St. Petersburg Coastal and Marine Science Center
While there has been significant recent focus on the microbial associates of the deep-sea coral Lophelia pertusa, most other deep-sea scleractinians and octocorals remain unstudied. Microbial associates have been shown to be key players in coral biology, serving functions such as fixing nitrogen, capturing iron, cycling waste products, and producing antibiotics to keep unwanted microbes from infecting the coral. There is evidence that many corals maintain conserved bacterial communities, distinct from the water column, sediments, and nearby corals of other species. The coral's microbiome is also the most genetically adaptable part of the coral; faced with changing environmental conditions, the coral animal may take several generations to adapt, whereas the entire coral-associated microbial community (and all of its associated metabolic capabilities) can be changed on the order of hours to days. Changes in the microbial community can also be used as diagnostics of coral stress. Characterizing the microbial communities associated with deep-sea corals in these environments will increase our knowledge of the biodiversity in these ecosystems and provide insight into the variability or uniqueness of the corals between different canyons.
During research cruises in 2012 and 2013 to both Baltimore and Norfolk Canyons, we were able to collect multiple specimens of four deep-sea octocorals: Primnoa resedaeformis, Anthothela sp., Paramuricea sp., and Acanthogorgia sp. for microbiology. Bacterial associates will be identified from each coral by pyrosequencing. We will compare the bacterial communities on Primnoa from Baltimore and Norfolk Canyons with each other and also with a sister species, Primnoa pacifica, collected in the Gulf of Alaska, to determine how conserved the microbial communities are within and between species of the same genus. Similarly, we will compare the bacterial communities on Anthothela between canyons. Since the Paramuricea were only encountered in Baltimore Canyon and the Acanthogorgia in Norfolk, no biogeographic comparison is possible, but these analyses will provide a first look at the bacterial associates of those two cold-water gorgonians.