The Guanabara Ecological Station (ESEC) is divided between the municipalities of Guapimirim (42.49%), Itaboraí (35.61%) and São Gonçalo (3.57%) in Rio de Janeiro.

[5] The ESEC contains a flat tidal region of fluvial-marine sediments, rich in organic matter, that supports the mangroves.

Migratory birds include the osprey (Pandion haliaetus), semipalmated plover (Charadrius semipalmatus) and spotted sandpiper (Actitis macularius).

Due to the unique importance of the environments between the mouths of the Guaxindiba and the Guapi / Macacu rivers, the Brazilian Institute of Environment and Renewable Natural Resources (IBAMA) recommended creation of an ESEC to fully protect the area, which would result in increased marine life in the area and ensure sustainability of traditional extractive activities.

[5] The park was included in the Central Rio de Janeiro Atlantic Forest Mosaic, created in December 2006.