@book {2719,
	title = {Mapping Isotopic and Dissolved Organic Matter Baselines in Waters and Sediments of the~Gulf of Mexico},
	year = {2019},
	pages = {160 - 181},
	publisher = {Springer International Publishing},
	organization = {Springer International Publishing},
	address = {Cham},
	abstract = {The Deepwater Horizon oil spill released petroleum hydrocarbons that were depleted in δ13C and Δ14C at depth into the Gulf of Mexico. Stable-carbon and radiocarbon isotopic values and high-resolution mass spectrometry were used to follow the distributions of this petroleum and to track its transformation into petrocarbon, a term used to describe crude oil or transformed crude oil following biodegradation, weathering, oxygenation, or loss of lighter components. The term petrocarbon includes oil- or methane-derived carbon assimilated or incorporated into microbial biomass or into the food web as well as degraded and undegraded petroleum constituents. Here we report (1) the increase in the relative abundance of oxygen-containing carbon compounds making up the dissolved organic matter (DOM) with increasing depth through the water column, indicating the biodegradation of DOM as it was transported to depth in the water column, (2) the finding of 14C depletion in DOM indicating petrocarbon inputs, and (3) the decrease and subsequent increase of 14C in the isotopic composition of sinking particles indicating the capture of petrocarbon in sediment traps. In addition, we discuss the 14C depletion of this material once it is sedimented to the seafloor and the implications for oil spill budgets of seafloor petrocarbon deposition.},
	keywords = {Dissolved organic matter, FTICR-MS, Gulf baselines, High-resolution mass spectrometry, organic carbon, radiocarbon, Ramped pyrolysis, Sediment organic matter},
	isbn = {978-3-030-12962-0},
	doi = {10.1007/978-3-030-12963-710.1007/978-3-030-12963-7_10},
	url = {https://link.springer.com/chapter/10.1007/978-3-030-12963-7_10},
	author = {Chanton, Jeffrey P. and Jaggi, Aprami and Radovi{\'c}, Jago{\v s} R. and Rosenheim, Brad E. and Walker, Brett D. and Larter, Stephen R. and Rogers, Kelsey and Bosman, Samantha and Oldenburg, Thomas B. P.},
	editor = {Murawski, Steven A. and Ainsworth, Cameron H. and Gilbert, Sherryl and Hollander, David J. and Paris, Claire B. and Schl{\"u}ter, Michael and Wetzel, Dana L.}
}
@article {2641,
	title = {Petrocarbon evolution: Ramped pyrolysis/oxidation and isotopic studies of contaminated oil sediments from the Deepwater Horizon oil spill in the Gulf of Mexico},
	journal = {PLOS ONE},
	volume = {14},
	year = {2019},
	month = {Apr-02-2021},
	pages = {e0212433},
	abstract = {Hydrocarbons released during the Deepwater Horizon (DWH) oil spill weathered due to exposure to oxygen, light, and microbes. During weathering, the hydrocarbons{\textquoteright} reactivity and lability was altered, but it remained identifiable as "petrocarbon" due to its retention of the distinctive isotope signatures (C-14 and C-13) of petroleum. Relative to the initial estimates of the quantity of oil-residue deposited in Gulf sediments based on 2010-2011 data, the overall coverage and quantity of the fossil carbon on the seafloor has been attenuated. To analyze recovery of oil contaminated deep-sea sediments in the northern Gulf of Mexico we tracked the carbon isotopic composition (C-13 and C-14, radiocarbon) of bulk sedimentary organic carbon through time at 4 sites. Using ramped pyrolysis/oxidation, we determined the thermochemical stability of sediment organic matter at 5 sites, two of these in time series. There were clear differences between crude oil (which decomposed at a lower temperature during ramped oxidation), natural hydrocarbon seep sediment (decomposing at a higher temperature; Delta C-14 = -189 parts per thousand) and our control site (decomposing at a moderate temperature; Delta C-14 = -189 parts per thousand), in both the stability (ability to withstand ramped temperatures in oxic conditions) and carbon isotope signatures. We observed recovery toward our control site bulk Delta C-14 composition at sites further from the wellhead in similar to 4 years, whereas sites in closer proximity had longer recovery times. The thermographs also indicated temporal changes in the composition of contaminated sediment, with shifts towards higher temperature CO2 evolution over time at a site near the wellhead, and loss of higher temperature CO2 peaks at a more distant site.},
