Tropicultura (Jan 1991)
La pêcherie du lac Ihema (Rwanda) : production commerciale et rentabilité socio-économique (1981-1987)
Abstract
Lake Ihema fishery (Rwanda). Commercial production and socio-economical profitability (1981-1987). Among the small lakes in the flooded area of the river Akagera, in eastern Rwanda, lake Ihema (area : 90 km2, mean depth : 4 m) is the most important. The density of phytoplankton in the water is high but dissolved salts concentration is low. Ichtyofauna of the lake consists of 34 species which were occasionally exploited by tanzanian fishermen. That is why, since 1980, the government of Rwanda with the aid of the Belgian Cooperation Agency for Development have initiated an official fishery. Total yield, fishing effort and financial investments are analysed over a 7 years period (1981 to 1987) in order to precise the socio-economical efficiency of this cooperation project. Total fishery effort and total yield have increased regularly until 1983, reaching 186 tons with a fishing effort of 9.231 outings. Since that year, the production has stabilized at a level of 156-199 t/year with only two taxa exploited : Tilapia spp and Clarias gariepinus. The analysis of book-keeping and annual accountant balance of the Ihema fishery shows that the annual exploitation ratio fluctuates between 81 and 142, 5 % ; this indicates a difficult control of the expenditures at least during some years (1984, 1985 and 1986). The profit ratio shows a positive return (± 10 %) since 1981 to 1983, then a depression during 1984 and a continual increase during the next years to become positive again in 1987. Continuous evaluations of these simple parameters allowed to take some actions in order to maintain the efficiency of the fishery. This new activity will be maintained if there is a good fish stock management and rigorous accounts.
