USGS DISCOVRE: Benthic Ecology, Trophodynamics, and Ecosystem Connectivity – Lophelia II: Continuing Ecological Research on Deep-Sea Corals and Deep Reef Habitats in the Gulf of Mexico

Science Center Objects

Deep-sea coral habitats are complex ecosystems at the landscape and local level. While these systems may harbor substantial levels of biodiversity, they remain inadequately investigated.

Lophelia pertusa coral
Lophelia pertusa coral

The Science Issue and Relevance: Deep-sea coral habitats are complex ecosystems at the landscape and local level. While these systems may harbor substantial levels of biodiversity, they remain inadequately investigated. Deep coral ecosystems are of interest because the corals are long-lived and are likely vulnerable to human activities including bottom trawling, anchoring, pollution, and offshore oil and gas development. Deep corals are reliant on benthic-pelagic coupling for their food supply and contain complex food webs encompassing multiple trophic levels. However, detailed understanding of deep-sea coral food webs is in its infancy. It is critical to understand the nature and periodicity of particle flux and the degree of trophic interactions of deep-sea coral communities in order to evaluate ecosystem controls on abundance, biodiversity, and community function. The USGS has a long-term commitment to assist BOEM in their concern for preserving and protecting sensitive deep-sea ecosystems as the need for oil, gas, and alternative energy exploration increases in the northern Gulf of Mexico. This research will enhance understanding of the structure and function of significant biological communities and help BOEM define and delineate critical habitats in the OCS.

Diverse deep sea coral species
Diverse deep-sea coral species

Methodology for Addressing the Issue: Deep coral habitats have been sampled in from 2009-2015. Sampling areas in deep-sea coral habitats ranged from the central GOM through the West Florida Slope (300-2000 m). In situ, quantitative samples of Lophelia meio- and macrobenthic (< 1 mm) communities and their environment were collected using an ROV and surface deployed push cores. Food webs were examined using stable isotopes of collected fauna and their potential food sources, including surface sediments, sediment traps, and filtered seawater.    

Future Steps: Data collected on these cruises currently are being processed and analyzed to determine the importance of deep coral habitats to local and regional benthic abundance and biodiversity, and the trophodynamics of these systems. Our results will provide a useful baseline dataset for our current research. Our understanding of deep-coral communities in the Gulf of Mexico will allow us to compare them to similar hard habitats in the Mid-Atlantic region.

Related Project(s): Benthic Ecology, Trophodynamics, Ecosystem Connectivity of Mid-Atlantic Deepwater Hard Bottom Habitats with Emphasis on Canyon and Coral Communities

Additional Publications:

Cordes, E.E., Berlet, S.P., Cardman, Z., Dannenberg, R., Demopoulos, A.W.J., Georgian, S.E., King, C., McKean, D.L., and Young, D.M., 2014, Exploring deep-sea coral communities and the effects of oil and gas inputs to the Gulf of Mexico: Oceanography, v. 27(supplement), no. 1, p. 34-35, doi:10.5670/oceanog.2014.supplement.01.

Morrison, C.L., Baco, A.R., Nizinski, M.S., Coykendall, D.K., Demopoulos, A.W.J., Cho, W., and Shank, T.M., 2014, Population connectivity of deep-sea corals, in Hourigan, T.F., and Etnoyer, P., eds., The State of Deep Coral Ecosystems of the United States: Silver Spring, Md., NOAA Technical Memorandum, In Press, IP-051873