Northwest Fisheries Science Center

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Document Type: Journal Article
Center: NWFSC
Document ID: 8596
Title: Determining Oil and Dispersant Exposure in Sea Turtles From the Northern Gulf of Mexico Resulting From the Deepwater Horizon Oil Spill
Author: Gina M. Ylitalo, Tracy K. Collier, B. F. Anulacion, Kristy Juaire, Richard H. Boyer, Denis A.M. da Silva, Jennifer L. Keene, Brian A. Stacy
Publication Year: 2017
Journal: Endangered Species Research
Volume: 33
Pages: 9-24
Keywords: sea turtles,polycyclic aromatic hydrocarbons,dispersant,Gulf of Mexico,Deepwater Horizon Oil Spill

Documentation of exposure of threatened and endangered sea turtles to petroleum
and dispersant released into the northern Gulf of Mexico (GoM) during the Deepwater Horizon
(DWH) oil spill was a critical component of the Natural Resource Damage Assessment (NRDA)
process. Substances collected from the skin of oiled and suspected oiled turtles were analyzed for
petroleum hydrocarbons to determine oiling status and oil sources. Tissue, gastroenteric and bile
samples from a subset of visibly oiled and unoiled turtles that died during the spill in 2010 and in
2011 were analyzed for evidence of internal exposure and absorption of polycyclic aromatic hydrocarbons
(PAHs) and the dispersant component dioctyl sodium sulfosuccinate (DOSS). The volume
of external oil collected from sea turtles was sufficient to confirm the presence of petroleum
on 61% of turtles, and oil from the DWH spill was identified as the source in 97% of those turtles in
which conclusive comparison was possible. Visibly oiled turtles had higher concentrations of
tissue PAH or biliary fluorescent PAH metabolites compared to those determined in unoiled animals.
Findings in most of the unoiled turtles were suggestive of low-level PAH exposure from various
sources that may represent background values for sea turtles from the northern GoM. DOSS
levels were below the limit of quantitation in all samples analyzed except in an esophagus sample
of a heavily oiled sea turtle. Overall, the results for petroleum or petroleum-derived compounds of
both external and internal samples of sea turtles supported visual observations of oiling.

Theme: Habitats to Support Sustainable Fisheries and Recovered Populations
Foci: Assess the impacts of toxic chemicals and other pollutants across biological scales, and identify pollution reduction strategies that improve habitat quality.