The Digital High Resolution Acoustic Data for Improved Benthic Habitat/GeohazardsEvaluation study is focused on developing a better understanding of seafloor geology of the Gulfof Mexico continental slope in order to increase our predictability of geohazards andchemosynthetic communities, particularly in areas of hydrocarbon seepage-venting. Those arethe areas that are commonly accompanied by acoustic wipe-out zones in high resolution acousticdata sets. This report is a summary of research sponsored by the U.S. Department of InteriorMinerals Management Service (MMS), Gulf of Mexico Region OCS...

Previously, a two-dimensional depth-integrated hydrodynamic model was developed and flushing characteristics of Terrebonne/ Timbalier Basin and Bartaria Basin were examined using the hydrodynamic model forced by observed winds and tides. Since the previous study addressed only the combined impact of the wind and tidal forcings on the flushing and dispersion characteristics of those estuaries, relative impact of wind forcing versus that of tides needs to be examined.

The northwestern rim of the Gulf of Mexico is characterized by a broad, shallow self dominated by North American continental drainage, including The Mississippi/Atchafalaya River outflow produces buoyant, turbid plumes along the Louisiana coastline. This river system typical has a peak discharge during spring excess of 30,000 m/sec and a low in autum of about 10,000 m/sec.

The Coastal Marine Institute (CMI) at Louisiana State University was established for an initial six years (1992-1998) as a cooperative agreement between the State and the Minerals Management Service of the U.S. Department of the Interior. The basic intent of CMI was to direct the considerable research talents of a major research university towards Federal and State information needs in a State where Outer Continental Shelf development of the oil and gas industry is a major factor. Funding for all projects undertaken has been equally divided between MMS and Louisiana resources.

Because of their ability to remotely measure current velocity in the water column over a vertical range from a few meters to hundreds of meters, acoustic Doppler current profiles have become increasingly important constituents of physical oceanographic research since their development in the mid-1980s. Developed from the Doppler speed log that estimated ship speed at the surface relative to speed over the ocean bottom, the ADCP was engineered to measure current speed and direction at multiple depths throughout the water column.

The Gulf of Mexico, Sunbathing on sandy beaches, swimming and surfing, deepsea fishing, red snapper, reefs and oil platforms, SCUBA diving shrimp dinners. These are a few of the word associations and mental images that come to mind with the mention of this natural resource. Many are aware that this Habitat supports the Nation's most valuable commercial and recreational fisheries, as well as provides nearly 95 percent of the Nation's total offshore petroleum .

The Gulf of Mexico yields about 40 % of the commercial fish landings in the United States and supports 33 % of the countrys recreational fishery's. The region also possesses the vast majority of the nations coastal wetlands. Louisiana alone has over 3.8 million acres, but these areas are disappearing at an alarming rate.

Oil and gas exploration and production activities in the marine environment produce and release large quantities of organic, hydrophobic compounds and heavy metals. Unfortunately, the effects of these toxicant's and their casual linkages with bethic and pelagic biota are difficult to identify and are frequently poorly understood

Based on previous studies and new geophysical reconnaissance, nine sites in the Mississippi/ Alabama " pinnacle trend" area were selected for monitoring. Hard bottom community structure and dynamics were monitored because the potential sensitivity of these communities to OCS oil and gas industry activities is of interest to the Minerals Management Service, The client agency for which the USGS administered this program.

The Bureau's responsibility for managing and administering congressionally designated trails dates back to the passage of the National Trails System Act in 1968, which included the designation of Pacific Crest National Scenic Trail. This trail exists, in part, on BLM-managed land. In 1976, the Federal Land Policy and Management Act referenced the National Trails System, reaffirming BLM's involvement with these trails