title: Macondo oil in deep-sea sediments: Part 2 - Distribution and distinction from background and natural oil seeps.
abstract: Following the Deepwater Horizon oil spill, the spilled Macondo oil was severely weathered during its transport within the deep-sea plume as discrete particles, which were subsequently deposited on the seafloor. The Macondo oil deposited in deep-sea sediments was distinguished from ambient (background) hydrocarbons and naturally-seeped and genetically-similar oils in the Mississippi Canyon region using a forensic method based upon a systematic, multi-year study of 724 deep-sea sediment cores collected in late 2010 and 2011. The method relied upon: (1) chemical fingerprinting of the distinct features of the wax-rich, severely-weathered Macondo oil; (2) hydrocarbon concentrations, considering a core's proximity to the Macondo well or to known or apparent natural oil seeps, and also vertically within a core; and (3) results from proximal cores and flocculent material from core supernatants and slurp gun filters. The results presented herein establish the geographic extent of "fingerprintable" Macondo oil recognized on the seafloor in 2010/2011.
authors: NewFields Environmental Forensics Practice, LLC, 300 Ledgewood Pl., Suite 305, Rockland, MA, United States. Electronic address: sstout@newfields.com.
authors: Scott A
authors: SA
authors: Stout
authors: Payne Environmental Consultants, Inc., 1651 Linda Sue Ln., Encinitas, CA, United States.
authors: James R
authors: JR
authors: Payne
authors: NOAA, Assessment and Restoration Division, 1410 Neotomas Ave., Suite 110, Santa Rosa, CA, United States.
authors: Robert W
authors: RW
authors: Ricker
authors: NOAA, Assessment and Restoration Division, 345 Middlefield Rd., MS-999, Menlo Park, CA, United States.
authors: Gregory
authors: G
authors: Baker
authors: Industrial Economics, Incorporated, 2067 Massachusetts Ave., Fourth Floor, Cambridge, MA, United States.
authors: Christopher
authors: C
authors: Lewis
mesh_terms: D019015:Geologic Sediments / Q000032:analysis; D006838:Hydrocarbons / Q000032:analysis*; D008922:Mississippi; D061329:Oil and Gas Fields; D010578:Petroleum / Q000032:analysis*; D059392:Petroleum Pollution / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis; D014877:Water Pollution, Chemical
chemical_list: D006838:Hydrocarbons; D010578:Petroleum; D014874:Water Pollutants, Chemical
keywords: Biomarkers; Chemical fingerprinting; Deepwater Horizon; Flocculent; PAH; Weathering