Environmental assessment of a low-energy marine geophysical survey by the US Geological Survey in the northwestern Gulf of Mexico, April-May 2013 Marine geophysical survey by the US Geological Survey in the northwestern Gulf of Mexico, April-May 2013 Environmental assessment for USGS northwest Gulf of Mexico, 2013 Environmental assessment and determination pursuant to the National Environmental Policy Act, 42 U.S.C. 4321, et seq. and Executive Order 12114 low energy marine seismic survey by the U.S. Geological Survey in the deepwater Gulf of Mexico, April-May 2013

"The U.S. Geological Survey (USGS) plans to conduct a low-energy seismic survey onboard the oceanographic research vessel R/V Pelican, owned by the Louisiana Universities Marine Consortium, or aboard a similar vessel in the northwestern Gulf of Mexico during 17 April-4 May 2013. The survey will take place in the U.S. Exclusive Economic Zone (EEZ) in water depths 1500-2000 m. The seismic study will be conducted from the R/V Pelican with a towed pair of GI airguns, each with a discharge volume of 105 in³. There will be ~8 days of airgun operations during this survey. The purpose of the seismic survey is to develop technology and to collect data to assist the USGS in the characterization of naturally-occurring marine gas hydrates and to better understand the potential of gas hydrates as an energy source and their impact on seafloor stability. The USGS is requesting an Incidental Harassment Authorization (IHA) from the U.S. National Marine Fisheries Service (NMFS) to authorize the incidental, i.e., not intentional, harassment of small numbers of marine mammals should this occur during the seismic survey. The information in this Environmental Assessment (EA) supports the IHA application process and provides information on marine species that are not addressed by the IHA application, including seabirds and sea turtles that are listed under the U.S. Endangered Species Act (ESA) including candidate species, fish, and Essential Fish Habitat (EFH). The EA addresses the requirements of the National Environmental Policy Act (NEPA). Alternatives addressed in this EA consist of a corresponding program at a different time, along with issuance of an associated IHA; and the no action alternative, with no IHA and no seismic survey. This EA is tiered to, and incorporates by reference, material from the Final Programmatic Environmental Impact Statement/Overseas Environmental Impact Statement for Marine Seismic Research Funded by the National Science Foundation or Conducted by the U.S. Geological Survey (NSF and USGS 2011), for which the USGS Record of Decision was executed in February 2013 (USGS 2013)"--Abstract (page iv).