A widespread die-off of bottlenose dolphins off the Mid-Atlantic Coast- the worst of its kind in more than 25 years- is almost certainly is the work of a virus that killed more than 740 dolphins in the same region in 1987 and 1988, marine scientists said Tuesday.
Since July 1, 333 carcasses have littered shored from New York to North Carolina, a number that’s roughly 10 times more than normal for this time of year. Scientists don’t yet know how many dolphins have died offshore without reaching mid-Atlantic beaches, but it could be thousands. In July, NOAA declared the die-off an “Unusual Mortality Event”, which frees up federal funding and investigators to address the crisis.
“When we were doing examinations, we would find they were very skinny animals,” biologist Kim Durham, whose rescue team has recovered 27 dead dolphins, told CBS News. “They were compromised animals. Some of them had skin lesions- they were just very sick individuals.”
A NOAA team in charge of investigating the event is pointing to a type of morbillivirus as the culprit behind the bottlenose dolphins deaths. There is no easy way to identify morbillivirus infection just by looking at a carcass. Identifying the pathogen requires examination of tissue from the dead animals.
The virus poses no threat to people, although it is related to the virus that causes measles in humans and distemper in canines. Secondary infections could be dangerous. Authorities urge people to stay away from stranded dolphins.
The large number of deaths in Virginia “is not really surprising if you understand how the population of dolphins works,” said W. Mark Swingle, director of research and conservation for the Virginia Aquarium and Marine Science Center, which is part of a network if agencies that responds to marine animal strandings along the East Coast.
It is not clear what started the most recent problem, but Jerry Saliki, a virologist at the University of Georgia, said enough time had probably passed since the last mass die-off that herds of dolphins now lack natural immunity to morbillivirus. Pollution may be weakening dolphins’ immune system, said Smithsonian marine mammal biologist Charles Parker, who investigated earlier incidents.
“As the animals migrate south, passing back through Virginia and are going down to the Carolinas, if this event follows what we saw in 1987, we can expect the epicenter of the epidemic to move south with the dolphins,” Potter said. “It will run its course, but ther’s no way to know when the end will come.
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