4:28pm

Thu December 9, 2010
Environment

Seafloor Samples Show Troubling Effects Of Oil Spill

Originally published on Wed May 23, 2012 10:40 am

Scientists trying to determine the fate of the oil from the BP blowout recently dived in a mini-sub to look for it at the sea floor. And they found it -- or I should say we found it, since I was along on the dive.

To start our trip to the seafloor, three of us scrunched into the titanium hull of a submarine named Alvin, on the rear deck of the research vessel Atlantis, from the Woods Hole Oceanographic Institution.

The descent through half a mile of inky black water was gentle, almost meditative. And when the sub's lights finally illuminated the bottom, the scene was serene -- fish and shrimp paddled around near the seafloor, going about their business, and crabs scuttled along the bottom.

There was no black goo on the bottom, about 10 miles from the Macondo well. But biologist Samantha Joye from the University of Georgia says she wasn't expecting anything quite so blatant.

Instead, we saw a brown haze covering the seafloor, and Joye started noticing things that weren't quite right.

A once-magnificent fan coral was covered with brown fuzz -- dead.

We cruised along some more, with pilot Mike Skowronski guiding us past a feature called "Sleeping Dragon" -- a mound of methane ice, the size of a school bus. It is home to creatures adapted to living near natural petroleum seeps.

A few minutes later, the texture of the seafloor changed from smooth brown to bumpy, like cottage cheese.

"It's not typical," Joye said, peering through a camera that looks straight down on the bottom. "It should be flat, boring gray, and it's brown, very porous looking, spongelike material."

Joye said it looks a lot like samples she collected in September.

"That stuff contained a good bit of oil, so I think we're getting into the area where there's been substantial deposition of oil on the bottom," she said.

And the question foremost on her mind was: What's all this brown muck doing to life on the seafloor?

Oil 'Pudding' On The Seafloor

After nearly six hours of surveying the seafloor, the Alvin gently rose again to the surface.

Back onboard the Atlantis, the scientists went to work, examining many dozens of seafloor samples collected by Alvin and by a shipboard instrument called a multicorer.

The cylindrical samples of seafloor share a similar pattern: Those taken within a few miles of the Macondo well are covered with a 2-inch layer of muck that looks like chocolate pudding.

Laura Beer, a post-doc from Joye's lab, says you'd almost want to taste it -- that is, until you notice it's full of dead worms and other sea life. We see almost no living creatures in these samples.

The biologists say they were either smothered by the brown gunk or poisoned by it. Joye needs lab tests to figure out its exact composition, but judging by previous samples, she knows what to expect.

"It's oil and mucus and marine debris and everything else that's pulled out through the water column when [the oil] came down," she says. "When you're this close in [to the Macondo well], you could also get some tar and asphalt just coming out of the well and rolling downslope."

Mud samples she tested from her previous trip contain far less than 1 percent oil, she says, but that's still 1,000 times more oil than you'd usually find in gulf mud.

Her colleague, Andreas Teske from the University of North Carolina, Chapel Hill, says most of this "pudding" is probably oil from the BP well that has since passed through the digestive systems of all sorts of animals on its way to the seafloor. Teske says it reminds him a lot of the spring algae blooms that can choke coastal bays.

"We think something similar has happened here," he says. "It was not a spring bloom, but an 'oil bloom,' and we are looking right now at the remnants of this oil bloom."

'Years For The System To Recover'

Regardless of how it got there, Joye says this brown muck is killing life on the seafloor.

"It's going to take, I would suspect, years for the system to recover," she says. "And it's going to take more time for certain components of the system to recover."

Ian MacDonald from Florida State University says the dead fan coral was likely 500 years old when the brown muck came along to snuff it out.

"That really was one of the simple examples that really hit home to me, exactly what I have been concerned about," MacDonald says.

There are still government officials and scientists who want more proof before they are willing to say a lot of BP oil ended up at the bottom of the Gulf of Mexico, and MacDonald certainly respects that skepticism. After all, skepticism is a healthy element of science.

"At the same time, the evidence piles up, and after a while you say, 'Gee, there is oil on the bottom,' " MacDonald says. "And, as a simple statement at the end of this cruise, I have to say, 'Gee, there is oil on the bottom,' and that's too bad.' "

Copyright 2012 National Public Radio. To see more, visit http://www.npr.org/.

Transcript

GUY RAZ, host:

From NPR News, this is ALL THINGS CONSIDERED. I'm Guy Raz.

MELISSA BLOCK, host:

And I'm Melissa Block.

Last month in the Gulf of Mexico, scientists set out on an expedition to see how the Guld ecosystem is doing after the BP oil spill. Yesterday o nthe program, we heard from NPR's science correspondent Richard Harris, who joined them on the trip. He told us about a mini sub being used to explore the sea floor and to examine firsthand the damage done. Well, today, Richard gets a seat in the sub and takes us with him.

RICHARD HARRIS: To start our trip to the sea floor, three of us scrunch into the titanium hull of a submarine named Alvin, on the rear deck of the research vessel Atlantis.

