Bolama-Bijagos - Customary Taboo and UNESCO Statute Together Protect Africa's Largest Green-Turtle Nesting Ground (Guinea-Bissau)

The Bolama-Bijagos Archipelago off Guinea-Bissau comprises 88 low-lying islands and islets of mangrove, mudflat and savanna at the mouth of West Africa's only active river delta on the Atlantic coast. UNESCO designated the archipelago a Biosphere Reserve in 1996, and on 11 July 2025 the World Heritage Committee inscribed 'Coastal and Marine Ecosystems of the Bijagos Archipelago - Omati Minho,' covering more than 10,000 km2 of islands, sandbanks and mudflats, under natural criteria (ix) and (x).

Formal protection through the Joao Vieira and Poilao Marine National Park, managed by Guinea-Bissau's Institute for Biodiversity and Protected Areas (IBAP) with park rangers present for roughly the last decade, layers onto -- rather than replaces -- pre-existing Bijago customary law: Poilao and other nesting islands are considered sacred and taboo to outsiders, and several ethnic groups in the region traditionally do not eat turtle meat or eggs, a belief system that conservationists credit with protecting the nesting beaches long before any state agency existed.

The archipelago is Africa's most important green-turtle (Chelonia mydas) nesting ground and West Africa's second-most-important site for migratory shorebirds, with an estimated 870,000 birds recorded annually. On the 43-hectare island of Poilao alone, researchers have counted between roughly 7,000 and 29,000 green-turtle nests in a season -- around 5% of the species' global nesting population concentrated on one island.

The July 2025 World Heritage inscription is recent enough that its effect on funding and enforcement is not yet independently evaluated; IBAP's protected-area network operates in one of the world's lower-income countries, and its historical challenges have included limited ranger capacity and illegal fishing pressure -- the practice's durability rests heavily on the customary taboo system continuing to hold alongside statutory protection.