How can sea turtles be aged?
Patterns of growth rates in sea turtles have been difficult to assess, mainly because of a lack of methods available to age them. Techniques have been developed more recently that estimate age from the number of growth layers of bones. The humerus, one of the forelimb bones, gives the best indicator of age as they retain the greatest number of growth layers. There are limitations using growth layers for aging. In mature turtles, early growth layers are re-adsorbed, growth rates may not be constant and they are not necessarily annual. Growth studies have been conducted where a fluorescent chemical has been injected into adult sea turtles. When these turtles are located years later, the humerus has been examined beneath a microscope during biopsy, and growth layers are clear and countable. Unfortunately, this technique has not been used on young turtles, so unless the turtles age is known for definite, these techniques will only ever provide estimates. Techniques for using bones to deter
