COUNTRY FILES (Contd.)

MANZALAH LAGOON

Note: (see also FAO, 1980b)

Fig. 9 MANZALAH LAGOON
(Lemoalle, 1987)

Total annual catch and effort:

* (Lemoalle, 1987)
** (Shaheen et al., 1980)
*** (Ferlin, 1980)

1979–80: 40 000 t/yr (open water fisheries), plus 20 000–25 000 t/yr for howash or hoshas (enclosures and fish farms. The general evolution of the lagoon from the 1960's to 1980 revealed increased fishing with decreasing salinity and increased nutrient inputs (eutrophication) (cited in Lemoalle, 1987).

Potential annual yield:

31 000 t/yr (Balarin, 1986)
75 000 t/yr (Sadek, 1984)
140–250 kg/ha/yr (Sadek, 1984)

MARIUT LAGOON

Fig. 10. MARIUT LAGOON AND NOZHA HYDRODROME
(Lemoalle, 1987)

NOZHA HYDRODROME LAGOON

PORT FOUAD (= EL-MALLAHA) LAGOON

TIMSAH LAGOON

UM EL RISH LAGOON

7. BIBLIOGRAPHY

Ali, 1984
Atkins Land and Water Management, 1979
Balarin, 1986
Boulenger, 1907
C.A.P.M.S., 1982
Entz, 1984
FAO, 1974, 1980a, b
FAO/UNDP, 1975
Feidi, 1976
Ferlin, 1980
Hefny, 1982
Henderson, 1975
Ishak, Hamza, 1983
Kapetsky & Petr, 1984
Latif, 1984
Lemoalle, 1987
Marshall, 1984
Pisanty, 1981
Saad, 1982
Sadek, 1984
Shaheen et al., 1980
S.I.S., 1983a,b
Welcomme, 1972–1979
Wunder, 1960

ETHIOPIA

1. GEOGRAPHY AND CLIMATE

(adapted from Welcomme, 1979 and Balarin, 1986)

Ethiopia has a surface area of 1 223 600 km². 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 (see Fig. 2, Table 1) 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 km² 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.

2. HYDROGRAPHY

(adapted from Welcomme, 1979 and Balarin, 1986)

Aubray (1975) reports that 173 000 km² (14%) of Ethiopia consists of swamp (4%), lakes (1%), rivers and floodplains (9%). This is much higher than the figures given by FAO (1984) for wetland (0.7%, 9 200 km²) and water body (0.5%, 6 700 km²) areas. (See Fig. 3, Table 2.)

2.1 Lakes (see Fig. 2, Table 1)

The total lake area in Ethiopia was estimated as 7 500 km² by Aubray (1975), but the statistics listed in Table 1 show that this area may be as much as 8 800 km².

Ethiopia is moderately well supplied with natural lakes. Lake Tana (3 500 km², 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, Abiyata, Awasa, Chamo, Chew Bahir, Langano, Shala, Chamo and Ziway); these cover 40 percent of the lakes area.

The very high conductivity of the waters of some of these lakes shows them to be 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.

2.2 Rivers, Floodplains and Swamps

There are nine major rivers, totalling 6 400 km with an annual discharge (MAR) of 63 billion cubic metres, of which the Blue Nile accounts for 80% (Aubray, 1975). There are six major drainage basins (see Table 2 and Fig. 3). The major systems are those of the Nile in the 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.

The eastern streams and those in areas of high rainfall tend to be short, intermittent and torrential. Other rivers, such as the Abbai (Blue Nile), Baro, Omo, Webi Shebelli, Awash and Takazzi, are long and perennial. There is a great difference between discharge in the wet season (July-September) and that of the dry season. The Awash discharge, for example, previously ranged from 2 to 600 m³/s but, since the construction of the Koka Dam, now maintains a steady flow of 43 m³/s.

Available data on mean annual runoff (MAR) is summarized in Table 2. Of interest is the exceptionally high runoff shown by the Blue Nile, a characteristic of the wetter region.

