How Long Do Greenland Sharks Live? The 400-Year Estimate

How long do Greenland sharks live?

The Greenland shark of the Arctic and North Atlantic grows extremely slowly and appears to live longer than any other animal with a backbone. According to the 2016 study, published in the journal Science by a team led by Julius Nielsen of the University of Copenhagen, Greenland sharks have a lifespan of at least 272 years.

The study’s largest shark, a female 5.02 m (16.5 ft) long, was estimated at 392 years, with a likely range of 272–512 years. If that estimate is right, she was born around the 1600s, give or take more than a century. Newspapers often round this to “400 years,” which is a fair summary but not a precise age.

How do scientists tell a Greenland shark’s age?

Most fish are aged by counting growth rings in their ear stones or backbone, like tree rings. Greenland sharks have soft, poorly calcified vertebrae and no useful hard parts, so for decades their age was a mystery.

The breakthrough came from the eye. The center of a shark’s eye lens, called the nucleus, is made of proteins laid down before birth and never replaced. The carbon in it therefore reflects the time when the shark was formed. Scientists measured radiocarbon, a naturally radioactive form of carbon, in the lens nuclei of 28 female Greenland sharks between 81 and 502 cm (2.7–16.5 ft) long, caught during research surveys off Greenland between 2010 and 2013.

They used a clever time marker. Nuclear bomb tests in the 1950s and 1960s added a pulse of radiocarbon to the atmosphere and oceans. The smallest sharks carried this “bomb pulse,” which showed they were born after the early 1960s, and a shark about 2.2 m (7.2 ft) long appeared to date from the start of the pulse. Using these sharks as anchors and a growth model, the team then estimated the ages of the larger sharks, whose lenses held much older carbon.

When do Greenland sharks become adults?

The same study found that female Greenland sharks reach maturity at a length of roughly 4 m (13 ft), which corresponds to an age of about 150 years. That would probably make them the latest-maturing vertebrates known. Males mature at a smaller size, about 2.8 m (9.3 ft), but their ages have not been estimated in the same way.

This fits what was already known about their growth. A shark tagged off Greenland in 1936 and caught again in 1952 had grown only about 8 cm (3 in) in 16 years, and scientists estimate that adults grow about 1 cm (0.4 in) a year or less.

Why do Greenland sharks live so long?

Living slowly seems to be the key. Greenland sharks spend their lives in water that is usually between about −1 and 7 °C (30–45 °F). In such cold water, a cold-blooded animal’s chemistry runs slowly, so these sharks have a very low metabolism, grow slowly, swim slowly and mature late. Many other very long-lived animals, such as the bowhead whale and the ocean quahog clam, also live in cold northern seas.

Their genes may help too. The Greenland shark genome, first sequenced in 2024, is one of the largest known among sharks, and early analyses point to many genes linked to repairing DNA. Such genes may help protect cells over very long lives, but this research is only beginning. The Greenland shark’s slow pace of life is explored further in How slow is a Greenland shark?

How certain is the 400-year estimate?

The radiocarbon results are strong evidence that Greenland sharks live for well over two centuries, but the ages of the biggest sharks are estimates with wide error ranges. For the oldest shark, the 95% probability range spans about 240 years.

Several assumptions affect the result. The method assumes that the carbon in a shark’s lens reflects the carbon in its mother’s food at the time, and deep-water food webs can contain older carbon that makes an animal look older than it is. The growth model linking length to age is based on few sharks and cannot capture differences between individuals. That is why the study itself framed its main conclusion as a lifespan of at least 272 years, rather than a precise maximum, and why other ways of checking the ages are still being explored.

Greenland shark lifespan compared with other animals

Even at the lower end of its estimate, the Greenland shark outlives every other vertebrate measured so far. See the full list of the longest-living animals for more record holders.

Other sharks are long-lived too, but nowhere near this. The oldest age estimated for a great white shark is about 73 years.

Why a long life makes Greenland sharks vulnerable

A very long life sounds like an advantage, but for a species that matures at around 150 years and has few young, every adult lost is very hard to replace. Greenland sharks are caught as bycatch on longlines and in trawls and gillnets, especially in fisheries for Greenland halibut, and they were hunted in large numbers for their liver oil until the mid-20th century.

Because of this slow life history and ongoing bycatch, the IUCN Red List assessed the Greenland shark as Vulnerable in 2020. A shark accidentally caught today may have been swimming in the North Atlantic for longer than many modern countries have existed.