Oil and tar dredged up and deposited along Louisiana’s shoreline by Hurricane Isaac is from BP’s Macondo well, scientific testing has confirmed. Reappearance of tar leftover from the 2010 Deepwater Horizon oil spill could be a recurring sight along the Gulf Coast for years to come, scientists say.
Earlier this week, Louisiana officials restricted fishing in a large swath of the Gulf, encompassing about 13 miles of coastline and about one mile offshore. Federal and state health officials also warned coastal residents to avoid contact with oil, tar, and oily debris they find and report the substances to the appropriate authorities.
Tar mats have been spotted along the Gulf Coast from Louisiana to Florida ever since BP’s Deepwater Horizon rig exploded, killing 11 workers and releasing more than 20 million gallons of crude oil into the Gulf from the blown-out well a mile below the surface. BP’s attempts to curb the spill included burning the oil slick at the surface and treating oil with chemical oil dispersants on the surface and near the sea floor. While those efforts reduced the apparent size of the oil spill as it was spreading, scientists and environmental groups fear that several square miles of the Gulf floor is covered in toxic oil and tar.
Researchers estimate the one-fifth of the oil from the BP spill – about 42 million gallons – remains in the Gulf. Powerful storms such as Isaac are capable of churning up the residue thousands of feet deep and depositing it on shore.
Louisiana’s Wildlife and Fisheries Department and an adviser to Governor Bobby Jindal reported finding several tar mats of varying sizes contaminating several Louisiana beaches.
A laboratory analysis of the tar by Auburn University researchers found that it was the chemically the same as oil released in the Deepwater Horizon spill. Tar collected from Alabama beaches after Hurricane Isaac passed through the region were also found to be chemically identical to oil spilled from BP’s Macondo well.