* Nearly 10 times the average number of dead dolphins found
since July 1
* No sign the virus can be transmitted to humans
By Environment Correspondent Deborah Zabarenko
WASHINGTON, Aug 27 A measles-like virus that
suppresses the immune system could be the reason an
extraordinary number of bottlenose dolphins have died after
becoming stranded along the U.S. East Coast, a panel of dolphin
experts said on Tuesday.
Since July 1, 333 bottlenose dolphins have been found dead
along coastlines from New York to North Carolina, the highest
number in a quarter-century and almost 10 times the average of
33 for the same period and region over the last five years,
according to Teri Rowles of the National Oceanic and Atmospheric
Virginia has had the largest number of stranded dolphin
deaths, with 174, Rowles said in a telephone briefing.
The death toll is likely higher because there have been
reports of dolphin carcasses floating off the East Coast,
particularly in Virginia.
Rowles and other experts from NOAA, universities and marine
institutes have tentatively attributed the deaths to cetacean
morbillivirus, which is related to the virus that causes measles
Morbillivirus attacks dolphins' immune systems, leaving
infected animals thin and vulnerable to other diseases,
including pneumonia. Many of the stranded dolphins have lesions
on their skin, mouths, joints or lungs, NOAA reported.
Different kinds of morbillivirus stay within a closely
related species and there is no indication this outbreak could
jump to people, said Jerry Saliki of the University of Georgia.
This kind of dolphin die-off has not occurred in the
mid-Atlantic region since 1987-1988. If this outbreak follows a
similar course, it could last until May 2014 as dolphin
populations build up resistance to the virus, Rowles said.
NOAA has declared an Unusual Mortality Event, which offers
support for bottlenose dolphins in this area under the U.S.
Marine Mammal Protection Act.
NO DOLPHIN VACCINE
"At this point, there isn't anything to stop the virus,"
Rowles said. While there are vaccines against morbillivirus that
occurs in land animals, there is no vaccine that could be easily
deployed to populations of dolphins, she said.
This month, NOAA declared an Unusual Mortality Event for
bottlenose dolphins in Florida's Indian River Lagoon, where
dolphin strandings are nearly three times the historic average
this year. The agency did not offer a tentative cause for these
deaths, but many of the dolphin carcasses in Florida were
"There is a tipping point in populations," Stephanie
Venn-Watson of the National Marine Mammal Foundation said. "The
primary hypothesis is East Coast dolphins don't have the natural
immune response to fight off the virus."
Asked whether pollution could be a factor, Rowles said
experts are monitoring an area off Georgia where there are high
levels of polychlorinated biphenyls, or PCBs, in the water. PCBs
were banned in the United States in 1979, but they can remain at
manufacturing sites for decades and are known carcinogens,
according to the Environmental Protection Agency.
No stranded dolphins have been reported along the Georgia
coast, but that could change as the dolphins migrate south for
More information on the stranded dolphins is available
(Reporting by Deborah Zabarenko; Editing by Ros Krasny and