Marine mammals have not only fascinated and inspired human beings for thousands of years, but they also support a big business by providing flesh for sea-borne factories, sustaining Arctic lifestyles and traditions, and attracting tourists to ocean aquaria. While they are being harpooned, bludgeoned, shot, netted, and trained to jump through hoops, their habitats are being destroyed, their food supplies depleted, their waters polluted, and their breeding grounds invaded. Therefore, many species have or are becoming extinct. To prevent further extinctions, urgent action is needed. A common ground must be found that unites those for whom marine mammals are a source of pleasure and those for whom they are a business. This common ground must then be used as a basis for an effective global program of protection and management of marine mammal populations. This booklet attempts to identify that common ground, in order to promote quick and effective action to save the remaining marine mammals. It describes the wide variety of marine mammals, their characteristics and habitats, categories of fate (endangered, vulnerable, rare, and indeterminate), why certain species are becoming extinct, regulation of the whaling industry, uses (such as manatees clearing navigation channels of vegetation), economic factors, and other relevant topics. (JN)