What factors structure Anthozoan microbial communities?

Abstract

The coral holobiont is a complex and diverse composition of organisms including algae, bacteria and viruses. A number of factors suggested as vital in shaping these communities are considered here. The anthozoan host generates great diversity within its microbiota via spatial and metabolic structuring at both macro- and micro-scales; coral communities appear to be somewhat species-specific, yet spatial and temporal variation in coral microbiota suggests the significance of environmental agents. Increasing sea temperatures may cause fatal dissolution of the coral-algal partnership (coral bleaching), and although some adaptation to elevated temperature appears possible, anthropogenic stressors such as reduced pH and sedimentation have been implicated in microbial community shifts, coral disease, and decreasing holobiont resilience. Holobiont interactions appear vital in maintaining coral health, thus disturbance of any community members may cause problematic indirect effects. Enhanced understanding of holobiont health and function is therefore crucial for coral reef conservation.