Objectives of GulfCet II



From the Executive Summary of the Proposal
March 1996


The Texas Institute of Oceanography (TIO) within the Texas A&M University System (TAMUS) welcomes the opportunity to respond to the National Biological Service's (NBS) Request for Proposal (RFP) No. 1445-ORFP-95-005 entitled "Distribution and Abundance of Marine Mammals in the Northern Gulf of Mexico". We have assembled a scientific team with extensive experience and expertise for this study, hereinafter called "The GulfCet II Program" that will provide NBS with a high quality technical program at a competitive cost.

TIO has incorporated the extensive expertise in marine mammal biology, bioacoustics, and oceanography from the TAMUS units: Texas A&M University at Galveston and the Department of Oceanography. Externally, we have teamed with partners from the National Marine Fisheries Service (NMFS) at the Southeast Fisheries Science Center for their expertise and experience in aerial and shipboard surveys of marine mammals. Our team also includes a statistician from the National Biological Service's Wisconsin Cooperative Wildlife Research Unit at the University of Wisconsin at Madison and a scientist from the Center for Astrodynamic Research at the University of Colorado who has been modeling the Loop Current and eddies of the Gulf of Mexico using satellite altimetry. The program proposed herein is a logical extension of the long-standing and on-going studies of marine mammals in the Gulf of Mexico and throughout the world conducted by scientists at Texas A&M University and the National Marine Fisheries Service.

The senior personnel to bring this integrated program together are some of the most respected researchers in their fields. Overall program management is supplied by Dr. Randall Davis, a well-known physiological ecologist in marine mammalogy who was the program manager for the successful GulfCet I Program. He is aided by Dr. Gerald Scott, program manager for the NMFS part of the study, and by Dr. William Evans, deputy program manager. Dr. Scott has special expertise in survey design and interpretation, and Dr. Evans is a well-known marine mammal bioacoustician who has published extensively on the vocalizations, hearing, habitat use, and behavior of whales, dolphins, and porpoises. Dr. Doug Biggs, data manager, has a strong background in biological oceanography and in remote sensing of upwelling regimes. He is uniquely positioned to interface oceanographic data with distribution and behavioral information. Other key personnel will be mentioned in the following descriptions of eight main tasks that comprise this program.

The purpose of the GulfCet II program is to conduct studies on cetaceans at sea in the northern Gulf of Mexico to determine the seasonal and geographic distribution of cetaceans and to characterize their habitat in areas potentially affected by oil and gas activities now or in the future. This program will include systematic aerial overflights and shipboard surveys to document cetacean and sea turtle populations. This work will be accompanied by physical and biological oceanographic data acquisition designed to further characterize habitats and reveal cetacean-habitat associations. The work is intended as an areal and temporal extension of the GulfCet I Program.

The specific objectives of the study are to:

1. Obtain data on patterns of distribution and minimum abundance of offshore cetaceans using line-transect survey techniques. The data will include incidental recordings of sea turtles and birds.

2. Identify possible associations between cetacean high-use habitats and the ocean environment, and attempt to explain any relationships which appear to be important to cetacean distributions.

An important goal of this program is to determine which cetacean species may potentially be affected by present and future oil and gas activities based on analyses of seasonal and geographic distribution of each species, as well as interpretation of behavioral information collected during this study and from previous surveys. Evaluation will result in the determination of which species could potentially be affected, estimation of the proportion of the population this would represent, geographic and temporal degree of effect, and effect on critical activities (i.e., breeding, feeding, and mating areas).

The study area will include the entire continental slope of the northern Gulf of Mexico (e.g., the continental slope north of 26 degrees N latitude) between the 100- and 2,000-m isobaths. We will conduct synoptic shipboard surveys of the entire study area using line-transects methods. We will focus additional shipboard and aerial survey effort on the Eastern Planning Area, which was not included in the GulfCet I program and for which there is little information on cetacean abundance and distribution. Finally, we will conduct focal shipboard studies (i.e., south of the Mississippi River delta and along the edge of eddies) in order to better understand the effect of oceanographic features on cetacean distribution.

To accomplish this program, seven Tasks have been identified.

Task 1 consists of acquiring a permit to conduct the shipboard surveys. This will be a Marine Mammal Permit from the Office of Protected Species and Habitat Programs of NMFS, to survey and observe marine mammals. The permit will be applied for within one month of contract award by the program manager, Dr. Davis. He is thoroughly familiar with the requirements and protocols of permit application and has had many previous marine mammal research permits.

Task 2 consists of a training program for field observers in order to standardize techniques of marine mammal identification and data collection. This task, to be coordinated by TAMU and NMFS personnel, is important to insure quality and consistency of data, and to reduce interobserver variability as much as possible. The task will be led by Drs. Bernd Würsig, Jeff Norris and Keith Mullin, who have studied Gulf of Mexico marine mammals for many years.

Task 3 forms the major field portion of the program. It consists of a series of: 1) seasonal aerial surveys and simultaneous shipboard visual and acoustic surveys using line-transect techniques to determine minimum abundance and distribution of cetaceans; 2) estimates of the distribution and density of nekton (especially organisms in the deep scattering layer) using sonar and net tows, and hydrographic and remote sensing data acquisition to characterize habitat and the association of cetaceans with prey availability and physical oceanographic features; and 3) aerial and shipboard behavioral observations to determine cetacean response to the survey platform. These research activities will be accomplished by a multi-disciplinary team of scientists from Texas A&M University (Drs. Biggs, Davis, Evans, Norris, Wormuth, and Würsig), the NMFS (Drs. Scott, Mullin, and Blaylock), the National Biological Service (Dr. Ribic) and the Center for Astrodynamic Research in Colorado (Dr. Leben).

The final four tasks of the program are designed for oversight and quality control (Task 4, Scientific Review Board), data processing (Task 5), data integration (Task 6), and the protocols and types of data reporting (Task 7). Particular investigators will be in charge of data processing and integration, and the Program Manager will oversee and take final responsibility for reporting. However, all principal investigators are dedicated to ensuring that data are analyzed and presented in a fashion that will enable the integration of visual survey data, acoustic survey data, behavioral information, and oceanographic characterizations. The ultimate goal of this program is to improve the ability of NBS/MMS to assess the effects of oil and gas exploration and production on the distribution, abundance, behavior, and habitat of marine mammals in the northern Gulf of Mexico.