Polycyclic Aromatic Hydrocarbons in Red Snapper, Lutjanus campechanus, and Sediment Samples After the Deepwater Horizon Oil Spill

Abstract

The Deepwater Horizon oil spill occurred on 20 April 2010, which led to approximately 4.9 million barrels of oil entering the northern Gulf of Mexico. Red snapper, Lutjanus campechanus, are an important species in the Gulf of Mexico, and were potentially exposed to polycyclic aromatic hydrocarbons (PAHs) from this oil spill. To assess this potential PAH exposure, red snapper tissue samples were collected from 2010 to 2014, and analyzed for several PAHs. All red snapper tissue samples showed mean total PAH concentrations < 10 ppb. Significant differences were observed in total (± SD) PAH by year, with muscle tissue in 2011 having the highest concentration (5.4 ± 2.5 ppb) among all samples types and years. Sediment samples were also analyzed for PAHs and these showed no evidence of contamination above background levels. Several condition indices were used to determine if any physiological changes occurred in red snapper condition, gonadal tissue, or liver tissue following the oil spill. Significant differences were observed in gonadosomatic index and Fulton’s K (condition factor); however these were not attributed to the oil spill and more likely normal yearly variations due to temperature and nutrition status. Lesions were observed in 10 of 3,934 (0.25%) red snapper collected during this study. These levels of lesions were at similar levels to non-oil exposed fishes. Based on low levels of PAH in red snapper and sediment samples, and low rate of external lesions it is unlikely that adult red snapper in the northern Gulf of Mexico on the Alabama-Mississippi continental shelf were affected by the Deepwater Horizon oil spill.