Tanbi Wetland Complex

The Tanbi Wetland Complex is a Ramsar-listed Wetland of International Importance covering approximately 63 square kilometers of estuarine wetland immediately surrounding Banjul, the capital of The Gambia. Designated as a Ramsar site in 1996, Tanbi encompasses the mangrove-lined creeks (bolongs), tidal mudflats, and intertidal wetlands of the Gambia River estuary adjacent to the capital city. The complex includes the Banjul Island wetlands, the Oyster Creek area, and connected estuarine systems that have remained relatively intact despite their location within the greater Banjul metropolitan area. Tanbi is one of the most accessible urban wetlands in West Africa and provides critical ecosystem services to the capital.

Tanbi supports significant waterbird populations including African fish eagle, osprey, goliath heron, and various kingfisher species as year-round residents. Migratory Palearctic waders, herons, egrets, and cormorants use the mudflats and mangrove margins in large numbers. The Gambia River estuary adjacent to Tanbi contains hippopotamus, Nile crocodile, and African manatee. The mangrove and estuarine habitats function as a critical fish nursery, supporting the artisanal fisheries of surrounding communities. Fiddler crabs, shellfish, and invertebrate communities are abundant in the tidal mudflats and provide a critical food base for shorebirds.

Tanbi's defining vegetation is mangrove forest, predominantly Rhizophora racemosa (red mangrove) in permanently flooded zones and Avicennia nitida (white mangrove) in higher intertidal areas. Areas of Laguncularia racemosa and Conocarpus erectus occur on the upper marsh margins. The tidal mudflats between mangrove patches support sparse algal and cyanobacterial mats and specialized invertebrate communities. Small patches of transitional grassland and shrub occur at the landward edge. The mangrove ecosystem is the primary driver of the wetland's productivity, trapping sediment, cycling nutrients, and providing structure for the associated fauna.

Tanbi occupies the active estuarine and tidal zone of the Gambia River at its Atlantic mouth. The geology is entirely Quaternary—tidal mudflats of clay and silt deposited by the Gambia River and reworked by tidal action. Banjul Island itself is a low-lying alluvial formation surrounded by tidal channels. The wetland complex is geologically very young and highly dynamic, with tidal channels shifting course over years to decades. Sea level rise driven by climate change poses a direct and significant threat to the low-lying tidal wetlands. Sandy beach substrates occur at the outer margin of the complex facing the Atlantic.

The Tanbi Wetland experiences the coastal tropical climate of Banjul, with a wet season from July to October and a dry season from November to June. Annual rainfall averages 900–1,000 mm. Ocean breezes keep temperatures moderate throughout the year. The harmattan from December to February brings cooler, drier conditions. The tidal regime imposes a twice-daily cycle of flooding and draining that drives the ecology of the wetland. Tidal range is approximately 0.5-1.0 meters. The wet season brings higher freshwater input from the Gambia River, temporarily reducing salinity in the estuary.

Banjul (formerly Bathurst) was established by the British on St. Mary's Island in 1816 as a base for suppressing the slave trade on the Gambia River. The surrounding wetlands provided resources for both the colonial settlement and the indigenous Mandinka and Wolof communities of the North Bank. The mangroves of Tanbi have been harvested for fuelwood, construction, and shellfish since time immemorial. The growth of Banjul as the national capital and the urbanization of the surrounding area on the South Bank (Kombo St. Mary) has encroached on the wetland margins. The wetland's proximity to Banjul makes it a resource for urban and peri-urban communities.

The Tanbi Wetland Complex was designated a Ramsar site in 1996, recognizing its international importance as an estuarine wetland. Management is the responsibility of The Gambia's Department of Parks and Wildlife Management and Department of Fisheries. The complex has been the subject of ecological surveys documenting its biodiversity and ecosystem services. Urban development pressure has been a persistent management concern. International support for Tanbi conservation has come from wetland conservation organizations recognizing its significance as an urban wetland providing ecosystem services to Banjul.

Tanbi is most productively experienced by boat through its mangrove creeks (bolongs), offering close encounters with waterbirds, crocodiles, and the dramatic tidal mangrove forest. Pirogue excursions from Denton Bridge on the North Bank Road are the standard tourist activity. The urban contrast—mangrove wilderness within sight of Banjul's buildings—is a distinctive experience. Birdwatching from Denton Bridge provides access to African fish eagle, various kingfishers, and herons without a boat. Sunrise and sunset boat excursions are popular. The wetland is accessible as an easy half-day from anywhere in the greater Banjul area.

Denton Bridge on the North Bank Road (approximately 5 km from central Banjul) is the main access point for pirogue excursions into the Tanbi creeks. Boat operators offer excursions from Denton Bridge. No dedicated visitor infrastructure exists within the wetland itself. The wetland is easily reached by taxi from Banjul or the Atlantic coast hotels. Accommodation is not necessary as Tanbi is a day excursion destination from Banjul. Early morning excursions provide the best birdwatching. The wetland is accessible year-round with each season offering different wildlife highlights.

Tanbi faces severe pressure from Banjul's urban expansion, with mangrove clearing for development occurring along the wetland margins. Pollution from the city—sewage, solid waste, and agricultural runoff—degrades water quality. Unsustainable mangrove cutting for fuelwood and construction removes habitat and reduces the wetland's carbon storage and coastal protection functions. Climate change-driven sea level rise is an existential threat to the low-lying tidal wetland. Conservation advocacy highlights Tanbi's ecosystem services including coastal protection, fish nursery function, and carbon storage. Strengthening legal protection and community stewardship of the mangrove resource is the central conservation priority.