Photo-ID for Capture Mark Recapture Study of Sea Turtles in Musandam, Oman, 2019–2023

The Sultanate of Oman has 26 officially declared protected areas, 3 of which encompass critical nesting and foraging grounds for multiple sea turtle species. Traditional research and monitoring in Oman started in the 1970s with a range of activities focusing on flipper tagging and satellite tagging nesting females and nesting success surveys, but this method has limitations, due to potential tag loss and erosion of tag information. To date, most efforts have been concentrated on Masirah Island, with limited and sporadic initiatives in Ras al Hadd Turtles Reserve and the Dimaniyyat Island Nature Reserve (DINR). Little historical information has been collected on turtles in the Musandam Nature Reserve. This study utilizes Photo-ID as a population-monitoring technique, which offers a noninvasive method for identifying and monitoring sea turtles based on unique facial scale patterns, targeting sea turtle populations around the primarily Musandam Peninsula from 2019 to 2023. This technique has the advantage of including male and juvenile individuals of the population that are excluded from nesting sea turtle research, which is female focused. Over the monitoring period 828 sea turtle encounters were recorded, leading to the identification of 147 individual green turtles (Chelonia mydas) and 9 hawksbill turtles (Eretmochelys imbricata). The data highlight a significant juvenile sea turtle population with sporadic adult sightings, suggesting a use of the region's habitats for foraging and resting. Here we underscore the importance of Photo-ID in filling knowledge gaps concerning in-water sea turtle activity and spatial distribution, particularly for the identified juvenile population. This study provides baseline data on the in-water sea turtle population of Musandam. We demonstrate how Photo-ID contributes to long-term conservation efforts by improving population monitoring and population dynamics analysis, contributing to conservation efforts in Oman and in the northwest Indian Ocean.