	keywords = {C-14 ANALYSES; MARINE SNOW, degradation, fractionation, organic-matter, POLYCYCLIC AROMATIC-HYDROCARBONS; MICROBIAL COMMUNITY RESPONSE, radiocarbon, STABLE CARBON, surface sediments},
	doi = {10.1371/journal.pone.0212433},
	url = {https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0212433},
	author = {Rogers, Kelsey L. and Bosman, Samantha H. and Lardie-Gaylord, Mary and McNichol, Ann and Rosenheim, Brad E. and Montoya, Joseph P. and Chanton, Jeffrey P.},
	editor = {Cooper, Lee W.}
}
@article {2723,
	title = {Isotopic composition of sinking particles: Oil effects, recovery andbaselines in the Gulf of Mexico, 2010{\textendash}2015},
	journal = {Elem Sci Anth},
	volume = {6},
	year = {2018},
	month = {Sep-01-2018},
	pages = {43},
	abstract = {The extensive release of oil during the 2010 Deepwater Horizon spill in the northern Gulf of Mexico perturbed the pelagic ecosystem and associated sinking material. To gauge the recovery and post-spill baseline sources, we measured Δ14C, δ13C and δ34S of sinking particles near the spill site and at a reference site and natural seep site. Particulates were collected August 2010{\textendash}April 2016 in sediment traps moored at sites with depths of 1160{\textendash}1660 m. Near the spill site, changes in Δ14C indicated a 3-year recovery period, while δ34S indicated 1{\textendash}2 years, which agreed with estimates of 1{\textendash}2 years based on hydrocarbon composition. Under post-spill baseline conditions, carbon inputs to sinking particulates in the northern Gulf were dominated by surface marine production (80{\textendash}85\%) and riverine inputs (15{\textendash}20\%). Near the spill site, Δ14C values were depleted in October 2010 ({\textendash}140 to {\textendash}80{\textperthousand}), increasing systematically by 0.07 {\textpm} 0.02{\textperthousand} day{\textendash}1 until July 2013 when values reached {\textendash}3.2 {\textpm} 31.0{\textperthousand}. This Δ14C baseline was similar to particulates at the reference site (3.8 {\textpm} 31.1{\textperthousand}). At both sites, δ13C values stayed constant throughout the study period ({\textendash}21.9 {\textpm} 0.5{\textperthousand} and {\textendash}21.9 {\textpm} 0.9{\textperthousand}, respectively). δ34S near the spill site was depleted (7.4 {\textpm} 3.1{\textperthousand}) during October 2010{\textendash}September 2011, but enriched (16.9 {\textpm} 2.0{\textperthousand}) and similar to the reference site (16.2 {\textpm} 3.1{\textperthousand}) during November 2012{\textendash}April 2015. At the seep site, Δ14C values were {\textendash}21.7 {\textpm} 45.7{\textperthousand} except during August 2012{\textendash}January 2013 when a significant Δ14C depletion of {\textendash}109.0 {\textpm} 29.1{\textperthousand} was observed. We interpret this depletion period, also observed in δ13C data, as caused by the incorporation of naturally seeped oil into sinking particles. Determination of post-spill baselines for these isotopic signatures allows for evaluation of anthropogenic inputs in future.},
	keywords = {Deep Water Horizon Oil Spill, Gulf of Mexico, isotopes, radiocarbon, sediment trap, sinking particulates},
	doi = {10.1525/elementa.298},
	url = {https://www.elementascience.org/article/10.1525/elementa.298},
	author = {Chanton, Jeffrey P. and Giering, Sarah L. C. and Bosman, Samantha H. and Rogers, Kelsey L. and Sweet, Julia and Asper, Vernon L. and Diercks, Arne R. and Passow, Uta}
}
