The field of marine mammal science has made enormous strides in the last ten years as well as attracting a large amount of interest, due no doubt to the public appeal of whales, dolphins, and seals, which are never out of media attention. The purpose of this book is to review key topics through chapters on the major disciplines from invited authorities around the world. Subjects covered include evolution and genetics, life histories, ecology, physiology, behaviour, medicine (diseases, parasitology), survey methodology, and all the main conservation issues (pollution, fisheries interactions, and sound disturbance). The book has an ecological and conservation emphasis since these are subject areas calling for the most attention in the modern world, but other areas such as evolution, physiology, and medicine are also given in-depth treatment. The book is written at the level of the undergraduate or above, although its style should appeal to anyone with a serious interest in marine mammal science.