A survey of the genetic diversity of the Loggerhead and Green Sea Turtles of the Sultanate of Oman

Abstract

The Sultanate of Oman hosts large annual nesting aggregations of up to 23,000 Loggerhead Sea Turtles (Caretta caretta) and 10,000 Green Sea Turtles (Chelonia mydas). Both populations have until now been poorly sampled (eight samples for C. caretta and fifteen for C. mydas). Genetic diversity information is needed for both species because these populations are increasingly threatened as the coastlines of Oman become more developed. It is currently unclear how diverse these rookeries are relative to other rookeries in the Atlantic, Mediterranean, Indian, or Pacific oceans. We explored mitochondrial DNA (mtDNA) diversity in 100 C. caretta from Masirah Island and 42 C. mydas from Ras al Hadd, Oman. We also analyzed C. caretta with four nuclear DNA (nDNA) microsatellites to investigate nuclear diversity. Loggerhead populations in Oman showed extremely low mtDNA diversity, but high nDNA diversity, suggesting isolation of genetically impoverished matrilineal lines, but relatively high male-mediated gene flow. In contrast, C. mydas populations in Oman consist of two clusters of distinct haplotypes that yield extremely high estimates of haplotype and nucleotide diversity relative to other global rookeries. These results describe the diversity of C. caretta and C. mydas rookeries in Oman with implications for global conservation.