In A Nutshell
On April 20, 2010, the Deepwater Horizon oil rig exploded in the Gulf of Mexico, causing perhaps the largest maritime oil spill in history. British Petroleum, the charters of the oil rig, addressed the spill with the use of Corexit, a dispersant that would clean the oil and then allegedly biodegrade. Corexit did not clean the Gulf, nor did it biodegrade; it only diluted the oil. Corexit is also toxic to marine life.
The Whole Bushel
The Deepwater Horizon oil spill is perhaps the most infamous environmental disaster in recent history. High pressure methane gas caused the oil rig, which was located in the Gulf of Mexico around 65 kilometers (40 mi) off the coast of Louisiana, to explode. Eleven workers were killed and over 200,000,000 gallons of oil spilled into the ocean.
BP had chartered Deepwater Horizon. To address the situation, BP made use of the chemical Corexit, a dispersant similar to many detergents. More than 1.8 millions gallons of Corexit were applied to Gulf waters, with over 700,000 of that number being injected under the surface.
How do detergents work? Oils are lipids that tend to clump together. Detergent molecules surround oil molecules, forming a layer that separates each oil molecule from another. This stops clumping. The separated oil molecules are then dispersed throughout the water.
Essentially, Corexit did not actually clean the ocean or eliminate the spilled oil; it only diluted it. But then again, the same could be said of dirty clothes thrown in the washing machine, or oily dishes cleaned in the dishwasher—the difference being that the resultant dirty water is pulled away and disposed of.
Corexit also did damage all its own. Corexit is toxic, and is less effective than some other dispersants at handling a spill. It’s especially toxic to marine life, and not only because it was very ineffective at removing submerged oil. Additionally, the toxicity can be passed from fish to fish through bioaccumulation: If one fish eats another, it will absorb the toxic content of its prey.
Corexit was supposed to be biodegradable, that is, it was meant to break down into the environment. It didn’t, instead drifting along with the oil. The mixture of Corexit and crude oil created a harmful chemical that became water soluble. In other words, it can evaporate and return as polluted rain.
Here’s the best (read: worst) part: BP continued to use Corexit in spite of being forbidden to do so by the Environmental Protection Agency. While it did dilute the oil, evidence suggests that the ecosystem of the affected area has not recovered. Animals like dolphins and sea turtles are still dying at above-average rates as a result of the pollution.
Show Me The Proof
National Commission on the BP Deepwater Horizon Oil Spill and Offshore Drilling
BP Oil Spill Dispersants Drifted, But Didn’t Degrade
Corexit – BP Oil Spill
Huffington Post: Gulf Of Mexico Dolphin Deaths Point To Continued Effects Of BP Oil Spill, Group Alleges