Sign up for


and other email updates

2013-2014 Bottlenose Dolphin Unusual Mortality Event in the Mid-Atlantic


Under the Marine Mammal Protection Act of 1972 (as amended), an Unusual Mortality Event (UME) has been declared for bottlenose dolphins along the Atlantic coast from early July 2013 through the present. Elevated strandings of bottlenose dolphins have occurred in New York, New Jersey, Delaware, Maryland, Virginia, North Carolina, South Carolina, Georgia and Florida (through Brevard County).

All age classes of bottlenose dolphins are involved and strandings range from a few live animals to mostly dead animals with many very decomposed. Many dolphins have presented with lesions on their skin, mouth, joints, or lungs.


Bottlenose Dolphin Strandings by State
2007-2012 Average
(July 1 - April 13)
5 6 4 3 33 32 29 12 58 181
(July 1 - April 13)
35 135 64 68 346 210 114 67 180 1219

Note: Data are dolphin strandings that have been confirmed and responded to by Stranding Network Members. Florida data is through Brevard County. Current UME Data are considered preliminary and may be subject to change as more information becomes available.


The tentative cause of the UME is being attributed to 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. The information will be updated as results become available.

The UME investigation is still ongoing and additional contributory factors to the UME are under investigation including other pathogens, biotoxins, range expansion, etc. Further evaluations will continue over the next several months 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.


Brucella Bacteria

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. NOAA has been investigating Brucella in marine mammal populations across the United States since 2011 and is working closely with our stranding network partners, NOAA laboratories, the University of Illinois, the CDC and State Departments of Health, the National Park Service, and the U.S. Department of Agriculture.


Bottlenose dolphin stranding in NJ. Photo: Marine Mammal Stranding Center


Stranding Locations Map

The following map displays cetacean stranding locations along the Atlantic coast from late June 2013 through the present. Bottlenose dolphin stranding locations are represented by circle symbols, while stranding locations for all other cetacean species are represented by square symbols. Yellow symbols containing a black dot represent the stranding locations of cetaceans that have been confirmed positive or suspected positive for morbillivirus, while the green symbols represent the stranding locations of 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 located above the date range slider allow for additional filtering of the mapped locations by state, county, and suspected/confirmed morbillivirus. Clicking the Animate button will animate the spatiotemporal occurrence of the strandings within the currently defined date range that meet the selected filter conditions in the dropdown boxes. Clicking on a mapped location will open an information window containing limited data associated with the selected stranding.

Date Range:


1987-1988 Bottlenose Dolphin Mortality Event

It has been 25 years since the 1987-1988 bottlenose dolphin morbillivirus mortality event that occurred along the mid-Atlantic coast, involving over 740 animals and spanning 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 MMPA.


FAQs are available for: 

More Information

Additional References

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. Clinicial 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: April 17, 2014