@article {schwing_organic_2023,
	title = {Organic carbon and planktic foraminifera radiocarbon derived Holocene sediment accumulation rates in the northern slopes of the Gulf of Mexico},
	journal = {Deep Sea Research Part I: Oceanographic Research Papers},
	volume = {193},
	year = {2023},
	month = {03/2023},
	pages = {103959},
	abstract = {In the context of climate regulation and anthropogenic waste detoxification (e.g. oil spills), estimates of deep ocean sedimentation and carbon sequestration are of the utmost importance. Radiocarbon (14C) is a common radioisotope that can be used to establish millennial scale sediment accumulation rates. The objectives of this study were to: 1) establish ages for co-occurring total organic carbon (TOC) and planktic foraminifera (carbonate) in the northeastern Gulf of Mexico (GoM), 2) use these ages to estimate accumulation rates independently, 3) identify any evidence of redistribution, and 4) examine any offset between TOC and carbonate 14C ages as a tool to potentially identify selective TOC transport. Sediment samples were collected in May 2018 from the RV Point Sur using an Ocean Instruments MC-800 multi corer. Radiocarbon measurements of both planktic foraminifera and TOC subsamples were made at the National Ocean Science Accelerator Mass Spectrometry Facility (NOSAMS). Radiocarbon ages, calibrated using the OxCal 4.4, ranged from recent to 6407 BP. Linear (LAR: 4{\textendash}24~cm/kyr) and mass accumulation rates (MAR: 1.5{\textendash}11.5~g/cm2/kyr) were generally consistent with those reported by other recent studies in the GoM. At two sites, C14 ages decreased from the surface to the second sampling increment which was consistent with sediment redistribution. The TOC-carbonate offsets, which are indicative of lateral advection and organic matter aging, were lower than those found in the majority of other regions, which was consistent with less lateral transport or a more oligotrophic setting. The magnitude in radiocarbon age offsets with depth could potentially be used as a relative aging or transport assessment tool in areas with little resuspension.},
	keywords = {accumulation rates, Foraminifera, Gulf of Mexico, radiocarbon, Radiogeochemistry},
	issn = {0967-0637},
	doi = {10.1016/j.dsr.2022.103959},
	url = {https://www.sciencedirect.com/science/article/pii/S0967063722002722},
	author = {Schwing, Patrick and Chanton, Jeffrey and Bosman, Samantha and Brooks, Gregg and Larson, Rebekka A. and Romero, Isabel and Diercks, Arne}
}
@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 {560,
	title = {Tracing the intrusion of fossil carbon into coastal Louisiana macrofauna using natural 14C and 13C abundances},
	journal = {Deep Sea Research Part II: Topical Studies in Oceanography},
	volume = {129},
	year = {2016},
	pages = {89-95},
	abstract = {The Deepwater Horizon oil spill released a large volume of 13C and radiocarbon depleted organic matter to the northern Gulf of Mexico. Evidence of petroleum-derived carbon entering the offshore planktonic foodweb, as well as widespread oiling of coastal areas documented in previous studies suggests that hydrocarbons could have entered the near shore foodweb. To test this hypothesis, we measured radiocarbon (Δ14C\%) and stable carbon isotopes (δ13C) in an assortment of fish tissue, invertebrate tissue and shell samples collected within a year of the spill at seven sites from Louisiana to Florida USA across the northern Gulf of Mexico. We observed a west{\textendash}east gradient with the most depleted radiocarbon values found in Terrebonne Bay, Louisana and increasingly enriched radiocarbon values in organisms collected at sites to the east. Depleted radiocarbon values as low as -10\% in invertebrate soft tissue from Terrebonne suggest assimilation of fossil carbon (2.8{\textpm}1.2\%), consistent with the hypothesis that organic matter from petrochemical reservoirs released during the Deepwater Horizon spill entered the coastal food web to a limited extent. Further there was a significant correlation between radiocarbon and δ13C values in invertebrate tissue consistent with this hypothesis. Both oyster tissue and hard head catfish tissue collected in impacted areas of coastal Louisiana were significantly depleted in 14C and 13C relative to organisms collected in the unaffected Apalachicola Bay, Florida (p<0.014). Alternative explanations for these results include the influence of chronic hydrocarbon pollution along the western gulf coast or that the organisms ingest carbon derived from 14C depleted organic matter mobilized during the erosion of coastal marshes in southern Louisiana.},
	issn = {0967-0645},
	doi = {10.1016/j.dsr2.2015.05.014},
	author = {Wilson, Rachel M. and Cherrier, Jennifer and Sarkodee-Adoo, Judith and Bosman, Samantha and Mickle, Alejandra and Chanton, Jeffrey P.}
}
@article {2480,
	title = {Using Natural Abundance Radiocarbon To Trace the Flux of Petrocarbon to the Seafloor Following the Deepwater Horizon Oil Spill},
