COS 113-1 - CANCELLED - Demographic impact of stony coral tissue loss disease (SCTLD) in Pseudodiploria strigosa populations in Puerto Rico

Abstract: Stony coral tissue loss disease (SCTLD) has had devastating negative impacts in Puerto Rico’s coral reefs. This led the government to declare a state of ecological emergency in August 2021. We have addressed the demographic dynamics of the rapidly expanding outbreak across Puerto Rico since January 2021. The study has been conducted with symmetrical brain coral (Pseudodiploria strigosa) populations along a period of two years on three locations: Playa Carlos Rosario (PCR) and Punta Melones (PME) located in Culebra Island, and Vega Baja (VBA) located in the northern coast of Puerto Rico. We chose this species of coral because it is highly susceptible to SCTLD. Data evidences all study sites decreasing in population growth rates due to decreasing survival rates in time. Data also suggests that colony size is not associated to health status in our studied populations. We then developed a demographic model with the aim of understanding whether SCTLD dynamics vary spatio-temporally. The model projects the viability of all populations falling below 10% within four to eight years if not managed and indicates that Culebra sites are significantly different from VBA, being VBA the most affected by SCTLD. The main difference among these sites is water quality, therefore, it is possible that this factor plays an important role in SCTLD dynamics. Current analyses are being implemented comparing water quality parameters with demographic performance, and projections are being made considering different reef restoration alternatives. This study is very important because the information generated allows us to understand disease behavior in situ and will also allow the development of local SCTLD management strategies, along with the determination of priority areas for mitigation activities.