Simon Boxall, an expert at Britain's National Oceanography Center who has helped analyze various major oil spill cleanups, said several detailed experiments had been conducted since the Exxon Valdez spill, looking at areas that were left alone, as well as at areas cleaned up chemically or mechanically.
"The chemically cleaned up areas have taken the longest to recover and they are still damaged," Boxall said. "The areas that were left alone actually recovered much quicker."
Some 10,000 people were flown in to deal with the Exxon Valdez spill, and Boxall said scientists now wondered whether the "cleanup town" that grew up around it caused more environmental damage than the oil itself.
Christoph Gertler of Bangor University, who has been studying various potential bacterial remedies for oil spills, said reports by the U.S. National Oceanic and Atmospheric Administration suggested that dispersants were "changing the nature of the oil in a very unfavorable way," making it more difficult for naturally occurring marine bacteria to break it down.
Boxall said it was important to remember that oil coming from the BP well was a light crude that would break down and evaporate fairly quickly when it came to the surface.