Abstract:

The 2010 Deepwater Horizon (DWH) oil spill resulted in more than 3 million barrels of crude oil being delivered into the Gulf of Mexico with approximately 160,000 barrels of oil residue impacting over 1800 km of shoreline in the northern Gulf of Mexico. These data were generated to determine whether oil residues present in marsh sediments were a match for Macondo 252 (MC252) oil from the spill. Ten compound groups were analyzed and matches to MC252 oil were determined by assessing the quantitative composition of the hopane and sterane biomarker compounds. Heavily weathered oil residue was detected in November and February and was a possible match to MC252. Additional residues detected in February were a non-match to MC252, indicating that they came from a different crude oil than was spilled during the Deepwater Horizon accident.

Suggested Citation:

Corianne Tatariw, Nikaela Flournoy, Alice A. Kleinhuizen, Derek Tollette, Edward B. Overton, Patricia Sobecky, Behzad Mortazavi. 2018. Oil residue analysis from Chandeleur Island salt marsh sediments, September 2016 to February 2017. Distributed by: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/N7GQ6WCZ

Publications:

Tatariw, C., Flournoy, N., Kleinhuizen, A. A., Tollette, D., Overton, E. B., Sobecky, P. A., & Mortazavi, B. (2018). Salt marsh denitrification is impacted by oiling intensity six years after the Deepwater Horizon oil spill. Environmental Pollution, 243, 1606–1614. doi:10.1016/j.envpol.2018.09.034

Purpose:

The purpose of these data was to determine whether oil residues in salt marsh sediments came from the Deepwater Horizon spill.

Data Parameters and Units:

Date: month, day and year, Site number: represents the three sites that were visited on each date Latitude: Latitude of the site in decimal degrees Longitude: Longitude of the site in decimal degrees Replicate: used to differentiate between individual cores when replicate cores were collected Depth: depth of sediment core, centimeters (cm) Result: describes whether residues were a match for MC252 PDF Title: Identifies the pages that correspond to each sample, located in the upper right corner of each page

Methods:

Two sampling sites (“Site 2” and “Site 3”) in the Chandeleur Islands (LA) subjected to a range of oiling intensity were selected based on the Shoreline Cleanup and Assessment Technique (SCAT) data from the summer of 2010. SCAT oiling intensities are determined by the distribution, width, and thickness of oil bands. Site 2 (29.895448º -88.827780º) experienced light to moderate oiling. Site 3 (29.927599º -88.829308º) was 3.6 km north of Site 2 and was subjected to moderate to heavy oiling. Marsh sediment cores were collected from each site on four dates (20 September 2016, 19 October 2016, 15 November 2016, and 23 February 2017). Oil source-fingerprinting was conducted on homogenized 0-10 cm cores collected from Site 2 in September, October, November and February, and Site 3 (February only) to determine if oil residues present at Sites 2 and 3 were a match for Macondo 252 (MC252) source oil. Additional residue samples were collected in 0-5 cm cores at Site 2 in February, preserved at -80ºC, and homogenized immediately prior to petroleum fingerprint analysis. Oil source-fingerprinting profiles were determined from petroleum biomarker compounds as measured via GC/MS analytical methods at Louisiana State University. Source matching was done by visually comparing hopane and sterane biomarker compound concentrations in their respective m/z191 (hopanes), m/z 217 (sterane) and m/z 218 (sterane) ion chromatograms. The ion chromatograms of extracted field samples were compared to the equivalent data for biomarker compounds in the MC252 source oil.

Instruments:

Gas chromatograph/ Mass spectrophotometer (GS/MS) was used to characterize oil residues.

Individual Files: