Northwest Fisheries Science Center

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Document Type: Journal Article
Center: NWFSC
Document ID: 7434
Title: Health of bottlenose dolphins (Tursiops truncatus) in the Gulf of Mexico following the Deepwater Horizon oil spill
Author: Lori H. Schwacke, Cynthia A. Smith, Forrest I. Townsend, Randall S. Wells, Leslie B. Hart, Brian C. Balmer, Tracy K. Collier, Sylvain De Guise, Michael M. Fry, Louis J. Guillette Jr, Stephen V. Lamb, Suzanne M. Lane, Wayne E. McFee, Ned J. Place, Mandy C. Tumlin, Gina Marie Ylitalo, Eric S. Zolman, T. Rowles
Publication Year: 2013
Journal: Environmental Science & Technology
Volume: 48
Pages: 93-103
Keywords: cetacean,protected species,health effects,marine mammal,polycyclic aromatic hydrocarbons

The oil spill resulting from the explosion of the Deepwater Horizon drilling platform drew immediate concern for marine wildlife, including bottlenose dolphins in sensitive coastal habitats. To evaluate potential impacts on bottlenose dolphins, health assessments were conducted in Barataria Bay, Louisiana, an area that received heavy and prolonged oiling, and in a reference site, Sarasota Bay, Florida, where oil was not observed.  Dolphins were temporarily captured, received a veterinary examination including diagnostic ultrasound, and were then released. Dolphins sampled in Barataria Bay showed evidence of hypoadrenocorticism, consistent with adrenal toxicity as previously reported for laboratory mammals exposed to oil.  Barataria Bay dolphins were 5 times more likely to have moderate-severe lung disease, generally characterized by significant alveolar interstitial syndrome, lung masses and pulmonary consolidation. Of 32 dolphins evaluated from Barataria Bay, 48% were given a guarded or worse, and 17% were given a poor or grave prognosis, indicating that they would likely not survive. Disease conditions in Barataria Bay dolphins were significantly greater in prevalence and severity than those in Sarasota Bay dolphins, as well as those previously reported in other wild dolphin populations.  Many disease conditions observed in Barataria Bay dolphins are uncommon, but consistent with petroleum hydrocarbon toxicity.

Theme: Recovery and rebuilding of marine and coastal species