The site consists of the islands of Bazaruto, Santa Carolina, Benguerra and Margaruque, and also the San Sebastião peninsula on the mainland. There are high sand-dunes on the eastern side, but the rest of the land area is flat. The most important habitat for birds is the extensive intertidal flats which connect the islands. Vegetation on the islands is mostly scrubby, with a small patch of moderately well developed woodland on Benguerra island. Several freshwater lakes occur on Bazaruto island. The San Sebastião peninsula has well developed woodlands and forest and extensive marshes. The human population is dense on the islands and sparse on the peninsula. Human activities consist of subsistence farming and fishing. There is a well developed infrastructure for tourism.
See Box for key species. The site is an important wintering ground for migratory waders from the Palearctic. For six species of non-breeding waterbird, numbers exceed the 1% population thresholds. The largest congregations in southern Africa of Limosa lapponica (average 4,300 during 1996–1998) and of Dromas ardeola have been observed here. Flocks of Phoenicopterus ruber, which arrive in midwinter, include newly fledged young, and this is an important stop-over site for birds from breeding grounds in Botswana which disperse along the east coast of Africa. The number of waterbirds present during the austral summer regularly exceeds 20,000. The rare Falco eleonorae has been observed and may be a regular non-breeding visitor. The globally near-threatened Anthreptes reichenowi is likely to occur at San Sebastião, although not yet observed there. Rare birds observed in the marshes of San Sebastião include Vanellus crassirostris and Butorides rufiventris. One species of the East African Coast biome occurs, as do two of the Zambezian biome (Table 3).
Non-bird biodiversity: The islands support six endemic species of gastropod (Conus pennaceus, Epitonium pteroen, E. repandior, Fusiaphera eva, Thracia anchoralis, Limatula vermicola). Two lizard species are endemic to Magaruque and Benguera (Scelotes duttoni, Lygosoma lanceolatum). The following marine mammals are of conservation concern: Megaptera novaeangliae (VU), Tursiops truncatus (DD), Sousa chinensis (DD), Dugong dugon. Due to disturbance and persecution, sea-turtles have abandoned many breeding beaches in Mozambique, but here breeding by Caretta caretta (EN) is confirmed and breeding by Dermochelys coriacea (CR) and Eretmochelys imbricata (CR) is probable.
BirdLife International (2019) Important Bird Areas factsheet: Bazaruto Archipelago. Downloaded from http://www.birdlife.org on 07/12/2019.