Luke Sharp first saw the dead birds while surfing in Cherry Grove on a foggy December Saturday morning. Loud horns, likely from a boat, had been blowing all night.
“It was foggy,” Sharp said. “I don’t remember how cold or hot it was, it was super, super foggy.”
Dozens of birds from multiple species littered the beach at the high tide mark.
“Everybody has theories, but no one knows what happened,” Sharp said. “It was foggy the night before and we kept hearing a boat blow its horn all night long. The morning we went surfing, we came out of the water… it seemed like it was all different types of birds.”
The S.C. Department of Natural Resources reported that some members of the public had described a strange smell in the air, but Sharp didn’t smell it.
“It’s not unusual to occasionally see a dead bird,” said Sharp, a resident of more than 20 years and veteran surfer who also serves as the director of the Adaptive Surf Project.
But this was different.
“Something happened to kill all these birds,” Sharp said. “It wasn’t a normal thing that happened, something killed all these birds, obviously.”
The S.C. Department of Natural resources sent seven birds representing the various species that died to the University of Georgia’s Southeastern Cooperative Wildlife Disease Study for a necropsy.
The samples included three Laughing Gulls, a Herring Gull, a Brown Pelican, a Common Eider and a Northern Gannet.
In late April, four months after the birds washed ashore in Cherry Grove and Garden City, the test results came back. The cause of death? Still undetermined.
“I really don’t know what could have killed them,” said Coastal Carolina University biology professor Chris Hill, who reviewed the lab results. “A couple individuals seem to be quite sickly and parasite-ridden with bacterial infections. I’m a little stumped.”
The birds were in a variety of physical conditions, but there was no clear and uniform cause of death.
“One of the most relevant things seems to be it was a real mix of different kind of birds; gulls, pelicans, birds that feed in a variety of ways and some different places,” Hill said. “Some were really healthy, some were sickly, based on the lab results. No super obvious pattern to what’s going on there.”
The lab report said some of the public reported a smell in the air the weekend the birds washed up. People on social media speculated that it could have been a gas or oil spill from the ships involved with beach renourishment work. But the Coast Guard flew up and down the coast and could not see any evidence of a gas or oil spill.
If the cause had been something physical, like fish hooks, predators or people shooting at them for fun, the necropsy would have caught that.
Beach renourishment work itself wouldn’t have such an immediate impact on birds, Hill said, adding that since birds are very mobile creatures, they could fly miles up the coast to get away if something in the water was bothering them.
Hill hypothesized that the birds may have been killed by a toxin that didn’t show up in the lab report.
“The only thing I can think of would be some sort of chemical contaminate that they didn’t test for,” Hill said. “I assume they can’t test for everything, so maybe there was something obscure in the environment that might have killed them that they didn’t test for.”
Southeastern Cooperative Wildlife Disease Study wildlife pathologist Nicole Nemeth said the comprehensive testing covered everything from general toxins to heavy metals to algal blooms, and nothing stood out, but she hypothesized that there could be a cause of death that doesn't show up in any test.
“There could be something they were exposed to that we can’t test for,” Nemeth said. “A test may not exist; we may not have heard of it or it may not be a known cause of death. You can’t test for something you don’t know about.”
Nemeth said there was likely a combination of conditions that could have killed them, including adverse weather conditions and a toxic environment, but no definitive cause.
“It’s frustrating,” she said. “We look at all the birds, all the tissues we can, under the microscope. A few of these birds had various infections, but it was nothing consistent, nothing that would be surprising.”
Since the December incident, no other dead birds have washed up en masse, but Nemeth added that had “more birds washed up, we would keep trying.”