Underwater worms at the likely site of an abandoned oil well left black "castings" on the sandy mound above it, piquing the interest of researchers who want to know whether oil leaking from the well might be the reason.
Michael Hirshfield, chief scientist for the advocacy group Oceana, cautioned Tuesday that photographs taken by robots in about 250 feet of water south of Gulf Shores, Ala., aren't proof the worms are swallowing oil-stained sediment and producing black instead of the usual white wormholes.
"It's intriguing, but not definitive," he said in discussing a two-month research trip under way to study effects of the BP PLC oil spill in the Gulf of Mexico.
An Associated Press report earlier this summer showed nobody was checking more than 27,000 aging, abandoned wells.
Oceana said it decided to check out one such site after the AP report as part of a larger investigation of sensitive sites that could be affected by future oil spills.
The underwater robot couldn't take sediment samples -- just pictures, Hirshfield said. The photographs showed a lump about 3 to 6 feet high in the middle of a heavily trawled, very flat area. It was only the hump that was dotted with black -- wormholes on the flat sea floor around it were white.
"Talk about looking for a needle in a haystack," he said.
Hirshfield said that since the expedition began Aug. 11, studies by other researchers have indicated nearly 80 percent of the estimated 200 million gallons of oil from the BP spill remain in the Gulf. Federal officials say the total oil still in the Gulf is much less.
"This new information reinforces our concern for marine life in the Gulf," he said. "While it is good news that no new oil is gushing from the well, seafloor habitats and fish remain vulnerable to the oil that is already in the water. We hope our expedition will help us better understand the true impacts of this disaster, even after the media cameras are gone."
Oceana campaigns against offshore drilling but its research will be objective, said actor Ted Danson, an Oceana board member. He was joined by actor Morgan Freeman, New York-based Spanish model Almudena Fernandez and the mayor of San Pedro, Belize, Elsa Paz.
In the next two weeks, scientists on the 170-foot Oceana Latitude will set out 40 anchored and buoyed lines designed to capture undersea oil and create a 3-D map of any plumes around the wellhead. Plastic film that is especially sensitive to hydrocarbons will be attached on each line from the surface to the sea floor.
Each line will be left in the water for 5 days, then pulled up, put in a jar and exposed to light that will fluoresce if the film collected oil. It will take much more detailed lab work on shore to work up maps from the data, Hirshfield said. He said the film is far more sensitive than the scans used so far.
"That's going to be pure science," Danson said. "If what we find is that it's marvelously clean as a whistle and the fisheries are good to go, hallelujah! I don't think that's what they're going to find. But if they do, it's important to say so."
Danson, Freeman and Oceana CEO Andrew Sharpless all voiced opposition to offshore drilling.