New research suggests the Greenland shark is the oldest vertebrate on earth. Photo by Julius Nielsen/University of Copenhagen
COPENHAGEN, Denmark, Aug. 12 (UPI) -- New research suggests the enigmatic Greenland shark can be expected to live at least 272 years -- the longest life expectancy of all vertebrate animals on Earth.
A team of marine biologists, led by researchers from the University of Copenhagen, determined the shark's life expectancy by carbon dating the species' eye lenses.
The portion of the shark's eyes are metabolically inactive, left unchanged from birth until death. Thus, like a fossil, the shark's age can be measured using carbon-14 dating.
"We use well-established radiocarbon methods, but combine them in a new way," researcher Julius Nielsen said in a news release. "This approach, along with the extraordinary ages for these sharks makes this study highly unusual."
Researchers have previously used a similar dating method to measure the age of whales, but it's the first time the technique has been used to date fish.
Though the science of radiocarbon dating is relatively routine, studying Greenland sharks remains difficult. Little is known about the shark's behaviors and general biology. Over a period of three years, scientists carbon dated Greenland shark specimens caught as by-catch by commercial fishing operations in the North Atlantic.
Nielsen hopes the latest revelation -- detailed in the journal Science -- will encourage conservationists and fishery managers to improve protections for the unique species.
"Greenland sharks are among the largest carnivorous sharks on the planet, and their role as an apex predator in the Arctic ecosystem is totally overlooked," Nielsen said. "By the thousands, they accidentally end up as by-catch across the North Atlantic and I hope that our studies can help to bring a greater focus on the Greenland shark in the future."