Rio Bacanga flows through the urban landscape of São Luís, the capital of Maranhão state in northeastern Brazil. The river drains into Bacanga Lagoon, a brackish estuarine environment where freshwater and saltwater mix, creating a dynamic and ecologically complex system. This estuarine character means salinity levels vary considerably between sampling sites throughout the basin, influencing which fish species are present and how they behave at different points along the river and lagoon. The Bacanga basin sits within a heavily urbanized setting, which shapes both the fishing experience and the ecological conditions anglers will encounter.