The Rio Tatuamunha is a coastal river in the northeastern Brazilian state of Alagoas, flowing entirely within the municipality of Porto de Pedras on the north coast. It drains into the Atlantic Ocean at Tatuamunha Beach, forming an estuarine mouth shaped by the interaction of fluvial, tidal, and oceanic processes. The estuary is characterized by migrating sandbars and tidal plains, and the river supports extensive mangrove ecosystems along its banks. The entire river lies within the federally protected Área de Proteção Ambiental (APA) Costa dos Corais, which carries conservation regulations that paddlers should be aware of before visiting.

The river is perhaps best known as a sanctuary for marine manatees, and paddling here means sharing the water with these animals in their natural habitat. Mangrove channels branching off the main river can be explored by traditional canoe or kayak, and the wetland ecosystem supports a diverse array of bird species, making the area of interest for birdwatchers. Wooden footbridges and interpretive trails wind through the mangroves and connect to Tatuamunha Beach at the river's mouth, where the confluence with the sea offers open views.

Organized ecotourism on the river is managed by the Associação Peixe-Boi, which was founded in 2009 and handles guide accreditation and visitor access. The association runs guided boat tours lasting approximately one hour, limited to ten tours per day, with advance booking required to minimize disturbance to manatee habitat. Paddlers exploring the mangrove channels independently should be mindful of the conservation context and the presence of guided tour groups on the water. The river is approximately 14.1 miles in length, though no dedicated boat ramps or formal paddler access points exist.

The character of the paddling is calm and low-key, suited to flat-water paddling through mangrove-lined channels and the broad estuarine reach near the river's mouth. The village of Porto das Pedras is the primary gateway to the river, and the Associação Peixe-Boi serves as the main point of contact for organized access and local guidance.