	journal = {Environmental Science \& Technology},
	volume = {49},
	year = {2015},
	month = {Aug-01-2016},
	pages = {847 - 854},
	abstract = {In 2010, the Deepwater Horizon accident released 4.6{\textendash}6.0 {\texttimes} 1011 grams or 4.1 to 4.6 million barrels of fossil petroleum derived carbon (petrocarbon) as oil into the Gulf of Mexico. Natural abundance radiocarbon measurements on surface sediment organic matter in a 2.4 {\texttimes} 1010 m2 deep-water region surrounding the spill site indicate the deposition of a fossil-carbon containing layer that included 1.6 to 2.6 {\texttimes} 1010 grams of oil-derived carbon. This quantity represents between 0.5 to 9.1\% of the released petrocarbon, with a best estimate of 3.0{\textendash}4.9\%. These values may be lower limit estimates of the fraction of the oil that was deposited on the seafloor because they focus on a limited mostly deep-water area of the Gulf, include a conservative estimate of thickness of the depositional layer, and use an average background or prespill radiocarbon value for sedimentary organic carbon that produces a conservative value. A similar approach using hopane tracer estimated that 4{\textendash}31\% of 2 million barrels of oil that stayed in the deep sea settled on the bottom. Converting that to a percentage of the total oil that entered into the environment (to which we normalized our estimate) converts this range to 1.8 to 14.4\%. Although extrapolated over a larger area, our independent estimate produced similar values.},
	issn = {0013-936X},
	doi = {10.1021/es5046524},
	url = {http://pubs.acs.org/doi/abs/10.1021/es5046524http://pubs.acs.org/doi/pdf/10.1021/es5046524},
	author = {Chanton, Jeffrey and Zhao, Tingting and Rosenheim, Brad E. and Joye, Samantha and Bosman, Samantha and Brunner, Charlotte and Yeager, Kevin M. and Diercks, Arne R. and Hollander, David}
}
@article {68,
	title = {Using Natural Abundance Radiocarbon To Trace the Flux of Petrocarbon to the Seafloor Following the Deepwater Horizon Oil Spill},
	journal = {Environmental science \& technology},
	year = {2014},
	abstract = {In 2010, the Deepwater Horizon accident released 4.6?6.0 ? 1011 grams or 4.1 to 4.6 million barrels of fossil petroleum derived carbon (petrocarbon) as oil into the Gulf of Mexico. Natural abundance radiocarbon measurements on surface sediment organic matter in a 2.4 ? 1010 m2 deep-water region surrounding the spill site indicate the deposition of a fossil-carbon containing layer that included 1.6 to 2.6 ? 1010 grams of oil-derived carbon. This quantity represents between 0.5 to 9.1\% of the released petrocarbon, with a best estimate of 3.0?4.9\%. These values may be lower limit estimates of the fraction of the oil that was deposited on the seafloor because they focus on a limited mostly deep-water area of the Gulf, include a conservative estimate of thickness of the depositional layer, and use an average background or prespill radiocarbon value for sedimentary organic carbon that produces a conservative value. A similar approach using hopane tracer estimated that 4?31\% of 2 million barrels of oil that stayed in the deep sea settled on the bottom. Converting that to a percentage of the total oil that entered into the environment (to which we normalized our estimate) converts this range to 1.8 to 14.4\%. Although extrapolated over a larger area, our independent estimate produced similar values.; In 2010, the Deepwater Horizon accident released 4.6?6.0 ? 1011 grams or 4.1 to 4.6 million barrels of fossil petroleum derived carbon (petrocarbon) as oil into the Gulf of Mexico. Natural abundance radiocarbon measurements on surface sediment organic matter in a 2.4 ? 1010 m2 deep-water region surrounding the spill site indicate the deposition of a fossil-carbon containing layer that included 1.6 to 2.6 ? 1010 grams of oil-derived carbon. This quantity represents between 0.5 to 9.1\% of the released petrocarbon, with a best estimate of 3.0?4.9\%. These values may be lower limit estimates of the fraction of the oil that was deposited on the seafloor because they focus on a limited mostly deep-water area of the Gulf, include a conservative estimate of thickness of the depositional layer, and use an average background or prespill radiocarbon value for sedimentary organic carbon that produces a conservative value. A similar approach using hopane tracer estimated that 4?31\% of 2 million barrels of oil that stayed in the deep sea settled on the bottom. Converting that to a percentage of the total oil that entered into the environment (to which we normalized our estimate) converts this range to 1.8 to 14.4\%. Although extrapolated over a larger area, our independent estimate produced similar values.},
	issn = {0013-936X},
	doi = {10.1021/es5046524},
	url = {http://dx.doi.org/10.1021/es5046524},
	author = {Chanton, Jeffrey and Zhao, Tingting and Rosenheim, Brad E. and Joye, Samantha and Bosman, Samantha and Brunner, Charlotte and Yeager, Kevin M. and Diercks, Arne R. and Hollander, David}
}
