Terry Hazen of Lawrence Berkeley National Laboratory reported in the journal Science that a newly discovered species of microbe was apparently devouring one large underwater plume of oil from BP’s Deepwater Horizon spill. This report came on the heels of a Science piece just published by Woods Hole Oceanographic Institution confirming the existence of the huge (Manhattan-sized) plume and noting that microbes did not appear to be degrading it.
While the research may seem contradictory, Hazen and Richard Camilli, lead author of the Woods Hole research, say the studies are consistent and actually complement each other. Woods Hole researchers left the plume back in June when Hurricane Alex caused a mass exodus from the Gulf. At that time oil was still leaking and the researchers had found no evidence of any oil-eating microbes.
Hazen’s team, however, continued surveying the plume and he said that within two weeks after the spill was stymied in mid-July by BP’s static top-kill that the plume was virtually undetectable. Hazen attributed the plume’s demise to a never-before described species of oil-eating microbe. According to Hazen the microbe appears to be related to the order Oceanospirillaes and thrives in the cold (41 degrees Fahrenheit) deep, Gulf waters.
The discrepancy might be attributed to the different way in which the two groups sought to detect microbes. Camilli’s Woods Hole researchers looked for low oxygen levels, regarded as a sign of bacteria actively feeding on oil. Hazen’s team looked for different genes and enzymes that microbes emit when actively feeding on oil. Hazen concluded there were no concentrated areas of low oxygen because dispersants and ocean currents had spread the oil into a thin veil of tiny droplets. Hazen’s study found the oxygen saturation outside the plume to be 67 percent and the oxygen saturation inside the plume to be at 59 percent.
Camilli believes the Lawrence Berkeley work to be encouraging but notes there is no room for complacency, “The long-term ecological implications… remain uncertain and I don’t think anyone could rightly argue that dumping 4.1 million barrels of oil into the Gulf of Mexico was ecologically beneficial,” said Camilli.
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