Genetic structure of loggerhead turtle (Caretta caretta) populations in Turkey

This study investigates genetic structure of loggerhead turtle (Caretta caretta) for conservation purposes using both mitochondrial and nuclear DNA markers. To evaluate overall genetic structure of C. caretta at the Turkish nesting beaches and to compare it with previously published data from other nesting sites of the Mediterranean Sea, we have studied 256 hatchlings from 18 different nesting beaches. Seven distinct haplotypes were detected, of which three have previously been reported from the Mediterranean and one from the Atlantic. The remaining three haplotypes are described for the first time for C. caretta in the present study. Distribution of these haplotypes among the nesting sites showed a significant genetic structuring, indicating that females are philopatric and that gene flow among populations is restricted. Both mtDNA and microsatellite analyses determined genetic structuring (mtDNA: γ_st = 0.214, p < 0.01; nDNA F_st = 0.0004 p < 0.05) among nesting aggregates of C. caretta throughout the study area and enabled the detection of the different haplotypes to inform conservation strategies.