Fact check: Claim that a viral image shows a 392-year-old shark is unverified
The claim: Image depicts a 392-year-old shark
Greenland sharks are the longest-living vertebrates, some of them centuries old, a 2016 study revealed.
But an April 24 Facebook post about one shark is misleading users.
"This is a 392 year old shark that was recently discovered in the Artic Ocean. This guy was wandering the oceans back in 1627," reads the April 24 post.
At the time of publication, the post had 2,000 shares and almost 4,500 reactions. USA TODAY reached out to the poster for comment.
The image depicts a Greenland shark, but its age is unknown.
Age of shark in image is unknown
The image in the Facebook post was taken during a 2016 study led by Julius Nielsen, who was then a doctoral student at the University of Copenhagen.
Researchers analyzed 28 female sharks, most of which had died after being caught in fishing nets. They estimated the oldest of the animals tested had lived between 272 and 512 years. The midpoint of that range was 392 years.
Nielsen told USA TODAY the image is a screenshot from a video, which can be seen in a November 2020 Instagram post.
"The shark was big yes, but we cant say anything that precise about its age," Nielsen said in the post. "My guess is that this particular shark was older than 150 yr but it is obviously a guess."
Greenland sharks are native to the cold, deep waters of the North Atlantic, according to Britannica. They can reach a length of 23 feet, but most are between 6.5 feet and 13 feet.
Nielsen and researchers used radiocarbon dating of eye lens nuclei to estimate the age of the sharks and published their findings in the journal Science.
Nielsen highlighted the range of possible ages involved in a 2017 Instagram post, addressing the sharks in general (not the one in this specific image).
"We have not found any sharks to be 600 or 500 yr old," he said. "We have ESTIMATED (meaning that it has not been verified) that one shark was AT LEAST 272 yr old or in more detail that this shark was between 272-512 yr old with 95.5% certainty (the later also being an unverified estimate)."
Our rating: False
The claim that an image depicts a 392-year-old shark is FALSE, based on our research. The age of the shark in this image is not known, and the researcher involved says he can only guess it's at least 150 years old. A 2016 study estimated the oldest shark in their sample was between 272 and 512 years old, with 392 as the midpoint of that range. It's not clear if that is the shark in the photo, which means the person making this claim can't meet their burden of proof.
Our fact-checking sources:
- Facebook post, April 24
- National Geographic, Aug. 11, 2016, "272-Year-Old Shark Is Longest-Lived Vertebrate on Earth"
- USA TODAY interview with Julius Nielsen, April 27
- BBC News, Aug. 12, 2016, "400-year-old Greenland shark ‘longest-living vertebrate’"
- Science, Aug, 12, 2016, "Eye lens radiocarbon reveals centuries of longevity in the Greenland shark (Somniosus microcephalus)"
- Britannica, April 4, 2020, "Greenland shark"
- juniel82 Instagram post, Dec. 14, 2017
- juniel82 Instagram post, Sept. 11
Thank you for supporting our journalism. You can subscribe to our print edition, ad-free app or electronic newspaper replica here.
Our fact check work is supported in part by a grant from Facebook.