Responses of juvenile southern flounder exposed to Deepwater Horizon oil‐contaminated sediments

Abstract

The Deepwater Horizon oil spill released millions of barrels of crude oil into the northern Gulf of Mexico, much of which remains associated with sediments and can have continuing impacts on biota. Juvenile southern flounder (Paralichthys lethostigma) were exposed for 28 d in the laboratory under controlled conditions to reference and Deepwater Horizon oil-contaminated sediments collected from coastal Louisiana to assess the impacts on an ecologically and commercially important benthic fish. The measured polycyclic aromatic hydrocarbon (PAH) concentrations in the sediments ranged from 0.25 mg/kg to 3940 mg/kg suite of 50 PAH analytes (tPAH50). Mortality increased with both concentration and duration of exposure. Exposed flounder length and weight was lower compared to controls after 28 d of exposure to the sediments with the highest PAH concentration, but condition factor was significantly higher in these fish compared with all other treatments. Histopathological analyses showed increased occurrence of gill abnormalities, including telangiectasis, epithelial proliferation, and fused lamellae in flounder exposed to sediments with the highest tPAH50 concentrations. In addition, hepatic vascular congestion and macrovesicular vacuolation were observed in flounder exposed to the more contaminated sediments. These data suggest that chronic exposure to field collected oil-contaminated sediments results in a variety of sublethal impacts to a benthic fish, with implications for long-term recovery from oil spills. Environ Toxicol Chem 2017;36:1067-1076. © 2016 SETAC.

Species‐specific metabolism of naphthalene and phenanthrene in 3 species of marine teleosts exposed to Deepwater Horizon crude oil

“…Although the southern flounder in the present study had relatively high biotransformation rates for phenanthrene, they hypothetically suffered from metabolic fatigue and consequently, mortality. Moreover, southern flounder have been shown to have severe adverse effects across multiple endpoints when exposed to environmentally relevant concentrations of Deepwater Horizon –contaminated sediment .…”

Crude oil impairs immune function and increases susceptibility to pathogenic bacteria in southern flounder

“…Composite sediment and water samples were analyzed for PAH composition following the procedure discussed in Brown-Peterson et al (2015) ( S2 Table ). This concentration was selected as it is environmentally relevant to the Gulf Coast following the oil spill [ 43 ] and is a concentration we have previously demonstrated to have adverse effects in flounder [ 42 ].…”

The gut microbiome and aquatic toxicology: An emerging concept for environmental health

“…The effects of some environmental chemical contaminants on the microbiome of aquatic organisms have been investigated on a limited basis (Table ). Examples include triclosan, the heavy metal cadmium, PAHs, nanomaterials, and the fungicide imazalil (Gaulke et al ; Brown‐Peterson et al ; Jin C et al ; Zhai et al ), to name a few. Studies have identified a number of operational taxonomic units from phyla to genera that can change in abundance in the gut following contaminant exposures (Table ).…”

“…In the aftermath of the 2010 Deepwater Horizon oil spill, there were many reports demonstrating that the incursion of oil altered the microbial population spectrum of water and sediment significantly as a function of both time and distance from the oil release (Hazen et al ; Kostka et al ; Dubinsky et al ; Gutierrez et al ; Looper et al ; Mason et al ). However, there was relatively little research aimed at understanding the effects of oil contamination on the microbiomes of fish species in the affected area (Barron ; Whitehead et al ; Barron et al ; Brewton et al ; Brown‐Peterson et al ). This was somewhat surprising, given that there is increasing evidence that exogenous factors can have significant effects on the microbiome of organisms (Carlson et al ; Gaulke et al ).…”