New scientific research has challenged a century-old belief about the Greenland shark, revealing the creature’s ability to see, despite previously being thought to be blind due to parasitic copepods infecting its eyes. This discovery changes the narrative surrounding the ancient Arctic predator, which can live for over 500 years.
Shattering Old Myths
For centuries, the Greenland shark has been portrayed as a sluggish, blind scavenger drifting through the icy waters of the Arctic. The assumption was that the parasitic copepods attached to the shark’s eyes, which dangle like grotesque tassels, caused irreversible blindness. However, a recent study led by Canadian marine ecologist Jena Edwards and a team of global researchers has upended this long-held view. The study, published in January 2026, finds that despite the parasites and the cloudy appearance of their eyes, Greenland sharks possess structurally intact retinas capable of perceiving light, contrast, and possibly even movement.
“We assumed they were stumbling through the dark. We were wrong,” Edwards remarked, calling the discovery a “paradigm shift” in marine biology. The research suggests that these sharks’ visual systems are not only resilient but have evolved to adapt to the dark, cold depths of the Arctic seas. Rather than aimlessly scavenging, Greenland sharks may be more calculated hunters than previously imagined.
Unraveling the Mystery
Until now, the notion that these ancient sharks were scavengers seemed plausible, especially after their presence in the stomachs of polar bears and caribou was assumed to be the result of feeding on already-dead animals. But the new findings suggest that Greenland sharks may actively hunt, stalking the icy waters of the Arctic with their newly uncovered ability to see.
Along with revealing the sharks’ surprising predatory potential, the study sheds light on the remarkable resilience of the species. Carbon dating has confirmed that these sharks can live for over 500 years, with some individuals possibly born before the construction of Fort Jesus in Mombasa in 1593, offering a stark perspective on their age.
However, there is a lingering puzzle. While these sharks have evolved a sophisticated visual system, the parasitic copepods still cling to their eyes. Researchers speculate that this could indicate a biological relationship between the shark and the parasites, though the exact nature of this connection remains unclear. Some believe the copepods may serve a function, possibly even assisting the sharks in surviving the harsh conditions of the deep Arctic.
As climate change accelerates and Arctic ice continues to melt, there are concerns that the shark’s new reliance on vision might prove to be a disadvantage. The increased penetration of light and shifting prey patterns could overwhelm the sharks’ sensory adaptations, threatening their survival in the face of environmental changes.
For now, the Greenland shark continues its slow, silent patrol beneath the icy waters, a living testament to an ancient world that has long since passed. As scientists continue to explore this newly uncovered aspect of its biology, they are left to ponder whether this majestic predator can survive in a rapidly changing Arctic environment.
