Assessing marine environmental status through microphytobenthos assemblages colonizing the Autonomous Reef Monitoring Structures (ARMS) and their potential in coastal marine restoration

Microphytobenthos is potentially highly sensitive to environmental alterations, but has been rarely utilized in monitoring studies. Here we investigated the use of microphytobenthos colonizing Autonomous Reef Monitoring Structures (ARMS) to assess the marine environmental quality. We analysed microphytobenthic assemblages in terms of abundance, biomass and species composition on ARMS deployed in northern Adriatic Sea along a gradient of increasing impacts. We show that microphytobenthic variables changed significantly across sites, with lowest abundance and biodiversity in the highly impacted site. Moreover, the specific analysis of Diatoms revealed that genera like Entomoneis and Cylindrotheca could be used as indicators of nutrient enriched and stressed conditions. We provide evidence that the analysis of microphytobenthos colonizing artificial substrates could be used as a tool for detecting altered environmental characteristics. We also show that the ARMS, recreating hot spots of microphytobenthic biodiversity, and protect them from grazing, could be potentially utilized to restore degraded hard substrates. Our result indicates that microphytobenthos can be easily incorporated in future monitoring and restoration programmes to assess and improve marine environmental health