Biology, Nesting Behavior, Genetic Diversity, and Conservation of Leatherback Sea Turtles: Insights From Thailand and Global Perspectives

Abstract

Sea turtles are large reptiles that inhabit the world's oceans and include seven extant species within two families: Cheloniidae and Dermochelyidae. These species are threatened globally, with several subpopulations listed as Endangered or Critically Endangered by the IUCN. Thailand hosts five sea turtle species, including leatherback turtles (Dermochelys coriacea ), which are significant for their nesting sites along the Andaman Sea coast. Conservation efforts in Thailand include beach patrols, hatcheries, and community education to mitigate threats such as poaching and habitat destruction. Leatherback turtles, classified as “Vulnerable” by the IUCN and listed in CITES Appendix I, face challenges in estimating global population size due to their highly migratory nature. They are the largest sea turtles, with distinct physical characteristics such as leathery skin, lack of scales, a hard shell, and backward-pointing spines in the throat that aid the passage of food. Leatherbacks reach sexual maturity at around 13–14 years of age and exhibit natal homing behavior for nesting. These turtles have low hatching rates; only 50% of eggs hatch, and just 2% of those hatchlings survive. Population genetic studies of leatherback turtles have been key to better understanding threats to survival, revealing low global mtDNA haplotype diversity, with notable recent radiation originating from the Indo-Pacific region. Despite this low diversity, there is significant population structuring, which hints at hidden nesting populations and foraging grounds that may contribute to genetic variability. For that reason, relocating nests to favorable locations is one possible conservation measure. Other strategies must address habitat loss, pollution, bycatch, and climate change in protection efforts for this species, as well as ensuring global population connectivity to maintain the genetic diversity of these highly migratory turtles.