Novel Ex-situ Stony Coral Tissue Loss Disease Treatment Protocol v1

Stony Coral Tissue Loss Disease (SCTLD) is a highly lethal coral tissue loss disease that has shown to cause catastrophic loss of coral cover and biodiversity in Caribbean coral reef ecosystems. The unprecedented loss to SCTLD has demonstrated significant harm to reef functionality, making intervention and mitigation strategies essential. Current in-situ and ex-situ treatment methods have shown varying levels of success. Here, we present a 10-day ex-situ treatment protocol demonstrating a 94% success at treating coral colonies across four genera with SCTLD-like lesions (n=34 with Dendrogyra cylindrus, Montastraea cavernosa, Pseudodiploria strigosa, Orbicella faveolata, O. annularis, and O. franksi) with a 0% reinfection rate after treatment (ex-situ) (Pelose et al., In prep). The three main components of the treatment include a pre-cleaning procedure to remove necrotic tissue, hydrogen peroxide (H2O2) dips to oxidize potential pathogens on exposed skeleton and the coral's outer tissue layer, and a multicomponent antibiotic treatment dip to eliminate any remaining potential pathogens. This protocol explains how to conduct this novel treatment and provides recommendations for coral collection and preparation methods, coral husbandry, and post-treatment care.