Why Greenland Sharks Can Live 400 Years — and Why a Cull Plan Sparked Alarm

A plan by local officials in Greenland to pay fishers for killing 1,000 Greenland sharks put a rarely discussed deep-sea animal into international headlines in 2026. The debate centers on a species that scientists describe as the longest-living vertebrate known, with individual sharks potentially alive for centuries.

What triggered the debate

The municipal council in Avannaata, which includes the fishing town of Ilulissat on Greenland's west coast, approved a plan offering fishers 300 Danish kroner (about $45) for every Greenland shark heart they brought in, according to Yahoo News. The stated target was 1,000 sharks.

Fishers supported the idea because the sharks damage longline gear and take fish caught on the lines. One halibut fisher, Henrik Jensen, said he lost up to 6,000 hooks and as much as 30,000 kroner (roughly $4,500) in a single day when sharks stripped his lines, Yahoo News reported.

Greenland's national fisheries ministry later questioned whether the municipality had legal authority to issue such a wildlife cull, and the plan was halted, Yahoo News reported.

The conservation group Oceans North Kalaallit Nunaat opposed the cull. Marine conservationist Nick Dulvy told Yahoo News that Greenland sharks are "probably — biologically — the most sensitive species in the ocean to overfishing."

How scientists learned sharks can live 400 years

Greenland sharks have no bony structures that record annual growth rings the way fish ear bones or shark vertebrae normally do, so researchers could not age them with standard methods for decades. In 2016, a team led by Julius Nielsen published a study in the journal Science using radiocarbon dating of proteins in the shark's eye lens, according to ScienceDaily's summary of the paper.

The team analyzed eye lenses from 28 female Greenland sharks caught as bycatch in research surveys, ranging from 81 to 502 centimeters in length, according to ScienceDaily's summary of the study.

The results pointed to an average lifespan of at least 272 years for the sharks studied. The largest individual, measuring 502 centimeters, was estimated at about 392 years old. That finding led the researchers to describe the Greenland shark as the longest-lived vertebrate known, with a likely maximum lifespan exceeding 400 years, according to ScienceDaily.

Why they grow and age so slowly

The same 2016 study found Greenland sharks grow at only about 1 centimeter per year, among the slowest growth rates recorded in any vertebrate. Because growth is so slow, reaching the roughly 400-centimeter body length needed for sexual maturity takes females an estimated 156 years, according to the study results summarized by ScienceDaily.

Adult Greenland sharks typically reach 400 to 500 centimeters (13 to 16 feet) in length. Despite their size, they are among the slowest-swimming shark species yet migrate more than 1,240 miles a year, according to Yahoo News.

The sharks live mainly in the cold, deep waters of the North Atlantic and Arctic Ocean, which slows their metabolism further. A Vulnerable classification by the International Union for Conservation of Nature (IUCN), noted by Yahoo News, reflects concern that a species maturing after roughly a century and a half can recover from population losses only very slowly.

Why the cull proposal worried scientists

Because Greenland sharks reproduce so late and so slowly, conservationists argue the population cannot absorb large, concentrated losses the way faster-reproducing fish can. Oceans North Kalaallit Nunaat's objection, cited by Yahoo News, centered on the sharks' mobility: because the sharks travel over long distances each year, removing sharks from one fishing area would not necessarily stop other sharks from moving in to replace them, making a cull an ineffective fix for damaged gear while still risking long-term harm to a slow-recovering species.

Greenland's fisheries ministry did not rule on the ecological merits of the plan when it intervened; it questioned whether the Avannaata municipality had the legal standing to authorize a wildlife cull at all, per Yahoo News. That procedural objection halted the 1,000-shark plan.