Elucidating the Origins of Stranded Loggerhead Sea Turtles (Caretta caretta) in the Eastern Mediterranean through Mitochondrial DNA Mixed-Stock Analysis

Abstract

It is widely recognized that the examination of haplotypes among sea turtles inhabiting nesting beaches holds significant importance. Yet, an effective conservation effort of a population also requires an investigation of the origin of sea turtles that strand on the shore, especially as many of these result from interactions with fisheries. In consideration of this, we analyzed the haplotypes of 542 stranded individuals from the Eastern Mediterranean and identified a total of 9 different haplotypes. Two of these were new haplotypes, one individual was found in Marmaris, Türkiye, and the other in a stranded species in northern Cyprus. Mixed-stock analysis demonstrated that the majority of the individuals stranded in western Türkiye originated from nesting beaches in the same area (33%), followed by Dalyan, Türkiye (25%), and Cyprus (21%). The partial mixed-stock analysis of individuals stranded in the Dalyan–Dalaman region of Türkiye revealed that most originated from Dalaman (45%) and Dalyan (21%), followed by western Greece (11%). The partial mixed-stock analysis for the Eastern Mediterranean showed that the majority of individuals originated from western Türkiye (69%), followed by Cyprus (11%) and Dalyan (7%). These findings, by quantifying the relative contributions of each region, provide valuable insights for guiding conservation efforts regarding Caretta caretta in the Mediterranean marine environment.