FALMOUTH, Massachusetts – Microbial activity within the Macondo oil slick was much more effective at reducing the oil than predicted, according to a study by the Woods Hole Oceanographic Institution. A report scheduled for release today noted that the bacteria in the slick degraded the oil five times faster than the bacteria outside the slick.
The WHOI release said the study team was taken aback by the ability of the microbes in the Gulf of Mexico to breakdown the oil in the first place.
“We thought microbe respiration was going to be minimal,” said WHOI chemist and senior study author Benjamin Van Mooy. “We found that the answer (to how the microbes reacted) was ‘quick’ by a lot.”
The investigators found that bacteria responded at a very high rate based on measuring changes in the oxygen levels of water taken from the slick.
Van Mooy said he is not sure what fraction of the oil removal is due to microbes, as there were other contributors including evaporation, dilution, and dispersion, but the five-fold increase suggested that the bacteria contributed significantly.
“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 said in their paper.
The lead author of the paper, Bethanie Edwards, said the study indicates “that microbes had the metabolic potential to break down a large portion of hydrocarbons and keep up with the flow rate from the wellhead.”
Follow-up studies are going to investigate what happened to the energy generated by the digestion. A mystery to the scientists is why the oil-eating microbes did not seem to use that energy to reproduce at the predicted rate.
Study of Macondo oil spill in the Gulf puzzles scientists