Artificial night lighting in the Mediterranean: Management priorities and constraints for sea turtle conservation

Artificial light at night (ALAN) is an escalating anthropogenic threat that disrupts coastal and marine ecosystems worldwide, yet its impacts on Mediterranean sea turtles remain poorly quantified. We surveyed 27 experts across 16 Mediterranean countries to evaluate perceived ALAN effects on sea turtle nesting sites and nearshore habitats, identify research gaps, assess monitoring limitations, and prioritize mitigation strategies. Respondents consistently highlighted hatchlings as the most vulnerable life stage, particularly during sea-finding and early dispersal, with ALAN causing disorientation, increased predation risk, and reduced recruitment. Standardized monitoring of ALAN impacts is largely absent, with financial constraints representing the main barrier, alongside gaps in communication, education, and policy. Experts ranked the highest-priority mitigation measures as updating monitoring programs to incorporate ALAN, reducing light exposure on nesting beaches through shielding, downward-directed and long-wavelength lighting, shaded corridors, and nature-based solutions, and integrating advanced technologies into conservation planning. Measures such as policy reform, public awareness campaigns, and scenario-based coastal planning were considered of moderate priority, emphasizing that practical, site-specific interventions may yield the most immediate benefits. Limited expert consensus on the prioritization of mitigation strategies indicates persistent uncertainties and critical regional knowledge gaps that hinder effective conservation planning. ALAN is an established but under-addressed threat to Mediterranean sea turtles. Effective conservation will require integrating evidence-based research, standardized monitoring, and targeted mitigation measures at nesting and nearshore habitats. Implementing such strategies will not only safeguard sea turtle populations in the Mediterranean but also provide a globally relevant framework for managing ALAN in other coastal ecosystems.