In a study published this week in the Proceedings of the National Academy of Sciences, researchers revealed what they've called a "bathtub ring" of oil that has formed on the seafloor. Researchers measured levels of hopane, a chemical found in oil
that doesn't decompose easily, along with spatial analysis to determine where the oil came from.
In the area surrounding the Macondo well the top layer of higher concentrations of oiled sediment remains on the top layer of the sea floor, said David Valentine, a geochemistry professor at the University of California at Santa Barbara, who authored the study.
Researchers analyzed the placement of the chemical in the Northern Gulf, and found patterns that point straight at the Macondo well as the source, Valentine said in email. He said it became clear this was recently placed oil due to an exceptional amount concentrated near the well.
In those areas, the top layer of hopane was sometimes ten times as great than in areas further away from the well.
BP cast doubt on the accuracy of the study's findings. In a statement, Jason Ryan , a company spokesman, said the researchers did not use "rigorous chemical fingerprinting" when they identified the oil.
A fingerprinting analysis can be used to determine where petroleum products originated. Valentine said fingerprinting was performed, but has not yet been published, adding: "We chose to use the spatial analysis because it appears more accurate given the magnitude of this spill."
Bookmarks