Dolphins Found Washed up on Our Shore

Akira Suwa/ The Philadelphia Inquirer

Since July 9, 2013, there have been a total of 25 dolphin strandings along the Jersey Coast according to the Marine Mammal Stranding Center in Brigantine, NJ. Strandings have been reported along the Atlantic coastline with a total of 124 dolphins washing up along the shores (the majority in Virginia). Pneumonia has beenresponsible for four of the dolphin deaths while another tested positive for Morbillivirus, a measles-like virus.

While although pneumonia and Morbillivirus have been identified as causes, the overall cause of the deaths is unknown.  The Morbillivirus has been known to affectspecies of dolphins in the past 20 years with one notable event occurring inthe 1980s in which 742 dolphins presented with the virus.  This virus has been known to affect species of cetaceans off the coasts of Ireland, France, Italy, Greece, and Turkey.[1]

The macroscopic presentation of this disease involves deteriorating body condition along with prominent lesions on the lungs and central nervous tissues. The Morbillivirus also causes secondary infections, such as pneumonia, due to the “immune suppressive nature of the virus”.[2]  What is concerning most about Morbillivirus is how it is spread. Thevirus is capable of spreading through contact transmission between groups ofdolphins.

The New Jersey Department of Environmental Protection hasbeen informed of the deaths and has stated that there is no correlation betweenthe deaths and the water quality which “has been excellent this summer”.  Instead, it is an indication of a “natural disease cycle.”

The discoveries have led federal agency to declare anunusual mortality event for Bottlenose dolphins. This declaration will provide scientists with additional research funding in order to find the root cause of the deaths.

Perry Habecker, chief of large-animal pathology at the University of Pennsylvania, stated that “’human interaction’- such as aggressive commercial fishing, toxic wastes, and even plastic bags- can contribute to spikes of mortality in marine-mammal populations such as whales, seals and dolphins.”  But, for now, the primary cause of death has yet to be identified. Scientists will know more once they run diagnostic tests on tissue and blood samples.

How can you help? If you see a stranded dolphin, do not touch it. Alert local officials and keep pets away from the animal.

[1] Rubio-Guerri, Consuelo; Melero, Mar; Esperón, Fernando; Belliére, Edqige N.; Arbelo, Manuel; Crespo, Jose L.; Sierra, Eva; García-Párraga, Daniel; Sánchez-Vizcaíno, Jose M. 2013. Unusual striped dolphin mass mortality episode related to cetacean morbillivirus in the Spanish Mediterranean Sea, BMC Veterinary Research, 9:106.

[2] Reidarson, Thomas H.; McBain, Jim; House, Carol; King, Donald P.; Stott, Jeffrey L.; Krafft, Amy; Taubenberger, Jeffrey K.; Heyning, John; Lipscomb, Thomas P. 1998. Morbillivirus Infection in Stranded Common Dolphins from the Pacific Ocean. Journal of Wildlife Diseases. 34(4) 771-776.