@article {2933,
	title = {Limited Presence of Permafrost Dissolved Organic Matter in the Kolyma River, Siberia Revealed by Ramped Oxidation},
	journal = {Journal of Geophysical Research: Biogeosciences},
	volume = {126},
	year = {2021},
	month = {Jan-07-2021},
	issn = {2169-8953},
	doi = {10.1029/2020JG005977},
	url = {https://www.webofscience.com/wos/woscc/full-record/WOS:000677821700019?AlertId=4d48b20a-7d27-4fa2-a6a8-37f0daa89864\&SID=8EgwPROzuFaD4cTggN2},
	author = {Rogers, Jennifer A. and Galy, Valier and Kellerman, Anne M. and Chanton, Jeffrey P. and Zimov, Nikita and Spencer, Robert G. M.}
}
@article {2670,
	title = {Life history of northern Gulf of Mexico Warsaw grouper Hyporthodus nigritus inferred from otolith radiocarbon analysis},
	journal = {PLOS ONE},
	volume = {15},
	year = {2020},
	month = {Dec-01-2021},
	pages = {e0228254},
	abstract = {Warsaw grouper, Hyporthodus nigritus, is a western Atlantic Ocean species typically found at depths between 55 and 525 m. It is listed as a species of concern by the U.S. National Marine Fisheries Service and as near threatened by the International Union for the Conservation of Nature. However, little information exists on the species{\textquoteright} life history in the northern Gulf of Mexico (nGOM) and its stock status in that region is currently unknown. Age of nGOM Warsaw grouper was investigated via opaque zone counts in otolith thin sections (max age = 61 y), and then the bomb 14C chronometer was employed to validate the accuracy of age estimates. Otolith cores (n = 14) were analyzed with accelerator mass spectrometry and resulting Δ14C values overlain on a loess regression computed for a regional coral and known-age red snapper Δ14C time series. Residual analysis between predicted Δ14C values from the loess regression versus Warsaw grouper otolith core Δ14C values indicated no significant difference in the two data series. Therefore, the accuracy of otolith-based aging was validated, which enabled growth and longevity estimates to be made for nGOM Warsaw grouper. Dissolved inorganic carbon (DIC) Δ14C values collected from the nGOM support the inference that juvenile Warsaw grouper occur in shelf waters (<200 m) since DIC Δ14C values in this depth range are enriched in 14C and similar to the Δ14C values from otolith cores. A Bayesian model was fit to fishery-dependent age composition data and produced von Bertalanffy growth function parameters of L1 = 1,533 mm, k = 0.14 y-1, and t0 = 1.82 y. Fishing mortality also was estimated in the model, which resulted in a ratio of fishing to natural mortality of 5.1:1. Overall, study results indicate Warsaw grouper is a long-lived species that is estimated to have experienced significant overfishing in the nGOM, with the age of most landed fish being <10 y.},
	doi = { https://doi.org/10.1371/journal.pone.0228254},
	url = {https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0228254},
	author = {Barnett, Beverly K. and Chanton, Jeffrey P. and Ahrens, Robert and Thornton, Laura and Patterson, William F.},
	editor = {Patterson, Heather M.}
}
@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}
}
@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 {2721,
	title = {Sources of carbon to suspended particulate organic matter in the northern Gulf of Mexico},
	journal = {Elem Sci Anth},
	volume = {7},
	year = {2019},
	month = {May-10-2020},
	pages = {51},
	abstract = {Suspended particulate organic carbon (POCsusp) in the Gulf of Mexico is unique compared to other seas and oceans. In addition to surface primary production, isotopic analysis indicates that microbial cycling of oil and riverine inputs are primary sources of carbon to POCsusp in the Gulf. To characterize POCsusp from seep sites and non-seep north central Gulf (NCG) sites potentially affected by the Deepwater Horizon (DWH) spill, we analyzed 277 and 123 samples for δ13C and Δ1C signatures, respectively. Depth, partitioned into euphotic (300 m), was the main driver of spatial δ13C differences, with deep depths exhibiting 13C depletion. Both deep depths and proximity to sources of natural seepage resulted in 14C depletion. A two-endmember mixing