The rivers are usually very deeply incised in their upper courses and their irrigation potential consequently impracticable without artificial control. There is, however, considerable scope for the construction of dams for the production of hydroelectric power and, therefore, also for water control, irrigation and fish production. None of the rivers is navigable except for the lower Baro.

In the south there is the drying Chew Bahir Lake/Swamp (Lake Stefanie), and in the northeast the Danakil Depression is characterized by swamp and salt lakes, notably the Aussa swamp, the salt Lake Abbe and the Assole Lagoon.

The Pibor and the Baso (tributaries of the Sobat River) develop a common floodplain-swamp.

Hot springs and mineral springs occur at several places within the Rift Valley, but no documentation is available.

Fig. 1. MAP OF ETHIOPIA

2.3 Reservoirs

There are two large reservoirs (Fincha and Koka) and three smaller impoundments (Zula, Legadadi and Abarda).

2.4 Coastal Lagoons

There is only one small lagoon near Bera'isole.

Numbers refer to Table 1.

Fig. 2. DISTRIBUTION OF MAJOR ETHIOPIAN LAKES AND RESERVOIRS
(Balarin, 1986)

Table 1. MORPHOLOGICAL DATA OF MAJOR LAKES AND RESERVOIRS
(adapted from Balarin, 1988)

* f=fishery; i=irrigation, p=power generation
Sources: Aubray, 1975; CSO, 1980; FAO/UNDP, 1982; Giudicelli, 1984; Tedla, 1973; Welcomme, 1972.

Letters refer to Table 2.

Fig. 3. RIVER SYSTEMS OF ETHIOPIA
(Gamachu, 1977)

Table 2. MAJOR RIVER SYSTEMS AND HYDROLOGICAL ZONES
(Balarin, 1986)

Sources: Aubray, 1975; CSO, 1980; FAO/UNDP, 1982; Gamachu, 1977; Tedla, 1973.

2.5 Aquaculture

Aquaculture development is practically non-existent and there is a confusion between fish farming and fisheries management.

In view of the absence of any form of classical aquaculture, transplantation of fish into natural water bodies is hereunder considered as a form of extensive aquaculture.

Fish farming activities consist of fish pond experiments (reported by Meskal, 1974, 1975, 1976) and the establishment of a Fisheries Research Station at Sebeta where fish are reared in ponds for subsequent transplanting into natural water bodies. Over the years considerable fish transportations have taken place under the auspice of fish farming but in reality, as these stockings were of natural water bodies, such practices are actually a part of fisheries management. Unfortunately transfers have not been adquately documented; what is known has been summarized by Tedla and Meskal (1981).

3. FISHERY PRODUCTION/POTENTIAL

3.1 Fish production and per caput supply

Table 3. FISH PRODUCTION - Ethiopia, 1970–1987

¹ Source: FAO
² Source: FAO Fisheries Department FISHDAB
1979–87 data includes estimates of catches from small lakes which the Fish Marketing Corporation does not collect and catches in other lakes where fishermen sell directly to local villages or use for their own consumption. Marine catches from the Red Sea include estimates of quantities directly exported (illegally) to nearby countries.
³ No aquaculture in Ethiopia (Vincke, 1989, pers.comm.).

3.2 Inland catch range and potential yield

Table 4.

Sources:
^a Balarin, 1986
^b Khan, 1983
^c Welcomme, 1979
^d Feyissa, 1983
^e IDET-CEGOS, 1979
^f Giudicelli, 1984
^g Aubray, 1975
^h EEC project, 1979–1984
ⁱ FAO/UNDP, 1982
^j Welcomme, 1972
^k Gasse, 1987

4. STATE OF THE FISHERY

(adapted from Balarin, 1986 and Welcomme, 1979)

4.1 Yield

A description of the inland fishery has been adequately given by Aubray (1975), FAO/UNDP (1982) and Feyissa (1983). Available data have been summarized in Table 4, which indicates a potential annual yield of inland fish between 21 000 and 70 000 t.

The total inland catch is estimated at 3 500 t/yr, with a potential estimated by Aubray (1975) of 23 000–30 000 t/yr for lakes and up to 10 000 t/yr for rivers.

