This article seeks to show how the State was delimiting and prohibiting some artisanal fishing practices in the early twentieth century, in order to protect marine resources under rational principles and conservationism for the benefit of the national treasury, changing the logic of common property and freedom fishing. Thus, this article states that after the enactment of the Fisheries Act of 1907 in Chile, both a process of fiscal appropriation and enclosure of coastal and marine common spaces and goods was initiated, as well as a process of State intervention in practices of artisanal fishers, especially in what, how and when to fish. This intervention radically changed the practices of artisanal fishing and the relationship between man and the sea during the first decades of the 20th century.