Briev
Live
Science

Tides Rapidly Expand and Shrink Guinea-Bissau's Bijagós Islands Twice Daily

Twice daily tides in the Bijagós Archipelago of Guinea-Bissau flow through sand channels, mudflats and mangroves, causing islands to grow and shrink within hours.

Bi-daily tidal movements sweep through the complex network of sandy passages, mudflats and mangrove forests surrounding the 88 islands of the Bijagós Archipelago in Guinea-Bissau. At low tide, extensive intertidal zones emerge, temporarily enlarging the islands, then recede as the water returns. Satellite imagery from 28 November 2025 captures the stark contrast between high- and low-tide shorelines, highlighting the region's dynamic coastal environment.

Why it matters

Knowing how tides reshape the Bijagós islands aids in managing coastal resources and protecting vulnerable ecosystems.

In this story

tidessand channelsmudflatsmangrove forestsintertidalBijagós ArchipelagoGuinea-Bissausatellite imagerycoastal dynamics