Rio Guaratuba is a stream flowing through the coastal zone of Paraná, Brazil, draining toward the Baía de Guaratuba and its surrounding estuarine environment. The river moves through a landscape shaped by the Atlantic Forest biome, with its lower reaches influenced by tidal exchange and brackish conditions that attract a diverse mix of coastal and estuarine fish species. This blend of freshwater inflow and marine influence makes the Rio Guaratuba a productive and ecologically rich fishery, particularly for anglers targeting species that thrive in transitional coastal habitats.