The objective of the research is to examine how environmental stressors impact the health and persistence of corals and their associated microbial communities. Coral colonies consist of an animal host as well as a resident community of microorganisms that includes bacteria, dinoflagellate algae, and viruses. Environmental changes can cause shifts in the microbial composition of corals, as well as coral bleaching and disease. Nutrient enrichment and heat stress are two environmental stressors known to cause shifts in coral microbial communities, as well as coral bleaching and mortality. However, the specific trajectories of coral and reef decline are poorly understood. This project will compare coral microbial communities, coral metabolic attributes, as well as colony health and reproductive output via an ongoing manipulative nutrient enrichment experiment (led by Dr. Deron Burkepile, UCSB) and across a natural island-wide nutrient enrichment gradient. We plan to collect samples to assess coral metabolism, colony reproductive and bleaching status, as well as coral microbial community analysis from two Acropora species around the island.