Several dams have been constructed in Ethiopia, East Africa to support electricity and/or irrigation. Fishes were introduced to some of these dams. Thus, the objective of this study was to assess the dynamics and cond...Several dams have been constructed in Ethiopia, East Africa to support electricity and/or irrigation. Fishes were introduced to some of these dams. Thus, the objective of this study was to assess the dynamics and condition factor of Oriochromis niloticus in Korir and Lailay Wukro Dams, Northern Ethiopias. The study was conducted by deploying two gill net, every month in the littoral and pelagic zones of the two dams from August 2011 to May 2012. A total of 524 O. niloticus, 278 from Lailay Wukro and 246 from Korir dams were collected. The monthly catch per unit effort （CPUE） showed significant variation among months, the highest catch was in May and the least was in January 2012 （P 〈 0.000）. Catches of fish encountered higher in the littoral （69.1%） than in the pelagic zones （30.9%） （P 〈 0.000）. The condition factor of O. niloticus in the two reservoirs remains high, in Korir 2.05 and in Lailay Wukro 1.65 （P 〈 0.000）. In these small tropical dams, O. niloticus mature as they are smaller in size （Ls0： TL average 22.5 cm）. The ratio of male to female was 1.3：1 （P 〈 0.016）. The two dams have favorable condition for high production of O. niloticus. This high potential for fish production in the dams may be sustainable if the local authorities set a regulation to control the illegal fishing activity.展开更多
文摘Several dams have been constructed in Ethiopia, East Africa to support electricity and/or irrigation. Fishes were introduced to some of these dams. Thus, the objective of this study was to assess the dynamics and condition factor of Oriochromis niloticus in Korir and Lailay Wukro Dams, Northern Ethiopias. The study was conducted by deploying two gill net, every month in the littoral and pelagic zones of the two dams from August 2011 to May 2012. A total of 524 O. niloticus, 278 from Lailay Wukro and 246 from Korir dams were collected. The monthly catch per unit effort （CPUE） showed significant variation among months, the highest catch was in May and the least was in January 2012 （P 〈 0.000）. Catches of fish encountered higher in the littoral （69.1%） than in the pelagic zones （30.9%） （P 〈 0.000）. The condition factor of O. niloticus in the two reservoirs remains high, in Korir 2.05 and in Lailay Wukro 1.65 （P 〈 0.000）. In these small tropical dams, O. niloticus mature as they are smaller in size （Ls0： TL average 22.5 cm）. The ratio of male to female was 1.3：1 （P 〈 0.016）. The two dams have favorable condition for high production of O. niloticus. This high potential for fish production in the dams may be sustainable if the local authorities set a regulation to control the illegal fishing activity.
