Marine protected areas (MPAs) are being created worldwide and are important tools for conservation and fisheries management. However, the impact of MPAs on artisanal fishing communities is still poorly understood. In this research, we sought to understand the perceptions of artisanal fishers living around the Arvoredo Biological Reserve, a no-take MPA located in southern Brazil, and their relationship with the MPA. The fishing communities in this study are located in Tijucas Bay, an estuary located within the buffer zone of this MPA but outside its boundaries. Data collection was conducted using interviews and participatory mapping with artisanal fishers. The results show that fishers have detailed knowledge about different species, the bay, and the connections between the bay and the MPA. The fishers noted that the proper functioning of the MPA relies on avoiding industrial fishing in its borders and to limit trawling within the bay. Such measures are already in the MPA management plan, but lack of compliance is a perceived constraint. Data also show that local ecological knowledge is important to support the monitoring and evaluation of MPAs. •The fishers perception compliances with the MPA scientific management plan.•The fishermen LEK is an important tool for monitoring and evaluating the MPA.•Detailed local knowledge about the species and the relation with the MPA.