Data from: Defining conservation units with enhanced molecular tools to reveal fine scale structuring among Mediterranean green turtle rookeries

Understanding the connectivity among populations is a key research
priority for species of conservation concern. Genetic tools are widely
used for this purpose, but the results can be limited by the resolution of
the genetic markers in relation to the species and geographic scale. Here,
we investigate natal philopatry in green turtles (Chelonia mydas) from
four rookeries within close geographic proximity (~ 200km) on the
Mediterranean island of Cyprus. We genotyped hypervariable mtSTRs, a mtDNA
control region sequence (CR) and 13 microsatellite loci to genetically
characterise 479 green turtles using markers with different modes of
inheritance. We demonstrated matrilineal stock structure for the first
time among Mediterranean green turtle rookeries. This result contradicts
previous regional assessments and supports a growing body of evidence that
green turtles exhibit a more precise level of natal site fidelity than has
commonly been recognised. The microsatellites detected weak male
philopatry with significant stock structure among three of the six
pairwise comparisons. The absence of Atlantic CR haplotypes and mtSTRs
among these robust sample sizes reaffirm the reproductive isolation of
Mediterranean green turtles and supports their status as a subpopulation.
A power analysis effectively demonstrated that the mtDNA genetic markers
previously employed to evaluate regional stock identity were confounded by
an insufficient resolution considering the recent colonisation of this
region. These findings improve the regional understanding of stock
connectivity and illustrate the importance of using suitable genetic
markers to define appropriate units for management and conservation.