You know we love a good sea turtle question, and this comes from one of our own members, Ella, through our Ask an Expert opportunity!
Ella was curious about how long loggerhead sea turtles can live, so we asked Cait, one of our senior sea turtle biologists, for some insight!
It’s estimated that their lifespans are between 80–100 years (which is accurate for all seven sea turtle species). However, we’re unsure of how long they can live – with both human and natural threats, sea turtles face many obstacles on a daily basis that make it difficult to know for certain how long these reptiles can survive.
But what if we could use genetics as a means of chipping away at this mystery?
At the University of Georgia’s Warnell School of Forestry and Natural Resources, new genetic technology has been developed that’s changed the way we tag sea turtles and gives us insight into their lifespans.
By using a single egg from each loggerhead nest that’s documented along the coastlines from Georgia to Maryland, researchers can use the maternal DNA in the egg’s shell to determine which female turtle the eggs are from, all without being intrusive during the nesting process. The egg collection is done through permits issued by multiple state and federal agencies. Meticulous data collection and documentation of each nest helps to pinpoint which nest belongs to which female, giving us a way to connect the individual turtle’s nesting habits and create a map of overall loggerhead nesting locations.
By using this method, researchers can actually determine family ties between nesting female turtles and therefore, lifespans. For example, Big Bertha, a famous loggerhead sea turtle who nests in Georgia, was first tagged by researchers in 1980 and was most recently documented nesting in 2016. Through genetic testing using an egg from one of her nests, researchers also determined that Big Bertha has daughters who are currently nesting. So, since her daughters are at least between 30-35 years old (loggerhead sea turtle reproductive maturity is at that age range), it puts Big Bertha between 85-91 years old. This makes her the oldest living documented nesting sea turtle in the world!
Here at the Sea Turtle Care Center™, we’ve treated a number of adult nesting females, most notably Awendaw. Awendaw was a 300-pound nesting loggerhead who was discovered with a severe boat strike injury on Bulls Island, an important nesting beach in the Cape Romain National Wildlife Refuge. After a year of healing and rehabilitation, the Care Center released Awendaw back into the ocean for a second chance at a long life as a reproductive member of her species. Who knows — maybe she’ll be the next Big Bertha!
Slow and steady, just like a turtle, we’re learning more and more about the intricate details of loggerhead sea turtle nesting habits and, by association, their lifespans!
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