DEBORAH AMOS, host:
The television pictures of pelicans covered in oil is a daily reminder of what's happening to wildlife along the Gulf Coast, but scientists say there's also a toll that's much harder to see. NPR's Elizabeth Shogren has our story.
ELIZABETH SHOGREN: Everybody feared the oil would rise to the surface like in salad dressing, causing big problems in the marshes and on the surface of the Gulf. Now some scientists are focusing on contamination thousands of feet below the surface.
Professor PROSANTA CHAKRABARTY (Louisiana State University): It's so depressing and just heart-wrenching.
SHOGREN: Prosanta Chakrabarty is a fish scientist from Louisiana State University. He says BP and the government increased the problem underwater by spraying huge quantities of chemical dispersants at the spewing well.
Prof. CHAKRABARTY: Fish strategy even to this day is out of sight, out of mind. But, in fact, just because it's below the surface doesn't mean it's not doing damage. It just means that we can't tell what it's doing.
SHOGREN: Several research vessels are on the Gulf now, hunting for oil. Samantha Joye is a University of Georgia marine scientist. She's analyzing water samples from the deep as she and her team cruise the Gulf.
Dr. SAMANTHA JOYE (University of Georgia): The first one I smelled, I just sort of went whoa and stepped back. It's a very intense smell.
SHOGREN: She says she found levels of benzene and other toxic gases much higher than she's ever seen before from natural causes.
Dr. JOYE: I cannot think of another explanation that makes all of our data tell a cohesive story other than it's emanating from the spill.
SHOGREN: Her team is mapping what they think is a massive plume of polluted water that stretches more than 12 miles from the well to the west and southwest. It's two miles across and a couple thousand feet tall. The closer to the well the samples were taken, the more highly concentrated the oil and gas are. Other independent scientists have found different big plumes, and federal scientists are on the hunt now, too. But so far, federal officials and BP say they cannot confirm that Deepwater Horizon is creating big underwater plumes. Joye believes she'll have the proof soon.
Dr. JOYE: We're going to fingerprint this petroleum that we're finding in these plumes.
SHOGREN: The scientists say they've seen a lot of dead jellyfish, but they know Deepwater Horizon's toll is much greater than what they can see. Oil is toxic at 10 parts per million, and even BP's data shows concentrations at that level. But everyone agrees almost nothing is known about the effect all that oil is having far underwater.
Dr. FRANK MULLER-KARGER (University of South Florida): What is the impact? We don't know.
SHOGREN: Frank Muller-Karger is an oceanographer at the University of South Florida.
Dr. MULLER-KARGER: How large is the impact? We don't know. Where exactly is it happening below the surface? We don't know. So all of these things are frustrating.
SHOGREN: Muller-Karger says what he does know is it's springtime, when the deep waters of the Gulf are full of fish eggs. After a couple of days, an egg turns into something called a larva.
Dr. MULLER-KARGER: And it starts feeding on whatever it sees, and it expects to see food, not little oil droplets. And it will eat oil droplets, because they just open their mouth and eat whatever they see. So this is what's happening, and it's happening to sensitive species like the bluefin tuna.
SHOGREN: Scientists say it should not have surprised BP and the government that so much of the oil stayed submerged. Government studies had predicted it would do this. Prosanta Chakrabarty from Louisiana State University is especially worried about a community of bizarre-looking ancient fish that live in the deep depths of the Gulf. One of them, a pancake batfish, is a new species that he helped discover.
Prof. CHAKRABARTY: And now their once very stable habitat is covered in oil.
SHOGREN: These fish hide out near the bottom, but there's very little food for them there.
Prof. CHAKRABARTY: What happens is, at night, they use the cover of darkness to kind of come up closer to the surface to eat.
SHOGREN: That's means they're swimming a mile or more, sometimes every day.
Prof. CHAKRABARTY: We don't know if they can avoid plumes that are miles long and hundreds of feet deep.
SHOGREN: And Chakrabarty says while there are lots of plans to clean up the oil on the surface, no one has any strategy for cleaning up the deep water.
Elizabeth Shogren, NPR News.
NPR transcripts are created on a rush deadline by Verb8tm, Inc., an NPR contractor, and produced using a proprietary transcription process developed with NPR. This text may not be in its final form and may be updated or revised in the future. Accuracy and availability may vary. The authoritative record of NPR’s programming is the audio record.