Nuclear weapons testing in the 1950s and 1960s may at last have a silver lining, because researchers can now measure radiocarbon levels to tell when animals (including humans) were born and when they died, critical information in helping to track poachers of elephants, hippos, rhinos and other wildlife.
The technique, outlined in the latest issue of the Proceedings of the National Academy of Sciences, measures radiocarbon-14 deposited in tissue, such as horns, hooves, nails, tusks, hair and teeth. It then uses that information to determine the animal’s birth and death data.
The testing method could help curb the illegal ivory trade, which is wiping African elephants off the planet.
“Ivory seizures and illegal trade of animals is on the scale of many billions of dollars each year,” senior author Thure Cerling, a University of Utah geochemist, told Discovery News. “Where did this material come from? Is it from recently poached animals? Is it from some government stockpile? These are important questions that can serve as a starting point for further investigative work.”
Cerling explained that all animals living today, including humans, have radiocarbon-14 from the bomb testing present in our tissue.
The radiation goes into the environment, into the food chain and then into us. Cerling and his team compare radiocarbon levels in tissues against the fluctuating “bomb curve” of radiocarbon in the atmosphere, pinpointing when the tissues formed and, in some cases, when the animal died.
Radiation from past nuclear bomb testing has been diminishing, so the new testing technique will work until carbon 14 isotopes in the air match background levels about 15 years from now.
Lead author Kevin Uno, a researcher at Columbia University’s Lamont-Doherty Earth Observatory, told Discovery News that the new testing method provides "a valuable tool to help stem poaching and also illegal trade further up the ladder.”