Mortality rate, exploitation and recruitment in Oreochromis niloticus (Linnaeus) in Nyanza Gulf of Lake Victoria, Kenya
An analysis was done on length frequency data to study mortality, exploitation rate and recruitment in Oreochromis niloticus in Nyanza Gulf, Lake Victoria. The fishing mortality (F) and natural mortality (M) were 0.468 y super(-1) and 2.0 y super(-1) respectively. The exploitation rate was 57.2%. Yield per recruit under the fishing regime was 250 g. Its predicted value at maximum sustained yield was 530 g, which could be obtained at a fishing mortality of 1.5 y super(-1). The recommended value was 500 g to be obtained at a fishing mortality of 1.0 y super(-1). The maximum biomass per recruit (B/R) was 1132.48 g while the optimum was 1068.38 g. The biomass recruit under the present fishing regime is 534.19 g which is too low. There is severe overfishing as there are a lot of immature fish in the catch. The analysis shows that the yield can double if the recommended mesh size is adopted in the fishery.
- Conference Papers