PNAS: Uta Passow Demonstrates Contaminants From Deepwater Horizon Lingered for Months Before Sinking

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Between April 20 and July 15, 2010, millions of barrels of crude oil gushed into the Gulf of Mexico from a blown well beneath the Deepwater Horizon oil rig; it was the largest marine oil spill in U.S. history. Although the oil was undetectable in surface waters within a few weeks after the well was capped, oil was found in seafloor sediments for months thereafter. Because the mechanisms that transport petroleum hydrocarbons to the ocean floor are not well understood, the deeper environmental consequences were unclear.

A new study by UC Santa Barbara research oceanographer Uta Passow and other scientists working in the Gulf of Mexico has found that contaminants from the oil spill lingered in the subsurface water for months after oil on the surface had been swept up or dispersed. The investigators also detailed how remnants of the oil, black carbon from burning oil slicks and contaminants from drilling mud combined with microscopic algae and other marine debris to descend in a "dirty blizzard" to the seafloor. Their findings appear in the Proceedings of the National Academy of Sciences.

"This sedimentation is primarily due to marine snow " so-called dust bunnies of the ocean "composed of tiny phytoplankton, zooplankton feces, mucus and other debris that sinks and carries with it suspended or dissolved substances," explained co-lead author Passow of UCSB's Marine Science Institute.
 

Photo: 

UCSB research oceanographer Uta Passow. Photo Credit: SONIA Fernandez

News Date: 

Tuesday, May 31, 2016