Assessments of a potentially novel coral disease affecting key reef building corals on Florida’s Coral Reef

As part of the Florida Keys strike team’s regular monitoring and treatment of SCTLD-affected corals, observers began noticing lesions on Orbicella faveolata colonies that progress across the colony more rapidly than classic SCTLD. Additionally, these lesions did not appear to respond to antibiotic applications. Tentatively termed FLP – fast lesion progression – this potentially novel disease may have implications for some of the largest reef-building corals in Florida. Observations were compiled in a white paper by Neely in March 2023 and disseminated to the DAC and other potentially interested parties. This report documented rapid lesion progression, a potential seasonality that can result in halted lesions as water temperatures cool, observations potentially going back to 2019, the absence of Vibrio coralliilyticus on the lesions, and a general but not conclusive non-responsiveness to antibiotics.The project goals include:1. Quantitatively documenting the above anecdotal observations; and2. Collecting samples to be used by collaborators to conduct the first steps in describing this disease and comparing/contrasting it with SCTLD and other known diseases.The project tasks include:1. Tagging and monitoring colonies with FLP in order to a) identify disease progression rates, b) identify any seasonal component in progression rates or disease activity, c) identify whether these metrics are consistent across three reefs within the Florida Keys region. 2. Assessing photographs from 2019-2020 intervention work to assess the presence of FLP from past years. Using these historical records, we will estimate prevalence of FLP among actively diseased colonies from six reefs in 2019-2020. We will also use photos from the 2019-2020 timeframe and from the 2022-2023 timeframe to assess amoxicillin effectiveness on FLP lesions during both time periods.3. Collect tissue samples from FLP-affected coral colonies and associated controls and facilitate the delivery of samples to collaborators. Samples from active FLP lesions, unaffected areas of diseased colonies, and apparently healthy colonies will be taken and sent to collaborators for analysis and eventual comparison to SCTLD. Analyses will include histology (FWC), TEM (UNCW), and microbiome (UF).