Deepwater Program: Exploration and Research of Northern Gulf of Mexico Deepwater Natural and Artificial Hard Bottom Habitats with Emphasis on Coral Communities: Reefs, Rigs and Wrecks

The objectives of this study are:

1. Discover and describe new locations at greater than 300m depth in the GoM with extensive coral community development, particularly including Lophelia pertusa.
2. Gain a more comprehensive understanding of the fundamental processes that control the occurrence and distribution of Lophelia and other extensive coral communities at depths greater than 300 m in the GoM through both laboratory experiments and field data collection.
3. Document and understand the relations between coral communities on artificial and natural substrates with respect to community composition and function, phylogeographic and population genetics, and growth rates of the key cnidarian foundation fauna.

Our specific biological objectives:

1. To discover and characterize new sites:
2. Characterize key sites at the largest scale with high resolution bathymetry, side scan sonar imaging, 3D seismic data, and current models
3. Characterize the coral density at all study sites at the 10 to 100 m scale with randomized photo transects and general site descriptions.
4. Characterize the community composition at the 1 to 10 m scale at significant coral sites (man-made and natural) with analysis of close up imagery, replicate 5x5m photomosaics, and quantitative community collections.
5. Analyze connectivity among all sites in the GoM (man-made and natural), and to other sampled populations, with comparative community, phylogeographic and population genetic analyses.
6. Compare the structure, species richness and diversity of communities tightly associated with Lophelia on man-made structures and from natural sites in the GoM
7. Experimentally determine the tolerance and growth response of Lophelia to temperature, pH/alkalinity, dissolved oxygen and electrical current.
8. Characterize and constrain growth rates of key species of colonial cnidarians (pioneer colonies) using analyses of images of the largest colonies on man-made structures of known age.
9. Characterize key variables at sites with the most significant communities of coral colony development over one year by monitoring temperature, currents, larval seasonal distribution and sediment quality and quantity at 2-4 sites between 2009 and 2010.

By integrating this information, we will develop a predictive model to examine the potential occurrence of significant assemblages of L. pertusa or other cnidarians at unexplored sites and artificial reefs in the deep GoM.

  Historic Shipwreck Component

The proposed study will be multidisciplinary in scope.  It will focus on the archaeological and biological aspects of up to six shipwrecks in the north-central portion of the GoM.  Water depths at the designated investigation sites range from 554m to 2,286m.  Each shipwreck will be investigated to determine identity, site boundaries, National Register eligibility, preservation state and stability, associated biological communities, and an artificial reef effect on meiofauna and/or mobile fish communities.

Our specific archaeological objectives:

1) To record each vessel through detailed imagery to establish its type, date of construction, and positive identification if possible.
2) To establish nationality, ownership (past and present), use history, cause of loss, mission and cargo at time of loss through fieldwork and historical research.
3) To determine the extent and condition of the artifact assemblage on each vessel and the presence of diagnostic artifacts.
4) To determine potential eligibility to the National Register of Historic Places through archival research and the analysis of imagery and to prepare a National Register nomination form for potentially eligible vessels.
5) To assess impacts of biofouling communities to these shipwrecks to determine the stability of these sites and rate of deterioration.

Our specific bacteriological objectives:

1) Determine the rates of deterioration of test coupons placed on platforms and sited on specific shipwrecks that have already been visited and were installed on previous expeditions to those sites of interest. Determination may take the form of passive observations of the coupon condition within the platform of interest. If significant deterioration rates have already occurred then the platform may be recovered for on-ship and in-laboratory investigations.
2) Fresh test platforms may be deployed to either replace recovered platforms or to determination the deterioration rate at a fresh site of archeological significance.
3) Examine recovered natural samples from deteriorating sites and localized waters that may contain active bacterial communities traditionally associated with corrosive or bio-concretious growths.
4) On selected recovered test coupons conduct such experiments as would allow a more precise projection of the rates of deterioration of test material through the rates of pitting (in the event of mild steel) to losses in physical composition (in the event of cloths and wood.
5) Recovered bacteriological communities from the sites of interest will be subjected to laboratory analysis to determine major bacterial communities, degrees of activity (using the ATP methodology), and identification of community structures by fatty acid methyl ester analysis (MIDI/BART technologies).

Acting under acts of Congress, BOEM serves as a prudent manager of the nation’s seafloor mineral resources.  That management role requires development of critical energy resources without unacceptable impact on other ocean users, the natural environment, and the human environment.  The primary strategy that BOEM employs to eliminate or minimize environmental impact is to identify sensitive habitat and then restrict or otherwise mitigate exploration, development, and production activity.  Typically, reefs, other live bottoms, critical fish habitats, etc. are classed as sensitive on the basis of accumulated prior knowledge and directed BOEM studies.  The vast areas of seemingly homogenous soft bottoms are classed as insensitive.  Even in the case of such insensitive areas, BOEM and EPA regulations seek to limit the area and degree of impact.

Increased oil and gas activity beyond the shelf break and US recognition of the 200 m EEZ greatly increased BOEM’s environmental coverage.  Faced with a very poorly studied and remote environment, BOEM supported a series of deep surveys (Carney, 2001) along the Atlantic and GoM continental margins in the 1980’s.  These studies confirmed the existence of vast soft sediment habitats, but also recognized previously known live bottoms, and found unexpected chemosynthetic communities.  Both deep live bottoms and chemosynthetic communities can be classed as sensitive habitats.  It can be noted that the core participants in the propose work participated in these previous surveys in many ways.

The results of BOEM’s first study of upper slope chemosynthetic communities, Chemosynthetic Ecosystems Study (BOEM Report 95-2001) began the trend continuing to this day of submersible-based investigation in a mixed exploration and detailed-study mode.  A second study, Stability and Change in Gulf of Mexico Chemosynthetic