Current view: Text account
Site description (2001 baseline):
Site location and context
Ile Alcatraz (0.75 ha) is a lateritic rock islet on the continental shelf of the Atlantic Ocean, 40 km south-west of Iles Tristao (IBA GN004). The Ile de Naufrage (0.25 ha) is a sandbank 2 km south-west of Ile Alcatraz which is exposed even at high tide. Ile Alcatraz is unvegetated and covered with guano to a depth of about 3 m, which is the cause of its white appearance. The Ile de Naufrage is also unvegetated and reaches a maximum height of c.3 m above high water. The intertidal area is mainly sandy.
See Box for key species. Ile Alcatraz holds the only known breeding colony of
Sula leucogaster between Cape Verde and São Tomé and Príncipe. There is breeding activity throughout the year. The Ile de Naufrage provides a roost for thousands of terns including
Sterna maxima,
S. hirundo,
S. sandvicensis,
S. albifrons and
Chlidonias niger.
Non-bird biodiversity: Among mammals, the dolphin Sousa teuszi (DD) and the sirenian Trichechus senegalensis (VU) are reported from the area; sea-turtles also occur.
Pressure/threats to key biodiversity
The area was designated a Ramsar Site in 1992. Guinean industrial and artisanal fishermen avoid this area of shallow waters because of the dangers of navigation. It is necessary to ensure that foreign fishermen do the same. In the past (40–60 years ago) guano on the island was extracted for phosphate, a practice which had a serious negative impact on the population of
Sula leucogaster. The designated shipping lane to the port of Kamsar passes a few dozen kilometres south of the site and there is, therefore, some risk of oil pollution. The islands are state owned.
Recommended citation
BirdLife International (2024) Important Bird Area factsheet: Ile Alcatraz et Ile du Naufrage (Guinea). Downloaded from
https://datazone.birdlife.org/site/factsheet/ile-alcatraz-et-ile-du-naufrage-iba-guinea on 23/12/2024.
