It is no news that the Deepwater Horizon oil spill in 2010 was the largest accident of this type in the entire history of the petroleum industry. Hence BP's having to pay a $4.5 billion (€3.52 billion) fine for damages caused to the environment.However, a recent report made public by scientists working with the Georgia Institute of Technology and the Universidad Autonoma de Aguascalientes in Mexico states that, as bad as the oil spill would have been on its own, the dispersant used in order to tackle it only made things about 52 times worse.
As the researchers who looked into this issue explain, once the compounds used for the chemical clean-up became acquainted with the 4.9 million barrels of oil that were floating about in the Gulf of Mexico, toxicity levels pretty much went through the roof.
Green Car Congress quotes study leader Roberto Rico Martinez, who wished to draw attention to the fact that, “Dispersants are preapproved to help clean up oil spills and are widely used during disasters.”
“But we have a poor understanding of their toxicity. Our study indicates the increase in toxicity may have been greatly underestimated following the Macondo well explosion,” this specialist went on to add.
According to the laboratory-based experiments carried out by these scientists, the mixture of Corexit 9500A (i.e. the dispersant used to deal with the Deepwater Horizon oil spill) and oil had a toxicity about 52 times greater than that of the oil alone.
This translated into an increased mortality rate of the microscopic animals found at the base of the food web in the Gulf of Mexico.
Needless to say, this means that the marine species feeding on these microorganisms (eg. fish, shrimp, crabs) were also greatly affected, simply because they were left without their main source of nutrients.
“What remains to be determined is whether the benefits of dispersing the oil by using Corexit are outweighed by the substantial increase in toxicity of the mixture,” argued Biology Professor Terry Snell.
Furthermore, “Perhaps we should allow the oil to naturally disperse. It might take longer, but it would have less toxic impact on marine ecosystems.”