Caratterizzazione ecologica di siti destinati a ripopolamento di Ostrea edulis in Adriatico settentrionale

Biogenic habitats are three-dimensional structures created by ecosystem engineers that increase seabed complexity, providing substrate and refuge and supporting high biodiversity and key coastal ecosystem functions. In restoring reefs formed by the European flat oyster (Ostrea edulis) in the north-central Adriatic Sea, a major challenge is scarce pre-intervention information and standardised metrics, limiting our ability to disentangle restoration effects from natural variability. This thesis establishes a pre-intervention ecological baseline for two candidate restocking sites: (i) an offshore area near Riccione–Misano Adriatico (Emilia-Romagna), within the “Fuori Riccione–Misano Adriatico” Biological Protection Area, and (ii) an area in the Casteldimezzo–Monte Castellaro sector (Marche), off Casteldimezzo (Pesaro-Urbino). Sampling used a Van Veen grab and field sieving at 500 µm; macrozoobenthos was preserved for taxonomic analysis and sediment subsamples retained for grain-size characterisation. Community differences were assessed with Bray–Curtis-based multivariate analyses and visualised by principal coordinates analysis (PCoA). Hypotheses were tested with two-way PERMANOVA and pairwise comparisons; biological–environment links were explored with DistLM. Results contrast between sites: at Riccione–Misano Adriatico, community structure reflects a Station × Year interaction, consistent with a persistent sedimentological filter; at Casteldimezzo–Monte Castellaro, variability is mainly temporal, with weak, inconsistent spatial differences. Overall, the sites are not ecologically interchangeable and post-intervention monitoring should be site-specific, accounting for spatial heterogeneity and sediment effects and ensuring enough temporal replication to distinguish restoration signals from background variability.