How Old Are Sea Turtles?

One of the most common questions that we receive in our center is from guests inquiring about the age of our sea turtle patients.

There are several myths associated with identifying the age of a sea turtle, one of which being counting the rings on the carapace. This is not true, nor can the age of a sea turtle be determined by its size.

Individual sea turtles grow at different rates depending on various environmental factors, including diet and accessibility to food.  Since we are unable to identify our patient ages, we use a classification system based on the straight length of their carapace (the dorsal part of the shell structure).  The five classifications are hatchling, post-hatchling, Juvenile, sub-adult, and adult.

Nanette Foundation

Classifications vary depending on the species of sea turtle. Listed below are the size ranges established for the various species of sea turtles which are commonly seen as patients in our hospital.

Green Turtle – Under 5cm
Hawksbill – Under 5 cm
Loggerhead – Under 5 cm
Kemp’s Ridley – Under 5cm

Green Turtle – Over 5cm, Under 10cm
Hawksbill – Over 5cm, Under 10cm
Loggerhead – Over 5 cm, Under 10cm
Kemp’s Ridley – Over 5 cm, Under 10cm

Nanette Foundation

Green Turtle – Over 10cm, Under 60cm
Hawksbill – Over 10cm, Under 50cm
Loggerhead – Over 10cm, Under 60cm
Kemp’s Ridley – Over 10cm, Under 45 cm

Sub adult:
Green Turtle –Over 60cm,Under 90cm
Hawksbill –Over 50cm,Under 70cm
Loggerhead –Over 60cm,Under 90cm
Kemp’s Ridley –Over 45cm,Under 60cm

Nanette Foundation

Green turtle – Over 90cm
Hawksbill – Over 70cm
Loggerhead – Over 90cm
Kemp’s Ridley – Over 60cm

There have been times in the past when we have received small Leatherback sea turtles in our hospital as patients; however, there is not yet enough data available for a size range to have been established.

The amount of time it takes sea turtles to reach adulthood varies by species.  For example, Loggerhead sea turtles are believed to reach adult hood (sexual maturity) between the ages of 17 and 33 while this is believed to occur in Kemp’s Ridleys between the ages of 7 and 15.

Currently in our hospital we have patients representing each of the different size classifications.