Genetic lineages do not predict stony coral tissue loss disease resistance or survivorship among coral restoration outplants in Florida

As stony coral tissue loss disease (SCTLD) has spread across Florida's Coral Reef (FCR), there has been an emphasis on restoring the losses in coral cover through outplanting. This research is part of a larger project assessing the efficacy of restoring SCTLD-susceptible corals Montastraea cavernosa (great star coral), Orbicella faveolata (mountainous star coral), and Pseudodiploria clivosa (knobby brain coral) in SCTLD enzootic areas. As part of Florida's largest coral restoration experiment to date, 1,165 cement bases with 5,825 coral fragments from 99 source colonies were outplanted across 6 regions throughout FCR and monitored monthly over 2 years for survival, disease, and growth. Before outplanting, coral tissue samples were collected for genotyping and initial algal symbiont analysis using 2bRAD and ITS2 sequencing. Neither host genetic lineages nor pre-deployment algal symbiont types significantly predicted SCTLD susceptibility, disputing the hypothesis of SCTLD-resistant “super coral” lineages. Overall, SCTLD prevalence remained low on outplanted colonies during the first 14 months post-outplanting. This study suggests that current restoration efforts should not be constrained by concerns over SCTLD-related losses. Given the absence of evidence for SCTLD-resistant lineages in the species we tested, efforts should continue to focus on promoting genetic diversity among outplanted corals.