Description

Abstract: Aquaculture systems have the benefit of being highly intensive with demonstrated economic returns. Aquaculture can be an efficient strategy for economical land use and serve as an alternative means of livelihood for rural communities. Consequently, fish farming can play a major role in environmental conservation and restoration programs by reducing extensive land use. However, regional variability in climate, soils, and water quality are limiting constraints on aquaculture success. This study was conducted to assess the potential for culture of two warm water fish species, Nile tilapia (Oreocromis niloticus, Linnaeus) and African catfish (Clarias gariepinus, Burchell) at the high altitudes of the River Njoro watershed. Growth performance of Nile tilapia and African catfish were evaluated for 180 days in ponds fertilized with organic manure and stocked at a rate of two fish per square meter for tilapia, and 0.5 fish per square meter for catfish. Results from this study demonstrated remarkable growth in Nile tilapia but poor growth and condition in African catfish. After several attempts, African catfish eggs fertilized for the study failed to hatch, most probably due to low temperatures and the poor water quality of the Njoro River. These results demonstrate the feasibility of Nile tilapia culture at high altitudes of the watershed, while African catfish culture was limited by poor growth performance and seed availability. The farming of Nile tilapia is therefore recommended in the Njoro River watershed as a potential alternative livelihood strategy to intensive agriculture.