COMPARISON OF LENGTH-FREQUENCY ANALYSES FOR ESTIMATION OF GROWTH-PARAMETERS FOR A POPULATION OF GREEN TURTLES

We compared the ability of four length-frequency analysis programs to generate accurate von Bertalanffy growth parameters for a population o f green turtles (Chelonia mydas) of known growth rates. The four progr ams were ELEFAN I, Shepherd's length composition analysis (SLCA), proj ection matrix method, and MULTIFAN. ELEFAN failed to identify a set of parameters that qualified as a best Bt. The parameter estimates gener ated by SLCA successfully described six of the 10 length distributions from the population of green turtles. The parameter estimates produce d by the projection matrix method failed to describe adequately any of the 10 length distributions. MULTIFAN generated a set of growth param eter estimates that successfully described all of the 10 length distri butions. Although MULTIFAN had the best performance, it requires subst antially more initial information and estimates than do the other prog rams. The best approach-particularly with a poorly studied population- may be to conduct initial analyses with SLCA, followed by analyses wit h MULTIFAN. Length-frequency analysis is a useful method for the study of growth in populations of immature sea turtles. Further study is re quired to determine whether these methods are appropriate for populati ons of sea turtles that include mature individuals.