Inter- and intra-habitat bacterial diversity associated with cold-water corals

The discovery of large ecosystems of cold-water corals (CWC), stretching along continental margins in depths of hundreds to thousands of meters, has raised many questions regarding their ecology, biodiversity and relevance as deep-sea hard-ground habitat. This study represents the first investigation that explicitly targets bacterial diversity from distinct microbial habitats associated with the cosmopolitan reef-building coral Lophelia pertusa, and also compares natural (fjord) and controlled ( aquarium) conditions. Coral skeleton surface, coral mucus, ambient seawater and reef sediments clearly showed habitat-specific differences in community structure and operational taxonomic unit (OTU) number. Especially in the natural environment, bacterial communities associated with coral-generated habitats were significantly more diverse than those present in the surrounding, non-coral habitats, or those in artificial coral living conditions (fjord vs aquarium). These findings strongly indicate characteristic coral-microbe associations and, furthermore, suggest that the variety of coral-generated habitats within reef systems promotes microbial diversity in the deep ocean. The ISME Journal (2009) 3, 756-759; doi: 10.1038/ismej.2009.15; published online 12 March 2009