The site comprises much of the estuary, fringing mangrove and woodland of the Rio Mansôa, together with an area of the northern shore of the Canal do Gêba, the estuary of the larger Rio Gêba, immediately to the east. The site includes two large, predominantly mangrove-covered islands—Ilha de Jeta and Ilha de Pexice—as well as several smaller ones in the mouth of the Rio Mansôa. Eastwards the site extends along the shoreline of the Canal do Gêba as far as the Ilhéu dos Pássaros, an islet near the northern shore of the estuary of the Rio Gêba, a little way downstream of the city of Bissau. The banks of the mouth of the Rio Gêba are bordered with mangroves and soft mud, while there are sandbars and mudbanks in the channel. The site includes 175,000 ha of mudflats, 3,000 ha of mangrove and 13,000 ha of marsh.
See Box and Table 2 for key species. The Ilhéu dos Pássaros is an important roost-site where over 15,000 birds have been recorded. Counts only exist for the eastern parts of the site, the Rio Gêba area, which alone held over 37,000 wintering waders. A count of 1,500 Phoenicopterus minor were recorded in March 1990.
Non-bird biodiversity: The mammal Trichechus senegalensis (VU) occurs.
BirdLife International (2021) Important Bird Areas factsheet: Rio Mansôa and Gêba estuary. Downloaded from http://www.birdlife.org on 15/04/2021.