Abstract
Biological and life-cycle information is essential to any fisheries management program. We have investigated temporal changes in growth parameters in the von Bertalanffy growth curve for green turtles, Chelonia mydas, in waters around the Ogasawara Islands. The variance model of individual variability of growth used in our study was one derived from the stochastic differential equation with the white noise of constant intensity. Maximum likelihood estimates of the parameters were made using the data of 102 recovery records of tagging experiments from 1974 to 1995. The estimations were carried out for each of two models of linear and sudden changes in the parameters, and the best model was selected using Akaike's information criterion. The selected model was that all of the parameters excepting asymptotic straight carapace length were linear functions of year and that the asymptotic length was constant over the years. The estimated values of the growth coefficient in 1974 and 1995 were 0.0317 and 0.192 per year, respectively, and the estimated value of the asymptotic straight carapace length was 97.2 cm. Implications of the results and future issues to be resolved in near future are discussed.
Published Version
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