Population structure and connectivity of green turtles (Chelonia mydas) in Southeast Asia

Genetic diversity, migratory routes and genetic connectivity are essential for conservation of endangered animals. Previous genetic data of green turtles (Chelonia mydas) in Southeast Asia were incomplete due to limited... [ view full abstract ]

Genetic diversity, migratory routes and genetic connectivity are essential for conservation of endangered animals. Previous genetic data of green turtles (Chelonia mydas) in Southeast Asia were incomplete due to limited samples, and were obtained only from nesting rookeries. In this study, we compared the genetic relationships among and between rookeries, and foraging grounds of green turtles in Southeast Asia. Mitochondrial DNA control region sequences of 511 turtles from 11 rookeries (Malaysia and Vietnam), in combination with previously reported Indo-Pacific rookeries, indicated the presence of a genetic barrier in the Torres Strait and Celebes Sea. Mitochondrial DNA region was also determined in 149 green turtles from seven foraging sites in Malaysia. Bayesian mixed stock analyses indicated contemporary movement across this historical genetic barrier, from Micronesian rookeries to foraging grounds in the Celebes Sea (i.e. Sipadan Island and Tun Sakaran Marine Park). Isolation by distance was generally supported for relationships among rookeries, and the high migratory connectivity did not result in a lower genetic distance between rookeries. Differences between rookery connectivity and migratory connectivity in green turtles in Southeast Asia are likely due to migration to natal regions after long-distance movement.