Determining the geezerhood of sea turtles is notoriously difficult . The size of it of the animal can not be used as a measure , and the want of teeth rules out another potential marking . estimate motley on the eld the marine reptiles can hit , withmany expertssuspecting that they can probably get to around 100 year old . But researchershave now demonstrated that the historic period of ocean polo-neck , and even the meter at which they reach intimate due date , can be calculated by seem at the carbon signatures found in their plate , the resultant role of the atomic bomb examination carried out at the meridian of the Cold War . Their issue are published in theProceedings of the Royal Society B.
By look at the scute – or bony external plates – of dead Hawaiian Eretmochelys imbricata sea turtles , the researchers were able-bodied to weigh the growth lines within them ( a minuscule like reckon tree rings ) . They were then able-bodied to forecast that the hawksbill turtles formed on average eight line per year , allowing them to figure out the polo-neck ' growth rates . In addition to this , they also work out that the turtle get to intimate maturity at an amazing 29 years of years , which goessome way to explainwhy the Hawaiian population of these reptilian has been so slow at retrieval after being decimate for their desirable shell .
The nuclear turkey test in the Pacific , such as this one on Bikini Atoll in July 1946 , loose flock of extra carbon-14 into the atmosphere , and afterwards the oceans . United States Department of Defense / Wikimedia Commons
Bomb radiocarbon is actually widely used to calculate the age of marine organism , from corals and sponges to fish . The carbon-14 in the marine environment shifted dramatically after the nuclear examination that took place in the Pacific during the middle of the century . But until now , the manipulation of this technique to get reliable age estimates for sea turtles had never been achieved , mainly because the reptilian get all their carbon-14 not from the environment , but from their diet , and this alters the amount of carbon-14 then lock away away in their tissue .
By look at the bomb - test carbon-14 accumulated in the racing shell of the turtles and comparing it to the background rates found in Hawaii ’s red coral , as well as with imprisoned turtle for which the ontogenesis pace are known , the researchers were able-bodied to calculate the ages of the godforsaken turtles when they died , the rates at which they grew , and even at what point they reached intimate maturity . The scientists analyzed 36 different turtleneck that were collected from between 1962 and 2013 to give them a time frame spanning the stop during which the nuclear bomb trial took shoes .
The researchers managed to acquire 36 Hawaiian hawksbill turtle shells , many from museums due to their rarity . Kyle Van Houtan / Duke University
The researchers were also capable to see how the turtles ' diets have alter over the past 50 years , and it ’s not great . Up until around the eighties , the turtles were chiefly omnivore , eat both animal and plant matter , but now they appear to be principally herbivores , swear on thing like algae . This could be an indication that there has been a shift in nutrient supply that has forced them to become vegetarian , and could also be impeding their recuperation .
This is the first true marker for get on ocean turtles , and it is skip that by using this method , researcher will be able to roll it out with other species worldwide , and to facilitate expand our noesis of these leatherneck animal .
