Development of alternative in situ treatments for stony coral tissue loss disease and investigation of temperature as a driver of stony coral tissue loss disease dynamics

In healthy corals, the surface mucus layer supports diverse and robust microbial populations that are an order of magnitude more abundant than microbes in the surrounding seawater (Brown & Bythell 2005). The abundant organic carbon available in the surface mucus layer of corals is in stark contrast to the surrounding typically oligotrophic tropical seawater and induces stiff competition between heterotrophic bacteria that feed on the mucus. As such, there is a high selection pressure for coral-associated bacteria to both produce and be resistant to antimicrobial compounds (Mao-Jones et al., 2010). Marine host-associated bacteria, such as commensals of corals and sponges, have been a rich source of natural products with antimicrobial properties (Blunt et al., 2016). By using probiotics as alternative in situ treatments for SCTLD, we are thus 10harnessing the natural production of antimicrobial compounds and other be11neficial services from bacteria sourced from healthy Florida corals. The establishment (or restoration) of probiotic strains has the potential to provide a long-lasting protection against this disease.