Ecological dynamics of fish populations in Lake Hayq, Awash Basin, Ethiopia

Abstract

Lake Hayq, located in the South Wollo Zone of Ethiopia furnishes essential ecosystem services. The objective of the study was to determine the ecological dynamics of fish species in the lake. The data were collected between January and December 2018. Fish specimens were collected from three sites (Shore, Open water and Ankerkeha River mouth) during four seasons using different gillnets and beach seins. The fishes caught were identified into species and their length and weight were measured immediately in the field. A total of 3 commercially important fish species, Cyprinus carpio (C. carpio), Oreochromis niloticus (O. niloticus) and Clarias gariepinus (C. gariepinus) were identified from Lake Hayq. The most dominant species was C. carpio followed by O. niloticus, and C. gariepinus. The fish abundance was greater during the dry season at Shore site of the lake which might be associated with more food and availability of refuge for larva and juvenile fishes. O. niloticus was introduced into Lake Hayq in 1970s for food security purpose whereas C. carpio was accidentally introduced into the lake in 1994 via the tributary, Ankerkeha River from nearby, Lake Ardibo. Currently, C. carpio is being dominant species in Lake Hayq that might compete with O. niloticus for food.