A couple vacationing in Long Beach was left disgusted and looking for answers Tuesday night when they discovered the dismembered body of a dolphin along the shoreline at Alamitos Beach.

While walking on the beach at night, they were alarmed to see the dolphin’s head separated from its body, which was lying close by, partially covered by sand.

Nearby were innards and some of the animal’s internal organs, which turned out to be a telltale sign of what happened.

The dolphin had been dissected as part of a necropsy performed by wildlife experts trying to figure out why it had washed up on the beach earlier that day, according to Gonzalo Medina, marine safety chief with the Long Beach Fire Department.

Around 9:45 a.m. Tuesday, the animal’s intact carcass had come ashore, and — as is standard procedure — lifeguards contacted the Marine Mammal Care Center, which has an animal hospital in San Pedro, Medina said.

The Ocean Animal Response and Research Alliance sent out a team, including a biologist who performed a necropsy on the beach to try to determine the cause of death, Medina said.

After the necropsy, they buried the carcass in the sand — but apparently not deep enough.

It was found about 11 hours later by Kristen and her boyfriend, Gabriel — who asked to be identified only by their first names after they received some criticism for posting pictures of the dolphin online as they tried to figure out what happened.

The “half-hearted attempt at covering the dolphin” did not work, Kristen said. The carcass, she said, had been completely uncovered by the waves by around 9:30 p.m. Tuesday.

When a dead animal washes ashore, Medina said it’s not abnormal for biologists to bury a corpse if they can’t immediately truck it away or otherwise dispose of it.

“Every situation is different,” he said.

After their gruesome discovery, Kristen and Gabriel said they called multiple local agencies, but they didn’t immediately get any answers. The only one that took a report was the West Coast Marine Mammal Stranding Network, they said.

After staying with the carcass for roughly 45 minutes, they decided to head back to their hotel.

The couple returned to Alamitos Beach the next day shortly after noon and found the dolphin had been removed and in its place was “a massive hole in the sand surrounded by tire tracks,” Kristen said.

What killed the dolphin in the first place is still unknown. The results of the necropsy were pending Thursday.

Editor’s note: This story was updated to add that the team that performed the necropsy was from the Ocean Animal Response and Research Alliance.