Coral reefs are located in some of the world’s most oligotrophic waters, yet corals are highly productive organisms and excellent cyclers of nutrients.  Much of the success of corals is attributed to the symbiosis between the coral and symbiotic dinoflagellates, known as zooxanthellae.  The photosynthetic zooxanthellae provide a significant supply of carbon and nutrients to the coral, and the breakdown of this symbiosis, commonly referred to as bleaching, can lead to coral death.

    In fact, corals are actually made up of a variety of disparate groups of organisms that includes the cnidarian coral host, symbiotic dinoflagellates, Bacteria and Archaea, and endolithic algae and fungi.  These organisms coexist in a complex gradient of associations and symbioses to create the coral holobiont, though very little is known about the nature of associations between the coral host and other microbial partners outside of the zooxanthellae.

    Our group is studying associations between Bacteria, Archaea and corals from a wide variety of perspectives and scales:

1. •We are investigating the onset of stable coral-microbial associations during the  coral developmental cycle
   

2. •We are studying the composition of coral-associated bacterial communities (1) within a single coral colony, (2) between colonies of the same species in close proximity, (3) between colonies of the same species from different locations on the same island/atoll, (4) between colonies of the same species across the Hawaiian archipelago, and (5) between colonies of different species at the same geographic scales. 
   

3. •We are investigating health-compromised (e.g. diseased or bleached) corals to determine if visual assessments indicative of compromised health are accompanied by shifts in bacterial community composition compared to healthy conspecifics. 
   

4. •We are isolating strains of coral-associated bacteria and bringing them into the laboratory for study.  Our goal is to isolate and propagate bacteria that we know from cultivation-independent studies to be common members of the coral-associated microbial community.  These model systems will be used to explore, under controlled laboratory conditions, potential interactions between the coral and microbe.