The inland fishery of commercial importance revolves around the Rift Valley System, Lake Tana and 7 000 km of rivers (Tables 1 and 2). It would appear that little has been reported of the past performance of this sector. Statistics have remained below 1 000 t/yr (Table 3). With the establishment of FPMC (Fish Production & Marketing Cooperation, Govt. Dept.) in 1978, fishery development was reactivated, in particular the production from inland waters.

The status of the fishery resource is given in Tables 3 and 4 and the range of values presented are an indication of the uncertainty of the statistics. The present activities are all in the hands of artisanal fishermen, now numbering between 2 000 and 7 000, from a once-active 25 000 fishermen population. The vessels are mostly non-operational and only a few boats are motorized. Major reconstruction and rehabilitation are necessary.

Aubray (1975) estimated that 1 000 professional fishermen were active on the main highland lakes, yielding between 800 and 1 000 t/yr. Some 2 000 subsistence operators were catching 400 t/yr. The bulk came from Lakes Ziway and Abaya, where 200 small canoes were operating, using baited hand lines for Nile perch, as well as some beach seines and gill nets, mainly for tilapia.

About eight cooperatives operate on Lake Ziway, selling around 1 334 t fish (1983) to the FPMC.

Over 93 species of fish are listed by Tedla (1973) and their distribution is indicated by total species number in Tables 1 and 2. Of these, Tilapia, Lates, Barbus, Clarias and Bagrus make up the bulk of the fishery, Tilapia accounting for nearly 80% of the catch. There have also been a number of introductions of indigenous and non-indigenous species throughout the major waterways of Ethiopia.

4.2 Factors influencing yield

Apart from physico-chemical limitation of productivity in the salt lakes, most water bodies appear to have considerable potential for increased yield. At present this is not realized mainly because of local food customs (there is no fish-eating tradition in Ethiopia) and the consequent lack of interest in fishing within the country, but this situation may be changing.

There appears to be a widespread need for improved stocking of selected fish species (see Section 2.5). Some water bodies have, probably for historical-zoogeographical reasons, depauperate ichthyofaunas, and the filling of vacant ecological niches could be expected to increase fishery yields substantially. Some lakes with relatively high salination could probably benefit from the introduction of salt-tolerant or brackishwater species.

No research has been carried out to evaluate the true potential of the inland lakes.

4.3 Future development possibilities

The main inland fisheries are within easy reach of the major urban centres and it is almost inevitable that, with a present catch of about (and probably even below) 10% of the estimated potential, the inland fisheries of Ethiopia will develop considerably over the next few decades. The sector has already grown considerably due to the setting up of a marketing service within the government (FPMC).

Together with an updated and comprehensive reassessment of the actual potential yields of the water bodies, including their stocking/restocking capacity, there is an urgent need for the development of an effective statistics collection network.

5. KEY BIBLIOGRAPHY

Balarin, 1986
Gasse, 1987

6. WATER BODIES DIRECTORY

LAKE ABAYA (MARGHERITA)

* Loffredo & Maldura, 1941
** Talling & Talling, 1965

LAKE ABBE (= ABHE BID HAYK)
(International water)

LAKE ABIJATA (ABIYATA)

* Loffredo & Maldura, 1941
** Talling & Talling, 1965

Fisheries data
Major fish species: tilapia
                               There is no fishing.

LAKE AFRERA YE'CH'EW

LAKE ASALE

LAKE AWASA

LAKE BABIGATA

LAKE CHAMO (RUSPOLI)

LAKE CHEW BAHIR (STEFANIE)

LAKE HAIK

LAKE HORA (HORO)

LAKE LANGANO

LAKE SHALA

* Loffredo & Maldura, 1941
** Talling & Talling, 1965

Fisheries data
                               Low production, unfished (Gasse, 1987).
No. of fish species: 1: Oreochromis niloticus (cited in Gasse, 1987).

LAKE TANA

* Grabham & Black, 1925
** Bini, 1940

Fig. 3. LAKE TURKANA - RUDOLF
(Welcomme, 1972)