Benthic Colonization on New Materials for Marine Ecosystem Restoration in Porto Cesareo, Italy

Suitable colonization materials are a pursued target in marine restoration programs. Known for making nutrients available while reducing pollutants and the risk of pathogens in terrestrial ecosystems, Biochar and Bioferment materials of organic origin were tested during a two-year experiment. We tested the efficacy of these materials for restoration purposes through experimental concrete tiles treated with Biochar (B) and Bioferment (F) and tiles made of concrete, which were used as controls (Ct) for the colonization of marine organisms in the marine protected area of Porto Cesareo, Southern Italy (20 m depth). Tiles were monitored for photographs from October 2019 to September 2021. Initially, Biochar treatment presented a higher percentage of total benthic cover (81.23 +/- 2.76, median +/- SE), differing from Bioferment treatment and control tiles (45.65 +/- 5.43 and 47.95 +/- 3.69, respectively). Significant interaction between treatments and times suggests changes in community structure related to Polychaeta cover increase in Bioferment and control materials from the second monitoring time. Furthermore, the underwater instability of Bioferment on the tiles could explain the similarity with control tiles in marine organisms' covers. Hence, Biochar is shown to be a material with optimal stability in seawater, demonstrating greater capacity for marine organisms' colonization in less time compared to the other two materials.