professor of Environmental Sciences, Louisiana State University: Look at that.
TOM BEARDEN: Ed Overton is getting an up-close-and-personal look at the Gulf Coast's oily nemesis.
ED OVERTON: You know, the other was pretty blank gunk. It's the reddish-brown colors right at the surface.
TOM BEARDEN: Overton is an environmental sciences professor emeritus as Louisiana State University. He was one of several scientists who accompanied reporters and photographer aboard a five-boat flotilla arranged by the National Wildlife Federation.
The trip started out from a marina in Venice, and the goal was to get as close to the main oil slick as possible. The weather had other ideas. Thunderstorms and lightning blocked the path.
ED OVERTON: All right, let's follow these guys. We will go out to the right. And, hopefully, the weather's going to head more southeast -- I mean southwest, and we're going southeast.
TOM BEARDEN: Despite the detour, it wasn't hard to find a large patch of thick, heavy crude floating on the surface. The hulls of the boats were heavily stained within minutes.
ED OVERTON: The thicker oil is just how the oil moves through the environment. It's not all coming up at one spot. The plume comes up and it disperses out. Some of it comes up pretty quick. Some of it takes a longer time. And it's globbing up, and, when it gets to the surface, it starts moving -- not a lot of strong currents out here. You have got winds on the surface and currents, but this is kind of a meandering area, as opposed to a loop.
TOM BEARDEN: So, what happens if it just lingers here?
ED OVERTON: Well, it just lingers here, and the bacteria will ultimately degrade it. That's what we were hoping, but I think what's happening, we're just piling on and piling on, and it's filling up. And, pretty soon, we're going to override the capacity for the environment to remove it, and some of it will start globbing onshore.
TOM BEARDEN: We have seen some reports of underwater streams of oil that are not readily visible from the air.
ED OVERTON: Right.
TOM BEARDEN: What about those?
ED OVERTON: Good question. That's -- that's -- that's exactly what I would like to get samples of, if we could get -- get them out here. It's, of course, hard to find, because you don't see them. You can look down and you can't see them. You have really got to just be lucky to find them.
This oil should float. It's not floating. Why? And -- and that's the $64 question, from my perspective. I would like to understand, why is this oil -- is it because of the dispersants? There's natural dispersion. What's going on? Well, I'm hoping that they will find some oil under the surface and -- have they got the camera down?
TOM BEARDEN: LSU scientists lowered a remote-controlled submersible to try to see the oil suspended in the water column, oil that had probably been broken up by chemical dispersants. The results were disappointing. The camera quickly became fouled by the surface oil.
Kevin Boswell is an LSU biologist who helped deploy the camera.
KEVIN BOSWELL, oceanographer, Louisiana State University: We didn't fare so well in terms of the cleanliness of the equipment. It's pretty nasty stuff.
And, so, the quality of the data, we're a little compromised, just the fact that the lens cover is still pretty covered in oil. However, for the most part, you know, we were able to put it down, and we did document that there is, indeed, these small particulates that look a lot like oil particles we saw on the surface.
TOM BEARDEN: Overton is frustrated by the fact that there just isn't much data on a spill like this.
ED OVERTON: A spill of this magnitude under these conditions has never happened. There have been some very minor deepwater test spills in Norway, a couple of releases, a decade ago.
And they -- they raised questions, but there was no follow-up, no further tests, no research. And, again, you know, I go back to the offshore royalties from all of these wells are generating billions of dollars of revenue. And none of that money was -- just -- if you had taken just a fraction of it and put it, we would have had a better understanding of what's going on. But we didn't. So, we're here now.
TOM BEARDEN: Should that requirement be in some sort of regulation, federal regulation, to...
ED OVERTON: I would certainly hope that we have learned that, you know, we don't want to do this again without being prepared, and some sort of -- at least a portion of those moneys would go back into understanding the environment that you're drilling in. It's just crazy. It's absolutely nuts.
It's not terribly sticky. I mean...
TOM BEARDEN: Overton also thinks the mutual accusation society of government and industry is also nuts.
ED OVERTON: There are things that could be done, but it's not being done. So, this is a massive effort, and we need to cooperate together and stop pointing fingers.
There will be plenty of time for fingers and there will be plenty of time for hearings to figure out what caused the accident and what to do about it in the future. The -- the new regulations, restrictions on certain types of drilling without proper precautions, all of that is going to come.
But, right now, we have got a spill. We have got to work on that. We have got to work together. We don't need to be getting people irritated at each other. We need -- we need a team, a cohesive team that's working toward the successful conclusion of this damn thing.
TOM BEARDEN: As more thunderstorms began to build up to the west, the assembled boat captains decided to call it a day, for safety reasons, and began the run back into the Mississippi River.
We're proceeding at a high speed across the Gulf. At times, we cross streams of oil, and the white spray turns black.
The group made it back to the dock in Venice before the thunderstorms arrived. The people running the cleanup operation dread this kind of weather, because it tends to push oil toward the shore, where it can kill wildlife.
DOUG INKLEY, senior scientist, National Wildlife Federation: This is an eel that we pulled right out of the middle of the oil.
TOM BEARDEN: Doug Inkley, a senior scientist for the National Wildlife Federation, says it's killing animals offshore, too.
DOUG INKLEY: Obviously, it is not a very healthy environment out there for critters like this, which are an important part of the ecosystem. We also saw an Atlantic sharp-nosed shark that was obviously disoriented and swimming in very tight circles on the surface, something our captain had never seen before. And it was obviously distressed by the oil.
TOM BEARDEN: For weeks, many scientists have been urging BP to allow them to place sensors near the well to get more accurate data on how much oil is being released. They say that information will be valuable in making plans to clean it all up.