Impacts of Agricultural Land Use on Crater Lake Water: A Comparison between Lake Nkuruba and Saka in Kabarole District

Abstract

ABSTRACT Most freshwater lakes in developing countries are experiencing a challenge of impaired water quality and ecological imbalances originating from human activities. Land use for agriculture has been suggested as a major threat to aquatic biodiversity. Two volcanic freshwater crater lakes (Nkuruba and Saka) in western Uganda were thus studied to evaluate the extent agricultural use in the surrounding landscape was impacting on quality of water. The forested lake (Nkuruba) was used as a control because it has less amounts of agricultural land use around its wall as compared to Lake Saka. The study revealed that agricultural land use has negative impacts on the quality of water. In particular: turbidity (SD) was less than 0.5m in the agricultural lake; Dissolved Oxygen levels in the agricultural lake were very high on the surface compared to the forested one, but greatly decreased with depth due to high algal growth on the surface; High Electrical Conductivity was observed in both lakes but maximum concentrations of ions were observed in the agricultural lake. However, pH and temperature values from both lakes seemed to be neutral when compared to results that were observed by other researchers. Therefore conservation strategies such as afforestation, reforestation, minimal use of pesticides and fertilizers, and regular assessment of water need to be adopted for better conservation and management of freshwater ecosystems