In the cold, dark waters of the North Atlantic and Arctic swims an animal that may be older than any other living vertebrate on Earth. The Greenland shark grows so slowly and lives so long that some individuals cruising the depths today were likely alive before the American Revolution — and possibly before the first European colonists reached the shores that would become the United States. For centuries this ghostly, slow-moving predator was largely ignored by science, but a landmark study revealed that its lifespan stretches across a span of history that is hard to comprehend.
The finding reshaped how biologists think about longevity in the animal kingdom. If the oldest estimates hold, the Greenland shark does not merely outlive humans by a wide margin; it outlives entire nations, carrying within its body a living record that reaches back to a world without electricity, telephones or modern medicine.
The radiocarbon study that rewrote the record
The breakthrough came from a 2016 study published in the journal Science, led by marine biologist Julius Nielsen. Because the Greenland shark has no hard, bony structures with growth rings that scientists normally use to age fish, researchers turned to an unusual clock: the lens of the eye. The radiocarbon analysis of eye-lens tissue from 28 female sharks allowed the team to estimate ages that stunned even the researchers who ran the numbers.
The results indicated a lifespan of at least 272 years, with the largest shark in the sample — measuring just over five meters, or roughly 16 feet — estimated at around 392 years old. The statistical range on that oldest individual stretched from about 272 to 512 years. Even taking the most conservative figure, the study established the Greenland shark as the longest-lived vertebrate known to science, surpassing the previous record holder, the bowhead whale.
How nuclear tests helped date a shark
The dating method itself is a quirk of twentieth-century history. Atmospheric nuclear weapons tests in the 1950s and early 1960s flooded the environment with a pulse of radioactive carbon-14, a marker that scientists call the “bomb pulse.” That carbon worked its way into the ocean’s food web and into the tissues of animals alive at the time, including the developing eye lenses of young sharks.
Because the eye lens forms early and its central proteins are not replaced over an animal’s life, the tissue at the core of the lens preserves a chemical snapshot from when the shark was born. Sharks whose lens cores carried the bomb-pulse signal had to have been born after the tests began, giving researchers a firm reference point. From there, they calibrated the ages of the older sharks whose lenses predated the nuclear era. As the researchers explained, this combination of eye-lens chemistry and radiocarbon calibration was what finally cracked the mystery of the species’ age.
A life lived in the slow lane
Such extreme longevity is inseparable from how the Greenland shark lives. It inhabits frigid water, often at great depth, where temperatures hover near freezing, and its metabolism is correspondingly sluggish. The animal grows only about a centimeter per year, one of the slowest growth rates measured in any shark, and it drifts through the water at a pace so leisurely that it has been clocked among the slowest-swimming fish for its size.
That glacial pace extends to reproduction, which carries stark implications for the species’ survival. The 2016 study estimated that females do not reach sexual maturity until they are around 150 years old, meaning an individual must survive for a century and a half before it can produce young. The Greenland shark’s biology makes it exquisitely vulnerable to overfishing and environmental change, because a population depleted today could take generations of human lifetimes to recover. Scientists have long theorized that cold temperatures and slow metabolism are linked to longevity across many species, and the Greenland shark stands as perhaps the most extreme illustration of that principle in the vertebrate world.
A predator wrapped in strange biology
Beyond its age, the Greenland shark is one of the ocean’s oddest large animals. Many individuals are nearly blind, their eyes commonly host to a parasitic copepod that dangles from the cornea, yet the sharks appear to navigate and hunt effectively without keen sight, relying on other senses in the lightless deep. They are opportunistic feeders, scavenging carcasses and catching fish and marine mammals, and remains of seals and even land animals have turned up in their stomachs, hinting at ambush behavior or scavenging along the coasts.
Their flesh is another curiosity with a long human history. Greenland shark meat is naturally toxic when fresh because it is loaded with compounds that help the animal cope with the cold and pressure of the deep, and eating it untreated can produce symptoms resembling severe intoxication. In Iceland, people learned centuries ago to make it safe by burying and fermenting the meat for months to produce a pungent traditional dish. That practice is a reminder that these animals have shared the northern seas with humans across the very centuries their bodies have quietly recorded.
Living witnesses to centuries of history
Put in the context of human history, the numbers are staggering. The United States declared independence in 1776, roughly two and a half centuries ago. A Greenland shark that is 272 years old — the study’s floor estimate for its longest-lived subjects — would have been born in the 1700s, before that founding moment, and the oldest individuals in the population may have been swimming when European settlers were still establishing their first footholds along the Atlantic coast. Even the lower end of the age range — the floor estimate of 272 years — secures the species’ status as the longest-living vertebrate ever documented, a distinction the 2016 findings established beyond the previous record held by the bowhead whale.
The idea that a single animal alive right now could predate a nation captures why the Greenland shark has fascinated scientists and the public alike. Each old individual is, in effect, a living archive of ocean conditions stretching back hundreds of years, and studying them offers a rare window into how the deep sea has changed over centuries. For an animal that spends its life hidden in cold darkness, moving barely faster than the currents around it, the Greenland shark has turned out to hold one of the most extraordinary stories in the natural world.
This article was produced with AI assistance and reviewed by Morning Overview editors.
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