Estimating the Age, Growth and Maturity of Green Turtles in the Eastern Mediterranean

ABSTRACT A comprehensive understanding of population dynamics of green turtles ( Chelonia mydas ) is contingent on a thorough examination of age distribution, annual growth rates (GRs) and age at maturity. The aim of this study was to determine the age distribution and growth parameters and to estimate the age and size at maturity of dead green turtles on Samandağ beach. The number of lines of arrested growth (LAGs) counted by skeletochronology from the humerus of 79 individuals was adjusted using a correction factor. The mean curved carapace length (CCL) was measured to be 49.5 cm. The mean age was estimated to be 17.4 years. The von Bertalanffy growth function was the most parsimonious model for the relationship between age and size. The annual GR of 3 ± 1.34 cm/year was calculated using a back‐calculation model. It has been observed that the estimated GR decreases with an increase in the CCL. Three methods were used to estimate the age at sexual maturity (ASM): (i) Fabens' modified von Bertalanffy GR, (ii) data obtained from the best‐fitting growth model and (iii) segmented regression analysis. As a result of these models, the ASM was 37.5 years (min. 24.5 years), 40.5 years (min. 24.5 years) and 31 years (range 29–32 years), respectively. The population of Samandağ has an asymptotic length that is lower than that of Atlantic populations, but similar to that of Pacific populations. This study indicates that 72% of the Samandağ green turtle population that stranded on the eastern Mediterranean were juvenile and subadult individuals. This highlights the need to prioritize the protection of marine habitats in management plans.