A federal investigation suggested a faulty cementing procedure led in part to the failure of BP's Macondo well last year. The failure led to a gas explosion on the Deepwater Horizon rig that killed 11 workers and led to one of the worst environmental disasters in the history of the oil industry.
A study published by Wood Hole Oceanographic Institution concluded from changes in oxygen levels in the oil slick that bacteria helped decompose the oil.
The authors note that microbes were able to metabolize a significant portion of the oil that leaked from the wellhead.
"Extrapolating our observations to the entire area of the oil slick supports the assertion microbes had the potential to degrade a large fraction of the oil as it arrived at the surface from the well," the researchers were quoted by the online Offshore Magazine as saying.
Benjamin Van Mooy, one of the report's authors, was quoted as saying researchers had expected a minimal amount of microbial degradation of the oil from Macondo.
"We found that the answer (to how the microbes reacted) was 'quick' by a lot," he said.
He cautioned, however, that researchers weren't sure how much of the overall oil degradation was attributed to microbes versus evaporation or other factors.