DISCOVRE - Diversity, Systematics and Connectivity of Vulnerable Reef Ecosystems Project

Science Center Objects

This project uses amplicon sequencing, and functional microarrays to examine the microbiomes of several deep-sea coral species, with priority given to species that are also of interest to the population genetics group: Desmophyllum dianthus, Lophelia pertusa, Enallopsammiasp. and Acanthogorgia sp. The project also uses metagenomics to survey benthic habitats including coral mounds, cold seeps, and sediment.

Christina Kellogg

Rearch Coordinatior Dr. Christina Kellogg.

Microbial Ecology of Deep-Sea Coral Ecosystems

Microbial ecology is the study of microbes (bacteria, archaea, fungi, viruses), how they interact with each other, their host if they are living on/in a plant or animal, and their environment. Microbes are responsible for important ecosystem services, including biogeochemical cycling, nutrient availability, and structuring ecosystems by providing settlement cues to some invertebrates.

Deep-sea Coral Microbiomes

Microbial associates have been shown to be key players in coral biology, serving functions such as fixing nitrogen, chelating 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. Shifts in the coral-associated microbial community can also be used as diagnostics of coral stress, so it is critical to determine baselines prior to impacts (e.g., oil spill, environmental change) in order to determine the magnitude and effects of the changes. 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, or between canyon and slope communities.

A wall of Desmophyllum dianthus cup corals with bonus octopus neighbor.

A wall of Desmophyllum dianthus cup corals with bonus octopus neighbor. (Credit: Deepwater Canyons 2013 Expedition, NOAA-OER/BOEM/USGS. Public domain.)

Lophelia pertusa in Norfolk Canyons

Lophelia pertusa in Norfolk Canyons. (Credit: Deepwater Canyons 2013 Expedition, NOAA-OER/BOEM/USGS. Public domain.)

Benthic Metagenomes

Recently, researchers have begun using metagenomics to characterize the functional capabilities of an ecosystem, particularly in shallow coral reef systems. Water is sampled from just above the benthos and examined for all the microbial genes present, which can provide a picture of both which microbes are there and also the biogeochemical cycles these microbes are carrying out. This method will be used to examine and compare the microbial community functional abilities of deep-sea coral gardens, cold seeps, and soft sediments.

community of deep-sea corals including both hard and soft species

A community of deep-sea corals including both hard and soft species. (Credit: Ian MacDonald, Expedition to the Deep Slope 2007, NOAA-OER/BOEM. Public domain.)

squid jets over a bed of chemosynthetic mussels living on a cold seep

A squid jets over a bed of chemosynthetic mussels living on a cold seep. (Credit: Deepwater Canyons 2012 Expedition, NOAA-OER/BOEM. Public domain.)

sediment bottom with microbial life as well as tiny worms, crustaceans, and molluscs

A nondescript soft sediment bottom like this is still teeming with microbial life as well as tiny worms, crustaceans, and molluscs.  (Credit: Deepwater Canyons 2012 Expedition, NOAA-OER/BOEM. Public domain.)