This is a two year cooperative research project proposed by Dr. Gerald Kooyman, University of California at San Diego, and Ms. Moonyeen Nida Ramos Alava, Silliman University, the Philippines. This proposal is to conduct a study of population biology, ecology, and behavior of cetaceans (including dolphins) in the Philippines. The project requests funds to support the P.I. and a Ph.D. student to carry out a study in the Sulu Sea, the Philippines, to estimate the abundance of marine mammals and to understand the relationship between abundance and habitat types. They will also study feeding habits, and the behavior and social structure of cetacean species. Dr. Kooyman is a specialist in this area and has an outstanding record of research and publication. His Ph.D. student, Ms. Louella Dolar, has an in-depth understanding of the Sulu Sea ecosystem. This is an important area of marine biology. There is little or no available information on the cetacean species in Sulu Sea. This project will make a relatively large contribution to our state of knowledge on this species and can provide useful data on the conservation of this species. Furthermore, this project is leveraged dollar- for-dollar with funds from International Foundation for Science, Department of Environment and Natural Resources of the Philippines, and U.S. National Marine Fisheries Service. The relatively modest support from the National Science Foundation can yield large potential benefits.