Bioconstruction and Bioerosion in the Northern Adriatic Coralligenous Reefs Quantified by X-Ray Computed Tomography

The northern Adriatic continental shelf hosts several coralligenous reefs rising from the sedimentary bottom and characterized by three main benthic assemblages, respectively, dominated algal turfs, encrusting calcareous rhodophyte (ECRs) or erect sponges. Bioconstruction bioerosion processes have been investigated using recruitment travertine limestone tiles deployed in a random site for each assemblages off Chioggia, 6.1–14.4 km offshore 20.2–25.4 m depth. Tiles were retrieved after 3 12 years analyzed X-ray computed tomography (CT), allowing non-destructively identifying quantifying deposited eroded limestone. builders ECRs, serpulids, bryozoans, barnacles, bivalves Anomia ephippium , while most effective borers sponges genus Cliona bivalve Rocellaria dubia . deposition of was greater at MR08 ECRs (12.52 ± 2.22 kg –2 ), intermediate P213 (4.20 1.24 lower P204 turfs (2.20 0.72 ). At MR08, rate did not vary much over time (from 1.295 0.270 to 1.080 0.198 –1 other two sites, it significantly slowed down first survey period: 0.952 0.199 0.350 0.103 P213, 1.470 0.462 0.203 0.058 P204. amount increased with exposure time, no significant differences among 1.13 0.29 10.39 1.14 on average years, respectively. also slightly higher 0.682 0.208 1.105 0.088 mostly rhodensis addition C. viridis compared 0.267 0.078 0.676 0.172 ) 0.179 0.065 0.816 0.171 Overall, bioconstruction has overcome years. In estimated net balance essentially nil all sites. Combining field experiment CT analysis, this study provides quantification reefs, fundamental step toward their conservation.