TDI-Brooks Finalizes Report for Deepwater Atlantic Habitats II

TDI-Brooks International completed the final report for Contract M17PC00009, issued by the U.S. Department of the Interior, Bureau of Ocean Energy Management [BOEM]), titled “Deepwater Atlantic Habitats II: Continued Atlantic Research and Exploration in Deepwater Ecosystems with Focus on Coral, Canyon and Seep Communities.” This report is the final deliverable of the BOEM contract called Deep SEARCH, conducted in partnership with the U.S. Geological Survey. Initially, the study was a five-year, collaborative scientific research program focused on the outer continental shelf between Virginia and Georgia. 

The COVID crisis extended the program for another 18+ months. The region’s deep-sea coral, cold-seep and canyon communities as habitats of focus were surveyed. The overarching goal was to improve understanding of the functional role of these three habitat types in order to advance scientific knowledge and inform future management decisions. The intended application of the new science was to develop better predictive capacities for the community types encountered.

The sites were studied during five directly supported cruises, with detailed site descriptions of the geological, physical, chemical and biological conditions encountered. The results from six additional cruises conducted through collaboration with the ADEON project and NOAA-OER also contributed to the Deep SEARCH database  The research results, analyses and findings include the oceanographic, geological and geochemical setting of canyons, seeps and coral environments, deep-sea soundscapes, community structure and trophic function from microbes to fishes, population connectivity, life history of selected species, habitat suitability modeling deep-sea corals and seeps and educational outreach to the public.  

• The newly named Richardson Reef Complex is now understood to be one of the largest cold-water coral reef complexes in the world. Furthermore, the Richardson Reef Complex is part of one of the largest coral mound provinces in the world, the Million Mounds, which extends from Richardson in the northeast and south across the entire Blake Plateau, and down along the Florida coast to the Jacksonville Mounds.  
• The seeps along the continental shelf edge, visited for the first time, are remarkable for their extremely high rates of methane release and oxidation. Their chemistry fuels biological productivity that appears to also support local pelagic communities.
• Pamlico Canyon was found to be home to a very high diversity coral assemblage, to have high overall diversity of infauna and to exhibit some of the highest densities of sediment infauna observed at this depth.
• Deep SEARCH data indicates high connectivity among all habitat and community types. For example, interactions between the diel vertical-migrating mid-water community and the benthic zone of the Richardson Reef Complex, as well as those of midwater organisms with the walls of the canyons and shallow seeps were seen.
• The unique oceanographic conditions in the region have a corresponding influence on the various communities. The Gulf Stream cuts through the center of the study area, causing vertical mixing in its core down to 1,000 m. This promotes a rapid translation of food to depth and nutrients to the surface, which brings elevated trophic and genetic connectivity of the components of the ecosystem. These currents are highly variable at the seabed, (apparently) inducing a high degree of adaptive resilience of the deep-sea corals of the region in response to rapidly changing environmental conditions.

Through this study, TDI-Brooks has filled major data gaps for poorly known deepwater ecosystems, aiding the refinement of regional management strategies. Our improved understanding of the habitats and communities in offshore areas of the Atlantic Large Marine Ecosystem augments the capacity to predict the distribution of sensitive areas concerning the potential development of energy and marine minerals managed by the Bureau of Ocean Energy Management.