This article describes and analyzes the impact of mangrove protection/conservation policies regarding the Alvarado Lagoon System (ALS), in the Gulf Coast of Mexico, specifically the Costa de San Juan ejido, in the municipality of Alvarado, Veracruz. The paper focuses on how the State, with its laws and government programs, generates differentiated changes in the perception and management of the mangrove, and the territorial organization of the ejido. Therefore, we discuss the creation of local environmental subjects in the context of implementing a Wildlife Management Unit as part of the conservation policies of the Mexican State.