2013-2015 Bottlenose Dolphin Unusual Mortality Event in the Mid-Atlantic
Bottlenose dolphins have been stranding at elevated rates since July 2013 along the Atlantic coast from New York to Florida (through Brevard County). All ages of bottlenose dolphins are stranding. A few live animals have stranded, but most were found dead, many times very decomposed. Many dolphins have lesions on their skin, mouth, joints, or lungs.
This event has been declared an Unusual Mortality Event (UME).
Based upon preliminary diagnostic testing and discussion with disease experts, we think the mortality event may be caused by cetacean morbillivirus.
Report a stranding (live or dead) to the regional stranding network in the area.
|Bottlenose Dolphin Strandings by State|
(July 1 - June 30)
(July 1 - July 12)
* Florida data is through Brevard County.
Why are bottlenose dolphins stranding?
The tentative cause of the UME is cetacean morbillivirus, based upon preliminary diagnostic testing and discussion with disease experts. Here are our results showing the total number of morbillivirus cases identified so far, updated as results become available.
Brucella sp. bacteria have been found in joint, brain or reproductive organ lesions in dolphins in the UME area. Here are our results showing the total number of Brucella cases identified so far. The information will be updated as results become available. We have been investigating Brucella in marine mammal populations across the U.S. since 2011 and are working closely with our stranding network partners, NOAA laboratories, the University of Illinois, CDC, State Departments of Health, National Park Service, and USDA.
The UME investigation is ongoing and additional contributory factors to the UME are under investigation including:
- other pathogens
- range expansion
Further evaluations will continue as new animals are found or new evidence determines the direction of the investigation. These rigorous investigations may take several more months to complete. Additional studies are underway to better understand the characteristics of morbillivirus and the potential impacts of this virus on dolphin stocks. These studies are in collaboration with several NOAA laboratories and science centers, stranding network members, non-profit research organizations and academic partners.
Bottlenose dolphin stranding in NJ. Photo: Marine Mammal Stranding Center
The following map displays cetacean stranding locations along the Atlantic coast from late June 2013 through April 20, 2015.
Symbols and Colors:
Click to display data associated with that stranding.
- circles - bottlenose dolphins
- squares - other cetacean species
- yellow with black dot - positive or suspected positive for morbillivirus
- green - all other cetaceans
The date range slider filters stranding locations to those observed between the dates defined by the position of the two slider drag handles.
Dropdown boxes filter by state, county, and confirmed/suspected morbillivirus.
The Animate button shows spatiotemporal occurrence of the strandings within the currently defined date range that meet the selected filter conditions in the dropdown boxes.
Has this happened before?
In 1987-1988, a bottlenose dolphin morbillivirus mortality event was declared along the mid-Atlantic coast, involving over 740 animals from New Jersey to Florida. That massive die-off, along with a humpback whale mortality event in 1987 off the coast of Massachusetts and the 1989 Exxon Valdez oil spill prompted Congress to formally establish the Marine Mammal Health and Stranding Response Program with the specific instructions for the UME Program as Title IV of the Marine Mammal Protection Act (MMPA).
FAQs are available for:
- Report a live or dead stranded dolphin to the local marine mammal stranding network
- Media Availability Recordings
» August 26, 2013 Media Availability Recording [mp3]
» August 8, 2013 Media Availability Recording [mp3]
- Morbillivirus in Cetaceans Fact Sheet
- Morbillivirus in Pinnipeds Fact Sheet
- Brucella in Marine Mammals Fact Sheet
- Map of coastal bottlenose dolphin stocks
- Unusual Mortality Events
- National Marine Mammal Stranding Network
- DiGuardo, G., G. Marruchella, U. Agrimi and S. Kennedy. 2005. Morbillivirus infections in aquatic mammals: A brief overview. Journal of Veterinary Medicine Series A, 52(2): 88-93.
- Duignan, P.J., C. House, D.K. Odell, R.S. Wells, L.J. Hansen, M.T. Walsh, D,J. St. Aubin, B.K. Rima and J.R, Geraci. 1996. Morbillivirus infection in bottlenose dolphins: Evidence for recurrent epizootics in the western Atlantic and Gulf of Mexico. Marine Mammal Science, 12(4): 499-515.
- Geraci. 1989. Clinical Investigation of the 1987-88 mass mortality of bottlenose dolphins along the U.S. central and south Atlantic coast. Final Report to National Marine Fisheries Service, U.S. Navy, and Marine Mammal Commmission. April 1989. 63 pp.
- Lipscomb, T.P., F.Y. Schulman, D. Moffett and S. Kennedy. 1994. Morbilliviral disease in Atlantic bottlenose dolphins (Tursiops truncatus) from the 1987-1988 epizootic. Journal of Wildlife Diseases, 30(4): 567-571.
- McLellan, W.A., A.S. Friedlaender, J.G. Mead, C.W. Potter and D.A. Pabst. 2002. Analyzing 25 years of bottlenose dolphin (Tursiops truncatus) strandings along the Atlantic coast of the USA: do historic records support the coastal migratory stock hypothesis? Journal of Cetacean Research and Management, 4(3): 297-304.
- Rowles, T.K., L.S. Schwacke, R.S. Wells, J.T. Saliki, L. Hansen, A. Hohn, F. Townsend, R.A. Sayre and A.J. Hall. Evidence of susceptibility to morbilivirus infection in cetaceans from the United States. Marine Mammal Science, 27(1): 1-19.
Updated: July 29, 2015