Population characteristics of five major commercial fish species of the Tono Reservoir in northern Ghana

Five major commercial fish species, comprising Sarotherodon galilaeus , Oreochromis niloticus , Coptodon zillii , Clarias gariepinus and Auchenoglanis occidentalis of the Tono Reservoir fishery, were studied from January, 2015 to December, 2016 using length‐based models to establish the state of the stocks. Routines in the FAO‐ICLARM Stock Assessment Tools II (FISAT II) were used to determine the growth and mortality parameters, exploitation rates ( E ) and recruitment patterns of the length–frequency data generated from commercial fish landings and experimental catches. The growth coefficients ( K ) of the five fish species ranged 0.48–4.89 per year; asymptotic lengths ( L ∞ ) ranged from 18.38 to 76.16 cm; and hypothetical ages ( t 0 ) ranged between 0.03 and 0.28 years. All five fish species were exploited above the optimal exploitation rate ( E opt = 0.5), indicating overfishing of the species. There was a year‐round recruitment, with major and minor peaks corresponding with the major and minor spawning seasons. Fishing gear regulation and community‐based co‐management system were some management options recommended to enhance sustainable exploitation and management of the fishery.