Genetic Diversity in Leatherback Turtles (Dermochelys coriacea) along the Andaman Sea of Thailand

Abstract

The leatherback sea turtle (Dermochelys coriacea) is the largest and one of the most migratory turtle species, inhabiting oceans throughout the world. There has been a steady decline in leatherback populations over the past several decades due to human activities. They are considered endangered in Thailand and global, so conservation strategies are needed to study and protect the species, including determining their genetic diversity. A total of 8 microsatellite loci and 658 bp amplicon of mitochondrial DNA (mtDNA) were used to assess genetic data from 149 dead leatherback turtle hatchlings among 14 nests in five locations along the Andaman Sea, Thailand, between 2018–2020. The microsatellite findings show that the observed heterozygosity (Ho) ranged from 0.44 ± 0.09 to 0.65 ± 0.10. Population structures were further divided into two genetically distinct groups by Bayesian inference. For the mtDNA control region, our samples consisted of three haplotypes. Globally, there are 27 haplotypes of leatherback turtles, with a relatively low genetic diversity (h = 0.43). These results reveal the genetic status of leatherback turtles in Thailand and globally, and raise concerns about their relative genetic health, which highlight the need for proactive, long-term management and conservation strategies for this endangered species.

Population genetics of the critically endangered three-striped turtle, Batagur dhongoka, from the Ganga river system using mitochondrial DNA and microsatellite analysis

“…It was also evident from the haplotype network, which shows mostly single nucleotide differences between haplotypes. Similarly, high haplotype diversity have been reported in Loggerhead sea turtle 20 , whereas lower haplotype diversity in turtle species, e.g., in Leatherback turtles, Dermochelys coriacea 21 and Bog turtle, Glyptemys muhlenbergii 22 . Our data show a low nucleotide diversity with high haplotype diversity, which can be a signature of population expansion from a small effective population size 23 .…”

Natal Origin and Spatiotemporal Distribution of Leatherback Turtle (Dermochelys coriacea) Strandings at a Foraging Hotspot in Temperate Waters of the Southwest Atlantic Ocean

“…It should be noted that Dc9.1 has not been described to date for any nesting area in the Atlantic, yet has only been reported in the western and Indo Pacific [ 72 ]. It is unlikely that this indicates the movement of turtles from the Indo Pacific breeding areas to forage in the SWAO, but rather an artifact of incomplete baselines [ 73 , 74 ]. Furthermore, the presence of shared haplotypes among the rookeries contributes to the uncertainty of the mixed stock assignments.…”