Abstract
The Deepwater Horizon (DWH) oil spill resulted in large-scale contamination of bays, sounds, and estuaries in the northern Gulf of Mexico (NGoM), with Barataria Bay (BB), Louisiana, being one of the more heavily oiled bays.1,2 Natural and experimental oil exposure has been linked to adverse health conditions in humans and animals, including hematological aberrations, lung disease, and adrenal dysfunction.3-10 As part of a Natural Resource Damage Assessment designed to investigate the potential health impacts of the DWH oil spill on free-ranging bottlenose dolphins, capture-release health assessments were performed during 2011 in BB and a control site with no evidence of DWH oil contamination (Sarasota Bay [SB], Florida). Dolphins living in BB had increased prevalence of multiple health concerns, including impaired stress response, moderate-to-severe lung disease, hematologic abnormalities, and poor body condition.11 Follow-on health assessments were performed in 2013 and 2014 to look for evidence of recovery in BB. To address potential differences in geographic locations within the NGoM, dolphins from another oiled area (Mississippi Sound [MS], Mississippi/Alabama) were also evaluated in 2013. For BB dolphins, results showed overall resolution of hematologic derangements and poor body condition, while evidence of adrenal dysfunction and lung disease persisted, albeit at lower prevalence. MS dolphins had adverse health conditions similar to those observed in BB, strengthening the likelihood that these abnormalities were consequences of oil contamination within their home range. Long-term monitoring is needed to fully understand the impact of compromised health in NGoM dolphins on their ability to thrive post-spill.
Acknowledgments
We appreciate the efforts of the many researchers, veterinarians, and technicians who provided support for the dolphin health assessment fieldwork, especially Jay Sweeney, Jennifer Langan, Lydia Staggs, Deborah Fauquier, Eric Anderson, Elsburgh Clarke, Todd Speakman, James Daugomah, Larry Hansen, Larry Fulford, Veronica Cendejas, Mark Baird, Nicole Hatcher, Suzanne Lane, Lauren McGeorge, Amanda Moors, and Lauren Noble. We also recognize the organizations that provided staff and logistical support, including SeaWorld and Busch Gardens, National Institute of Standards and Technology, Northwest Fisheries Science Center, Louisiana Department of Wildlife and Fisheries, Texas Marine Mammal Stranding Network, Chicago Zoological Society, and Georgia Aquarium. We thank Stephanie Venn-Watson and Sylvain DeGuise for valuable insight on data interpretation. This work was part of the Deepwater Horizon NRDA being conducted cooperatively among NOAA, other Federal and State Trustees, and BP. The dolphin health assessments in SB were conducted by Chicago Zoological Society's Sarasota Dolphin Research Program staff, students, trained volunteers, and collaborators under NMFS Permit Nos. 522-1785 and 15543 and were supported by additional funding from Office of Naval Research, Dolphin Quest, Morris Animal Foundation's Betty White Wildlife Rapid Response Fund, Disney's Animal Programs and Environmental Initiatives, and Georgia Aquarium. The dolphin health assessments in BB and MS were conducted under NMFS Permit No. 932-1905/MA-009526. Protocols were reviewed and approved by Mote Marine Laboratory (SB) and NOAA Institutional Animal Care and Use Committees (BB and MS).
* Presenting author
Literature Cited
1. Deepwater Horizon oil spill phase I early restoration plan and environmental assessment. www.gulfspillrestoration.noaa.gov/wp-content/uploads/Final-ERP-EA-041812.pdf
2. Michel J, Owens EH, Zengel S, et al. Extent and degree of shoreline oiling: Deepwater Horizon oil spill, Gulf of Mexico, USA. PLoS ONE. 2013;8(6):e65087.
3. Coppock RW, Mostrom MS, Khan AA, Semalulu SS. Toxicology of oil field pollutants in cattle: a review. Vet Hum Toxicol. 1995;37(6):569–576.
4. Coppock RW, Mostrom MS, Stair EL, Semalulu SS. Toxicopathology of oilfield poisoning in cattle: a review. Vet Hum Toxicol. 1996;38(1):36–42.
5. D'Andrea MA, Reddy GK. Crude oil spill exposure and human health risks. J Occup Environ Med. 2014;56(10):1029–1041.
6. Lattin CR, Ngai HM, Romero LM. Evaluating the stress response as a bioindicator of sub-lethal effects of crude oil exposure in wild house sparrows (Passer domesticus). PLoS ONE. 2014;9(7):e102106.
7. Mazet JK, Gardner IA, Jessup DA, Lowenstine LJ, Boyce WM. Evaluation of the changes in hematologic and clinical biochemical values after exposure to petroleum products in mink (Mustela vison) as a model for assessment of sea otters (Enhydra lutris). Am J Vet Res. 2000;61(10):1197–1203.
8. Mohr FC, Lasley B, Bursian S. Chronic oral exposure to bunker C fuel oil causes adrenal insufficiency in ranch mink (Mustela vison). Arch Environ Contam Toxicol. 2008;54(2):337–347.
9. Mohr FC, Lasley B, Bursian S. Fuel oil-induced adrenal hypertrophy in ranch mink (Mustela vison): effects of sex, fuel oil weathering, and response to adrenocorticotropic hormone. J Wildl Dis. 2010;46(1):103–110.
10. Schwartz JA, Aldridge B, Lasley BL, Snyder PW, Stott JL, Mohr FC. Chronic fuel oil toxicity in American mink (Mustela vison): systemic and hematological effects of ingestion of a low-concentration of bunker C fuel oil. Toxicol Appl Pharmacol. 2004;200(2):146–158.
11. Schwacke LH, Smith CR, Townsend FI, et al. Health of common bottlenose dolphins (Tursiops truncatus) in Barataria Bay, Louisiana, following the Deepwater Horizon oil spill. Environ Sci Technol. 2014;48(1):93–103.