As the mid-Atlantic surf continues to shove dolphins ashore, dying or dead of an apparent marine virus–some with telling lesions both internal and external–officials are probing for answers and fearing the worst could be ahead.
The beaches of southeast North Carolina have experienced a dramatic pickup in such findings within the past 10 days, observers say.
“We’re seeing really significant impact in North Carolina and South Carolina now,” said Dr. William McLellan of the UNCW Marine Mammal Stranding Program. “We’re just reporting out today that we had 15 animals in North Carolina just this past week.”
Saturday marked the second known case this fall of an Atlantic bottlenose dolphin washing onto Bald Head Island’s shore, and–as with most of the recent cases on the East Coast–the Bald Head Island Conservancy (BHIC) says it’s likely that the morbillivirus (related to measles in humans but of the marine mammal sort) is to blame.
In headlines since late summer for its high impacts to the East Coast dolphin population, cetacean morbillivirus could be the cause of more than 900 bottlenose strandings between New York and South Carolina this year alone, according to the National Oceanic and Atmospheric Administration (NOAA).
It’s roughly a 260 percent increase over 2012’s figure. Most of the strandings NOAA counted were deceased.
“Very sad business and I’m afraid it might get worse before it gets better,” BHIC Executive Director Suzanne Dorsey said Monday.
The dolphin found Saturday, near the barrier island’s southwest tip, was a male and at least nine feet long, according to notes from BHIC, which took skin samples from the carcass for analysis. Results are pending.
The nonprofit pointed out other strandings reported over the weekend, including one at Sunset Beach, one at Holden Beach, two in the Beaufort vicinity and another in South Carolina.
The first known to Bald Head this year was on Oct. 16, but Dorsey said analysis couldn’t confirm morbillivirus because the dolphin died much earlier than it was found.
All in all this year, at least 17 bottlenoses hit North Carolina beaches as of Nov. 4, according to NOAA, though only seven were confirmed morbillivirus cases. The rest were “suspected” cases.
The findings on area beaches this past weekend will push North Carolina’s overall count at least into the 20s.
Experts are trying to figure out what is contributing to this “Unusual Mortality Event,” as they’re calling it. Several more months of investigation await, says NOAA.
A reference point is the morbillivirus outbreak of 1987-88 that killed more than 740 dolphins between New Jersey and Florida. A report published in 1994 in the Journal of Wildlife Diseases, as prepared by federal offices including the Department of Veterinary Pathology, said more than 50 percent of the inshore bottlenose population likely died in that period. Investigators said the cause was probably brevotoxin, from algal blooms of marine dinoflagellates.
McLellan, of UNCW’s Marine Mammal Stranding Program, worked for the Smithsonian at the time and was among the first investigators to respond. He agreed this year’s broil of morbillivirus has had the worst impact since, though the increased numbers could also be due to expanded observation on beach strands.
If anyone finds a stranded or dead dolphin ashore, the best thing to do is call the nearest pertinent law enforcement department, McLellan said.
He also urged “extreme caution” as the carcasses have attracted sharks to the surf; marks on some of the washed-up bodies testify to that, he said, and that’s “just a realistic part of what’s happening out there in the ocean right now.”
Information from BHIC advises persons who find a stranding to keep the animal within sight until officials respond, to splash water over its body if safe to do so (or use wet towels, though without blocking the blowhole) and to keep in mind the animal is federally protected.
The nonprofit expects strandings to continue into the winter months.