Lac de Tunis (6926)
Tunisia, Africa
Site overview
KBA status: confirmed
Global KBA criteria: D1a
Year of last assessment: 2016
National site name: Lac de Tunis
Central coordinates: Latitude: 36.8127, Longitude: 10.2443
Elevation (m): 5 to 5
Area of KBA (km2): 37.38602
Protected area coverage (%): 92.43
KBA classification: Global
Legacy site: Yes
Site details
Site description: Lake Tunis is a large, shallow lagoon, possibly a former mouth of the Medjerda river, once connected to the sea, but now separated from it on the eastern side by the coastal dunes on which Carthage and La Goulette stand. Tunis, the capital, is situated on higher ground to the west of the lake, and is gradually spreading all round it, joining up with Radès on the southern side. The lake is bisected by a ship canal and motorway. In the northern half of the lake is the island of Chikly which has a ruined Spanish fortress on it. The southern half of the lake includes the former salt-production pans at Radès/Mégrine. The lake formerly received most of the sewage effluent and rainwater run-off from Tunis, but in the 1960s and 1970s, a clean-up operation was carried out, with waste-water being piped to a treatment station at Ariana, and circulation of water in the shallow lake improved. In the 1980s, most of the northern shores of the lagoon were reclaimed for urban expansion, destroying all natural habitat. The same has occurred in the late 1990s in the southern half of the lagoon, and the saltpans have been closed and filled in. The current ornithological status of the lake is uncertain, as the reclamation work on the south of the lake is still in progress, but it is likely that it will retain very little of its former ornithological interest, although some birds originating from nearby Sebkhet Sedjoumi and Ariana may still occur.
Rationale for qualifying as KBA: This site qualifies as a Key Biodiversity Area of international significance that meets the thresholds for at least one criterion described in the Global Standard for the Identification of KBAs. KBA identified in the CEPF Ecosystem Profile of the Mediterranean Hotspot (2017). Taxonomy, nomenclature and global threat category follow the 2016 IUCN Red List.
Additional biodiversity: See Box for key species. Other wintering waterbirds found on Lake Radès include many hundreds of Podiceps nigricollis (a species rarely found in such numbers elsewhere in Tunisia), Casmerodius albus, Ardea cinerea, Plegadis falcinellus, Platalea leucorodia, Tadorna tadorna (200–2,000), T. ferruginea, Anas acuta (500–800), A. clypeata (1,000–2,000), Aythya fuligula, A. ferina, Fulica atra (500–4,000), Himantopus himantopus, Larus genei, L. ridibundus, L. cachinnans and Sterna albifrons. The island of Chikly has breeding colonies of about 70 pairs of Egretta garzetta and about 100 pairs of Larus cachinnans which breed at the base of the ruins, together with the occasional Tadorna tadorna, and with Falco peregrinus and F. tinnunculus in the ruins themselves. Elsewhere, around the shores of the lake, there were formerly extensive breeding colonies of Sterna albifrons and Glareola pratincola, with good populations of Charadrius alexandrinus, Himantopus himantopus and Burhinus oedicnemus; it is unlikely that many of these breeding waders will survive the recent reclamation. Non-bird biodiversity: None known to BirdLife International.
Habitats
Land use: hunting | urban/industrial/transport
| IUCN Habitat | Coverage % | Habitat detail |
|---|---|---|
| Marine Coastal/Supratidal | 50 | |
| Artificial - Aquatic | 50 |
Threats
Summary of threats to biodiversity at KBA: The site is a Hunting Reserve while the island of Chikly is also a Natural Reserve. The reserve is, however, poorly wardened and there is much disturbance from people, dogs and rats, so that breeding birds rarely succeed. The whole of the lagoon has undergone extreme change in ecological status, which was perhaps inevitable because of its proximity to the capital, and ornithological interest has decreased steeply in the last 20 years.
| Threat level 1 | Threat level 2 | Threat level 3 | Timing |
|---|---|---|---|
| Biological resource use | Hunting & collecting terrestrial animals | Intentional use (species being assessed is the target) | Ongoing |
| Natural system modifications | Dams & water management/use | Abstraction of surface water (unknown use) | Ongoing |
| Pollution | Domestic & urban waste water | Type Unknown/Unrecorded | Ongoing |
| Residential & commercial development | Housing & urban areas | Ongoing | |
| Transportation & service corridors | Roads & railroads | Ongoing | |
| Human intrusions & disturbance | Work & other activities | Ongoing | |
| Climate change & severe weather | Droughts | Only in the future |
Additional information
References: Arnoud and Lachaux (1974), Ben Maïz and Boudouresque (1984), Gaultier (1986, 1987b, 1988a), Hughes et al. (1997), Maamouri and Hughes (1991), Ministère de l’Agriculture, Direction Générale des Forêts (2000), Shili (1995).