Shark discovered in Greece could be plastic – 03/27/2023 – Science

The goblin shark is a deep-water fish whose frighteningly protracted jaws served as inspiration for the terrifying beings in the “Alien” movie franchise. Little is known about these elusive, rarely seen sharks. They are known to live in deep coastal waters around the world, but have never been found in the Mediterranean Sea.

But recently scientists reported finding what they said was a goblin shark washed up on a Greek beach. The announcement, made last year in the journal Mediterranean Marine Science, set off a series of events almost as bizarre as the species itself, involving contradictory scientific narratives, a retraction and the possibility that a plastic toy caused all the confusion.

According to the original scientific paper, the Mediterranean goblin shark was discovered in August 2020 by a man named Giannis Papadakis. After finding the animal, he placed it on some rocks and took a picture. The image reached the hands of a group of local scientists and, two years later, they published it together with records of another species found in the Mediterranean for the first time.

The article seemed to describe a success of citizen science, where people with no scientific background assist professional scientists with their research. But it wasn’t long before shark experts around the world began voicing doubts in a Facebook group about the authenticity of the goblin shark.

“It just didn’t feel right,” said David Ebert, author of “Sharks of the World.” According to him, several aspects of the shark found in Greece were unusual.

“He’s too small. His gills don’t look open,” he said. “It doesn’t look natural at all.”

Ebert and others were also skeptical because no scientist had examined the shark directly. The article was based solely on a photo and brief description by Giannis Papadakis.

In November, a group of shark researchers published a commentary article questioning whether the goblin shark found in Greece was a real animal.

“We have doubts” and “It’s a natural specimen” was what they said. The researchers argued that the lack of teeth, the overly rounded fins, and the low number of gill openings were not characteristic of goblin sharks.

Shortly after that, another image was shared on social media that would cause skepticism to rise tremendously. It was a photo of a plastic goblin shark sold by an Italian toy company, DeAgostini, which bore an uncanny resemblance to the animal found in Greece.

It was not possible to speak with the toy manufacturer, DeAgostini.

For Jurgen Pollerspock, shark researcher and one of the authors of the article that raised doubts about the authenticity of the Greek goblin shark, the toy “reveals great resemblance to the specimen in the published image”.

In response to the concerns expressed by Pollerspock and his colleagues, the authors of the original paper reiterated their assertions. They also corrected their estimate of the size of the specimen, from 76 cm to 18 cm, and suggested that there is a possibility that it is an embryo.

“Embryos of that size are not viable,” Pollerspock replied.

So this week, the authors of the original paper retracted it by admitting that there is too much uncertainty surrounding the discovery. Contacted by email, one of the writers declined to answer further questions.

Thus ended a nearly year-long saga that had many shark researchers questioning what they were seeing on their computer screens.

Pollerspock said it is possible there are goblin sharks lurking in the depths of the Mediterranean Sea, but so far none have been found.

Whether the shark in this image turns out to be a real fish or it was nothing more than a piece of plastic pollution, critics say the fact that the image was published in a scientific journal highlights the imperfections of the scientific peer review process.

“In my opinion, the problem and the responsibility rest with the journal editor and reviewers,” said Pollerspock.

According to him, the unusual appearance of the shark was not the only thing that should have alerted the reviewers of the scientific journal to the possibility of a problem. The fact that the claim made in the article is based on only one image provided by a citizen scientist would warrant closer scrutiny.

The editor of Mediterranean Marine Science did not respond to a request for comment.

Whether the researchers who published the now retracted paper on the Greek goblin shark admit to having published the photo of a toy or not, Ebert said he wouldn’t be surprised if something like that happens again, given the problems of peer review and the high incidence of plastic pollution of the seas.

“Anything is possible,” he said.

^{Translated by Clara Allain}