Hundreds of bottle-nosed dolphins have been dying on the East Coast, and the National Oceanic and Atmospheric Administration says a virus is likely to blame. Since July 1, 333 carcasses have littered shores 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. Morbilliviruses are responsible for measles in humans, rinderpest in cattle, and canine distemper in dogs, coyotes, wolves and seals. While there are no unifying anatomical findings that point toward the pathogen, many of the animals washing ashore have suggestive lesions in their mouths, lymph nodes, brain, or lungs. So far, nearly all of the carcasses – 32 out of 33 — fresh enough to be analyzed by these methods have tested positive for, or are strongly suspected of having, morbillivirus. Of those, genetic sequencing confirmed that 11 of the carcasses carry the cetacean form of the virus, which affects dolphins and porpoises. "We are now calling it a morbillivirus outbreak," Teri Rowles of the National Oceanic and Atmospheric Administration's Marine Mammal Health and Stranding Response Program said during a telephone press briefing on Tuesday. Sarah Rose, left, with the Virginia Aquarium Stranding Response Team begins a necropsy on a dead dolphin at the Virginia Aquarium Marine Animal Care Center, in Virginia Beach, Va., on Aug. 6, 2013. There, teams are finding about a dolphin a day, said Bob Schoelkopf, founding director of the Marine Mammal Stranding Center in Brigantine, NJ. “We’re expecting that if indeed this plays out the way that that die-off occurred, that we’re looking at mortalities being higher and morbillivirus spreading southward, and likely continuing to the spring of 2014,” Rowles said. This year, the virus seems to have entered a population that "simply [doesn't] have an immune response to effectively fight off the virus," Stephanie Venn-Watson of the National Marine Mammal Foundation said. And, though we know it’s spreading, there’s no way to vaccinate dolphins against the spread of the virus. “[The die-off] would probably end when the number of susceptible animals still out there to infect dwindles,” said Jerry Saliki, a virologist at the University of Georgia.
– The good news is that scientists now think they know why so many dead dolphins are washing up on shores along the East Coast—it's a virus akin to measles, reports Wired. The bad news is that they can't do anything but let it run its course. So far, about 330 dolphins have washed up, mostly in Virginia, a figure 10 times higher than normal. (And, of course, hundreds, perhaps thousands, more likely never reached shore.) A similar outbreak of this morbillivirus in 1987-88 caused 800 dead dolphins to wash ashore, and if the new outbreak follows the same pattern, the virus will probably remain in play until next spring. It's expected to move south along the Atlantic Seaboard. “At this point, there isn’t anything we can do to stop the virus,” says an official with the National Oceanic and Atmospheric Administration. "We don’t have a vaccine that is developed that could be easily deployed in a wild population of bottlenose dolphins.” The dolphins probably lost their immunity since the last outbreak, a vet tells NBC News. It's not clear how the outbreak started, but scientists figure the coastal dolphins picked up the virus from some other marine mammal. It's all but impossible this strain could spread to humans, notes ABC News.