Employing Extant Stable Carbon Isotope Data in Gulf of Mexico Sedimentary Organic Matter for Oil Spill Studies

Brad E. Rosenheim, Matthew A. Pendergraft, George C. Flowers, Robert Carney, José L. Sericano, Jeff Chanton, Zeynep Dincer, Terry L. Wade

Research output: Contribution to journalArticlepeer-review

Abstract

<p> <p id="x-x-x-x-sp0055"> We have compiled and mapped available <a href="https://www.sciencedirect.com/topics/earth-and-planetary-sciences/carbon-14" title="Learn more about carbon 14"> carbon isotope </a> data from sedimentary organic material sampled from the Gulf of Mexico prior to 2010. These data provide a baseline to which any changes in the Gulf of Mexico after the 2010 Deepwater Horizon <a href="https://www.sciencedirect.com/topics/earth-and-planetary-sciences/oil-spill" title="Learn more about oil spill"> oil spill </a> can be compared. The mean (&plusmn;1 <em> &sigma; </em> ) &delta; <sup> 13 </sup> C values, relative to PDB, are &minus;21.4&plusmn;1.9&permil; (entire Gulf of Mexico), &minus;21.7&plusmn;1.2&permil; (shelf sediments), &minus;20.4&plusmn;1.6&permil; (deepwater sediments), and &minus;25.2&plusmn;4.1&permil; (seep-affected sediments). We compare pre-spill mean &delta; <sup> 13 </sup> C values to carbon isotope measurements of sedimentary organic material from coretop samples collected after the 2010 Deepwater Horizon oil spill. The differences between the mean compiled &delta; <sup> 13 </sup> C values and the post-spill &delta; <sup> 13 </sup> C values are corroborated by qualitative relationships with the concentration of <a href="https://www.sciencedirect.com/topics/earth-and-planetary-sciences/polycyclic-aromatic-hydrocarbons" title="Learn more about Polycyclic Aromatic Hydrocarbons"> polycyclic aromatic hydrocarbons </a> (PAHs), a proxy for oil contamination, in the sediment. The relationships between &delta; <sup> 13 </sup> C of the sedimentary organic material and PAH concentrations allow estimation of background levels of <a href="https://www.sciencedirect.com/topics/earth-and-planetary-sciences/polycyclic-aromatic-hydrocarbon" title="Learn more about polycyclic aromatic hydrocarbon"> PAHs </a> on the shelf and in the deep Gulf of Mexico. Higher background levels of PAH on the shelf likely relate to Mississippi River outflow and its deposition of petrogenic PAH in riverine sediments. </p></p>
Original languageAmerican English
JournalDeep Sea Research Part II: Topical Studies in Oceanography
Volume129
DOIs
StatePublished - Jul 1 2016

Keywords

  • Petroleum
  • Carbon isotope
  • Sediment
  • Gulf of Mexico
  • Deepwater
  • Horizon
  • Radiocarbon
  • Sedimentary organic carbon

Disciplines

  • Marine Biology

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