Growth and mortality of buka fish, lates stappersii (boulenger, 1914) in the southern part of lake Tanganyika, Zambia.

Population growth parameters and mortality rates of Lates stappersii were investigated for the southeast and southwest arms of Lake Tanganyika, Zambia from April, 2022 to August, 2022. Exploitation ratio was studied. Furthermore, water quality parameters were investigated. Fish samples were procured from purse-seine fishers in Mpulungu and Nsumbu sectors of the lake. A total of 1,526 specimens with 642 females and 884 males for both sites were collected, examined and analyzed. The von Bertalaffy growth model was used to determine fish growth. The FordWalford plots were used to estimate the von Bertalanffy growth parameters (Asymptotic length , and growth coefficient, ). Exploitation ratios (E) were computed from estimated mortality rates (total mortality coefficient, Z; natural mortality coefficient, M and fishing mortality coefficient, F). To test for statistically
significant differences, T-test analysis was used. It was established that there was no significant difference in growth parameters between samples collected from Mpulungu and Nsumbu areas of Lake Tanganyika. No statistical differences were observed in two of the water quality parameters;
dissolved oxygen and temperature between the two areas. There was a difference in water transparency between the two areas. It was Further observed that fishing mortalities and exploitation ratios were consistently high and not significantly different between the two areas. The study therefore, established that both areas are inhabited by the same population of Lates. stappersii. From these results it is recommended that a fishery management strategy should not redistribute or focus on increasing fishing units in Nsumbu area to those in Mpulungu because this will not
result in corresponding catch yields but will only increase the current overexploitation of the stock.