Abstract

Pulmonary ultrasound exams were performed on wild bottlenose dolphins, Tursiops truncatus, in 2011 during capture-release health assessments¹ in Sarasota Bay (SB), Florida, and Barataria Bay (BB), Louisiana, as part of the Deepwater Horizon oil spill Natural Resource Damage Assessment. Long-term resident SB dolphins were used as a reference population for comparison with BB dolphins, as Deepwater Horizon oil did not reach SB, but did enter BB. Ultrasonographic examinations were performed as previously described,⁵ focusing on the left lung. Lung health was evaluated in 15 dolphins from SB, and characterized primarily as normal-mild lung disease (93%) with a low prevalence of moderate-severe lung disease (6.7%). This differed significantly from findings in the 28 dolphins evaluated in BB, where dolphins were 4.8 times more likely to have moderate-severe lung disease (32%; p = 0.054). Abnormalities detected in SB compared to BB included: alveolar-interstitial syndrome (AIS; 60% vs. 61%), pulmonary nodules (33% vs. 32%), pleural effusion (6.7% vs. 11%), pulmonary consolidation (6.7% vs. 21%) and pulmonary masses (0% vs. 11%). When comparing severity of alveolar-interstitial syndrome (AIS) between the two populations, dolphins in BB were 3.5 times more likely to have moderate-severe AIS compared to SB dolphins (p = 0.026). Pulmonary disease, particularly pneumonia, is the most common finding at death in both wild and managed dolphins.^1,2-4,6 Therefore, the high prevalence of lung disease detected in BB should be considered cause for concern and warrants follow-up over time to determine the impact on overall population health.

Acknowledgments

The authors thank Drs. Forrest Townsend, Jay Sweeney, Deb Fauquier, and Jennifer Langan for their assistance in image acquisition and expertise in dolphin health assessment. Veronica Cendejas provided technical expertise for the ultrasound examinations, and the Sarasota Dolphin Research Program staff and NOAA staff, especially Suzanne Lane and Leslie Hart, provided essential logistical support. The dolphin capture-release health assessments were part of a cooperative project among NOAA, other federal and state Trustees, and British Petroleum (BP). Field studies in Sarasota Bay were supported in part by Dolphin Quest, and were conducted under National Marine Fisheries Service Scientific Research Permit and approval by the Mote Marine Laboratory Institutional Animal Care and Use Committee.

* Presenting author

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