The Deepwater Program: Northern Gulf of Mexico Continental Slope Habitat and Benthic Ecology - DgoMB: Meios

A research program has been initiated by the Minerals Management Service (Contract No. 1435-01-99-CT-30991) to gain better knowledge of the benthic communities of the deep Gulf of Mexico entitled “The Deepwater Program: Northern Gulf of Mexico Continental Slope Habitat and Benthic Ecology.”

Increasing exploration and exploitation of fossil hydrocarbon resources in the deep-sea prompted the Minerals Management Service of the U.S. Department of the Interior to support an investigation of the structure and function of the assemblages of organisms that live in association with the sea floor in the deep-sea. The program, Deep Gulf of Mexico Benthos or DGoMB, is studying the northern Gulf of Mexico (GOM) continental slope from water depths of 300 meters on the upper continental slope out to greater than 3,000 meters water depth seaward of the base of the Sigsbee and Florida Escarpments. The study is focused on areas that are the most likely targets of future resource exploration and exploitation. However, to develop a Gulf-wide perspective of deep-sea communities, sampling in areas beyond those thought to be potential areas for exploration has been included in the study design. A major enhancement in the program is the extension of the transects onto the abyssal plain of the central Gulf of Mexico through collaborative studies with Mexican scientists. This additional work effort will allow assessment of benthic communities structure and function throughout the basin by sampling the deepest habitats in the region.

The program is designed to gain a better ability to predict variations in the structure and function of animal assemblages in relation to water depth, geographic location, time and overlying water mass. Biological studies are integrated with measurements of physical and chemical hydrographic parameters, sediment geochemical properties and geological characteristics that are known to influence benthic community distributions and dynamics. Eight (8) hypotheses are being tested on the basis of measures of benthic community structure. It is hypothesized that community structure varies as a function of: 1) water depth, 2) geographic location (east vs. west), 3) association with canyons, 4) association with mid-slope basins, 5) sea surface primary productivity, 6) proximity to hydrocarbon seeps, 7) time (seasonal and interannual scales), and 8) association with the base of escarpments.

This dataset includes the meiofauna abundance and biomass that were observed in this study. Meiofauna include nematode worms, harpacticoid copepods, and several other taxa. In some studies benthic forams are also included, but in this model, forams are considered part of the microbiota because they are single-celled organisms, rather than metazoans.