Now imagine a fish species that becomes mature at age two.
The same numerical loss means something very different.
This is why long-lived sharks are often especially vulnerable to sustained fishing mortality.
The problem becomes more serious because scientists still do not know enough about Greenland shark reproduction to calculate recovery rates with confidence.
A 2019 review stressed that population size, productivity, fertility, and natural mortality remained poorly understood.
Uncertainty does not make conservation less important.
For an animal with a life history this slow, uncertainty makes caution more important.
Humans once killed them by the tens of thousands
The Greenland shark's remote habitat did not protect it from exploitation.
For centuries, sharks were targeted around Greenland, Iceland, and Norway, especially for their large livers and the oil obtained from them.
A major review reports directed fisheries extending from the 1600s into the twentieth century. By the end of the eighteenth century, annual catches had reportedly reached around 15,000 sharks, and records for Greenland reached a peak of approximately 32,000 animals in 1910.
Another estimate cited by the same review suggests that northern European liver-oil fisheries may at times have removed around 50,000 Greenland sharks per year. Researchers remain uncertain whether those catches came from large interconnected populations or placed intense pressure on more local groups.
Those numbers look different after the 2016 longevity discovery.
A fishery removing thousands of animals annually is troubling for many species.
For a species that may require more than a century to produce mature females, historical extraction becomes especially difficult to evaluate.
The population consequences may extend far beyond the years in which the fishing occurred.
Human history can fit inside one shark's generation
This is where the animal's biology becomes almost impossible to separate from history.
Suppose a female shark was born around 1850.
Under the 2016 maturity estimate, she might not reach reproductive maturity until around 2006.
Between those dates, entire human industries rose and changed.
Steamships gave way to diesel vessels.
Commercial aviation appeared.
Radio became common.
Two world wars occurred.
Nuclear weapons were invented.
Humans reached the Moon.
Computers became household objects.
The internet expanded around the world.
For the shark, this enormous human transformation could fit inside the period before first reproduction.
That is not a metaphor.
It is the direct consequence of a life history measured in centuries.
The oldest shark's lens may have formed around the time of the Mayflower
The midpoint estimate of approximately 392 years, using the research team's 2012 terminal date, places the largest shark's birth around 1620.
The historical coincidence is striking.
The year 1620 is associated in American history with the Mayflower voyage and the establishment of Plymouth by English colonists.
The shark did not know any of this.
It may have been developing inside its mother while wooden sailing vessels crossed the Atlantic under conditions that modern crews would consider primitive.
The eye-lens proteins tested nearly four centuries later would already have been forming.
Those proteins survived longer than most human buildings.
They survived dynasties.
They survived political borders.
They survived technologies.
Eventually, scientists used nuclear-age chemistry to estimate when those proteins had formed.
A seventeenth-century biological structure was dated partly because humans detonated thermonuclear weapons in the twentieth century.
Few scientific stories connect history in such an unexpected way.
Nuclear weapons accidentally created a biological timestamp
Atmospheric nuclear testing was destructive and dangerous.
It also created chemical signatures that researchers later learned to use.
The bomb pulse appears in tree rings, human tissues, animal tissues, ocean sediments, and other carbon-containing material.
Scientists have used it in forensic science, ecology, medicine, and age validation.
In the Greenland shark study, the signal performed a particularly elegant role.
The youngest sharks contained bomb-pulse radiocarbon.
The oldest did not.
That boundary anchored the chronology.
Without atmospheric testing, researchers could still perform conventional radiocarbon analysis, but they would lose one of the clearest modern time markers for checking whether the biological model behaved correctly.
The irony is difficult to miss.
Weapons built to destroy became part of a method for revealing extreme life.
Why the researchers studied females
All 28 sharks in the 2016 sample were female.
That was not because males do not live long lives.
Females become larger.
Large body size was essential for investigating the oldest potential individuals.
Adult female Greenland sharks commonly reach four to five meters, while males tend to remain smaller.
Researchers interested in the upper limit of lifespan therefore needed the largest animals available.
This also means the famous 392-year estimate should not automatically be applied to every Greenland shark regardless of sex or size.
The study's strongest inference concerns very large females.
Much remains unknown about sex differences in growth, mortality, movement, and lifespan.
The species continues to guard basic facts about itself.
The word “known” matters in “longest-lived vertebrate known”
Science rarely proves that something is the absolute longest-lived animal that has ever existed.
The statement concerns species for which evidence exists.
The Greenland shark currently holds the vertebrate longevity record because researchers have evidence supporting lifespans beyond 272 years.
Other vertebrates also live extraordinary lives.
Bowhead whales can exceed 200 years.
Some long-lived fish survive for well over a century.
Certain turtles may live extremely long lives.
None has yet produced a stronger documented vertebrate lifespan estimate than the Greenland shark. NOAA still describes it as the longest-lived vertebrate. The 2026 Nature Communications study does the same.
The animal kingdom beyond vertebrates contains even longer-lived examples.
Some deep-sea corals, sponges, and other organisms can persist for centuries or millennia.
The Greenland shark's distinction is specifically vertebrate longevity.
That makes the comparison more meaningful.
It is an animal with a backbone, brain, complex sensory systems, muscles, internal organs, and active predatory behavior.
Its body must keep all those systems functioning for centuries.
It is not frozen in biological time
Long life should not be confused with suspended animation.
The shark is not spending centuries asleep.
It swims.
It searches for food.
It digests meals.
It migrates.
Its heart beats.
Its muscles contract.
Its sensory systems process information.
Its tissues repair damage.
Its immune system responds to threats.
It survives injuries and environmental changes.
Living for 400 years requires continuous biological work.
Cold may reduce the speed of that work.
It does not eliminate it.
This is why researchers are now increasingly interested in the molecular machinery behind the lifespan.
The question has shifted.
Scientists once asked, “How old can this shark become?”
They can now ask, “How does its body remain functional for so long?”
The 2026 genome offers several possible answers
The chromosome-level Greenland shark genome published in May 2026 identified several patterns that could be relevant to extreme longevity.
Researchers found evidence involving immune function, cancer resistance, and DNA repair. They also identified unusual amino-acid substitutions in histone H1.0, a protein involved in the organization and compaction of DNA inside chromosomes. Their models suggest these substitutions may improve chromatin stability and protection against molecular damage.
The study also raised a possible connection with ferroptosis, a type of cell death associated with iron and lipid damage.
These observations are hypotheses about mechanisms.
They do not mean inserting one Greenland shark gene into another animal would produce a four-hundred-year lifespan.
Longevity evolves as part of an entire life-history system.
Body temperature, metabolism, growth rate, reproduction, cellular maintenance, ecology, predation, and genetics interact.
The Greenland shark may be one of nature's most extreme examples of that interaction.
A huge genome does not automatically explain a huge lifespan
At approximately 5.9 billion base pairs, the Greenland shark genome is substantially larger than the human genome.
That fact is interesting but should not be misunderstood.
More DNA does not automatically mean longer life.
Some organisms have enormous genomes without exceptional longevity.
Others have compact genomes.
Genome size reflects evolutionary history, repetitive elements, gene duplication, and many other factors.
The value of the Greenland shark genome lies in its content and organization rather than simply the number of base pairs.
Scientists can compare its genes with those of shorter-lived sharks.
They can look for expanded gene families.