Innovative barriers reduce risk of injury and mortality for nesting green sea turtles on Breem Island, Saudi Arabia

Abstract Breem Island in the northern Red Sea hosts important nesting beaches for Green sea turtles, averaging more than 250 nests a year. However, the proximity of key nesting beaches to 1-2 m high rocky sea cliffs presents a hazard to female turtles returning to sea. Between 2018 and 2023, we documented 9 mortalities caused by falls from these cliffs. In 2024, to address this, we pilot tested 200-m curved barriers at the northern and southern edges of one section of cliff to prevent access to the area above the cliff. Monitoring during the 2024 nesting season, after barriers were installed, showed 23 instances of turtles being successfully redirected. Additionally, no tracks were observed behind the barriers and no mortalities were observed from the protected cliffs. Full assessment of impacts of these barriers on sea turtles, other fauna, and potentially also on beach dynamics will only be evident over longer timeframes, but the effectiveness of this relatively simple intervention in the first year after installation suggests potential for population-scale impacts for these long-lived and high priority species, and for wider application in the region and beyond.