Bottlenose dolphins are turning up dead or dying along East Coast beaches in such alarming numbers this summer that national officials have declared an "unusual mortality event" and formed a team of experts to investigate the cause.
The problem is particularly acute in New Jersey and Virginia, but stranded dolphins have also been reported in New York, Maryland and Delaware, Maggie Mooney-Seus of the National Oceanic and Atmospheric Adminstration's Marine Fisheries Service said Wednesday.
"It has been going on at least since the beginning of July," she said in a telephone interview.
Since July, at least 228 bottlenose dolphins have been found stranded in the region. A few have been alive when discovered on the sand, but all eventually died or were euthanized.
Nineteen stranded dolphins were found in New Jersey last month, compared with four in July 2012. An additional 40 have been found in New Jersey so far this month. New York reported 15 dead dolphins in July compared with one in July 2012. Virginia had 48 dead dolphins in July and 80 so far in August, according to the NOAA Marine Fisheries Service.
National officials became aware of the problem after New Jersey's Marine Mammal Stranding Center, which monitors such strandings, alerted them to the increase in dolphin deaths. The problem got so bad that the center's co-director Bob Schoelkopf said he was running out of body bags and space to hold the corpses, which are being autopsied to determine the causes of death.
"It's not a yearly thing," Schoelkopf said of the deaths, during an interview this month with New Jersey's News12.com. "Yearly we may see a dozen off and on throughout the year."
Schoelkopf and Mooney-Seus said the last time the area saw such a surge in dolphin deaths was in 1987-88, when 740 dolphins from New Jersey to Florida were found dead. The deaths were linked to morbillivirus, which can be passed from dolphin to dolphin and which is linked to the measles virus.
Scientists are looking at morbillivirus, as well as fungi and other diseases as they conduct necropsies on the dead dolphins.
One thing they have been able to rule out, so far, is contact with fishermen as the cause of the deaths, said Mooney-Seus. She added that marine experts also would investigate possible oceanic changes arising from oil spills, pollution and Hurricane Sandy.
"We have to look at everything," she said. "At this point we're not ruling anything out."