model based on Δ14C indicated that sources to POCsusp were 14{\textendash}29\% fossil carbon at NCG sites and 19{\textendash}57\% at seep sites, with the balance being modern surface production. A six-component Bayesian mixing model MixSIAR, using both 13C and 14C, suggested that riverine inputs were an important carbon source to POCsusp contributing 34{\textendash}46\%. The influence of seeps was localized. Below the euphotic zone at seep sites, 46 {\textpm} 5\% (n = 9) of the carbon in POCsusp was derived from environmentally degraded, transformed oil; away from seeps, transformed oil contributed 15 {\textpm} 4\% (n = 39). We hypothesized that, at NCG sites removed from hydrocarbon seep sources, isotopic signatures would be depleted following the spill and then shift towards background-like enriched values over time. At deep depths we observed decreasing Δ14C signatures in POCsusp from 2010 to 2012, followed by isotopic enrichment from 2012 to 2014 and a subsequent recovery rate of 159{\textperthousand} per year, consistent with this hypothesis and with biodegraded material from DWH hydrocarbons contributing to POCsusp.},
	doi = {10.1525/elementa.389},
	url = {https://www.elementascience.org/article/10.1525/elementa.389},
	author = {Rogers, Kelsey L. and Bosman, Samantha H. and Weber, Sarah and Magen, Cedric and Montoya, Joseph P. and Chanton, Jeffrey P.}
}
@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}
}
@article {2725,
	title = {Tropical peatland carbon storage linked to global latitudinal trends in peat recalcitrance},
	journal = {Nature Communications},
	volume = {9},
	year = {2018},
	month = {Jan-12-2018},
	abstract = {Peatlands represent large terrestrial carbon banks. Given that most peat accumulates in boreal regions, where low temperatures and water saturation preserve organic matter, the existence of peat in (sub)tropical regions remains enigmatic. Here we examined peat and plant chemistry across a latitudinal transect from the Arctic to the tropics. Near-surface low-latitude peat has lower carbohydrate and greater aromatic content than near-surface high-latitude peat, creating a reduced oxidation state and resulting recalcitrance. This recalcitrance allows peat to persist in the (sub)tropics despite warm temperatures. Because we observed similar declines in carbohydrate content with depth in high-latitude peat, our data explain recent field-scale deep peat warming experiments in which catotelm (deeper) peat remained stable despite temperature increases up to 9 {\textdegree}C. We suggest that high-latitude deep peat reservoirs may be stabilized in the face of climate change by their ultimately lower carbohydrate and higher aromatic composition, similar to tropical peats.},
	doi = {10.1038/s41467-018-06050-2},
	url = {http://www.nature.com/articles/s41467-018-06050-2},
	author = {Hodgkins, Suzanne B. and Richardson, Curtis J. and Dommain, Ren{\'e} and Wang, Hongjun and Glaser, Paul H. and Verbeke, Brittany and Winkler, B. Rose and Cobb, Alexander R. and Rich, Virginia I. and Missilmani, Malak and Flanagan, Neal and Ho, Mengchi and Hoyt, Alison M. and Harvey, Charles F. and Vining, S. Rose and Hough, Moira A. and Moore, Tim R. and Richard, Pierre J. H. and De La Cruz, Florentino B. and Toufaily, Joumana and Hamdan, Rasha and Cooper, William T. and Chanton, Jeffrey P.}
}
@book {2724,
	title = {Using Stable and Radiocarbon Analyses as a Forensic Tool to Find Evidence of Oil in the Particulates of the Water Column and on the Seafloor Following the 2010 Gulf of Mexico Oil Spill},
	year = {2018},
	pages = {639 - 650},
	publisher = {Elsevier},
	organization = {Elsevier},
