Population genetic of hawksbill sea turtle (Eretmochelys imbricata; Linnaeus, 1766) in the Persian Gulf: structure and historical demography

Abstract

Abstract This study focuses on the population genetics and historical demography of hawksbill sea turtles in the Persian Gulf. We selected eight distinct locations along the nesting habitat, covering a 750 km stretch, and collected samples from 127 hawksbill turtles using non-invasive methods. We analyzed the samples using 15 microsatellite loci and observed distinctive genetic structures on islands and beaches, even when separated by as little as 50 km. Qeshm Island exhibited the highest genetic diversity, while Shidvar, Kharkoo, and Nayband Bay showed lower genetic diversity, possibly due to limited nesting habitat availability and disturbances related to tourism. The study also identified population differentiation through fixation index (Fst) and gene flow (Nm) values, with moderate to high differentiation observed among most populations. We also used population structure analysis, migration analysis, and population history reconstruction to identify multiple genetic clusters and support a scenario of simultaneous dispersal in the Persian Gulf when the region became fully inundated with water approximately 10,000 years ago. Although the introduction of hawksbills to the Persian Gulf happened for the first time from the Oman Sea through the Strait of Hormuz, they were distributed in all habitats in a short time. The study highlights the significance of each coastal and island region in the Persian Gulf as a unique genetic reservoir for hawksbills and emphasizes the importance of conservation efforts to preserve the genetic diversity and resilience of these endangered marine turtles, particularly on islands in close proximity.