Microbial Ecology

Photo: Corals and sediment communities in the deep-water canyons are home to uncharacterized microbial diversity. Photo credit: Ian MacDonald, Lophelia II.

Off the eastern coast of the United States, several deep canyons cut through the continental shelf, acting like funnels for sediments to move from the shelf down to the deep seafloor. Exposed rock outcrops and ledges along the walls of these canyons provide important habitat for deep-sea corals and sponges, while the soft sediments in the valley are home to dynamic communities of tiny burrowing animals.  Our knowledge of the biodiversity in these complex ecosystems is limited; we know little about the macrofauna (fishes, crabs, sponges, and deep-sea corals) and even less about the microbiota (bacteria and fungi). This study will investigate the microbial biofilms that form on hard substrates (since the mixed community of bacteria in a particular biofilm can determine what animals will later choose to live there, affecting the eventual community structure of the visible fauna). The diversity of microbes associated with deep-sea corals and soft sediment communities in the canyons will also be characterized. For more information contact Christina A. Kellogg, St. Petersburg Science Center.

Related Publications:

Kellogg, C.A., 2011, Microbial ecology of deep-water mid-Atlantic canyons: U.S. Geological Survey Fact Sheet 2011–3102, 2 p.

See also Microbial Ecology: Corals >>

Photo: Christina Kellogg collects samples of deep-sea corals for microbiological analysis as soon as they are brought to the surface. Photo credit: Anne Simpson, University of Maine.

Photo: Working in the high northern latitudes in the summer means it stays light all day and almost all night. This photo of the research ship Velero IV was taken at 10pm! Photo credit: Christina Kellogg, USGS.

USGS and National Marine Fisheries Service (NMFS) researchers have just published the first microbiological characterization of three gorgonian (soft coral) species that inhabit the cold waters of the Aleutian Islands.  In a paper titled ‘Microbial consortia of gorgonian corals from the Aleutian Islands’ St. Petersburg Coastal and Marine Science Center (SPCMSC) scientists Mike Gray, Molly McLaughlin and Christina Kellogg and NMFS scientist Robert Stone used culture-based and 16S rRNA gene-based techniques to characterize the microbial ecology of the deep-sea gorgonian corals Paragorgia arborea, Plumarella superba, and Cryogorgia koolsae.  These corals are among a host of diverse and unique cold-water coral communities in the Aleutians.

 There are more than 50 coral species found nowhere else in the world in the waters of the Aleutians, which lie between Alaska and Russia and divide the North Pacific from the Bering Sea.  As much as 85% of the commercially important fish species in the area are associated with such deep-sea corals.  By understanding the microbial consortia associated with these corals, scientists gain a better understanding of their relationship with their environment and the ecosystem services they provide.  The article was published in the Federation of European Microbiological Societies Microbial Ecology.  You can read the study here: https://onlinelibrary.wiley.com/doi/10.1111/j.1574-6941.2010.01033.x/abstract  

For more information, contact:Christina A. Kellogg, St. Petersburg Science Center. 727-803-8747 x. 3128.

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The colorful landscape and incredible diversity of a deep-sea reef in the Aleutian Islands. Photo credit: Alberto Lindner, NOAA Fisheries.

Most people are familiar with tropical coral reefs, located in warm, shallow waters. However, corals also exist hundreds and even thousands of meters below the ocean's surface where it is cold and completely dark. In the last few decades, scientists have discovered and photographed incredible gardens of deep-sea corals off the coasts of North America, Great Britain, Europe, Scandinavia, Australia, and New Zealand. These corals survive without algal symbionts (because there is no light for photosynthesis) and may take a long time to grow. Thus the potential role of coral-associated microbes is even more interesting. It is possible that the microbes are helping to feed these corals, similar to the chemosynthetic bacterial symbionts that feed hydrothermal-vent worms. The microbial communities of these coldadapted corals are also likely to contain novel organisms, which will not only increase our understanding of microbial diversity but could also be a source of new enzymes or pharmaceuticals.

For more information, view Microbial Ecology of Deep-Sea Corals and the USGS DISCOVRE Expedition and contact Christina A. Kellogg, St. Petersburg Science Center.

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The great star coral (Montastraea cavernosa) with lesions caused by yellow blotch/band disease. Photo credit: USGS Image Gallery

Coral disease is now recognized as one of the major causes of reef degradation and coral death.  Although many coral diseases or syndromes are currently being monitored, few causative agents have been identified.  Moreover, these putative pathogens have not been consistently observed in all corals exhibiting signs of these diseases.  Further research has suggested that coral diseases may be secondary opportunistic infections, rather than the result of primary pathogens, making it imperative to understand the microbial shifts that occur from healthy to diseased corals.  This project will employ custom-designed microarrays to characterize several coral species on a microbial level.  Disease mechanisms will be studied by comparing the microbial profiles of healthy and diseased corals at two sites: Dry Tortugas National Park in the Gulf of Mexico, and Virgin Islands National Park in the Caribbean.  This will allow an unprecedented comparison of microbial communities between healthy and diseased corals, between species of coral, and between geographic locations.  Microarray data will provide a new baseline of information and may reveal previously unknown patterns underlying the diseased state.

Related Publication:

Kellogg, C.A., and Zawada, D.G., 2009, Applying new methods to diagnose coral diseases: U.S. Geological Survey Fact Sheet 2009-3113, 2 p. (Also available at https://pubs.usgs.gov/fs/2009/3113/.)

For more information contact Christina A. Kellogg, St. Petersburg Science Center.

See also Fish and Wildlife Disease: Corals >>

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