	abstract = {Over 600 million liters of oil and copious amounts of methane were released into the Gulf of Mexico between April 20, 2010 and July 15, 2010. We used stable and radiocarbon analyses as a forensic tool to trace these hydrocarbons from the Deepwater Horizon (DwH) well into suspended particulate organic carbon (POCsusp), sinking particulate organic carbon (POCsink), and sedimentary organic carbon on the seafloor. POCsusp samples were considerably depleted both in δ13C and Δ14C relative to surface production, with δ13C and Δ14C values as low as -37.2{\textperthousand} and -618{\textperthousand}, respectively. POCsink time series data revealed a modern Δ14C value due to a large diatom bloom in early September 2010, but values became depleted as oil contaminated particles continued to descend in the water column until the end of the year. Sediment cores collected in the vicinity of the DwH wellhead revealed evidence of oil contamination in the surface layer (0{\textendash}1 cm), as indicated by a depletion in Δ14C values compared to the layers below the surface. In addition to providing evidence of oil contamination using stable and radiocarbon analyses, our study was consistent with the existence of a pathway by which spilled oil was deposited onto the seafloor.},
	keywords = {Deepwater Horizon, isotopes, methane, Petrocarbon, POCsin, POCsusp, Sediment},
	isbn = {9780128044346},
	doi = {10.1016/B978-0-12-804434-6.00029-X},
	url = {https://linkinghub.elsevier.com/retrieve/pii/B978012804434600029X},
	author = {Bosman, Samantha H. and Chanton, Jeffrey P. and Rogers, Kelsey L.}
}
@article {2487,
	title = {Methane emissions proportional to permafrost carbon thawed in Arctic lakes since the 1950s},
	journal = {Nature Geoscience},
	volume = {9},
	year = {2016},
	month = {Oct-08-2017},
	pages = {679 - 682},
	abstract = {Permafrost thaw exposes previously frozen soil organic matter to microbial decomposition. This process generates methane and carbon dioxide, and thereby fuels a positive feedback process that leads to further warming and thaw1. Despite widespread permafrost degradation during the past ~40 years2, 3, 4, the degree to which permafrost thaw may be contributing to a feedback between warming and thaw in recent decades is not well understood. Radiocarbon evidence of modern emissions of ancient permafrost carbon is also sparse5. Here we combine radiocarbon dating of lake bubble trace-gas methane (113 measurements) and soil organic carbon (289 measurements) for lakes in Alaska, Canada, Sweden and Siberia with numerical modelling of thaw and remote sensing of thermokarst shore expansion. Methane emissions from thermokarst areas of lakes that have expanded over the past 60 years were directly proportional to the mass of soil carbon inputs to the lakes from the erosion of thawing permafrost. Radiocarbon dating indicates that methane age from lakes is nearly identical to the age of permafrost soil carbon thawing around them. Based on this evidence of landscape-scale permafrost carbon feedback, we estimate that 0.2 to 2.5 Pg permafrost carbon was released as methane and carbon dioxide in thermokarst expansion zones of pan-Arctic lakes during the past 60 years.},
	keywords = {Carbon cycle, Climate change, Cryospheric science},
	issn = {1752-0894},
	doi = {10.1038/ngeo2795},
	url = {http://www.nature.com/doifinder/10.1038/ngeo2795},
	author = {Walter Anthony, Katey and Daanen, Ronald and Anthony, Peter and Schneider von Deimling, Thomas and Ping, Chien-Lu and Chanton, Jeffrey P. and Grosse, Guido}
}
@article {2479,
	title = {Organic matter cycling across the sulfate-methane transition zone of the Santa Barbara Basin, California Borderland},
	journal = {Geochimica et Cosmochimica Acta},
	volume = {176},
	year = {2016},
	month = {Jan-03-2016},
	pages = {259 - 278},
	abstract = {Consumption of sulfate (SO42-) in the sulfate-methane transition zone (SMTZ) has often been considered to be due solely to anaerobic oxidation of methane (AOM). However, recent studies show SO42- fluxes into the SMTZ that exceed methane (CH4) fluxes, thereby challenging this conceptual model. Co-occurrence of organoclastic SO42- reduction (oSR) with AOM in the SMTZ has been hypothesized to be the cause for this flux imbalance, but conclusive evidence is lacking. To address this knowledge gap, we investigated organic matter cycling in the SMTZ of the organic-rich sediments of the Santa Barbara Basin, California Borderland, and examined the occurrence of oSR within this zone using bulk solute profiles and Δ14C and δ13C values of selected carbon pools. We also tested the hypothesis that the SMTZ acts as an oxidation front not just for CH4, but