Limnological Study of Lake Tanganyika with Special Emphasis on Pisciculture Potentiality

The water of Lake Tanganyika is subject to changes in physicochemical characteristics resulting in the deterioration of water quality to a great pace. The present investigation was carried out on Lake Tanganyika at 4 sampling sites and aimed to assess the water quality with reference to (i) its suitability for fish culture purposes, (ii) determining the trophic and pollution status of the sampled stations, (iii) assessing the qualitative and quantitative pattern of planktons diversity as fish food, (iv) establishing an inventory and taxonomic characterization of fish species diversity and (v) highlighting the effect of pollutants on the abundance and spatial distribution of fish species. The physico-chemical and biological parameters of water samples were compared to desirable and acceptable international standards for fish culture and the results of comparative analysis indicated that the Lake has a high fish potential as the most important of the water quality parameters were suitable for fish culture. The investigation revealed the occurrence of 75 species belonging to 7different orders and 12 families in all sampling sites and among the different species recorded, those belonging to the order Perciformes and the family Cichlidae were most dominant. The values of transparency, chlorophyll a and total phosphorus were indicative of eutrophication phenomenon. Besides, Kajaga and Nyamugari stations were found heavily polluted while Rumonge and Mvugo Stations were moderately polluted and for this purpose, three categories of fish species have been distinguished, depending on their adaptation level to pollution: polluosensitive species, polluotolerant species and polluoresistant species. With respect to planktons community results, it was found that all the values obtained were within the permissible limits recommended in pisciculture and, the abundance and diversity of phytoplankton species were far greater than those of zooplankton species with 115species belonging to 7differet families for phytoplanktons against 10species belonging to 4families for zooplankton population in all sampling stations