The Slatest

BP Acknowledges Existence of 25,000-Pound “Tar Mat” on Louisiana Coast

A berm built to capture spilled oil in Barataria Bay, Louisiana.

Mario Tama/Getty

New Orleans investigative publication the Lens has a new story about the BP oil spill cleanup that, if nothing else, will introduce you to an unfortunate concept: the “tar mat.”

Tar mats formed when Deepwater Horizon oil nearing the Louisiana coast became weighed down by the silt from the Mississippi River and sank to the bottom near the shoreline. Quickly covered by sand and sediments from the state’s rapidly-eroding coast, they have frequently been uncovered and washed ashore by stiff southerly winds, especially during tropical storms.

The Lens’ story is about BP’s statement that the Gulf of Mexico is “returning to baseline conditions” five years after the 200 million-gallon Deepwater Horizon spill. This assertion was condemned as “inappropriate and premature” by the National Oceanic and Atmospheric Administration, and would also seem to be contradicted by the Lens’ report of ongoing BP and Coast Guard work removing a 25,000 pounds-and-counting tar mat from a beach some 50 miles from New Orleans:

BP has been working to clean the beach since Feb. 23, well before their statement was released. However, they didn’t notify the Coast Guard of the mess until March 13, said Seth Johnson, a spokesman for that agency.

Meanwhile, a few miles to the west, two dead adult bottlenose dolphins had washed up on Queen Bess Island, continuing what has been a large die-off of dolphins in Barataria Bay since the oil washed into that critical coastal estuary five years ago.

Tests to confirm whether the oil in the mat came from the Deepwater Horizon have not yet been completed.