Protection and demarcation of fish breeding areas: is this the solution to increasing fisheries production of Lake Naivasha?

Abstract

Fish stocks overexploitation in Lake Naivasha and excessive water abstraction have caused drastic changes in the lake’s ecosystem and fisheries. Consequently, concerned stakeholders took measures to protect and safeguard the fragile lake ecosystem. A fishery study was conducted to identify fish critical habitats and recommended their protection through a participatory approach. These identified habitats formed the four protected areas in addition to the shoreline area. Gill net surveys are routinely conducted at nine sampling sites spread to cover the whole lake. In the study, 6 fish species were recorded at breeding and non-breeding grounds. Oreochromis niloticus was the most abundant in the breeding (72.1%) and non-breeding (56.6%) grounds. Size frequency data revealed that the majority of Cyprinus carpio in breeding grounds ranged between 24 and 36 centimetres whereas in non-breeding areas, they are slightly smaller, majority of individuals ranging between 23 and 32 centimetres. Male fish generally more than females in both breeding and fishing areas. Except for Oreochromis leucostictus which recorded 64% and 55% in fishing and breeding areas respectively, the spawning biomass was higher in breeding than fishing areas. Stakeholders need to strengthen monitoring and surveillance as a shared responsibility in co-management.