Short note on reduction in hatchling rate: case study of Rayong Province, Thailand

Abstract

The female green turtle (Chelonia mydas) along the Andaman sea coast and in the gulf of Thailand re-migrates every 2-5 years because of the need to accumulate sufficient fat for vitellogenesis and for reproduction. The green turtle nesting on the islands of Rayong Province, Thailand, was investigated during 2008-2009. The objective of this study was to monitor the nesting cycle and hatchling rate of juvenile green sea turtles, and possibly to provide important points to consider in the sea turtle conservation program. As a result of this study, it was found that a female turtle had a 1 year homing migration period, but the rate of hatching was only 13.4 percent. This is lower than the average hatching rate (80% SD) observed on Khram Island, Chonburi Province. This result indicated the critical circumstances of the sea turtle populations along the Rayong coast. Although there have been new female stock recruitment on nesting beaches, unfortunately there has been a reduction in hatching rate (86.3% of the eggs were not fertilized). For the further study, embryology of each embryonic stage should be investigated for more precise results. The female’s health status checking should be carried out to rule out the female infertility factor, and to know the main cause of the low hatching rate.