SAN FRANCISCO — Scientists in Berkeley, Calif., have discovered a voracious species of primitive oil-eating bacteria that have largely consumed the huge deep-sea plume of dispersed oil fouling the Gulf of Mexico since the Deepwater Horizon oil rig exploded in April.
As a result of the bacteria, the toxic plume that was once 22 miles long and more than 3,600 feet deep is now “undetectable,” Terry Hazen, chief microbiologist at the Department of Energy’s Lawrence Berkeley National Laboratory, reported Tuesday.
For millions of years, bacteria have been eating oil seeping from the sea floor, but Hazen and his colleagues found a particularly gluttonous form that multiplied rapidly in the months after the rig blast and spearheaded the plume’s disappearance from the gulf’s waters. “We’re still finding bacteria but no oil,” he said.
Because of its unique ability to consume oil swiftly, the bacteria could prove valuable in future oil spills once they are firmly identified and cultured for what Hazen calls “bioremediation.”
The plume was created by a chemical dispersant called Corexit 9500 that BP dumped around the wellhead in an effort to break up the torrent of crude oil gushing from the seabed. The plume continued spreading through the water, even after the underwater gusher was plugged July 15.
The spreading plume had aroused fears that it could devastate marine ecology in the gulf because many oil-eating bacteria consume oxygen as well — a process that could produce “dead zones.” But the newly found microbes devour the microscopic droplets with far less depletion of oxygen than other oil-eating bacteria.
