The Nile perch, Lates niloticus (L.), stock in Lake Victoria may be showing signs of overfishing as the average size of fish decreased rapidly in 2007 when the stock biomass fell by 50%. Fishers have increasingly abandoned large-meshed gillnets in favour of small hooks on long lines. This has allowed prey species (Rastrineobola argentea [Pellegrin] and haplochromines) to increase, shifting the…