Minerals Management Service Begins New Sperm Whale Seismic Study
(SWSS)

The U. S. Department of the Interior’s Minerals Management Service (MMS) announced the first results of a three-year study on sperm whales in the Gulf of Mexico to determine if offshore seismic surveys have effects on these endangered species. This first year of the Sperm Whale Seismic Study (SWSS) includes two research cruises. The first cruise was completed in July 2002 and the second cruise departed on August 21^st for four-weeks of experiments using digital tags, which record received sound levels and underwater swimming behavior. There were also experiments with an industry-provided seismic vessel. This cruise ended September 15^th.

Gulf of Mexico Regional Director Chris Oynes praised the initial results that include the successful tagging of an exceptional number of whales, coupled with DNA samples and photo ID’s of the whales. "This research is a result of strong intergovernmental coordination between MMS, the Office of Naval Research, Texas A&M Research Foundation (TAMRF), and the International Association of Geophysical Contractors (IAGC). This coordinated research saves the American taxpayers’ dollars."

Past MMS-sponsored studies have shown that at least several hundred sperm whales live in northern Gulf waters and are most often sighted near 1000-meter water depths. As the offshore petroleum industry moves into deeper waters, the potential for interaction with sperm whales and other deep-water cetaceans increases.

The initial SWSS cruise, made on a Texas A&M University (TAMU) research vessel Gyre, left port last June 19th and returned July 9th. The main tasks of this cruise were:

• deploy satellite tags (S-tags)
• collect physical oceanographic data
• survey for sperm whales (by visual and acoustic means)
• perform biopsies for DNA samples
• photograph sperm whale flukes (photo-ID)
• record surface behavior

The cruise enjoyed considerable success. Eighteen tags were placed on sperm whales. DNA samples were obtained from 16 of the tagged whales along with photographs of their flukes (tails). Altogether, 49 high quality photo-ID images were obtained of 32 different sperm whales. Physical oceanographic sampling was of equal success. Five CTD sampling stations were completed; 42 XBT’s were dropped to profile temperatures in the upper 760 meters of the water column, including supplemental sampling in the upper 200 meters; and continuous sampling was made for ocean current velocity, surface temperature/salinity, and chlorophyll fluorescence. Sample photographs of activity as part of the research cruise are attached.

The second SWSS cruise employed the TAMU vessel and an IAGC sponsored vessel, the Rylan T., equipped with Fairfield Industries seismic airguns. Despite tropical depressions and many days of marginal weather, the cruise deployed nearly 20 digital tags (D-tags). The highlights of the cruise were testing the behavioral response and measuring received sound levels for D-tagged sperm whales exposed to controlled approaches by the Rylan T.

Ultimately, SWSS results will be used by MMS to potentially evaluate what effects seismic surveys may have on sperm whales, whether some areas of the Gulf represent preferred use locations for whales, and what actions would mitigate adverse effects on these whales. Initial results of these cruises will be presented at the MMS Information Transfer Meeting in New Orleans in January 2003 with a final report on all matters by TAMRF scheduled in early 2005.

Additional details are attached.

MMS is the federal agency in the U.S. Department of the Interior that manages the nation's oil, natural gas and other mineral resources on the outer continental shelf in federal offshore waters. The agency also collects, accounts for and disburses mineral revenues from federal and Indian leases. These revenues totaled nearly $10 billion in 2001 and more than $120 billion since the agency was created in 1982. Annually, nearly $1 billion from those revenues go into the Land and Water Conservation Fund for the acquisition and development of state and federal park and recreation lands

n June 2002, the MMS signed a Cooperative Agreement with the Texas A&M Research Foundation (TAMRF) to conduct the Sperm Whale Seismic Study, which includes major funding from the MMS with additional support from the Office of Naval Research (ONR) and the International Association of Geophysical Contractors (IAGC). TAMRF manages the program that includes an international group of researchers. Major components of the study include sperm whale behavior studies led by Dr. Jonathan Gordon (Ecologic/University of Saint Andrews, Scotland) and Dr. Nathalie Jaquet (Texas A&M University-Galveston); satellite tagging led by Dr. Bruce Mate (Oregon State University); physical oceanographic analyses headed by Drs. Doug Biggs, Ann Jochens, Matt Howard (Texas A&M University), and Bob Leben (University of Colorado); and DNA analyses conducted by Dan Engelhaupt (Durham University, UK). In addition to this comprehensive research approach, a unique aspect of the study will be the use of digital tags (D-tags), developed at Woods Hole Oceanographic Institute (WHOI) with ONR funding, which record received sound levels and underwater swimming behavior of sperm whales. The D-tag provides a new method to determine sperm whale behavioral responses to test sound sources or ongoing seismic surveys in the Gulf of Mexico. The WHOI D-tag team includes Drs. Peter Tyack, Mark Johnson, and Patrick Miller. Initial deployments of the D-tag on sperm whales in the Gulf of Mexico and Mediterranean Sea in the past two years have already provided amazing details on normal sperm whale diving behavior and vocalizations. SWSS will initiate the first controlled-exposure experiments using a seismic airgun source provided by the IAGC.

The "S-tag" cruise has placed long-term tags (9+months), provided through ONR support, that transmits the surfacing location of tagged sperm whales to a satellite. This information will then be correlated with additional satellite remote-sensing oceanographic data and locations of active seismic vessels and offshore platforms. In contrast, D-tags provide extremely detailed information on sperm whale underwater behavior for about 9hours. In theory, S-tags indicate any long-term, broad scale response (avoidance, attraction) to industry activities, while D-tags evaluate short-term responses. The integration of data from all SWSS activities also will provide an account of normal sperm whale behavior for Gulf animals, habitat use, seasonal activity/migration activity (if any), and social structure.

Two sperm whales "fluke-up" near the Texas A&M Research Vessel Gyre.

Photo by Jonathan Gordon for SWSS.

Sperm whale dives near deep-water industry platforms in Gulf of Mexico

Texas A&M Research Foundation management team for SWSS, Dr. Doug Biggs, Dr. Matt Howard, and Dr. Ann Jochens, with cruise plan chart for the June, 2002 "S-tag" cruise.

Photograph by Bill Lang for SWSS.