What You Need to Know About Greenland Sharks

The Greenland shark is the slowest-growing and longest-living fish on Earth. These massive predators inhabit the deep waters of the North Atlantic and Arctic Ocean, where they move through near-freezing darkness at depths between 600 and 2,400 feet. A Greenland shark can live 400 years or longer — some scientists estimate certain individuals may exceed 500 years — making them older than any other vertebrate animal except some tortoises.

Greenland sharks are not a target for recreational fishing. They live too deep, in waters too cold and remote, and they move too slowly to make sport fishing practical. However, understanding where they live, how they behave, and why they matter helps explain the structure of deep Arctic ecosystems and the extreme adaptations that allow life to persist in the harshest ocean environments.

Key Takeaways

  • Greenland sharks live in Arctic and North Atlantic waters at depths below 600 feet, where temperatures stay near freezing year-round.
  • These sharks grow only about one centimeter per year and do not reach sexual maturity until they are roughly 150 years old.
  • Greenland sharks are ambush predators that feed on fish, seals, and whale carcasses, hunting in near-total darkness using a slow, energy-efficient strategy.
  • Many Greenland sharks are blind or nearly blind due to parasites that attach to their eyes, yet they hunt successfully in the deep ocean.
  • Commercial fishing has never targeted Greenland sharks directly, though they are occasionally caught as bycatch in deep-water trawls.

Habitat and Geographic Range

Greenland sharks live exclusively in cold northern waters. Their range spans the North Atlantic from the coast of Greenland and Iceland eastward to the Barents Sea, and northward into the Arctic Ocean. They are most abundant around Greenland, where they are called eqalussuaq in Kalaallisut, the language of Greenland.

These sharks prefer depths between 600 and 2,400 feet, though they occasionally move into shallower water during winter months in some regions. The water temperature at their typical depth stays between 28 and 32 degrees Fahrenheit — cold enough to slow their metabolism to a crawl. This extreme cold is central to their longevity: a slower metabolism means slower aging and a longer lifespan.

Greenland sharks are found nowhere else on Earth. Unlike many deep-sea species that also inhabit the Pacific or Indian Oceans, Greenland sharks are restricted to the North Atlantic and Arctic. This limited range makes them vulnerable to changes in ocean temperature and circulation patterns.

Size, Growth, and Lifespan

Adult Greenland sharks typically reach 12 to 16 feet in length, with females generally larger than males. The largest recorded specimens exceed 20 feet. Despite their size, they are not fast-growing animals. A Greenland shark grows approximately one centimeter per year — roughly 0.4 inches annually. At that rate, a shark must live for centuries to reach full adult size.

Scientists studying Greenland shark age have used radiocarbon dating on the lens of their eyes, which does not regenerate and accumulates carbon-14 throughout the shark's life. These studies suggest that some Greenland sharks are between 300 and 500 years old. One individual was estimated to be at least 392 years old at the time of capture, making it one of the oldest animals ever documented.

Greenland sharks do not reach sexual maturity until they are approximately 150 years old. This means a shark must live a century and a half before it can reproduce. Once mature, females likely produce only a few dozen pups every few years, making population recovery extremely slow if numbers decline.

Feeding Behavior and Diet

Greenland sharks are ambush predators that hunt in the deep, dark ocean using a sit-and-wait strategy. They feed on fish, including other sharks and large deep-sea species. They also scavenge whale carcasses that sink to the ocean floor, and stomach contents from captured sharks have revealed seal remains, suggesting they may feed on seals in shallower water or hunt them at the surface during winter.

Their hunting strategy reflects their slow metabolism. Rather than actively pursuing prey, Greenland sharks move slowly through the water and strike when prey comes within range. This energy-efficient approach allows them to survive on relatively little food in an environment where meals are scarce and energy is precious.

