| FishBase | Complete | Literature | Reference | |||
|---|---|---|---|---|---|---|
| Species | Families | Species | Families | |||
| Marine | Yes | |||||
| Freshwater | 98 | 20 | Yes | |||
| Total | 104 | 23 | Yes | |||
| Conservation | The following information is to be sought: - Status of knowledge of the freshwater fauna; - Existence of conservation plans; - Information on major aquatic habitats or sites within the country; - Current major threats to species; - Future potential threats to species; - Contact(s) for further information. |
| Geography and Climate |
Ethiopia is a landlocked country which has a surface area of 1,223,600 sq. km. More than 60 percent of the country lies above 1,000 m, with extensive plains over 2,000 m. Elevations range from 120 m below sea level in the Dallol Depression (Kobar Sink), south of Massawa, to over 4,620 m in Mount Ras Dushon, north of Lake Tana. In all, ten mountain peaks of the plateau region rise over 4,000 m. A great deal of the terrain is mountainous, rugged and deeply dissected by rivers. The southern half is bisected by the northern arm of the Rift Valley and ranges from 40 to 60 km in width, with escarpments 1,000 - 1,500 m high. The floor of the valley is occupied by a large number of lakes and the rift line forms the main river watershed.
The plateaux to the west of the rift system form the Central Highlands (2,000 - 2,500 m). To the east are the lower range of the Bale and Havar plateaux. The north-eastern part of the Rift Valley opens out into a delta-shaped plain, in the northern part of which lies the Dallol Depression, an area of 5,000 sq. km. below sea level. The Darcalli range separates these lower plains from the Red Sea. Only in a narrow coastal zone are there lowland areas below 200 m.
The climate is generally temperate on the plateau, but becomes hot and arid on the lowlands, and is desertic in the northeast and the south. On the plateau, there is a short wet season from February to April, and a major rainy season from June to September.
Ethiopia is an entirely agricultural country, where intensive use of marginal lands has often caused severe erosion. Rivers are consequently highly silted. There has been little development for irrigation except along the Awash River. Ref. Vanden Bossche, J.-P. and G.M. Bernacsek, 1990 |
| Hydrography |
Aubray (1975) (Ref. 12121) reports that 173,000 sq. km. (14%) of Ethiopia consists of swamp (4%), lakes (1%), rivers and floodplains (9%). This is much higher than the figures given by FAO (1984) (Ref. 12120) for wetland (0.7%, 9,200 sq. km.) and water body (0.5%, 6,700 sq. km.) areas.
Lakes: the total lake area in Ethiopia was estimated as 7,500 sq. km. by Aubray (1975) (Ref. 12121), but the statistics listed in Table 1 show that this area may be as much as 8,800 sq. km.
Ethiopia is moderately well supplied with natural lakes. Lake Tana (3,500 sq. km., 52% of the total lakes area) is the largest lake wholly contained in Ethiopia, but a small portion of Lake Turkana and over half of Lake Abbe are also within the territory. A chain of eight small- to medium-sized lakes are situated in the Rift Valley (Lakes Abaya, Abitaya, Awasa, Chamo, Chew Bahir, Langano, Shala, Chamo and Ziway); these cover 40% of the lakes area.
The very high conductivity of the waters of some of these lakes above them to the highly saline, soda-type lakes typical of the Rift Valley. In addition, there are numerous small, deep crater lakes. These are generally high-altitude lakes, with a mean altitude of 1,750 m; the lowest, apart from Lake Turkana, are the Abaya and Chamo lakes at about 1,250 m.
Other sizeable lakes are those associated with the Awash River (Lakes Beda, Yardi, Afambo and Gemeri) and the isolated Lake Afrera Ye'Ch'ew. Several of the lakes have an interlinking river system.
Rivers, floodplains and swamps: there are nine major rivers, totalling 6,400 km with an annual discharge of 63 billion cubic metres, of which the Blue Nile accounts for 80% (Aubray, 1975) (Ref. 12121). There are six major drainage basins. The major systems are those of the Nile int he northwest and the Indian Ocean systems of Bale and Horor. The Red Sea rivers are mostly short and torrential. There are several closed depressions and numerous lakes associated with the Rift Valley. The largest internal drainage system is the Awash River, running northward along the Rift Valley for over 500 km before dissipating in a complex of salt lakes and marshes (Lakes Abbe and Gemeri).
The Blue Nile (Abbai) River takes its source from Lake Tana and flows for about 760 km through Ethiopia. It is torrential and steeply encased by mountains for much of its course.
The Omo River flows south from the central highlands for some 600 km and discharges into Lake Turkana through a small marshy delta. Two other rivers, the Shabale (about 900 km in Ethiopia) and the Ganale (about 500 km in Ethiopia) drain the highlands toward the south and cross the Ogaden Desert before entering Somalia.
Reservoirs: there are two large reservoirs (Fincha and Koka) and three smaller impoundments (Zula, Legadadi and Abarda).
Coastal lagoons: there is only one small lagoon near Bera'isole. Ref. Vanden Bossche, J.-P. and G.M. Bernacsek, 1990 |