Influence of Marine Oil Snow on Oil Biodegradation
The Deepwater Horizon blowout that occurred on the 20th April of 2010 led to the release of an unprecedented volume of crude oil (~4.9 million barrels) into the Gulf of Mexico from a depth of 1500 m. This oil spill is the largest in US history and it caused significant damage to ecosystems in the Gulf and economies that depend on these. During initial investigations of the spill (within 2 weeks since its onset), unprecedented quantities of mucilaginous material containing entrained crude oil, termed Marine Oil Snow (MOS), had been observed on surface waters in and around the vicinity of the spill site. In subsequent days, sinking of this MOS material was implicated in vertical transport of the oil to the seabed with potentially negative consequences to benthic ecosystems.
Studies on MOS have shown it to harbour concentrated communities of microorganisms, including taxa that specialise in the biodegradation of hydrocarbons and/or that produce extracellular polysaccharides (exopolymers). It has thus been hypothesised that MOS may potentially act as a hotspot of microbial activity, and specifically for the biodegradation of oil hydrocarbons.
Georgia Waldram is a PhD student in the Gutierrez Lab who is investigating the role MOS may have played in the fate of the Macondo oil during the Deepwater Horizon spill. The project utilises a combination of oxygen microprobe approaches together with GC-MS and molecular techniques, including stable isotope probing (SIP) with 13C-labeling methods to determine oil biodegradation associated with MOS. The project is funded by MASTS SUPER-DTP Studentship and is in collaboration with St. Andrews University.