JULIUS NIELSENGreenland sharks roam the cold, dark waters off the of the coasts of northeastern North America, Greenland, and northern Europe. There, they have an unusual talent for staying alive, according to a study published this week (August 11) in Science.
Based on an analysis of 28 deceased female sharks, the animals have a lifespan of at least centuries, an international team found. The researchers had used a quirk of history to calibrate age with length of the animals. Nuclear testing in the mid-1950s led to a spike of the mildly radioactive carbon-14 (14C) isotope, which bled into the oceans by the early 1960s, Science reported.
To date the sharks, the researchers examined the animals’ eye lenses, which are formed before birth, Scientific American noted. Only the smallest sharks carried the 14C signature, suggesting they were born after the radiocarbon bomb pulse. The team estimated one shark was born around 1963.
Using such ground-truth estimates of age, as well as other known aspects of the shark’s ...