also for dissolved organic carbon (DOC) that is produced below the SMTZ and migrates upward. Mass balance calculations for the SMTZ based on reaction stoichiometry and Δ14C and δ13C values of associated carbon fluxes indicate that \~{}35{\textendash}45\% of total SO42- reduction in the SMTZ occurs via oSR, with the remainder attributable to AOM. The δ13C value of net DOC production is distinct from that of the fraction of bulk POC undergoing degradation, suggesting that pore-water DOC represents a compositionally unique slice of the metabolizable POC pool. DOC diffusing upward at 450 cm is virtually free of 14C and contain low levels of short-chain organic acids. Radiocarbon mass balance shows that >30\% of this pre-aged, and presumably refractory, DOC is removed from the pore waters within or immediately below the SMTZ. Although the SMTZ does not appear to be a major net DOC oxidation front, these results show that DOC dynamics provide unique insights into organic matter processing in these subsurface sediments.},
	issn = {00167037},
	doi = {10.1016/j.gca.2015.12.022},
	url = {http://linkinghub.elsevier.com/retrieve/pii/S0016703715007164http://api.elsevier.com/content/article/PII:S0016703715007164?httpAccept=text/xmlhttp://api.elsevier.com/content/article/PII:S0016703715007164?httpAccept=text/plain},
	author = {Komada, Tomoko and Burdige, David J. and Li, Huan-Lei and Magen, {\'e}dric and Chanton, Jeffrey P. and Cada, Abraham K.}
}
@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 { ISI:000337285500012,
	title = {Organic matter transformation in the peat column at Marcell Experimental Forest: Humification and vertical stratification},
	journal = {JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES},
	volume = {119},
	number = {{4}},
	year = {2014},
	month = {APR 28},
	pages = {661-675},
	type = {Article},
	abstract = {We characterized peat decomposition at the Marcell Experimental Forest (MEF), Minnesota, USA, to a depth of 2m to ascertain the underlying chemical changes using Fourier transform infrared (FT IR) and C-13 nuclear magnetic resonance (NMR) spectroscopy) and related these changes to decomposition proxies C:N ratio, C-13 and N-15, bulk density, and water content. FT IR determined that peat humification increased rapidly between 30 and 75cm, indicating a highly reactive intermediate-depth zone consistent with changes in C:N ratio, C-13 and N-15, bulk density, and water content. Peat decomposition at the MEF, especially in the intermediate-depth zone, is mainly characterized by preferential utilization of O-alkyl-C, carboxyl-C, and other oxygenated functionalities with a concomitant increase in the abundance of alkyl- and nitrogen-containing compounds. Below 75cm, less change was observed but aromatic functionalities and lignin accumulated with depth. Significant correlations with humification indices, identified by FT IR spectroscopy, were found for C:N ratios. Incubation studies at 22 degrees C revealed the highest methane production rates, greatest CH4:CO2 production ratios, and significant O-alkyl-C utilization within this 30 and 75cm zone. Oxygen-containing functionalities, especially O-alkyl-C, appear to serve as excellent proxies for soil decomposition rate and should be a sensitive indicator of the response of the solid phase peat to increased temperatures caused by climate change and the field study manipulations that are planned to occur at this site. Radiocarbon signatures of microbial respiration products in deeper pore waters at the MEF resembled the signatures of more modern dissolved organic carbon rather than solid phase peat, indicating that recently photosynthesized organic matter fueled the bulk of subsurface microbial respiration. These results indicate that carbon cycling at depth at the MEF is not isolated from surface processes.},
	keywords = {FT-IR spectroscopy, humification, NMR spectroscopy, organic matter, peatlands, vertical stratification},
	issn = {2169-8953},
	doi = {10.1002/2013JG002492},
	author = {Tfaily, Malak M. and Cooper, William T. and Kostka, Joel E. and Chanton, Patrick R. and Schadt, Christopher W. and Hanson, Paul J. and Iversen, Colleen M. and Chanton, Jeffrey P.}
