Abstract:

On July 23, 2013 a marine gas rig (Hercules 265) ignited in the northern Gulf of Mexico. The rig burned out of control for several days before being extinguished. We conducted a rapid-response sampling campaign near Hercules 265 after the fire to ascertain if sediments and fishes were polluted above earlier baseline levels. Sediment cores were collected to the SE of the rig at a distance of ~0.2 km, 8 km and 18 km using a multicorer, and demersal fishes were collected from ~0.2 to 8 km SE of the rig using a longline (508 hooks). Recently deposited sediments document that only high molecular weight (HMW) polycyclic aromatic hydrocarbon (PAH) concentrations decreased with increasing distance from the rig suggesting higher pyrogenic inputs associated with the blowout. A similar trend was observed in the foraminifera Haynesina germanica, an indicator species of pollution. In red snapper bile, only HMW PAH metabolites increased in 2013 nearly double those from 2012. Both surface sediments and fish bile analyses suggest that, in the aftermath of the blowout, increased concentration of pyrogenically-derived hydrocarbons were transported and deposited in the environment. This study further emphasizes the need for an ocean observing system and coordinated rapid-response efforts from an array of scientific disciplines to effectively assess environmental impacts resulting from accidental releases of contaminants.

Suggested Citation:

Romero, Isabel. 2015. Chemical analysis of sediment and fish species near the Hercules 265 blowout, Gulf of Mexico, 2013. Distributed by: Gulf of Mexico Research Initiative Information and Data Cooperative (GRIIDC), Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/N7MP517B

Publications:

Romero, I. C., Özgökmen, T., Snyder, S., Schwing, P., O’Malley, B. J., Beron-Vera, F. J., … Murawski, S. A. (2015). Tracking the Hercules 265 marine gas well blowout in the Gulf of Mexico . Journal of Geophysical Research: Oceans, n/a–n/a. doi:10.1002/2015jc011037

Purpose:

The dataset was developed to determine if the sediment and fish near the Hercules 265 marine gas rig experienced an increase in pollution after the rig suffered a blowout.

Data Parameters and Units:

Foraminifera abundance (%), sediment PAHs (ng/g), sediment biomarkers (ng/g), Fish Fork length (cm), Fish NPH (ug/g), Fish Phen (ug/g), Fish BAP (ng/g). The following is a list of PAHs used in the analysis: Naphthalene (N) and alkylated homologues (NC1-C4); Acenaphthylene (ACL); Acenaphthene (ACE); Fluorene (F); Dibenzothiophene (D) and their alkylated homologues (DC1-C2); Phenanthrene (P), Anthracene (AN) and their alkylated homologues (P/ANC1-C4); Fluoranthene (FL), Pyrene (PY) and their alkylated homologues (FL/PYC1-C4); Benz[a]anthracene (BAA), Chrysene (C) and their alkylated homologues (BAA/CC1-C4); Benzo[b]fluoranthene (BBF); Benzo[k]fluoranthene (BKF); Benzo[a]pyrene (BAP), Dibenz[a,h]anthracene (DA) and alkylated homologues (BP/PERC1-C4); Indeno[1,2,3-cd]pyrene (ID); Benzo[ghi]perylene (BGP). Spatial Information: The following are the coordinates for the 3 sample sites referenced in the dataset: Site 1: 28.37° N, 90.52° W; Site 2: 28.32° N, 90.39° W; Site 3: 28.22° N, 90.33° W; The fish used in the PAH analysis were collected by means of long line deployment between Sampling Sites 1 (28.37° N, 90.52° W) and 2 (28.32° N, 90.39° W).

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