A shark had taken some large bites out of its body, but only after its death. Its liver flapped out from the exposed flesh.
"We've had a few that look like this, a few that look perfect," said Danielle Monaghan, a field-stranding technician with the Marine Mammal Stranding Center in Brigantine, which was storing the dolphin carcass in a cooler made decades ago for use during the Vietnam War.
Since July 9, 21 dolphins have washed up on New Jersey beaches, with four found to have had pneumonia. One tested positive for a measles-like virus known as morbillivirus that was blamed for killing 742 dolphins in the 1980s.
In Virginia, meanwhile, 44 dolphins have washed up dead this season, according to federal officials.
The bottlenose dolphin found Thursday was spotted on the Clermont Avenue beach in Margate about 8:30 a.m., by a public works crew. Monaghan said its healthy teeth suggested that it was a young adult. Dolphins have washed up on beaches in Ocean, Monmouth, Atlantic, and Cape May Counties.
The elevated number of dead dolphins on New Jersey beaches, along with the even higher number along Virginia's coast, is alarming local marine mammal experts, state environmental officials, and officials with the National Oceanic and Atmospheric Administration.
"At this point, we don't know the cause," said Maggie Mooney-Seus, a spokeswoman with NOAA's Northeast Fisheries branch. She said a notice had been sent to the stranding partner network along the coast alerting about the elevated numbers showing up in Virginia and New Jersey.
"We'll monitor it to see if there's any kind of trends," she said. "Unfortunately, that information takes a while to do all the testing."
On Thursday afternoon, the New Jersey Department of Environmental Protection issued a statement saying it was monitoring the deaths, which officials said were not an indication that anything was wrong with the ocean water. Twenty of the dead were bottlenose dolphins, the other a common dolphin.
"While the underlying cause of the deaths has not been confirmed," the statement said, "they appear to be part of a natural disease cycle and not related to water quality, which has been excellent this summer."
Bob Schoelkopf of the Marine Mammal Stranding Center said the dolphins were being sent to the University of Pennsylvania's New Bolton Center for necropsies.
That effort was being hampered by layoffs two months ago at New Bolton, and also by a broken-down van among the Brigantine center's fleet.
Some of the dolphins were too decayed to yield any definitive results. The ones with pneumonia were found in Seaside Heights, Wildwood, Sea Isle City, and Holgate.
Troubling was the presence of the morbillivirus virus in one of the dolphins with pneumonia. Of the 742 deaths that virus was considered responsible for along the East Coast in 1987 and 1988, 90 were in New Jersey.
A fisherman's recent video of a shark feasting on a dead dolphin seven miles off the coast of Atlantic City was nothing out of the ordinary. Sharks rarely attack live dolphins, who are fast enough to elude them, said Monaghan.
"Quite a few of them are coming in half-eaten," said Schoelkopf. "There are sharks out there, and they're feeding. They're not attacking live dolphins. They're eating dead carcasses."
Mooney-Seus said the widespread geographic area where the dolphins were washing up suggested a disease as the culprit, rather than a fishing net or other human involvement.
"I would tend to think it's not an issue of fishing," she said, "We're seeing it in different states. Some have lesions, which is more likely a sign of some kind of disease."
One dolphin had a knife slit down its middle, as yet unexplained.
In Brigantine, Monaghan said they have been getting reports of one to two dolphins a day. Wednesday saw one in Atlantic City. A dolphin that washed up Sunday at the Pittsburgh Avenue beach in Ventnor attracted crowds of joggers and bicyclers before it was taken away.
Other dolphins have been reported dead in waters offshore, but have not washed in to be officially recorded.
Schoelkopf said the dolphins spread diseases to one another just like humans. "They're social animals," he said. "When they come up to breathe, one is exhaling, the other inhaling."
Schoelkopf's center was cooperating with the state to monitor the deaths. Noting that there is an increased risk of sharks feeding on dead or dying dolphins, Schoelkopf warned not to approach the animals or attempt to bring them ashore. Pets should also be kept away from them.
If you see a dead or dying dolphin, contact the Marine Mammal Stranding Center's 24-hour hotline at 609-266-0538.
Contact Amy S. Rosenberg at 609-576-1973 or firstname.lastname@example.org, or follow on Twitter or Instragram @amysrosenberg.