Valuation and mapping of the recreational diving ecosystem service of the Aegean Sea

Cultural ecosystem services (CES) provide a range of aesthetic and recreational benefits. However, they have not been extensively assessed due to methodological challenges, despite their use and non-use values for local and wider communities. Therefore, this study aimed to assess the economic importance and spatial distribution of recreational diving, a major non-extractive use of marine biodiversity, in the Aegean Sea. A comprehensive evaluation of diving value was conducted based on ecological features and divers' preferences and habits. The value of recreational diving as an ecosystem service in the Aegean Sea was estimated at €154.3 million annually, with €4.3 million (95 % CI, €1.4–8.4 million) as the willingness to pay (WTP) for biodiversity conservation, €135 million (95 % CI, €99-174 million) for divers' expenditures, and €15 million (95 % CI, €11-20 million) for diving centers' revenues. These values were determined through questionnaires distributed to divers and clubs to estimate the diving industry’s value. The value distribution across the Aegean was determined by divers' criteria for selecting dive sites, such as habitats, species-attractions, and distance to dive centers. The highest local value was €1.1 million km⁻² yr⁻¹ annually, and the lowest was €127 km⁻² yr⁻¹. Recreational diving is a crucial blue growth activity for the Aegean coastal communities and should be integrated into conservation strategies and marine spatial planning.