Oil spills happen all the time. But in 2010, the Deepwater Horizon disaster in the Gulf of Mexico showed the world what a real oil spill emergency looks like: 4.9 million barrels of oil dumped into the Gulf of Mexico. Experts watched the spill unfold in horror—but many were convinced that the Gulf would recover.
Turns out they were right. According to researchers at the University of Tennessee in Knoxville, the Gulf of Mexico has an incredible ability to bioremediate, thanks in large part to oil-eating bacteria that have been observed in the years since the spill.
The researchers, led by Dr. Terry C. Hazen, used a new approach to identify naturally occurring—but unknown—oil-munching bacteria in the Gulf. These bacteria in the past were identified by growing them in lab culture dishes and identifying them using microscopes. The new method ("ecogenomics") lets scientists instead use genetic information, DNA, and protein analysis, and and other data to analyze the bacteria.
Hazen spoke about the research at this year’s National Meeting & Exposition of the American Chemical Society (ACS): "The Deepwater Horizon oil provided a new source of nutrients in the deepest waters….With more food present in the water, there was a population explosion among those bacteria already adapted to using oil as a food source. It was surprising how fast they consumed the oil. In some locations, it took only one day for them to reduce a gallon of oil to a half gallon. In others, the half-life for a given quantity of spilled oil was six days."
Oil company executives would probably breathe a sigh of relief after reading this—after all, it theoretically reduces the burden on them to clean up after big spills. But it’s important to note that the research only applies to the Gulf of Mexico, which has so many oil-eating bacteria because of its natural oil seeps. These seep up to 1.4 million barrels of oil each year, no manmade spills required.
When Shell returns to drill in the Arctic Ocean (the company recently halted operations because of safety issues), oil-eating bacteria won’t gobble up their mess—and eventually, there will be a mess, judging by Shell’s current Arctic track record.
While oil-eating microbes do exist in the area, they have slower metabolic rates. From CBC News:
Ocean currents in the Arctic Ocean do circulate, but over a much larger area than the Gulf of Mexico, so it would take years for the bacteria to return to the same site, if they return at all. So any bacteria exposed to hydrocarbons will be swept away, which means new blooms will have to grow to replace them.
The cold temperatures also affect the nature of the oil, making it thicker and more viscous, which is harder for the bacteria to break down.
Oil-eating bacteria, while helpful, are not a real global cleanup strategy in the next drilling frontier. At least we know they can help us out in the current one.