In the Guaratiba mangrove, Canal do Bacalhau almost splits the Mangaratiba Island from the continent - The whole area is an APA - área de preservação ambiental, so the tourism and human population as a whole in this area is strictly controlled.

Besides beautiful scenery protected by the Brazilian navy, this canal is home to a wide variety of fauna and flora typical to the Atlantic rainforest, in fact, this paper from UFRRJ is an in depth study of the fish community in this ecosystem and gives a good idea of how important it is for the region.