SUMMARY
We determined the genetic diversity of the Green Turtle Chelonia mydas (Linneaus, 1758) nesting at Kosgoda rookery, the second largest sea turtle aggregation on the southwestern coast of Sri Lanka. Skin tissue samples were collected from 68 nesting females and genetic diversity was estimated using six microsatellite loci. High genetic diversity was observed within the population as all loci analyzed were highly polymorphic with a total of 149 alleles observed. The mean number of alleles per locus was 24.7 and the mean observed and expected heterozygosity across all loci were 0.75 and 0.93, respectively. It appears that five out of six loci were not in Hardy-Weinberg equilibrium, while micro-checker analysis suggested that the Kosgoda Green Turtle population was possibly in equilibrium. The viability of a population is unlikely to be reduced if high genetic diversity is maintained within it. Although the Green Turtle population nesting at Kosgoda is small compared to other nesting rookeries in the world, the high genetic diversity observed suggests that the population may not be undergoing a bottleneck.