DNA Metabarcoding Assessment of Benthic Communities in North Adriatic Sea Combining Autonomous Reef Monitoring Structures (ARMS) and LifeWatch ERIC

The accelerating global loss of biodiversity requires effective monitoring methods. Monitoring hard-bottom benthic communities is particularly challenging; thus, non-destructive and standardised sampling tools, e.g., Autonomous Reef Monitoring Structures (ARMS), are increasingly used globally. Recently developed DNA metabarcoding approaches allow a broader description of the ecological communities. In parallel, bioinformatic pipelines have advanced to efficiently manage the large volume of data, and distributed virtual infrastructures such as LifeWatch ERIC (LWE), have emerged to facilitate the sharing of Findable, Accessible, Interoperable, and Reusable (FAIR) data. This work investigates the spatial and temporal variability of benthic communities in the Northern Adriatic Sea using ARMS and DNA metabarcoding within LWE. From 2021 to 2023, ARMS were deployed in Venice for one year (Long-Term monitoring), and for three months (Short-Term monitoring) in two sites near Ravenna (Harbour and Marina), characterized by different levels of human stressors. After retrieval, samples have been processed by amplifying the Cytochrome c Oxidase subunit I and the 18S rRNA markers. In Venice, significant temporal changes in benthic communities were found between 2021 and 2023, likely due to fluctuations in environmental parameters. In Ravenna, the benthic communities differed significantly between Harbour and Marina sites, probably reflecting the different levels of human impact. Both sites showed a temporal variability in the communities, possibly associated with changing environmental conditions. The Marina community showed more frequent shifts than the Harbour community. The use of a multi-marker approach, standardised protocols within the ARMS-MBON (Marine Biodiversity Observation Network) and LifeWatch ERIC represent promising pathways to monitoring marine benthic biodiversity and reinforcing the need for a more FAIR use of methods and data within the scientific community.