How To Tell The Age Of A Sea Turtle?

Sea turtles are one of the longest-living animals. They can live up to 80 years! A lot of people wonder about how to tell the age of a sea turtle. It is impossible to know the exact age of a sea turtle unless you know when it hatched. 

You may have heard about the scutes counting method to determine a turtle’s age. But the technique is not effective for sea turtles. Skeletochronology is the only method that can give a close to accurate estimation of a sea turtle’s age. 

In this article, I will tell you how scientists and researchers use skeletochronology to know a sea turtle’s age. There are also a few ways to tell at which stage of life a sea turtle is based on visual signs.

Skeletochronology Testing

Skeletochronology is the only scientific method for finding a sea turtle’s nearly exact age. Unfortunately, the test can only be performed on a dead sea turtle. Moreover, performing the test is not possible for average turtle enthusiasts. 

For this test, scientists or turtle researchers examine the humerus, ilium, scapula, and femur bones of a dead sea turtle to determine its age and growth rate. These bones develop LAGs (lines of arrested annual growths). Scientists slice a piece of bone from the dead turtles and count the annual rings formed in the bones.

Hence, it is understandable why skeletochronology testing is done only on dead sea turtles. Even this scientific method may not give the exact age of a sea turtle.

Checking the Size

Is it possible to know a sea turtle’s age based on its size? Well, it is complicated. There are seven species of sea turtles. Even the same species of turtles can have different sizes depending on where they live. 

The life cycle of sea turtles is divided into Nesting (Eggs), Hatchlings, Juveniles, and Adults. Most sea turtle hatchlings are born under 5cm (Leatherback hatchlings can be 5 to 8cm long). But as they age, their size difference becomes prominent. 

Here is how large different species of sea turtles get when they reach adulthood:

Sea Turtle Species	Average Size
Leatherbacks	4 to 6 feet in carapace length (130 – 183 cm)
Green Sea Turtles	3 to 4 feet in carapace length (83 – 114 cm)
Loggerheads	2.5 to 3.5 feet in carapace length (80 to 110 cm)
Flatbacks	3.25 feet in carapace length (99cm)
Hawkbill	2.5 to 3 feet in carapace length (71 – 89 cm)
Oliver ridley	2 to 2.5 feet in carapace length (61 to 80 cm)
Kemp’s ridley	2 feet in carapace length (61cm)

Visual Signs of Aging 

You may not know the exact age of a sea turtle, but you can look at some visual signs of aging on a sea turtle to know which life stage it is going through. Apart from being large, adult sea turtles may have slightly discolored shells. An old sea turtle’s carapace cab be more worn and torn. Their skin is also much rougher than young adults and hatchlings, 

Baby or juvenile sea turtles have a softer shell than adult sea turtles. Their shells are also much more vibrant in color. The skin of young turtles is smooth and softer. 

You can also tell a female sea turtle has become an adult when they start to lay eggs. Only sexually mature female sea turtles lay eggs every 2 to 3 years. 

It is not possible to guess a sea turtle’s age by counting the rings of its scutes. The scutes on a sea turtle carapace are not the same as freshwater or land turtles. They do not form circles that you can count to determine the age of a turtle. 

Before You Go

There might be only a few ways to determine a sea turtle’s age, but there are more effective ways to determine a pet turtle’s age. To learn more, read the following article here:

How To Tell The Age Of A Turtle? [Illustrated Guide]