Quirks & Quarks

Oil Spill Treatment Slowed the Clean-up

New research shows that microbial break down of spilled oil from the Deepwater Horizon disaster, might have been slowed down by the toxic chemical dispersants used to break up oil slicks.

Chemical Dispersants likely slowed biodegradation of oil after Deepwater Horizon disaster

The Deepwater Horizon oil rig in flames (US Coast Guard)
When the Deepwater Horizon oil well blowout spewed 5-million barrels of oil into the Gulf of Mexico, one of the main tools used against the oil was a chemical dispersant called Corexit. 7-million litres of this detergent-like chemical was used to break up oil slicks, in part to disperse the oil into the water and prevent contamination of coastlines, birds, and marine mammals.

It was also thought that dissolving the slicks like this would increase the rate at which natural bacteria would bio-degrade the oil. But work by Dr. Samantha Joye, a microbiologist in the Department of Marine Sciences at the University of Georgia, and her colleagues, has shown that Corexit seems to inhibit, rather than facilitate, the ability of microbes to break down oil, leaving the toxic oil in the water for longer.

This throws into question a big part of the case for using chemical dispersant on oil spills.

Related Links

Paper in PNAS
- University of Georgia release
The Atlantic story
- Associated Press story