Estabulishment of biologging approach to sea turtle in the neritic environment

Abstract

Data loggers are emerging as a powerful tool for quantifying behavioral parameters of aquatic animals. However, in the history of the study about sea turtles, this approach has been applied only into gravid female turtles which land on the same beach several times within a nesting season because data loggers require physical recovery for data retrieval. Therefore, our knowledge of ecology on sea turtles in the neritic and oceanic environment is still rudimentary. We, in this study, developed an automatic time scheduled release system that allows the loggers to be located and retrieved using VHF radio and ultrasonic signals without recapturing sea turtles. The data logger-recovery experiment was conducted on sea turtles in the neritic environment of the Yaeyama Islands, Okinawa, Japan. We recovered four data loggers and two time scheduled operated release systems at the time we programmed without the data loggers falling out. We demonstrated a high collection rate of data loggers by the recovery system, which means there is viability for the use of various data loggers in the study of ecology of sea turtles.