Planktonic and Fisheries biodiversity of Alkaline Saline crater lakes of Western Uganda

摘要

Eight (8) selected saline crater lakes in Western Uganda were sampled for fish biodiversity. Water samples collected from each of these lakes were analysed for zoo- and phyto- planktonic composition and abundance. In situ, physico-chemical parameters including average depth, salinity, temperature, conductivity, Dissolved Oxygen and pH were taken at each sample collection point. The Mean ± SD of the different parameters ranged between 0.2±0.0 m and 2.3±0.3 m for average depth,0.0±0.0 mgl -1 and 205.0±15.3 mgl -1 for salinity, 27.9±0.3°C and 34.4±2.4°C for temperature, 18.6±0.1 mscm-1 and 106.3±3.5 mscm-1 for conductivity, 1.7±0.4 mgl -1 and 6.0±1.0 mgl -1 for Dissolved Oxygen and 9.6±0.1 and 11.5±1.0 for pH. With the exception of the Lakes Bagusa, where Anabaena circinalis Rabenhorst ex Bornet et Flahaulwas found to dominate the algal biomass, and Bunyampaka and Nyamunuka where no Spirulina platensis (Nordstedt) Gomont was found, the rest of the studied lakes had S. platensis dominating their algal biomass. All lakes showed very low zooplankton abund- ances and biodiversity, with Lake Kikorongo (the one with the highest zooplankton biod- iversity) having Brachionus calyciflorus Pallas, 1766 as the most abundant, only ranging between 50 to 100 individuals/litre. None of the lakes had fish at the time of sampling.