The contributions in this volume represent some of the work that has been (or is being) carried out on cetaceans in the Indian Ocean. The limitations of the research documented will be apparent. We believe, however, that they do provide a useful background to any plans to increase and direct research on cetaceans within the Indian Ocean. From the review papers it is clear that the Indian Ocean is home to a tremendous variety and abundance of marine mammals. From research reports it is clear that there are numerous opportunities for meaningful research.