Prospects for the fishery on the small pelagic Rastrineobola argentea in Lake Victoria

The pelagic cyprinid dagaa plays a crucial role in the disrupted ecosystem of Lake Victoria. It is the main utilizer of zooplankton, a major prey for the introduced Nile perch and, after Nile perch, economically the second-most important species in the fishery. Light fishery for dagaa was started in the 1960s and boosted during the 1980s. In spite of an intensified exploitation by man, Nile perch and piscivorous birds, the dagaa population increased significantly. Spatial and temporal distribution patterns of dagaa and its potential predators restricted the harvestable fraction of the dagaa stock mainly to mature fish. An increase in recruitment to the reproducing part of the population and a reduction in generation time enhanced the prospects for a sustainable fishery. However, a recent increase in the use of mosquito seines forms a potential danger for the fishery, since dagaa seems to use the inshore waters as spawning areas and nurseries.