Greenland shark

How it lives

Greenland sharks grow very slowly, about 1 cm a year, and reach maturity very late. Radiocarbon dating of eye lenses from 28 females suggested a life span of at least 272 years, with the oldest estimated at about 392 years, and maturity at about 156 years, give or take 22. Females give birth to live young, and litters are thought to be up to about 10 pups of roughly 38 cm. Gestation is not known well; one estimate is 8 to 18 years. Nearly every shark carries a parasitic copepod on the cornea of the eye, which probably reduces its vision.

Where it goes

The Greenland shark lives in cold water of the North Atlantic and Arctic Ocean, from the surface down to depths of nearly 3,000 m, although it is most often reported at about 200 to 600 m. In a camera study in the Canadian Arctic, about three quarters of the sharks were seen at 0 to 0.5 degrees C. It is described as a mobile, non-shoaling predator and scavenger. Its long-distance movements are not well described in the sources read.

We only draw a journey on the map when scientists have tracked it or clearly documented it. For this animal we have not found one yet.

Populations

The IUCN lists the Greenland shark as Vulnerable (assessed 2019, published 2020), an upgrade from Near Threatened. The main threat is accidental catch in fisheries, for example bottom trawls and gillnets for Greenland halibut, and Wikipedia gives a figure of about 3,500 sharks caught per year. FishBase rates the shark as very highly vulnerable to fishing because it grows and breeds so slowly. The global population size is not known. A baited-camera study in five areas of northern Nunavut, Canada, found local densities of about 0.4 to 15.5 sharks per square kilometre, and most sharks seen were not yet mature. I did not find a population estimate for Greenland waters.