The Nile perch fishery ofLakeVictoria: current status and management challenges

The Nile perch, L ates 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 ( R astrineobola argentea [ P ellegrin] and haplochromines) to increase, shifting the fishery to one dominated by species at lower trophic levels. These changes do not reflect deterioration in the environment because evidence suggests that conditions in the lake have improved and prey species sensitive to deoxygenation have increased. Management authorities have been criticised for relying only on the control of fishing effort rather than taking a holistic approach. However, fishing effort appears to be the main cause of the fishery problems and is the only aspect that can be controlled as environmental problems are too intractable.