We’re still trying to assess the long-term damage of the explosion and sinking of the Deepwater Horizon oil rig in 2010, and a new study has some findings that might help clarify that process. While we know largely where most of the 160 million gallons of oil went—it contaminated 1,000 square miles of ocean floor—we now know more about how it’s biodegrading as well.
That oil contained some 125 major components, each of which biodegrades at a different rate, and each of which is present in differing amounts in different areas. The new study has found that most of those components are biodegrading faster while suspended in water than they do when they’ve settled on the ocean floor. This implies that the biodegrading process has slowed down over the last six years.
We also know that concentration of oil in a given spot can also impact the biodegrading rate, with higher concentrations taking longer to break down than lower. That makes sense when you think about it, but now we have more solid evidence that this is the case, and might help us determine better ways to deal with future oil spills
Dispersants were used to help spread the oil out after the spill. This might sound unhelpful, but it is partly responsible for the faster biodegrading of some parts of the spill.
“Our evidence is circumstantial but points to rapid biodegradation of suspended oil,” says study co-author David Valentine. “Since dispersant promotes and prolongs suspension of oil, it is likely that the decision to apply dispersant ultimately boosted biodegradation.”
Future use of dispersants might be made more efficient by having a better idea of how quickly some components will break down, and how to better disperse them.
Obviously, avoiding oil spills in the first place would be preferable, but given the increasing number of pipeline ruptures and oil rig leaks, it seems to be an inevitable part of the oil industry. Luckily, there are a lot of researchers trying to clean up the messes left by oil companies.