Depth utilization and swimming speed of female green turtles at Huyong Island, Thailand

Abstract

The resident depth and swimming speed of female green turtles Chelonia mydas nested at the Huyong Island, Thailand were examined. Four types of data loggers were used to record depth and swimming speed of turtles during the inter-nesting period with an interval of 1 second. Field experiments were conducted from 2003 to 2007 and the data was obtained from a total of 10 turtles. The turtles used the depth between 0 and 92.72 m and the mean resident depth ranged from 6.27 ± 6.29 to 20.66 ± 9.47 m (n = 10 turtles). Mean swimming speed of the turtles ranged from 0.04 ± 0.09 to 0.27 ± 0.25 m s-1 (n = 5 turtles). The nesting rookery and female green turtles at the Huyong Island are protected by the National Acts in Thailand. However, tour boats can go on a cruise around the island, suggesting an impact accident between boats and turtles. Therefore, the data on shallow depth utilization and the slow swimming speed of the turtles obtained through this study provide important information for the proper implementation of conservation of the green turtles.