Government scientists have declared it an “unusual mortality event” and are investigating the cause, said Maggie Mooney-Seus of NOAA Fisheries.
More than 155 Atlantic bottlenose dolphin carcasses have been found since the deaths began in June.
Mooney-Seus tells Earthweek that carcasses could begin washing up as far south as Florida within the next few months as the marine mammals begin to migrate southward.
Tissue samples from three of the dead dolphins found in New Jersey tested positive for morbillivirus.
It’s an infectious pathogen similar to distemper, which attacks the central nervous systems of dogs and can cause breathing problems, vomiting, brain swelling and often death.
Since it is impossible to inoculate a wild animal population from such a disease, the current die-off “has to run its course,” said Virginia Aquarium spokeswoman Linda Candler.
The last time morbillivirus was linked to a mass dolphin die-off was in 1987 and 1988, when more than 740 bottlenose dolphins perished from New Jersey to Florida.
Photo: Virginia Aquarium and Marine Science Center