Assessing the Exploitation Status of Sarotherodon galilaeus (Linnaeus, 1758) in Samendéni Reservoir, Burkina Faso

This study examined the growth, mortality, and exploitation rate of the Sarotherodon galilaeus population in Samendéni Reservoir, located in the West Sudanian savannah in the Region of Hauts-Bassins, Burkina Faso. Fish samples were monthly collected from October 2021 to September 2022, and specimens measured from 9 to 32cm in total length with a mode in the interval [17;19[cm length class. Analysis of the length-frequency data of 1714 specimens using the ELEFAN method incorporated in FISAT software, indicated a growth constant (K) of 0.37 year^-1, and asymptotic length (L∞) of 33.6cm total length for the population. The growth performance index, longevity, and theoretical age at birth (t₀) were estimated to be 2.621, 8.10 and -0.6952 years, respectively. The length at first capture (L_c=16.21cm) was lower than that at first maturity (Lm₅₀ =18.717cm for males and 18.103cm for females), indicating that most of the harvested stocks were juveniles. The total mortality (Z), natural mortality (M), and fishing mortality (F) coefficients recorded 1.59, 0.93, and 0.66 year^-1, respectively, indicating natural mortality as a major contributor to total mortality. The recruitment pattern was a continuous model with a single peak and revealed a recruitment period in May. The exploitation rate (E= 0.25) of the population suggests underexploitation of the stock; however, increasing fishing gear mesh size and regulating fishing efforts are needed to protect the S. galilaeus stock.