Greenland Sharks are sluggish leviathans. They churn through the cool Arctic waters at speeds of 1 mile per hour. They also grow slowly, about your pinky finger’s width per year. Some adult specimens have been seen at 16 feet long, suggesting these giants lead incredibly long lives. But how long?
A study, the first of it’s kind, was published in August’s Science, and it measured the overall age of the species. It turns out these sharks can live in excess of 500 years, reaching sexual maturity around 150 years old. This makes them the among the oldest vertebrates known, surpassed only by sedentary species, like some bivalves.
The research team, led by Julius Nielsen, a biologist with the University of Copenhagen, used radiocarbon dating to date eye proteins, which are formed at birth, in the sharks. They used the bodies of 28 sharks, all accidentally killed by fishing vessels or scientific surveys, so no wild creatures would be harmed.
RadioCarbon dating can often have errors that range in centuries, but the team created a more accurate estimate by using the smallest of the sharks first. These assumably younger sharks all had markers for the “bomb pulse”, a marked increase in global radiocarbon known to come from the hundreds of nuclear weapons tested between 1950 and 1970. Armed with the knowledge that these sharks were born during the ‘Atomic Age’, and extrapolating for their predictable growth rate, the ages of the sharks were able to calculated fairly accurately.
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