To connect or not to connect? Floods, fisheries andlivelihoods in the Lower Rufiji floodplain lakes,Tanzania

Abstract
For seven years, village-based recorders monitored fish catches and water levels in seven floodplain-associated lakes of the Lower Rufiji, Tanzania. The lakes differ in the number of days and volume of inflows fromthe river, and thus provide a natural experiment to explore the links between catch composition, income per hour offishing (IPHF) and hydrological connectivity, and to analyse the response of the users. The fishers adapt their fish-ing mode and equipment to achieve a rather constant IPHF of between 0.2 and 0.8 US$/fisher/hour. In situationsof low connectivity, during a series of drought years, the less well-connected lakes lost many species and became avirtual monoculture ofOreochromis urolepis.Only in one extreme case was average fish size significantly reduced,indicating a high fishing pressure. Catch was therefore highly resilient to shifts toward illegal, non-selective andactive fishing techniques. Fish diversity and lake productivity were quickly re-established when the larger lakesreconnected. The potential impacts of changes in the flood hydrograph (through dams, increased abstraction orclimate/land-use changes) are assessed, and management options discussed.
Description
Keywords
floods, floodplains, tropical fisheries, ecosystem service, livelihoods, participatory monitoring
Citation
Olivier Hamerlynck , Stéphanie Duvail , Leen Vandepitte , Kassim Kindinda ,Dorothy W. Nyingi , Jean-Luc Paul , Pius Z. Yanda , Aggrey B. Mwakalinga , Yunus D. Mgaya& Jos Snoeks (2011) To connect or not to connect? Floods, fisheries and livelihoods in theLower Rufiji floodplain lakes, Tanzania, Hydrological Sciences Journal, 56:8, 1436-1451, DOI:10.1080/02626667.2011.630002