Buried oil from Deepwater Horizon disaster still harming wetlands
http://www.nola.com/environment/index.ssf/2017/07/buried_oil_from_deepwater_hori.html#incart_river_home
Oil spilled seven years ago in the Deepwater Horizon disaster in the Gulf of Mexico might no longer be visible, but it's still taking a toll on Louisiana's fragile wetlands. A new study by Louisiana State University indicates that crude oil from the 2010 BP oil spill has become lodged in wetland soils, where it remains almost as toxic as the day it flowed into the gulf.
"We found oil four to five centimeters down in the layers of marsh, which we expected to see," said John White, associate director of LSU's Coastal Studies Institute. "What was surprising was that the oil was still causing plants to die."
Oil degrades from exposure to oxygen and sunlight. But buried under the yearly pile-up of dead plant material, the oil's potency was preserved, the study found.
"When we dug up some of the oil, we thought, 'How bad can it be now?'" White said. "But four- or five-year-old oil still had a lot of volatile compounds. It was almost as harmful as the original oil."