Distributions and accumulation rates of polycyclic aromatic hydrocarbons in the northern Gulf of Mexico sediments

Puspa L Adhikari; Kanchan Maiti; Edward B Overton; Brad E Rosenheim; Brian D Marx

doi:10.1016/j.envpol.2016.01.064

Distributions and accumulation rates of polycyclic aromatic hydrocarbons in the northern Gulf of Mexico sediments

Environ Pollut. 2016 May:212:413-423. doi: 10.1016/j.envpol.2016.01.064. Epub 2016 Feb 16.

Authors

Puspa L Adhikari¹, Kanchan Maiti², Edward B Overton³, Brad E Rosenheim⁴, Brian D Marx⁵

Affiliations

¹ Department of Oceanography and Coastal Sciences, Louisiana State University, Baton Rouge, LA 70803, United States; Department of Environmental Sciences, Louisiana State University, Baton Rouge, LA 70803, United States. Electronic address: padhik2@lsu.edu.
² Department of Oceanography and Coastal Sciences, Louisiana State University, Baton Rouge, LA 70803, United States.
³ Department of Environmental Sciences, Louisiana State University, Baton Rouge, LA 70803, United States.
⁴ College of Marine Science, University of South Florida, St. Petersburg, FL 33701, United States.
⁵ Department of Experimental Statistics, Louisiana State University, Baton Rouge, LA 70803, United States.

PMID: 26895564
DOI: 10.1016/j.envpol.2016.01.064

Abstract

Sediment samples collected from shelf, slope and interior basin of the northern Gulf of Mexico during 2011-2013, 1-3 years after the Deepwater Horizon (DWH) oil spill, were utilized to characterize PAH pollution history, in this region. Results indicate that the concentrations of surface ΣPAH43 and their accumulation rates vary between 44 and 160 ng g(-1) and 6-55 ng cm(-2) y(-1), respectively. ΣPAH43 concentration profiles, accumulation rates and Δ(14)C values are significantly altered only for the sediments in the immediate vicinity of the DWH wellhead. This shows that the impact of DWH oil input on deep-sea sediments was generally limited to the area close to the spill site. Further, the PAHs source diagnostic analyses suggest a noticeable change in PAHs composition from higher to lower molecular weight dominance which reflects a change in source of PAHs in the past three years, back to the background composition. Results indicate low to moderate levels of PAH pollution in this region at present, which are unlikely to cause adverse effects on benthic communities.

Keywords: Deepwater horizon oil spill; Gulf of Mexico; Polycyclic aromatic hydrocarbons (PAHs); Radiocarbon (Δ(14)C); Sediment.

MeSH terms

Animals
Environmental Monitoring* / methods
Fishes
Gas Chromatography-Mass Spectrometry
Geologic Sediments / analysis
Geologic Sediments / chemistry*
Gulf of Mexico
Petroleum Pollution* / analysis
Polycyclic Aromatic Hydrocarbons / analysis
Polycyclic Aromatic Hydrocarbons / chemistry*
Seawater / chemistry*
Water Pollutants, Chemical / analysis
Water Pollutants, Chemical / chemistry*

Substances

Polycyclic Aromatic Hydrocarbons
Water Pollutants, Chemical