@article {2669,
	title = {The southern Gulf of Mexico: A baseline radiocarbon isoscape of surface sediments and isotopic excursions at depth},
	journal = {PLOS ONE},
	volume = {15},
	year = {2020},
	month = {Mar-04-2021},
	pages = {e0231678},
	abstract = {The southern Gulf of Mexico (sGoM) is home to an extensive oil recovery and development infrastructure. In addition, the basin harbors sites of submarine hydrocarbon seepage and receives terrestrial inputs from bordering rivers. We used stable carbon, nitrogen, and radiocarbon analyses of bulk sediment organic matter to define the current baseline isoscapes of surface sediments in the sGoM and determined which factors might influence them. These baseline surface isoscapes will be useful for accessing future environmental impacts. We also examined the region for influence of hydrocarbon deposition in the sedimentary record that might be associated with hydrocarbon recovery, spillage and seepage, as was found in the northern Gulf of Mexico (nGoM) following the Deepwater Horizon (DWH) oil spill in 2010. In 1979, the sGoM experienced a major oil spill, Ixtoc 1. Surface sediment δ13C values ranged from -22.4{\textperthousand} to -19.9{\textperthousand}, while Δ14C values ranged from -337.1{\textperthousand} to -69.2{\textperthousand}.
Sediment δ15N values ranged from 2.8{\textperthousand} to 7.2{\textperthousand}, while the \%C on a carbonate-free basis ranged in value of 0.65\% to 3.89\% and \%N ranged in value of 0.09\% to 0.49\%. Spatial trends for δ13C and Δ14C were driven by water depth and distance from the coastline, while spatial trends for δ15N were driven by location (latitude and longitude). Location and distance from the coastline were significantly correlated with \%C and \%N. At depth in two of twenty (10\%) core profiles, we found negative δ13C and Δ14C excursions from baseline values in bulk sedimentary organic material, consistent with either oil-residue deposition or terrestrial inputs, but likely the latter. We then used 210Pb dating on those two profiles to determine the time in which the excursion-containing horizons were deposited. Despite the large spill in 1979, no evidence of hydrocarbon residue remained in the sediments from this specific time period.},
	keywords = {Gulf of Mexico, hydrocarbons, Oil spills, Oils, Petroleum, Sediment},
	doi = {10.1371/journal.pone.023167810.1371},
	url = {https://www.ncbi.nlm.nih.gov/pubmed/32294128},
	author = {Bosman, Samantha H. and Schwing, Patrick T. and Larson, Rebekka A. and Wildermann, Natalie E. and Brooks, Gregg R. and Romero, Isabel C. and Sanchez-Cabeza, Joan-Albert and Ruiz-Fern{\'a}ndez, Ana Carolina and Machain-Castillo, Maria Luisa and Gracia, Adolfo and Escobar-Briones, Elva and Murawski, Steven A. and Hollander, David J. and Chanton, Jeffrey P.},
	editor = {Potter-McIntyre, Sally}
}
@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}
}
