Gulf Oil Spill: How BP's Dispersants May Contaminate Seafood for Years

(MoneyWatch)  BP's (BP) decision to dump nearly one million gallons of chemical dispersants into the Gulf of Mexico was probably an earnest, well-intentioned attempt to lessen the effects of this depressingly humongous environmental disaster. But these chemicals are likely to wreak havoc on the the billions of dollars of seafood that comes from the Gulf.

The dispersants, chiefly Corexit, work to break up oil so that it can be broken down more easily. BP has said it is using them, in part, to stem the tide of oil washing to shore and into fragile marshes.

That all sounds good, but the problem with chemicals like Corexit, outside the fact that they are inherently toxic, is that they don't actually get rid of the oil -- they just spread it around. The result is that oil that normally would float on the surface now seeps deeper into the water where its various components, many of them toxic, become available to not only fish but the tiny plants and organisms that fish and other marine animals eat. In other words, the oil -- and human carcinogens like napthalenes, benzene, toluene and xylenes -- enters the food chain.

And as we've seen with mercury, once a toxin enters the ocean food chain, it can stay there for a long time. So ten years from now, when the black pelicans and thick globs of oil are gone, there will very likely still be seafood -- shrimp, bluefin tuna and maybe snapper and grouper -- that are contaminated with BP's oil. This could mean a permanent end to the Gulf's thriving seafood industry, a scenario some fisherman are already preparing for.

Oil floating about underneath the water is not theoretical. Teams of university scientists have already identified huge plumes down as much as 3,300 feet. But that didn't stop BP's CEO Tony Hayward from adding another entry to his list of boneheaded remarks when over the weekend he denied that there were any underwater plumes, even though multiple research teams have confirmed them.

BP has always contended that marine microbes will come to their rescue and ultimately break down the oil. But this sort of thing doesn't happen overnight. University of Louisville microbiologist Ronald Atlas noted that it takes "weeks to months to years, depending on the compounds and concentrations -- not hours or days." And the farther down the water column oil goes, the longer it takes for microbes to do their job since colder, deeper waters inhibit microbial growth. And while Mother Nature slowly does her job, toxins enter the food chain.

Making matters worse, if that's possible, the Corexit that's been injected at the site of the oil spill, a mile below the surface, may have the unintended consequence of killing the microbes it is meant to help, thanks to the fact that it contains the toxic solvent 2-butoxyethanol.

And let's not even talk about what happens if the oil gets into the Gulf Stream.

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