Increased accumulation rate of oil-associated marine snow and oil mineral aggregates on the sea floor resulted from the Deepwater Horizon (DWH) oil spill significantly affected the Gulf of Mexico (GoM) ecosystem. Oil-associated marine snow reaches the deep marine seafloor due to its increased settling velocity, and serves a unique flux of labile carbon for microorganisms residing in marine sediments. Long-term evaluation of geochemical parameters, microbial activity, and microbial community structures will unravel the recovery process of marine sediment microbial communities disturbed by marine oil snow deposition. This sequencing effort will allow us to track community change and evaluate how marine snow sedimentation influenced these changes in sediment microbial community composition and function in a long-term perspective. Lead PI, Samantha Joye mjoye@uga.edu