- Coral reefs are diverse ecosystems and serve many purposes including preventing erosion on coastlines and acting as a source of food, income, and culture. Acropora cervicornis, a staghorn coral, has faced a significant 80-89% decline in the Caribbean, attributed to a poorly-characterized epizootic, White Band Disease (WBD). Previous studies showed that Aquarickettsia rohweri, a bacterial parasite, is strongly associated with WBD in these corals and whose growth is stimulated by nutrient exposure. This study developed new methods to compare the individual and combined impacts of nitrate, phosphate, ammonium, on the coral microbiome of a disease-susceptible and -resistant genotype of A. cervicornis. Illumina MiSeq sequencing of the 16S rRNA gene amplicons were utilized to evaluate differences in the relative bacterial abundances while quantitative PCR (qPCR) analysis was performed to determine the absolute abundance of A. rohweri. The increase in abundance of A. rohweri over time can most likely be credited to off-reef incubation in aquaria and excess canal water nutrients rather than the amended nutrient exposure. Although further research is needed to better understand which nutrient most stimulates A. rohweri proliferation in A. cervicornis corals, this study provides insight on a method that can more thoroughly and accurately study these dynamics.
- Key Words: coral, Acropora cervicornis, Aquarickettsia rohweri, parasite, nutrients