The proximity to marine infrastructure affects fish diversity, the occurrence of non-indigenous species, and the dynamic of the sessile communities

Abstract

Marine urbanization is changing coastal ecosystems. In this study, we examined how the proximity to recreational marinas influences the structure and recruitment of the sessile community, the diversity of fish, and predation pressure. Sessile communities on marinas supported 68 % more non-indigenous species than those farther from marine infrastructure. Conversely, native species occupied more space in natural habitats, where the diversity of fish was greater. Predation did not influence the diversity or structure of the sessile community, regardless of the habitat type. Nevertheless, predation pressure may be underestimated in artificial habitats due to the lack of connection between platforms and the seafloor. Sessile recruitment tended to be more abundant in artificial habitats. Our findings indicate that even when substrate composition, orientation, and connectivity to the seabed are standardized, proximity to marine infrastructure increases the prevalence of non-indigenous sessile species and diminishes the diversity of potential predatory fish, thereby altering the dynamics of sessile communities.