When British Petroleum (BP) caused the Deepwater Horizon Oil Spill in April 2010, the environmental damage reached gargantuan proportions. The oil company used dispersants, but the technique was actually counter productive, just creating the appearance of the oil going away.
After the 172 million gallon (650 million liter) spill, BP applied a chemical dispersant called Corexit 9500 by plane in order to disperse the oil and help natural microbes to eat the oil faster. The oil appeared to dissipate, and that was deemed sufficient by most people, who didn't monitor the microbes and chemicals, said University of Georgia marine scientist Samantha Joye.
She thought this was not really satisfying, so she recreated the situation in the lab, using the dispersant, BP oil, and water from the gulf. What she found was that the dispersant didn't help the microbes at all - if anything, it actually hurt them.
"The dispersants did a great job in that they got the oil off the surface," Joye said. "What you see is the dispersants didn't ramp up biodegradation." In fact, she found the oil with no dispersant "degraded a heckuva lot faster than the oil with dispersants," Joye said.
In order to be as broad as possible with their lab simulations, she and her team studied the response of almost 50,000 species of bacteria in the Gulf, seeing how they reacted to water with oil, and water with oil and dispersant. The trends were similar for all species: dispersants simply didn't help, they just created the appearance of helping.
Let's translate this a bit; after the major oil spill, BP used a substance that prevents big puddles of oil forming on the surface of oceans, but doesn't do anything to prevent it from spreading to sea life; it made the oil sink, basically.
Not only does Corexit not help, it can actually prevent some microbes from eating the oil, and to make it even worse, it's actually toxic, and tends to bioaccumulate; but wait, it gets even worse. One paper concluded that the oil hazard was 52 times higher for wildlife due to the use of Corexit, because it broke the oil droplets and made them easier to ingest. So what BP did only made it seem like they're doing a good thing, when in fact, it made things even worse.
Journal Reference: Chemical dispersants can suppress the activity of natural oil-degrading microorganisms.
