Impact of light pollution on the success of loggerhead turtle nesting in Chebba, Tunisia.

Background: Artificial light has a significant ecological influence and has become a worrying threat to some species, such as sea turtles, whose nesting and hatching may be impacted by light. The beaches of the Chebba area, following the Kuriat Islands, serve as one of the key nesting sites for Caretta caretta. Human activities and light pollution particularly impact the beaches of Essir and Sidi Messaoud. Aim: This study aims to document the impact of artificial lighting on the success of loggerhead nesting in Chebba and to propose actionable recommendations to mitigate against it. Methods: Loggerhead nesting on Chebba beaches was investigated from 2013 to 2024. Field observations were made during the nesting seasons to evaluate hatchling orientation and mortality rates in regions with different levels of light pollution. Results: At Essir Beach, 100% of hatchlings were disoriented by the presence of light sources, and several cases of mortality were observed. In contrast, only 21% of hatchlings showed signs of disorientation at Sidi Messaoud, where there is minimal artificial lighting, and no mass mortality was recorded. The frequent presence of people and trampling on the beaches also hindered nest detection during non-daily surveys. Conclusion: Despite being often considered minor, the Chebba nesting beaches significantly contribute to regional reproductive output and genetic diversity. These beaches deserve targeted conservation measures to reduce light pollution through targeted actions, including shielding or eliminating lights visible from the beach, using red-spectrum lamps, and implementing awareness campaigns. This underscores the need for conservation measures to safeguard these small but ecologically valuable nesting sites.