A new study led by the University of Georgia found that chemical dispersants often used in oil spill cleanups can actually inhibit the microorganisms that naturally degrade oil.
To examine the microorganisms, researchers used a controlled lab setting to simulate conditions of the Gulf of Mexico directly following the 2010 Deepwater Horizon oil spill. They replicated the concentrations of oil and dispersants after the spill and found that the presence of dispersants “significantly altered” the composition of microbes in the area.
The dispersants appeared to promote the growth of Colwellia, which are microorganisms that are capable of degrading the dispersants. However, in simulations with oil but no dispersants, the growth of an oil-degrading microorganism, Marinobacter, was stimulated.
“The fact that dispersants drove distinct microbial community shifts that impacted oil degradation efficiently came as a big surprise,” lead author Dr. Samantha Joye, professor of marine science at the University of Georgia, explained in a news release. “It is critical to quantify the factors that influence the efficiency of oil biodegradation in the environment, and that includes dispersants.”
Oil dispersants are widely used in emergency responses to oil spills, but the amounts used in the Gulf of Mexico were unprecedented. The results of this study show that they are not necessarily the right solution.
“These compelling results show the naturally occurring communities of oil-degrading microorganisms, especially Marinobacter, are quite proficient at degrading oil and that oil biodegradation was more efficient in the absence of chemical dispersants,” Dr. Joye said.
To learn more:
- Read the full news release: Oil dispersants can suppress natural oil-degrading microorganisms, new study shows
- Read the PNAS study: Chemical dispersants can suppress the activity of natural oil-degrading microorganisms
- Read more about Joye’s work with Ecosystem Impacts of Oil & Gas Inputs to the Gulf: New article in Science calls for more natural baseline data collection in world’s oceans
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