Blind, slow and 500 years old or are they? How scientists are unravelling the secrets of Greenland sharks

"By most accounts, it is a clumsy and near-sightless relic drifting in the twilight waters of the Arctic, lazily searching for food scraps. But the Greenland shark, an animal one researcher (lovingly) said, looks like it's already dead, is also one of the least understood, biologically enigmatic species on the planet. But this month, scientists made a groundbreaking discovery: the sharks are not, in fact, blind."

"Their sedate pace is undercut by the remains of caribou, polar bear, moose, narwhal and beluga found in their stomachs and not all the prey is believed to be from scavenging. This type of dating method is challenging to use for ageing animals that are hundreds of years old Nigel Hussey, Greenland shark expert We're taking blind shots in the dark."

Greenland sharks are large, slow-moving Arctic predators often described as clumsy and near-sightless but now found to possess vision. Individuals reach about 20 feet and feed on large carcasses including caribou, polar bear, moose, narwhal and beluga, suggesting scavenging and active predation. Ageing methods are difficult for animals that may live for centuries, which complicates claims about their longevity. Sparse data, logistical challenges and the sharks' deep, cold habitat hinder research. Newly revealed visual capability overturns a major assumption and increases uncertainty about how climate change and other pressures will affect the species.

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