Due to multiple threats, seahorses, data-poor and threatened fish, demand urgent conservation actions. Successful long-term conservation relies on strategic planning for pragmatic actions to mitigate threats. In Brazil, the three seahorse species are considered vulnerable. The Rio Formoso Estuary (RFE) exemplifies these challenges, with local pressures—particularly from expanding tourism and intensified nautical traffic—posing a threat to seahorse populations. This estuary represents a complex social-ecological system, characterized by remarkable biodiversity and a multitude of human activities, including tourism, artisanal fishing, and shellfish collection. Evidence shows that populations are decreasing, however, there is no systematic management plan for the species, urging for pragmatic actions. In my first grant, we established that mangroves, vulnerable ecosystems, play a pivotal role in influencing seahorse presence and abundance in the RFE. To effectively plan for the conservation of these critical environments, frameworks integrating social-ecological systems are essential, recognizing the interconnectedness between humans and the natural world and adapting management approaches accordingly. We employed participatory mapping and interviews with artisanal fishers to gather insights about seahorses, their threats, and local community priorities. Combining this valuable local knowledge with existing data we identified the main threats to seahorse in the RFE, and some place-based actions that the local community pointed out as necessary to protect seahorses. Additionally, we identified the priority sites for threat management. These findings provide essential insights and a spatial framework for seahorse conservation in the RFE.