Macrobenthic biodiversity and functional patterns in three Adriatic marinas.

Synergistic pollution effects are pronounced in tourist marinas, but their impact on macrobenthos has not yet been sufficiently researched. In this study, the macrofauna communities in three marinas of the central Adriatic Sea were analysed: Spinut and Strožanac (Croatia) and Marina Dorica (Italy). Structural and functional diversity was analysed using sediment samples and physico-chemical parameters at five stations per marina, considering confinement gradients and human activities. In Spinut and Marina Dorica, species abundance, richness and diversity were determined by confinement gradients and sediment grain size, with sandier stations favouring diverse marine species, whereas finer sediments favoured estuarine/euryhaline species and surface deposit feeders. In both marina, high concentrations of heavy metals were found near boathouses, which affected biodiversity in Spinut but not in Marina Dorica. These results highlight the complex interplay of natural and anthropogenic factors in shaping marinas biodiversity, emphasizing the importance of monitoring strategies for sustainable marina management.