Population parameters and exploitation rates of four commercial fish species of Awach Kibuon River: Towards sustainable management of riverine fisheries of the Lake Victoria Basin

Abstract

The study estimated population parameters of four leading commercial fish species of Awach Kibuon River in Lake Victoria Basin, Kenya to inform management interventions for sustainability. Length data were collected monthly from January to December 2020 and length-frequency analysis conducted in FiSAT II software utilizing ELEFAN I Routines. Exploitation rates (E = 0.63) for Protopterus aethiopicus (Heckel, 1851) and (E = 0.56) for Clarias gariepinus (Burchell, 1822) indicate overfished stocks (E > Eopt) whereas exploitation rates (E = 0.31) for Synodontis victoriae (Boulenger, 1906) and (E = 0.32) for Oreochromis niloticus (Linnaeus, 1758) signify optimal exploitation (E = Eopt). There were year-round recruitments with bi-modal annual pulses in the populations of O. niloticus, S. victoriae, and P. aethiopicus. These results are crucial for sustainable management of riverine fisheries in the Lake Victoria Basin. This study recommends reduction of fishing pressure on P. aethiopicus and C. gariepinus to enhance their sustainability.