Greenland Shark: The Centuries-Old Shark That Can Live for Nearly 400 Years
Fact Check: The Greenland shark (Somniosus microcephalus) is genuinely one of the longest-lived vertebrates known to science. A landmark 2016 study estimated that the largest female examined was approximately 392 years old, although the estimate carried substantial uncertainty. Scientists therefore describe Greenland sharks as capable of living for centuries rather than claiming that a particular shark has been proven to be exactly 400 years old.
Deep beneath the cold waters of the North Atlantic and Arctic Oceans lives a shark unlike almost any other.
The Greenland shark is slow-moving, slow-growing and exceptionally long-lived. Scientific research has shown that some individuals can survive for centuries, making this mysterious shark one of the most remarkable animals ever studied.
Its extraordinary lifespan is not simply an internet legend. It comes from scientific research using radiocarbon dating of tissues in the shark's eye.
How Long Can a Greenland Shark Live?
In 2016, researchers published a landmark study in the journal Science examining the ages of 28 female Greenland sharks ranging from 81 to 502 centimeters in length.
The researchers used radiocarbon dating of the nuclei of eye-lens cells to estimate the animals' ages.
The largest shark in the study, measuring about 5 meters long, was estimated to be 392 years old.
However, that number comes with considerable uncertainty. The researchers calculated an age estimate of 392 ± 120 years, meaning the estimated age range was approximately 272 to 512 years.
That uncertainty is important. It means scientists cannot say that the shark was definitely exactly 392 or 400 years old.
What the research does demonstrate is extraordinary: Greenland sharks can live for at least several centuries and are considered the longest-lived vertebrates known to science.
How Scientists Estimated the Shark's Age
Determining the age of a Greenland shark is difficult because these animals do not have the same obvious annual growth structures used to age many other fish.
Instead, researchers turned to the shark's eyes.
The central part of the eye lens contains proteins that are formed early in life and remain remarkably stable. Scientists can analyze radiocarbon in these tissues and use known changes in atmospheric radiocarbon levels to estimate when the tissues were formed.
This method allowed researchers to estimate the ages of Greenland sharks that were otherwise extremely difficult to age accurately.
A Shark That Grows Extremely Slowly
Greenland sharks are also remarkable because of their exceptionally slow growth.
The species can reach several meters in length, but individuals grow very slowly over their lives. This slow pace is one reason scientists believe that Greenland sharks require such long periods to reach maturity.
The 2016 study estimated that female Greenland sharks reach sexual maturity at approximately 156 years of age, although the exact age at maturity remains subject to scientific uncertainty.
That means a Greenland shark may spend well over a century growing before reaching reproductive maturity.
Why Does It Live So Long?
Scientists do not yet have a single definitive explanation for the Greenland shark's extraordinary lifespan.
Its biology appears to involve several unusual characteristics, including extremely slow growth, a low-energy lifestyle and adaptation to cold, deep-water environments.
However, it would be misleading to say that scientists have already discovered one specific mechanism responsible for its centuries-long life.
The relationship between cold temperatures, metabolism, growth rate and longevity remains an active area of research.
The Greenland Shark Genome May Hold More Clues
In 2024, an international research team announced the first major genome work on the Greenland shark.
The shark's genome contains approximately 6.5 billion base pairs, making it one of the largest genomes sequenced among sharks.
Researchers identified expansions and duplications involving genes associated with DNA repair, as well as other genetic features that could potentially be relevant to longevity.
These findings are fascinating, but they should be interpreted carefully.
The researchers proposed that enhanced DNA-repair mechanisms may contribute to the species' exceptional lifespan, but further research is required to determine exactly how these genetic features influence aging.
Where Do Greenland Sharks Live?
Greenland sharks are primarily associated with the cold waters of the North Atlantic and Arctic Oceans.
They are capable of living at substantial depths and have been recorded from relatively shallow waters to depths exceeding 1,800 meters.
Their range includes waters around Greenland, Iceland, Canada and other parts of the North Atlantic and Arctic regions.
Because much of their lives are spent in remote and deep environments, many aspects of their behavior remain poorly understood.
What Do Greenland Sharks Eat?
Greenland sharks are opportunistic predators and scavengers.
