Northern Gulf of Mexico Continental Slope Habitats and Benthic Ecology Study

Numerous descriptive studies of the continental shelf are available. In contrast, the topography, geology, geophysics, currents, chemistry, and biota of the continental slope are somewhat less well known. An MMS-sponsored study, the Northern Gulf of Mexico Continental Slope Study (NGOMCS), concentrated on the geologic features, water masses, chemistry, and biologic communities of the northern Gulf from the 300-m isobath to abyssal depths. Largely as a result of that study, the Gulf of Mexico is regarded as a well-sampled and geographically well-defined deep-sea system. The relatively old (~14 years) NGOMCS investigations were designed and conducted without knowledge of chemosynthetic communities and seafloor geological processes, and without access to new technologies, methods, and instruments now available. MMS has also funded two multidisciplinary chemosynthetic communities' studies. The MMS awarded an ongoing study, "A Management Overview for Resource Development in Continental Slope Habitats", as a part of the Coastal Marine Institute (CMI). This study is reinvestigating the habitats and communities of the continental slope with a more modern understanding of its environmental (especially geological and geochemical) complexity. The oil and gas industry is moving into deeper and deeper water and in recent years, has leased tracts in depths greater than 3,000-m. This has placed archibenthal and deep pelagic communities within the range of any potentially adverse environmental effects. Over the past two decades, biological and geological investigations on the northern Gulf of Mexico continental slope have changed our thinking on the nature of deep-sea benthic biogeochemical processes and animal community structure. Discoveries of chemosynthetic communities and their potential for benthic primary productivity, a better understanding of deep geological processes and its resulting topographic and chemical complexity, and other revelations now suggest that the deep Gulf of Mexico is far more complex than previously believed and certainly more complex than many parts of the world ocean. This study, known informally as the "Deep GoM Benthos" study, or "DGoMB", is designed to test a series of working hypotheses based on the best available geochemical, physiographic, and oceanographic information for the Gulf.

The primary objective of this study is to gain a refined view and understanding of benthic communities and habitats on the Gulf of Mexico continental slope. The objective further includes efforts to elucidate several trophic and biogeochemical processes, to erect and quantify major pathways in an ecological model, and to test a number of working hypotheses made possible with modern data.