Was a Shark Born in 1620 Really Found? A Fact-Check of a Viral Social Media Claim
- 13 hours ago
- 3 min read
Videos circulating on social media claim that “a Greenland shark born in 1620 has been discovered. These sharks live longer than any other living creature on Earth and reach reproductive age at 120 years old.”
The videos are often presented as sensational stories, suggesting that sharks born in the early 17th century are still swimming in the oceans today. But how accurate is this claim?
Where Did This Claim Come From?
In 2016, a study published in the journal Science attracted worldwide media attention. A team of researchers led by Danish scientist Julius Nielsen attempted to determine the age of Greenland sharks using an unusual method.
Because Greenland sharks do not possess hard structures such as growth rings that can reliably reveal age, researchers analyzed proteins in the sharks’ eye lenses using radiocarbon dating.
The results suggested that one of the largest sharks examined was approximately 392 years old. However, the estimated age range extended from about 272 to 512 years.
Over time, these findings were simplified and exaggerated on social media, eventually turning into the claim that “a shark born in 1620 was found.”
Can Scientists Determine a Shark’s Exact Year of Birth?
No.
Scientists can estimate the age of a Greenland shark, but they cannot determine its exact birth date.
For example, the shark estimated to be around 392 years old could actually be considerably younger or older. The original study itself emphasized the substantial margin of error associated with the age estimates.
Therefore, the specific date “1620” is not a scientifically established fact but rather an interpretation derived from age estimates.
Why Do Greenland Sharks Live So Long?
According to researchers, their remarkable longevity may be linked to the extremely cold Arctic waters they inhabit, their exceptionally slow metabolism, and their slow growth rate.
Greenland sharks grow at an average rate of roughly one centimeter per year. They move slowly, expend little energy, and appear to age much more gradually than many other animals.
Recent genetic research has also suggested that their longevity may be related to genes involved in DNA repair, immune system function, and cellular protection mechanisms.
Do They Reach Sexual Maturity at 120 Years Old?
Not exactly.
Scientific studies indicate that Greenland sharks reach sexual maturity extremely late in life. Estimates suggest that females become reproductively mature at around 150 years of age, with some calculations placing the age of maturity at approximately 156 years.
While some sources mention 120 years, this figure is not considered the scientific consensus.
Are They the Longest-Lived Creatures on Earth?
No.
The Greenland shark holds the record as the longest-lived vertebrate known to science. However, it is not the longest-lived organism on Earth.
Some mollusks, deep-sea glass sponges, coral colonies, and clonal marine organisms can survive for hundreds or even thousands of years, exceeding the lifespan of Greenland sharks. Therefore, it is more accurate to describe the Greenland shark as the longest-lived vertebrate rather than the longest-lived living organism.
Why Does This Matter?
This case illustrates how scientific findings can become distorted when shared on social media.
The original research presented a probabilistic estimate with a wide margin of uncertainty. Online, however, that estimate evolved into a definitive claim that a shark born in a specific year had been discovered.
As a result, a scientific estimate was transformed into what appeared to be a confirmed historical fact.
Conclusion
The Greenland shark is indeed one of the longest-lived vertebrates known to science, with some individuals estimated to live for around four centuries or more.
However, there is no scientific evidence that a shark born specifically in 1620 has ever been found. Scientists can only estimate the age of these animals. Furthermore, the claim that Greenland sharks outlive all other living organisms is also incorrect.
Final Verdict: Partly True.