Species-specific biofouling drives interfacial bio-geochemical degradation of celadon recovered from the shipwreck at Fenliuweiyu

This study investigates the species-specific bio-geochemical degradation of Yue kiln celadon (specimen FL-3) recovered from the Five Dynasties shipwreck at Fenliuweiyu. Analyses (OM, SEM-EDS, XRD, ATR-FTIR, and microbiome) reveal distinct degradation products induced by barnacles, red coral, bryozoans, and Rhizocaulus. Barnacles generate organic-membrane-encapsulated pyrite (FeS2); red coral leads to the formation of hydroxyapatite (Ca5(PO4)3(OH)), and with iodine enrichment; bryozoans create deep pits containing goethite (α-FeO(OH)) and pyrolusite (MnO2) all wrapped in organic membranes, and with minor pyrite (FeS2); Rhizocaulus formed lamellar organic membranes that contain remnants of sieved diatom. Sediment microbiome analysis suggests that sulfate-reducing bacteria (Proteobacteria) and organic matter degradation accelerate glaze bio-geochemical degradation. These results support organic template-guided mineralization and microbial metabolism as key degradation mechanisms. The severe pitting caused by bryozoans highlights their destructive potential. These findings provide critical insights for developing conservation strategies for marine ceramics.