The enunciation 'other-than-humans' is problematized around the implementation of the Lafkenche law (law 20.249) and the production of favorable and unfavorable narratives for the implementation of Coastal and Marine Spaces of Indigenous Peoples (ECMPO). Based on post-humanist approaches and the ontological turn in anthropology, this article explores theoretically the ontological manifestations of the relation of human and ‘other-than-humans’ in the implementation of the Law: on the one hand, Indigenous Peoples who affirm an equitable and affective relationship between the both worlds; and on the other hand, the position of other territorial actors involved in the process, who impose narratives that instrumentalize and fragment this relationship. The disagreement of these ontologies is the basis of misunderstandings and tensions in the implementation of the Lafkenche Law, and often defines the future of the ECMPO and the adhesion or rejection of this public policy.