Rare Shark Found Dead With Empty Stomach, Possible Mysterious Infection

A post-mortem examination into a rare Greenland shark which washed up dead on the Cornwall coast showed it had an empty stomach and signs of a possible mysterious infection.

Rosie Woodroffe—a biologist at the Zoological Society of London (ZSL) Institute of Zoology—found the dead shark on March 13 on Newlyn beach in the U.K.

However, once teams from the marine strandings network at Cornwall Wildlife Trust arrived, the body had disappeared.

Wildlife teams looked for the dead shark over the next 24 hours, and it finally reappeared with the going out of the tide. It was then taken for a post-mortem evaluation.

The stranding occurred just a few days after French research organization, the Association for the Study and Conservation of the Selachians, reported a rare sighting of a Greenland shark off the coast of French island of Ushant.

A closer look at the tail during the post-mortem in Cornwall showed that the stranded shark was likely the same one.

Greenland sharks are a "near threatened" species. They live in deep waters of about 650 to 1,640 feet below the surface of the ocean, but occasionally venture up to the shallows of bays and river mouths in the winter.

They are rarely seen and have the longest lifespan of any vertebrate. Scientists think they can live for at least 250 years, if not up to 500 years. The stranded shark was thought to be around 100 years old.

Rob Deaville, who works at the UK-wide Cetacean Strandings Investigation Programme (CSIP), tweeted updates on the post-mortem evaluation.

He said on Twitter that the necropsy of the shark, conducted by CSIP pathologist James Barnett and volunteers, found the animal to be female, with evidence of being alive when it washed up on the shore.

At the time of the initial sighting, it was unclear whether the shark had washed up already dead.

There were also "possible signs of infection," although this requires further investigation, Deaville said. Deaville tweeted there was "no evidence of recent feeding."

Scientists have found that the species only need about 200g of fish per day to survive, but this shark's stomach was "largely empty," meaning the shark may have been "nutritionally compromised."

It is hard for scientists to determine just how underfed the shark was, as there is little data on the species.

Abby Crosby, who manages the Marine Strandings Network project at the Cornwall Wildlife Trust, told Newsweek that there are no records of a Greenland shark ever washing up in Cornwall before.

"Our Marine Strandings Network has been running for over 20 years now. This is only the second Greenland shark to strand in the U.K. after one stranded in 2013," she said.

Deaville said on Twitter that as there has only been a "small handful" of Greenland shark strandings recorded in the U.K., this necropsy likely represents the first one ever carried out on the species in the country.

Marine wildlife strandings are a phenomenon where animals are found washed up on beaches, unable to return to the water. In most cases, the animals die, but scientists are not sure what causes it.

Scientists have previously suspected pathogens in the water may be partially to blame for marine wildlife strandings, although more evidence needs to be gathered to determine this.

On Twitter, Woodroffe said she "can't stop thinking" about the Greenland shark.

"She has shared the Earth with thylacines and passenger pigeons. She swam calmly in the deep ocean as wars raged above her," Woodroffe said.