The News Desk is a collection of news, notes and breaking items affecting the Fredericksburg community.
Morbillivirus causing mass dolphin deaths
Nearly three weeks after a dead bottlenose dolphin appeared in the lower Rappahannock River, the National Oceanic and Atmospheric Administration has released a tentative cause behind more than 300 dolphin deaths from New York to North Carolina.
In a teleconference Tuesday, Teri Rowles, coordinator for the NOAA Fisheries Marine Mammal Health and Stranding Response Program, confirmed 333 bottlenose dolphin mortalities from July 1 to Aug. 26, with a peak of 174 mortalities from Virginia alone.
“This outbreak is likely due to morbillivirus,” Rowles said.
Of those confirmed dolphin mortalities, 32 were suspected or tested positively for cetacean morbillivirus, which can lead to skin lesions, pneumonia and brain infections in dolphins.
Two Farnham residents discovered a dead bottlenose dolphin in the Rappahannock River in Richmond County on Aug. 7 with visible lesions. It was later recovered by the Virginia Aquarium Stranding Response Team.
NOAA issued an Unusual Mortality Event for bottlenose dolphins in the Mid-Atlantic from July onward due to the high number of mortalities in the area. Rowles said the average number of strandings and mortalities for those dates and locations is 36.
The last mortality event for bottlenose dolphins with comparable numbers occurred from June 1987 to May 1988 and involved 740 dolphins in an area from New Jersey to Florida.
Rowles said that, given the number of mortalities at this point in addition to the migration patterns of dolphins, this die-off could last through Spring 2014.
The event “will last as long there are susceptible animals that could be infected,” said Jerry Saliki, a professor at the University of Georgia.
Four suspected morbillivirus cases have been confirmed in Virginia, though additional testing is pending.
Mark Swingle, director of research and conservation at the Virginia Aquarium, said this mortality event has been “certainly unprecedented” in both sheer number and strain on local resources.
“It creates a financial burdens on organizations,” he said.
With the NOAA-issued Unusual Mortality Event, additional funds were dispensed for stranding response units, but those dollars are limited, Rowles said.
An additional two dolphins tested positive for the brucella bacteria, which manifests in joint, brain or reproductive organ lesions.
Though it is not yet clear what brought about the episode, officials suggested that a lack of immunity had reached a critical threshold for among dolphins.
Officials also confirmed that morbillivirus is not a danger to people.
“There is no indication that this particular virus could jump to humans,” Saliki said, “given the species gap between marine mammals and humans.”
Dawnthea Price: 540/374-5444