770,000 Gallons of Dispersant from BP Spill Didn't Degrade

Perhaps one of the most controversial elements of the BP spill saga was the oil giant's use of large quantities of chemical dispersent Corexit to attempt to break down the oil both spewing from the wellhead and on the slick on the ocean surface. The EPA told BP to stop the practice, but the company continued anyways, and nobody was willing to make them stop. The company maintained all along that the dispersants would break down along with the oil -- but a new study reveals that this wasn't the case. Some 771,000 gallons of dispersant, it turns out, simply swirled around in the sea for months. Yes, it turns out that, according to a study recently published in Environmental Science & Technology, the dispersants, far from immediately degrading, they rode underwater plumes for months.

According to Care2, the study "found that popular to contrary belief, the dispersant did not degrade but instead moved with the oil plumes until at least September, 2010." And of course, as anyone who's followed the dispersant saga knows, there's this: "Prior to the Gulf oil spill disaster, no deepwater applications of dispersant had been conducted, and thus no data existed on the environmental fate of dispersants in deepwater." Furthermore, it's still unclear whether the dispersants did any good at all -- or whether they perhaps made things worse.

And the jury's still out. As so often happens, questions merely beget more questions:

"When you read about Corexit, it's supposed to biodegrade," Carys Mitchelmore of the University of Maryland's Center for Environmental Science told WiredScience. But specific rates have not generally been reported, she adds. So the dispersant's apparent persistence in the new paper is somewhat unexpected.
So now, do are we not only uncertain as to whether the dispersant's use was dangerous to underwater ecosystems, but we're uncertain whether the stuff biodegrades like it's supposed to, either. Nice.

More on Chemical Dispersants
"People are Dropping Dead" from BP Dispersants : Toxicologist ...
Gulf Spill Exclusive : Shocking Marine Life Destruction and Angry Locals

Tags: Gulf Oil Spill | Oil | Oil Spill | United States

Best of TreeHugger