Our Indo-Pacific Manta Migration Study Program is designed to provide new population data to further our knowledge of habitats and migration patterns. Planning has already begun to study manta populations and migratory behavior. The Manta Network intends to organize and lead expeditions ultimately to all the ten target research areas. Photo identification, satellite tagging, and DNA tissue sampling will yield the answers to many of the migration questions.

Before protection and conservation programs can be created, several critical questions must be answered including understanding habitat preferences, extent of home range, migratory rates and routes, and seasonal changes in abundance and distribution. Although we have some knowledge about movements of a few local manta populations (Kona, Yap and Archipelago de Revillagigedo), we know nothing about long distance migratory behavior. This three-year study will sponsor and coordinate four teams of scientists. It will employ local dive operators in ten locations in the Pacific and Indian Oceans. A combination of short-term and long-term studies will be initiated. Baseline information will be assembled at each sampling site including visual surveys, photo identification, fisheries surveys, and an examination of local environmental parameters. Establishing the large-scale movements is critical to the development of any conservation, management plan. Recent technological advances in satellite telemetry make possible the use of relatively small satellite tags to examine large-scale movements over a relatively short period of time. These small devices are secured to the animal using a harmless dart. While the tag is secured to the manta, it records temperature, depth, and light level data. From temperature and depth we can examine habitat preferences and behavior. From relative changes in light levels it is possible to estimate latitude and longitude for movements over a nine month period of active data collection. At a predetermined time, the tag releases from the animal, floats to the surface and uplinks its data to the polar orbiting Argos satellites. The data is then transmitted back to the scientist via email. The four two to three people teams will work with the site location's local sponsor to perform the sampling. Due to the high cost of travel, equipment and boat time for the locations across the Pacific and Indian Oceans, the project intends to obtain as much information at each site about the local manta population as possible. In addition to assembling all available historic and present-day information about each site, field researchers will be prepared and trained to create a comprehensive and consistent record of each sampling site.

In addition to the satellite telemetry work, activities at each site will include visual surveys, photo identification, and DNA tissue sampling. Photographic and video documentation of the field work will be performed, as well as interviews with locals and government conservation officials. The teams will be trained on all aspects of requirements and techniques for the field collection. DNA analysis can be used to infer population structure and levels of connectivity between regions, providing an important complement to satellite telemetry. The mitochondrial and nuclear DNA sequences from mantas in different regions around the Pacific and Indian Oceans will be examined for evidence of divergence and phylogenetic relatedness. Tim Clark at the University of Hawaii is conducting a large genetic survey of the mantas in the Pacific and will conduct genetic analysis. He already has an extensive DNA sequence library and a collection of samples from around the globe that will prove invaluable in this study. Samples can be collected from free-swimming mantas using a modified biopsy needle that is secured to the end of a pole spear. Additional tissue samples either targeted or caught incidentally in the area may be obtained from fisheries. Due to the high cost of each satellite tag and its uplink service, only a few tags can be deployed at each site. Approximately 50 satellite tracking devices will be deployed and monitored across 10 sampling locations. Sampling will occur within an 18-month time frame. As each satellite tag retains up to nine months of data, it is important to deploy all within the shortest period of time. The availability of manta populations, ocean conditions, boat operators, and team schedules will dictate the actual order of deployment. The goal is to begin to release the first tag in October 2004 and the final tag no later than March 2006.