}
@article {2482,
	title = {Surface production fuels deep heterotrophic respiration in northern peatlands},
	journal = {Global Biogeochemical Cycles},
	volume = {27},
	year = {2013},
	month = {Jan-12-2013},
	pages = {1163 - 1174},
	abstract = {[1] Multiple analyses of dissolved organic carbon (DOC) from pore waters were conducted to define the processes that govern carbon balance in peatlands: (1) source, reactivity, and transport of DOC with respect to vegetation, peat, and age of carbon substrate, (2) reactivity of DOC with respect to molecular size, and (3) lability to photoxidation of surficial DOC. We found that surface organic production fuels heterotrophic respiration at depth in advection-dominated peatlands, especially in fens. Fen DOC was Δ14C enriched relative to the surrounding fen peat, and fen respiration products were similar to this enriched DOC indicating that DOC was the main microbial substrate. Bog DOC was more variable showing either enrichment in ∆14C at depth or ∆14C values that follow peat values. This variability in bogs is probably controlled by the relative importance of vertical transport of labile carbon substrates within the peat profile versus DOC production from bog peat. These results extended our set of observations to 10 years at one bog-fen pair and add two additional bog-fen pairs to our series of observations. Anaerobic incubations of peat, rinsed free of residual DOC, produced DOC and respiration products that were strikingly similar to the peat values in a bog and two fens. This result demonstrated conclusively that downward advection is the process responsible for the presence of modern DOC found at depth in the peat column. Fen DOC has lower C/N values and up to twice as much LMW (<1 kDa) DOC as bogs due to differences in organic inputs and greater microbial processing. Fluorescence irradiation experiments showed that fen DOC is more photolabile than bog DOC.},
	doi = {10.1002/2013GB004677},
	url = {http://doi.wiley.com/10.1002/2013GB004677https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002\%2F2013GB004677},
	author = {Elizabeth Corbett, J. and Burdige, David J. and Tfaily, Malak M. and Dial, Angela R. and Cooper, William T. and Glaser, Paul H. and Chanton, Jeffrey P.}
}
@inbook {1407,
	title = {Methane accumulation and release from deep peat: Measurements, conceptual models, and biogeochemical significance},
	booktitle = {Carbon Cycling in Northern Peatlands},
	series = {GEOPHYSICAL MONOGRAPH SERIES},
	year = {2009},
	note = {id: 1972},
	month = {2009},
	pages = {145-158},
	publisher = {American Geophysical Union},
	organization = {American Geophysical Union},
	abstract = {Northern peatlands account for more than half the world{\textquoteright}s wetlands but are currently estimated to contribute only about a third of the total methane emissions from all wetlands. Increasing data on the dynamics of methane gas bubbles in peat deposits now suggest that these estimates may need to be scaled upward. Rates of methanogenesis may remain high in deep peat strata because of the downward transport of labile root exudates permitting the widespread production of gas bubbles. Recent investigations using an array of methods have reported free-phase gas volumes of 10{\textendash}20\% within both deep and shallow peat strata and episodic ebullition fluxes exceeding 35 g CH4 m-2 per event. Gas bubbles accumulate in overpressured pockets that episodically rupture in response to steep declines in atmospheric pressure or declining water tables. Although these ebullition fluxes are highly variable in both time and space, they appear to dominate the annual methane emissions from northern peatlands and represent a major and underappreciated element of the global methane cycle.},
	keywords = {Carbon cycle (Biogeochemistry){\textemdash}Northern Hemisphere, Carbon sequestration{\textemdash}Northern Hemisphere, Greenhouse gases{\textemdash}Northern Hemisphere, Peatlands{\textemdash}Environmental aspects{\textemdash}Northern Hemisphere},
	isbn = {9780875904498},
	author = {Glaser, Paul H. and Chanton, Jeffrey P.},
	editor = {Baird, A. J.}
}
