Lontra felina is an Endangered mustelid that lives in the exposed rocky shores of Peru, Chile and Argentina. Principal’s threats this species are habitat destruction and illegal hunting. Available information about marine otter is not sufficient to allow appropriate take action to support the conservation of the species. This research, which involves an innovative, easy and effective methodical study, will contribute to the knowledge base of marine otters by means of analysing their population density and distribution in unexplored areas of southern Chile. This information will assist scientists and government agencies to determine the real status of otter and to establish relevant conservation areas.