Many Greenland sharks are partially or completely blind. A parasitic copepod, Ommatokoita elongata, attaches to the shark's cornea and lens, causing scarring and vision loss in most individuals. Despite this handicap, Greenland sharks hunt successfully, suggesting they rely heavily on smell and the ability to sense electrical fields produced by muscle contractions in other animals.

Reproduction and Population Structure

Greenland sharks are ovoviviparous, meaning females carry eggs internally and give birth to live young. Litter size is small — typically between 2 and 10 pups per pregnancy. The long gestation period and low reproductive rate mean that Greenland shark populations grow and recover very slowly compared to other fish species.

Population numbers are not well documented. Greenland sharks are not commercially fished and are rarely caught in large numbers as bycatch. This lack of harvest data makes it difficult to assess whether populations are stable, increasing, or declining. Climate change and warming Arctic waters may alter their distribution and food availability, but the long-term consequences remain unclear.

Fishing and Human Interaction

Greenland sharks have never been the target of recreational or commercial fishing. The combination of their remote habitat, extreme depth, slow movement, and low population density makes them impractical to fish for. They are occasionally caught as bycatch in deep-water trawls and longlines set for other species, particularly in Greenlandic and Icelandic waters, but these captures are incidental rather than intentional.

Historically, Greenland sharks were hunted by indigenous peoples in Greenland and were valued for their liver oil, which was used as fuel and for other purposes. This hunting pressure was never large enough to significantly impact populations, and it has largely ceased in modern times.

Greenland sharks are protected under various international agreements and national laws in Arctic nations. They are listed as Vulnerable on the IUCN Red List due to their slow reproduction, late maturity, and susceptibility to bycatch in deep-water fisheries.

Why Greenland Sharks Matter to Science

Greenland sharks are subjects of intense scientific interest because they challenge our understanding of aging, longevity, and metabolism. Studying how these animals live so long and grow so slowly may reveal biological mechanisms that slow aging in vertebrates. Their extreme longevity also makes them valuable indicators of long-term changes in Arctic ocean conditions and food webs.

Research on Greenland sharks has also improved our knowledge of deep-sea ecosystems. These sharks are apex predators in their environment, and their presence shapes the behavior and survival of other deep-water species. Understanding their role in the food web helps scientists predict how Arctic ecosystems might respond to climate change and warming ocean temperatures.

Frequently Asked Questions

Can you catch Greenland sharks for sport or food?

Greenland sharks are not pursued by recreational anglers. They live too deep and too far north, and they move too slowly to make sport fishing practical. They are occasionally caught as bycatch in commercial deep-water fisheries, but this is accidental rather than intentional. In Greenland, some traditional hunting of Greenland sharks continues on a very small scale, but this is not a significant fishery.

How do Greenland sharks see if they are mostly blind?

Most Greenland sharks have severely reduced vision due to parasitic copepods that damage their eyes. They compensate by relying on their sense of smell and their ability to detect electrical fields produced by muscle contractions in other animals. This sensory combination is effective enough to hunt successfully in the deep, dark ocean where vision would be of limited use anyway.

Why do Greenland sharks live so long?

The extreme cold of their habitat slows their metabolism dramatically, which slows aging and extends lifespan. Combined with their slow growth rate and low reproductive demands, this creates conditions where living for centuries is biologically sustainable. Scientists are still working to understand the specific genetic and physiological mechanisms that allow such extreme longevity.

Are Greenland sharks endangered?

Greenland sharks are listed as Vulnerable, not Endangered, but they face real risks. Their slow reproduction and late sexual maturity mean populations recover very slowly from overfishing or other losses. Climate change and warming Arctic waters may alter their habitat and food availability, though the long-term effects are not yet clear.

Where can you see Greenland sharks?

Greenland sharks live in deep ocean water and are not visible from shore or accessible to recreational divers. They are occasionally displayed in museums and research institutions, and some documentary footage exists from deep-sea research expeditions. Most people will never see a living Greenland shark, but museum specimens and scientific publications offer ways to learn about them.