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2013 Bottlenose Dolphin Unusual Mortality Event in the Mid-Atlantic

Overview


Photo Credit: NOAA

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

Bottlenose dolphin strandings are over nine times the historical average for the months of July and August for the Mid-Atlantic Region. 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.





Morbillivirus

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 four dolphins. 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

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

FAQs are available for the on going Mid-Atlantic bottlenose dolphin UME and cetacean morbillivirus.

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: September 24, 2013