(Soundbite of submarine)

Unidentified Man: Pay attention on the main. Release the latch and lower away when ready.

HARRIS: The descent through half a mile of inky black water is gentle, almost meditative. And when the sub's lights finally illuminate the bottom, the scene is serene - fish and shrimp paddle around near the sea floor, going about their business, and crabs scuttle along the bottom.

(Soundbite of submarine)

HARRIS: So, the surface doesn't look black and covered with oil in that sense.

Professor SAMANTHA JOYE (Biologist, University of Georgia): No, no, no. No. And it - I don't think it would.

HARRIS: Yet,´┐Żbiologist Samantha Joye, from the University of Georgia, quickly notices things that aren't quite right down here. A once magnificent fan coral is covered with brown fuzz, dead.

(Soundbite of submarine)

Unidentified Man: We're going to be heading towards Sleeping Dragon. Target 19.

HARRIS: Pilot Mike Skowronski guides us past a mound of methane ice, the size of a school bus. It's home to creatures adapted to living near natural petroleum seeps. And as we glide along, suddenly, the texture of the seafloor changes.

Mr. MIKE SKOWRONSKI (Pilot, Alvin): Now cruising over a spot and looking at it through the downward-facing camera and looks like cottage cheese.

HARRIS: Is that typical?

Prof. JOYE: No, it's not typical. It should just be flat, boring gray, and it's brown, you know, very porous looking, spongelike material.

(Soundbite of radio)

Unidentified Man: (unintelligible)

HARRIS: Joye says it looks a lot like samples she collected in September.

Prof. JOYE: That stuff contained a good bit of oil, so I think we're getting into the area where there's been substantial deposition of oil on the bottom.

HARRIS: And the question foremost on her mind is: What is all this brown muck doing to life on the sea floor?

Mr. SKOWRONSKI: Now we're heading back to target seven to pick up the camera and then I'll call you to drop weights.

HARRIS: Once the Alvin lets go of its iron weights, the sub rises gently to the surface.

(Soundbite of radio)

Unidentified Man: (unintelligible)

HARRIS: And back onboard the Atlantis, the scientists go to work, examining many dozens of sea floor samples collected by the Alvin and by a shipboard instrument called a multicorer.

(Soundbite of tapping)

HARRIS: There's a familiar pattern. Sea floor samples taken within a few miles of the Macondo well are covered with a 2-inch layer of muck that looks like chocolate pudding. Laura Beer, from Joye's lab, says you'd almost want to taste it.

Ms. LAURA BEER: It's, like, about 55 percent chocolate.

HARRIS: I'm holding out for the 72 percent.

Ms. BEER: Me too.

HARRIS: Humor softens a grim reality - this material is full of dead animals, worms being the most obvious - that were either smothered by the brown gunk or poisoned by it. Joye needs lab tests to figure out its exact composition, but judging by previous samples, she knows what to expect.

Prof. JOYE: It's oil and mucus and marine debris and everything else that's pulled out through the water column when it came down. So, when you're this close in, you could also get some tar and asphalt just coming out of the wellhead and rolling downslope.

HARRIS: Samples she's tested from her previous trip contain far less than one percent oil, she says, but that's still 1,000 times more oil than you'd usually find in gulf mud.

Her colleague, Andreas Teske from the University of North Carolina in Chapel Hill, says most of this pudding is probably oil from the BP well that has since passed through the digestive systems of all sorts of animals on its way to the sea floor. You know those spring algae blooms that sometimes choke coastal bays...

Professor ANDREAS TESKE (University of North Carolina at Chapel Hill): We think that something similar has happened here. It was not a spring bloom, but an oil bloom, and we are looking right now at the remnants of this oil bloom.

HARRIS: Regardless of how it got there, Samantha Joye says this brown muck is killing life that lives on the bottom, and it's not just a passing thing.

Prof. JOYE: Because it's going to take, I would suspect, years for the system to recover. And it's going to take more time for certain components of the system to recover.

HARRIS: Like that dead fan coral. Ian MacDonald from Florida State University says it was likely 500 years old when the brown muck came along to snuff it out.

Professor IAN MACDONALD (Florida State University): That really was, you know, one of these sort of simple examples of that that really hit home to me, exactly what I've been concerned about.

HARRIS: There are still government officials and scientists who want more proof before they are willing to say that a lot of BP oil did end up at the bottom of the Gulf of Mexico. MacDonald certainly respects that skepticism. It's a healthy element of science.

Prof. MACDONALD: At the same time, the evidence piles up, and after a while you say, well, gee, there is oil on the bottom. And I think, you know, as a simple statement at the end of this cruise, I have to say, gee, there is oil on the bottom. And that's too bad.

HARRIS: The scientists are now analyzing their samples back in their labs on solid ground to understand better what they saw at the bottom of the Gulf of Mexico.

Richard Harris, NPR News. Transcript provided by NPR, Copyright National Public Radio.