Impacts of Oreochromis Nilticus Cage Culture on Water Quality of Winam Gulf of L. Victoria, Kenya

Abstract

Lake Victoria, Kenya has realized an increased number of fish cage culture for the last 10 years. The water quality monitoring study was undertaken at different private cage fish farm within the Winam gulf of L. Victoria, Kenya. In-situ measurements of key environmental parameters: temperature, dissolved oxygen, pH and total dissolved solids variables were taken each month for a period of 8 months. Environment parameters did not vary spatially or temporally between the cages and open waters of the gulf and were generally within safe ranges for freshwater habitats. This was attributed to the fact that the study areas were all within the same geographical space and lack of variation in micro-climatic conditions during the study period. The environmental variables were within the National Environmental and Management Authority (NEMA) and the desirable levels for cage culture. The study recommended that the efforts to promote commercial cage culture enterprises in Winam Gulf of L. Victoria and other water bodies should be enhanced on condition that the cages are sited in deep waters of the gulf with low cage concentration in a particular site and reduced stocking densities in order not to compromise the environmental quality, which can cause undesirable changes in natural biological productivity processes.