Differential disease incidence and mortality of inner and outer reef corals of the upper Florida Keys in association with a white syndrome outbreak

The Florida Keys Reef Tract has suffered extraordinary losses in live coral cover over the past four decades and is now battling an unprecedented coral disease outbreak. Here, colonies of Siderastrea siderea (Ellis and Solander, 1786) and Pseudodiploria strigosa (Dana, 1846) were tracked over 3 yrs (2015–2017) across two pairs of inner and outer reef sites in the upper keys, offering a unique perspective into the distribution of disease throughout the reef tract. We found that outer reef colonies of both coral species exhibited greater disease incidence and mortality associated with this ongoing epidemic, while inner patch reef colonies remained largely unaffected. These findings suggest that ecological or biological factors that differentiate coral populations across these reef zones may play an important role in susceptibility to disease.