Their diet can include fish and other marine animals, while stomach-content studies have also found evidence of scavenging.
Scientists have documented a wide variety of prey items, reflecting the shark's ability to exploit food available in its environment.
Their slow swimming speed does not necessarily prevent them from feeding successfully. Instead, their lifestyle appears adapted to the cold, deep-water ecosystem in which they live.
Reproduction Takes a Very Long Time
The Greenland shark's reproductive biology is another area where scientists are still learning.
Female Greenland sharks are estimated to mature at around 4 meters in length, corresponding to an estimated age of roughly 156 years based on earlier research.
However, the exact length of pregnancy or gestation remains unknown.
Some older estimates proposed an extremely long gestation period, potentially lasting many years, but a detailed reproductive study concluded that the available evidence is insufficient to establish a reliable gestation time.
This is an important distinction because the Greenland shark is sometimes described online as having an established 8- to 18-year pregnancy. That figure should be treated as a hypothesis rather than a confirmed biological fact.
Why Long Life Also Makes the Species Vulnerable
Living for centuries may sound like an evolutionary superpower, but extreme longevity comes with an important disadvantage.
Greenland sharks grow slowly and reproduce late. This means populations may have difficulty recovering from significant losses.
The species is currently classified as Vulnerable by the International Union for Conservation of Nature (IUCN).
One of the major concerns is fisheries bycatch. Greenland sharks can become unintentionally caught in trawl, longline and gillnet fisheries.
Because these sharks can take well over a century to reach maturity, the loss of mature individuals can be especially important from a conservation perspective.
Climate Change May Add Another Challenge
Greenland sharks live primarily in Arctic and North Atlantic environments that are undergoing significant environmental change.
Scientists are still working to determine exactly how changes in ocean temperature, sea-ice conditions, food availability and other environmental factors will affect the species.
Because the Greenland shark has such a slow life history, rapid environmental changes could potentially pose challenges for populations.
However, the precise long-term effects of climate change on Greenland shark populations remain uncertain and require further research.
The Shark That Can Outlive Centuries
The Greenland shark offers an extraordinary perspective on time.
The oldest estimated individual in the landmark 2016 study may have lived through centuries of human history. But the remarkable number—392 years—should always be understood as a scientific age estimate with a large uncertainty range, not as a precisely measured birthday.
What is beyond dispute is that Greenland sharks are exceptionally long-lived animals.
The combination of slow growth, late maturity, deep-water ecology and extreme longevity makes them one of the most unusual vertebrates on Earth.
What Scientists Still Don't Know
- Exactly how Greenland sharks prevent or repair age-related cellular damage.
- How their DNA-repair mechanisms contribute to longevity.
- The exact duration of their reproductive cycle and gestation.
- The total size of wild Greenland shark populations.
- How climate change will affect their distribution and long-term survival.
- How much of their extreme longevity is controlled by genetics versus environmental factors.
The Pader Fact Check
LEGITIMATE — BUT THE “400-YEAR-OLD SHARK” CLAIM NEEDS CONTEXT.
Scientific research supports the conclusion that Greenland sharks can live for centuries. The largest shark examined in the 2016 landmark study was estimated at 392 ± 120 years.
Therefore, calling the Greenland shark a “400-year survivor” is reasonable as a general description of its extraordinary longevity, but it should not be interpreted as proof that a particular living shark has been precisely dated to 400 years old.
Sources and Further Reading
- PubMed — Eye lens radiocarbon reveals centuries of longevity in the Greenland shark
- University of Copenhagen — The Longest-Living Vertebrate Genome
- Government of Canada / COSEWIC — Greenland Shark Assessment
- Scientific study — Assessing the reproductive biology of the Greenland shark
- Smithsonian Ocean — In the Eyes of One Shark, Age Is Nothing to Fear
Photo note: The existing images from the original version of this article have been retained. Before monetized republication, verify the original photographer, publisher or rights-holder for each image and obtain the appropriate permission or license where required.
Editorial note: The Pader distinguishes scientifically established findings from estimates and hypotheses. Greenland shark age estimates, reproductive biology and the genetic mechanisms behind longevity are presented according to the strength of the available scientific evidence.