AGE AND GROWTH OF LOGGERHEAD SEA-TURTLES (CARETTA-CARETTA) OF COASTALGEORGIA - AN ASSESSMENT OF SKELETOCHRONOLOGICAL AGE-ESTIMATES

Loggerhead sea turtles stranded on Cumberland Island (CI), Georgia pro vide skeletal samples to estimate the ages of individual turtles by sk eletochronology. An initial study in 1986 used an average-thickness of humeral cross-section protocol to estimate individual ages and the mi nimum carapace length (CL) of nesting females to predict the average a ge at sexual maturity for the CI sample. The original data and two new CI samples are analyzed by average-thickness, correction-factor, and regression-growth protocols to reassess the original age estimates, to test the reliability of the three protocols, and to predict growth ra tes and age of sexual maturity. All protocols show moderate to high va riation in one or more steps of the calculations of the age-estimates. The lowest variation occurs in the correction-factor protocol, and th is protocol's assumption for the estimation of the number of resorbed growth layers matches best the observed pattern of bone growth in Care tta. The skeletochronological results show growth patterns (von Bertal anffy model) with asymptotes of 96 - 117 cm curved carapace length (CC L) and growth coefficients of 0.040 - 0.106 for the CI samples. These patterns predict sexual maturity occurring from 20 - 63 yr, assuming 9 2 cm (SCL) as the mean size at sexual maturity. Growth rate estimates range from 30 - 40 mm yr(-1) for 40 - 49 cm SCL turtles to 10 - 35 mm yr(-1) for 80 - 89 cm straight carapace length (SCL) turtles.