The discovery of a Greenland shark in County Sligo, Ireland, in April 2026, has captivated marine biologists and researchers alike. This particular shark, measuring around 3 meters (10 feet) long and weighing over 200 kilograms (440 pounds), was estimated to be over 150 years old, born during the reign of Queen Victoria and the presidency of Abraham Lincoln. The shark's age, while impressive, is just a fraction of its potential lifespan, as Greenland sharks are believed to live for an astonishing 400 years, with some estimates suggesting even longer lifespans. This longevity raises intriguing questions about the secrets to their survival.
The stranding provided a unique opportunity to study a species that is often shrouded in mystery. Researchers, including marine biologist Emilie De Loose and PhD researcher Jasmine Stavenow Jerremalm, conducted a necropsy, carefully examining the shark's body and organs. The process was meticulous, considering the potential risks of handling an animal that could carry diseases from its long life.
One of the most fascinating aspects of the necropsy was the shark's eyes. Contrary to popular belief, Greenland sharks have highly specialized vision adapted to the dim Arctic waters. Their eyes and retinas are intact and capable of functioning in low-light conditions, a remarkable adaptation for their deep-sea habitat. This discovery challenges the notion that these sharks have poor vision and highlights the complexity of their sensory systems.
The necropsy also revealed the shark's massive liver, weighing 50 kilograms (110 pounds), and a heart that was surprisingly healthy despite the shark's advanced age. The heart's functionality, despite showing signs of aging, suggests that Greenland sharks have evolved mechanisms to resist age-related degeneration, particularly in their cardiovascular system. This finding is particularly intriguing in light of the shark's slow metabolism and low energetic needs, which may have evolved to cope with resource-scarce environments.
The study of Greenland sharks is crucial for understanding their biology and ecology. However, researchers face challenges due to the species' elusive nature and the limited data available. Basic aspects of their behavior, such as mating and pupping grounds, remain unknown, making it difficult to estimate population sizes and assess their health and risks from threats like fishing bycatch.
Despite these challenges, the stranding in Ireland has provided valuable insights into the mysteries of Greenland sharks. As researchers continue to study these ancient creatures, we may uncover more secrets to their extraordinary longevity and gain a deeper understanding of the ocean's most resilient species.
