The wetland lies at the mouth of the Gambia River and separates the capital Banjul from the urban centres of Serekunda, Bakau and their suburbs. Most of the site is low, open Avicennia mangrove scrub and taller Rhizophora mangrove cut by tidal creeks. There are small patches of saline mudflats between the mangrove and the rice-fields, which border much of the site to the south and west. In the north, the main highway linking Banjul to the mainland roughly follows, for some 10 km, the boundary between the mangrove and the shifting sand beaches and tidal lagoons of the Atlantic coast. In the extreme north-west there is a small area of freshwater marsh around Cape Creek. In the east the Bund Road, created to stabilize the land around Banjul, has enclosed several shallow lagoons whose tidal ranges are controlled. The largest expanses of mudflats are on the river immediately south of these lagoons and at the Mandinari flats, 5 km upriver.
See Box for key species. The area holds large numbers of non-breeding terns, gulls, herons, egrets and Palearctic waders. Larus audouinii is recorded occasionally in small (less than 10) numbers. The main concentrations of waders are at the Bund Road lagoons and adjacent mudflats. Gulls and terns flock here and on the Atlantic coast, particularly at the mouth of Cape Creek and the lagoons at the Wadner Beach Hotel. There is a roost of several thousand Bubulcus ibis in the mangrove around Cape Creek. In addition to the species listed below, Arenaria interpres, Calidris minuta and C. ferruginea also occur commonly in winter or on passage.
Non-bird biodiversity: Mammals: Trichechus senegalensis (VU) still occurs.
BirdLife International (2018) Important Bird Areas factsheet: Tanbi wetland complex. Downloaded from http://www.birdlife.org on 21/11/2018.