Guinea Bissau

Introduction

The coastline of the Republic of Guinea Bissau is about 350 km long, and consists of an irregular mainland with numerous rias and the estuaries of the Cacheu and Geba rivers, and a group of offshore islands, the Bissagos (Bijagos) Archipelago. The coastal plain is dissected by an intricate network of mangrove-fringed tidal channels, and the outer shores are sandy, with many shoals (Berthois 1958). Wave energy is generally low, partly because the northwest and southwest Atlantic swells are dissipated across a broad sector of continental shelf, and partly because of the protection of the archipelago. Tides are semidiurnal. They are augmented across the broad continental shelf and into the funnel-shaped estuaries and inlets, so that Cacheu in northern Guinea Bissau has a mean spring tide range of 2.8 m, while Bissau, on the north coast of the Geba estuary, has a mean spring tide range of 5.1 m, increasing to 6.4 m at Port Gole. Bubaque, in the archipelago, has a mean spring...