Modern coral reefs are the result of thousands of years of growth and development, but their demise is occurring at alarming rates around the World. In the Caribbean alone, over 60% of live coral cover has been lost in many reefs in just 30-40 years. Consequently, their ecological and economic benefits to coastal communities are also declining. Disease outbreaks and more intense and frequent bleaching (loss of the microalgae in coral tissues) events associated with increasing water temperatures are some of the main factors for coral reef mass mortalities. The highly infectious and deadly Scleractinian Coral Tissue Loss Disease (SCTLD), first identified in 2014 in Florida, is quickly moving through the Caribbean causing extensive mortalities across important reef-building corals. Current research is focused in after-infection events to identify the pathogen and characterize the signs, patterns and consequences of SCTLD transmission. This study investigates coral tissues and the coral-associated bacteria communities before, during and after the infection has occurred in reefs in Puerto Rico. The societal broader impact of the project relates to the significant ecosystem services provided by coral reefs, which are threatened by SCTLD. The project will also support training of a graduate student.
Questions about etiological variability and the temporal dynamics of the microbiome in SCTLD-affected coral species remain unanswered. Specifically, this proposal addresses the following questions: (1) What are the changes in the microbiome composition and abundances of the susceptible coral species when infected with SCTLD? (2) What is the variability in virulence, prevalence and mortality within and amongst species in different phases of the infection and in different habitats? The research site is in La Parguera Natural Reserve, southwest Puerto Rico, where the research team has characterized and monitored several reefs and environmental conditions from the shore to the shelf edge since 2003. This project includes surveys of permanent transects and molecular characterization of tissue/mucus samples, and microbial communities within those, collected from healthy colonies of two to three of the most susceptible coral species (i.e., Meandrina meandrites, M. jacksoni and Orbicella faveolata) and colonies of two resistant species (i.e., Montastraea cavernosa, Porites astreoides) at the long-term monitoring site. The expected arrival of SCTLD to Puerto Rico in Fall 2019, offers the team of researchers a unique window of opportunity to capture reef biological conditions before, during and after infection to complement other research efforts to better understand the ecological dynamics, prevalence and consequences of this new deadly coral disease.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
