Gulf of Mexico Archaeological Information
Why are archaeological resources a consideration in oil and gas exploration and development?
The National Historic Preservation Act (NHPA) of 1966, as amended, is Federal legislation developed to ensure that our Nation's historical and archaeological properties are not lost through neglect or inadvertently damaged by activities permitted or funded by Federal agencies. Specifically, BOEM and BSEE, as Federal bureaus, are required under Section 106 of the Act to institute procedures to assure that Federal plans and programs contribute to the preservation and enhancement of non-federally owned sites, structures and objects of historical, architectural or archaeological significance.
Archaeological sites on the OCS are most likely to be either prehistoric Native American sites dating from the time at the end of the last Ice Age when sea levels were about 200 feet lower then they are today, or historic shipwrecks. Historic shipwrecks dating from as early as the 16th century A.D. and as recent as World War II have been discovered, largely through industry surveys, in all parts and in all water depths of the Gulf of Mexico. In order to comply with Section 106 of the NHPA, BOEM and BSEE requires that the oil and gas industry conduct surveys of the seafloor using remote-sensing instruments before they undertake any bottom disturbing activities. These instruments usually include a magnetometer, which detects ferrous metals, a sidescan sonar, which creates a picture of the seafloor using reflected sound waves, and a subbottom profiler, which detects variations in the sediment underlying the seafloor. The data collected by these instruments are reviewed by archaeologists, who write reports on their findings for submittal to BOEM or BSEE, as appropriate. The two agencies have agreed between themselves that BOEM will take the lead in ensuring compliance of both agencies with historic preservation regulations.
BOEM has specific guidelines contained in NTL 2005-G07 for conducting remote-sensing surveys and writing reports for archaeological sites on the OCS. Pending new guidance, this NTL only applies to specific areas defined as Archaeology Survey Blocks and the requirements differ depending upon whether the block has been determined to have a probability for historic shipwrecks, historic shipwrecks in deep water, or for submerged prehistoric sites. The most recent additions to the list of archaeological survey blocks are contained with NTL 2011-JOINT-G01.
As of March 2011, BOEM will require an assessment of the impacts of offshore oil and gas operations on a host of natural, biological, and cultural resources to ensure their protection. Bottom-disturbing operations such as well placement, anchoring, and pipelay activities can lead to damage to any resources that reside on the seabed, particularly archaeological resources such as historic shipwrecks. High-resolution surveys provide an effective tool analysts use to identify and help protect archaeological resources; however, such survey coverage was not always required and is often not available for all areas of the Gulf of Mexico. The lack of coverage has become especially problematic in deeper water where oil and gas activities are increasing and more shipwrecks are being identified.
To ensure adequate survey coverage is available for analyst review and to help with environmental reviews conducted for the agency's National Environmental Policy Act (NEPA) compliance, Pre-Seabed Disturbance Survey Mitigation was developed and may be imposed, as required, on industry activities. This new guidance document will augment NTL 2005-G07.
On occasion, the Gulf of Mexico Region needs more information about a particular remote-sensing target to determine if it is a significant archaeological site and will require the oil and gas industry to conduct an investigation by underwater archaeologists. These investigations involve the use of divers or remote operated vehicles (ROVs) and require that specific methodological guidelines are followed (see links below).
Archaeology Regulatory Links: