Potential fish yield and biology of some fish in Lake Hertale, Afar regional state, Ethiopia

The Afar region is characterized by an arid and semi-arid climate with erratic rainfall and is prone to frequent droughts despite being endowed with fresh and saline water bodies along the Awash River Basin. Lake Hertale is one of those fresh water bodies located in the middle of the Awash River Valley. The lake's fishery is presumed not to have been exploited before. The study attempted to describe some physico-chemical parameters, fish species composition, estimate production potential which are relevant to develop a lake fishery with the prospect of contributing to food and nutrition security. The nutrient and chlorphyl-a measurements indicated eutrophic state but with apparently comparative low primary biomass. Conductivity, dissolved oxygen and temperature were within the optimal range for warm water species along with slightly alkaline pH. It was found that Lake Hertale is home to four important fish species, namely, Nile Tilapia (Oreochromis niloticus), barbs (Lebobarbus intermidus), African catfish (Clarias gariepinus) and Common carp (Cyprinus carpio), Nile crocodiles, several species of birds and hippopotamus. Labeobarbus constituted 56%, followed by Nile tilapia with 31% of the total population. The African Catfish constituted only 9% of the catch. The mean lengths of African Catfish and Labeobarbus were 47.2 and 38 cm respectively. The mean lengths of Nile tilapia and Common carp were 22.8 and 21.7 cm respectively. The fish production potential of the lake was estimated from 94.3 to 238 tons per year, with an average production of 145.7 tons per year. The estimate production potential can support up to 21 to 28 fishers, with an average number of 25 fishermen to sustainably utilize the lake's fishery potential. Lake Hertale and other adjacent lakes in the Afar region of Ethiopia can complement to the fight against hunger and malnutrition. Besides, through appropriate fishery development intervention, it is possible to create employment for the predominantly pastoralist Afar community.