WHO guidelines emphasize the need for fungal studies in recreational waters. In this context, the MYCOSAND project was launched to assess fungal communities in sand and coastal water. This study focuses on the Mediterranean coast near to Montpellier (France) and provides a one-year seasonal survey across twelve beaches with different levels of urbanization. While previous research has focused on fecal indicator bacteria (FIB), recent findings suggest that this focus may be insufficient, given emerging concerns about antimicrobial resistance and the possible role of fungal communities.

A total of 799 fungal colonies were isolated from 96 samples. Fungal abundance showed marked seasonal variation, with a peak in fall (406 CFUs) and a minimum in winter (80 CFUs), and these differences were statistically significant (Chi-square test, p <  0.05). Filamentous fungi dominated (approximately 80% of isolates), including Aspergillus (14.1%), Penicillium (5.6%) and Fusarium (3.8%), while yeasts (13%) included Candida -like (5.3%) and Rhodotorula -like species (3.6%). Notably, an unusually high prevalence of Acremonium -like isolates was observed (n = 231), representing the most abundant genus, which contrasts with previous studies. Surprisingly, dermatophytes were absent.

Our results suggest an influence of climatic drivers on fungal communities and are consistent with findings from other studies conducted in coastal regions. Given the rising concerns about antifungal resistance, future research should assess fungal resistance patterns. This study highlights the importance of continued monitoring of fungal communities in coastal environments. To our knowledge, this study represents the first year-long survey of cultivable fungal communities in beach sand and bathing waters along the Mediterranean coast of southern France.