Temporal, Molecular-level Analysis of Barataria Bay sediments over a 4-year period (2011-2014) after the Deepwater Horizon Oil Spill by Fourier Transform Ion Cyclotron Resonance Mass spectrometry

Extraction and characterization of petrogenic carbon from coastal saltmarsh sediments collected from 9 to 48 months post-spill catalogue molecular transformations of petrogenic species in an active, dynamic saltmarsh ecosystem. We catalogue molecular-level degradation patterns that occur to oil compounds buried in salt marsh sediment in northern Barataria Bay by Fourier Transform Ion Cyclotron Resonance Mass Spectrometry. Tens-of-thousands, highly polar (acidic), oxygen-containing transformation products are identified at the level of molecular formula assignment, and monitored from 9 - 48 months post-spill. Samples were collected from northern Barataria Basin of Louisiana, USA, approximately 8km x 5km (coordinates N 29.44060° - 29.47459°, W 89.88492° - 89.94647°), with 21 sampling locations (seven each that received either no oiling [i.e., reference], moderate oiling, or heavy oiling) categorized based on the Shoreline Cleanup Assessment Technique (SCAT) Program (28 April 2010) and field observations. No cleanup events at the sampling sites were noted during this period.