The three largest lakes of the African Great Lakes system, Victoria, Tanganyika and Malawi, have distinctive fisheries and histories of fisheries management. All three provide essential and high quality food to their riparian populations and a range of other ecosystem services. Lakes Victoria and Tanganyika have highly commercialised and lake-wide, open-water fisheries. In Lake Malawi the commercial fishery is largely confined to the southern end of the lake, mainly exploiting demersal fish. Artisanal and low-level subsistence fisheries occur throughout all three lakes. The commercial fisheries of the three lakes are in various states of decline, and maintaining long-term maximum sustainable yields faces a number of serious challenges that relate both to the management of the fisheries and other pressures, notably eutrophication (especially in Lake Victoria), and climate induced shifts in productivity (documented in Lake Tanganyika).
Of the three lakes, Lake Victoria has undergone both the most dramatic change in fisheries practice and environmental degradation. Meeting the challenges of declining fisheries yields, the riparian countries depending on the fisheries of Lake Victoria adopted a strategy of fisheries management structured around geographically defined beach management units (BMUs). Although designed as a participatory approach coupled with locally motivated improved fisheries regulation, increased yield of fish have not occurred. While the BMUs have faced challenges in local governance that include widespread use of illegal gears and practices, the most fundamental limitation to sustaining yields is that the new structures do not have an effective mechanism to control entry to the fishery. This maintains an open-access reality, tragic to the commons. In Lake Tanganyika decline in commercial catches have been attributed to both overfishing and modest changes in thermal structure of the lake associated with modest increases in surface temperatures that restrict water and nutrient exchange between surface and deeper water, resulting in lower plankton productivity that cascade to fisheries production. In Lake Malawi, decline in all fisheries has been evident since the 1990s, although a long history of lakewide census of fishing effort that provides the potential to collect data to support fisheries management is hindered by the complexities of data analysis of the lakes highly diverse multi-species fishery. Policy options for all three lakes for improved and sustainable fisheries for more optimal management can be achieved through consistent review and collaboration among the riparian states, but are limited by current national and local institutional capacities. Prognosis for long-term sustainable fisheries in all the lakes requires a stronger socio-ecological approach so as to better connect local practices with national aspirations.