Population dynamics and yield estimation of Common Carp(Cyprinus carpio, Linnaeus, 1758)in Ayalew reservoir, Gamo Zone, Southern Ethiopia

Abstract

Common carp (Cyprinus carpio) is an introduced fish species in Ayalew reservoir. Thisstudy provides the first results on fishery dynamics of the species in the reservoir. Thestudy was aimed at estimating important population dynamics parameters and productionpotential. Total length (TL) and total weight (TW) data were collected from a total of 276fish samples (141 females and 135 males). The obtained data were analyzed using FiSATII software. Jones length based cohort analysis model and length-based Thompson andBell yield predictionmodels were employed to estimate the population and productionpotential. The mean total length was 26 cm and the dominant length groupsranged from17 to 33 cmwere 87%. The length-weight relationship parameters were (TW=0.0565TL 2.53 , R 2 = 0.95) and the condition factor K= 1.29. The parameters of vonVertalanffy growth curve were L∞ = 41 cm, k = 0.52, t =-2.29, θ = 2.9 and A0.95 = 5.5years. The estimated values of the total, natural and fishing mortalities were Z = 1.23,M=0.55 and F = 0.68, respectively. The current exploitation rate was 0.55 which indicatesslightly overexploitation. The estimated fish population and the annual fish yield were59,304 and 1.5 tons, respectively. However, investigation on reproductive biology,limnolocal aspects and stock enhancements should be required for the sustainability ofthese resources.