Monday, May 10, 2010

Oil and detergent

I'm quite glad that they've stopped trying to set fire to the oil spill from the bleeding wound of the former Deepwater Horizon, but I'm not sure how the use of dispersants is doing any better. From The Economist:
One of the things that the fishing boats helping the coastguard can do to help is spread dispersants. Oil is dangerous to seabirds because it dissolves the grease that insulates their feathers; they get cold and die. Dispersants cut the oil as washing-up liquid cuts the grease on dishes, allowing oil on the surface to spread down into the water. This lessens its effects on surfaces and shorelines, though it might make things worse for fish. Once dispersed the oil can then be broken down more easily by bacteria that have evolved to live off natural sources of hydrocarbons.
Hang on a moment. Didn't the use of detergents after other spills actually worsen the chance of environmental recovery? A quick Google search suggests this is a risky plan. From Physorg:
In March of 1989, the oil supertanker Exxon Valdez spilled 11 million gallons of crude oil into the Prince William Sound and impacted some 1,300 miles of coastline. It remains the largest oil spill in U.S. history. A combination of detergents and bioremediation were used in the clean-up. The detergents were nutrient rich, being high in phosphorous and nitrogen compounds. In addition, as part of the bioremediation effort, fertilizers were also used to promote microbial growth. After the first year, the treated areas were dramatically cleaner, Hazen says, but after the second year no improvements were observed. Long-term prospects for the treated area are grim.
 And this from LiveScience:
The detergents and the dispersed oil droplets all proved significantly more toxic to the coral than the crude oil itself, causing rapid, widespread death or stunted growth rates, even at doses recommended by the dispersant manufacturers...

Still, "there are limited alternatives for responding to spills," Merten said. "Essentially, there are mechanical methods [such as skimmers], in-situ burning or dispersants," Merten explained. "Generally, in open water, there is a very short window for using any method since the slick will spread and move with the wind and currents. Dispersants will continue to be considered as an option. After the oil spills, no one wins. Our job is to try to minimize further impacts, and there may be a time when dispersants help us do that for a portion of the spill."
And now, here's Bill Maher with some BP ads:

UPDATE: MoJo looks into the clean-up dilemma.