This book offers a multidisciplinary approach to conservation issues related to the marine otter (Lontra felina). The main goal is the systematization of different research efforts on this species, to contribute with conservation policy design and implementation. The authors contribute their achievements in conservation, ecology, status in freshwater habitats, habitat fragmentation effects, interaction with human activities and recommendations for an effective conservation of the species. The book is directed first and foremost towards researchers and authorities and people involved in conservation tasks of otters. Despite in the last decades some studies and efforts on Lontra felina has carried in Peru and Chile, some information can be gathered to fill the gaps on marine otter conservation in Peru. That is the main goal of the book Conservation of Marine Otter. Moreover, the publication will be the first book published at international level on Lontra felina with the participation of several experimented researchers on this threatened and endemic species.