Abstract:

High-resolution analyses of sediment cores collected in the aftermath of the Deepwater Horizon (DWH) were conducted to reconstruct the concentration, composition and flux of hydrocarbons to deep-sea (pre-2010, 2010, and 2011) in the DeSoto Canyon, Northeast Gulf of Mexico. Specifically, we analyzed total organic carbon (TOC), aliphatic, polycyclic aromatic hydrocarbon (PAHs), and short-lived radionuclide (234Th, 210Pb) compounds at 2 mm and 5 mm core intervals to elucidate possible hydrocarbon sources and transport pathways to sediments during the time covered in this study. Results showed higher TOC, total aliphatics and PAH fluxes after the DWH blowout (2010-2011) compared to pre-2010 years (up to 46-, 100-, and 50-fold increase; respectively). TOC in 2010-2011 was composed of a mixture of carbon sources including terrestrial, planktonic, weathered oil, and oil. Our results demonstrate that in deep-water oil spills relatively insoluble and dissolved oil hydrocarbons reached the deep-sea. Three distinct transport pathways of hydrocarbons were identified: oil-contaminated marine snow, sinking of burned-oil particles, and advective transport of dissolved-oil from the deep intrusion (at ~1000-1200 m depth). These pathways deposited particulate organic matter, oil-droplets, weathered oil, weathered burned-oil and dissolved hydrocarbon compounds into the deep-sea during 2010-2011. Although high concentrations of PAHs were observed in 2010 (up to 525 ng g-1) compared to pre-2010 years (up to 320 ng g-1), values were lower than urbanized and industrialized areas worldwide. Nevertheless, the large increase of PAH concentrations and large PAH fluxes observed in 2010-2011 may indicate a potential ecological risk to deep-sea environments. This dataset also includes data funded under FIO Y1.x031.000:0005.

Suggested Citation:

Romero, Isabel. 2013. Hydrocarbons in deep-sea sediments following the 2010 Deepwater Horizon oil spill in the Northeast Gulf of Mexico. Distributed by: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/N7ZG6Q71

Publications:

Romero, I. C., Schwing, P. T., Brooks, G. R., Larson, R. A., Hastings, D. W., Ellis, G., … Hollander, D. J. (2015). Hydrocarbons in Deep-Sea Sediments following the 2010 Deepwater Horizon Blowout in the Northeast Gulf of Mexico. PLoS ONE, 10(5), e0128371. doi:10.1371/journal.pone.0128371

Schwing, P. T., Romero, I. C., Larson, R. A., O’Malley, B. J., Fridrik, E. E., Goddard, E. A., … Mulhollan, J. (2016). Sediment Core Extrusion Method at Millimeter Resolution Using a Calibrated, Threaded-rod. JoVE, (114). doi:10.3791/54363

Romero, I. C., Toro-Farmer, G., Diercks, A.-R., Schwing, P., Muller-Karger, F., Murawski, S., & Hollander, D. J. (2017). Large-scale deposition of weathered oil in the Gulf of Mexico following a deep-water oil spill. Environmental Pollution, 228, 179–189. doi:10.1016/j.envpol.2017.05.019

Romero, I. C., Chanton, J. P., Roseheim, B. E., Radović, J. R., Schwing, P. T., Hollander, D. J., … Oldenburg, T. B. P. (2019). Long-Term Preservation of Oil Spill Events in Sediments: The Case for the Deepwater Horizon Oil Spill in the Northern Gulf of Mexico. Deep Oil Spills, 285–300. doi:10.1007/978-3-030-11605-7_17

Romero, I. C., Chanton, J. P., Brooks, G. R., Bosman, S., Larson, R. A., Harris, A., … Diercks, A. (2021). Molecular Markers of Biogenic and Oil-Derived Hydrocarbons in Deep-Sea Sediments Following the Deepwater Horizon Spill. Frontiers in Marine Science, 8. doi:10.3389/fmars.2021.637970

Purpose:

The data were collected to asses the concentration, composition and fluxes of hydrocarbons in sediments collected from the DeSoto Canyon located NE of the Deepwater Horizon; to reconstruct the hydrocarbon deposition history in the study area not previously available (pre-2010, 2010, and 2011); and to explain the possible sources and transport pathways of hydrocarbons to deep sediments during the period of the study.

Data Parameters and Units:

Stable isotope data are reported using conventional delta notation in permil (‰) units relative to the Vienna Pee Dee Belemnite (VPDB) standard. Hydrocarbon compounds are expressed as sediment dry weight concentrations.

Error Analysis:

The precision for replicate analyses of external standards (NIST 8573, NIST 8574, NIIST 1570) was 0.3‰ for d13C and 0.4‰ for d15N (1s, N=100). For analysis of PAHs recoveries from spiked samples included with each batch were generally within QA/QC criteria of 60-120%.

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