Oil from the 2010 Deepwater Horizon Oil Spill continues sinking to the Gulf of Mexico’s sea floor. Now a researcher from the University of Delaware is shedding light on a phenomenon he’s calling Marine Oil Snow.
If you’ve ever been snorkeling in the ocean, you may have seen little brown flakes floating around with the current. Those little flakes are called Marine snow, similar to decaying leaves falling onto a forest floor, this is the process where organic material from the upper layers of the ocean fall to the sea floor. Researchers have found that after oil spills like the Deep Water Horizon oil spill in the Gulf of Mexico, plankton and bacteria release a substance that merges the oil with the naturally occurring marine snow.
University of Delaware researcher Andrew Wozniak mimicked the process of marine oil snow formation in his lab. He found that as the oil containing particles make their journey to the ocean floor, they create microenvironments of bacteria that change the oil’s molecular composition.
“The oil that reaches the sediments and the deep coral reef look slightly different at the molecular level, and that’s important for understanding what happens to that oil and what impacts it might have on the biology down in the deep parts of the ocean and coastal systems," said Wozniak.
The bacteria that feed on the oil add highly toxic oxygenated compounds are called polycyclic aromatic hydrocarbons or PAH's. University of South Florida Marine Scientist Steve Murawski says he’s seen elevated PAH’s in marine life in the Gulf of Mexico.
“Certainly we’ve seen higher levels of PAH’s not only in the sediments in the small animals that live in sediments but also in the fishes and the crabs and other animals that we more relate to,” said Murawski.
Those toxic compounds lead to animal deaths, and Murawski notes the effects of the fallout are still being seen.
“We’re not sure exactly why but it could be that the sediments that have oil contamination are being re-suspended by storms, hurricanes, river inflow, and heavy winds so they keep stirring up the bottom. So we have a feeling that these toxic chemicals are going to be in the system for a while they’re not necessarily being land filled buried over by clean sediment,” said Murawski.
Though Marine Oil Snow helps with the dispersal of oil by bringing it down to the ocean floor and away from coastlines, the impacts of the Deep Water Horizon Oil spill are still being felt nine years later.