Kulfo River Stream Impact on the Sustainability of Aquatic Life in Chamo Lake at Arba Minch

Abstract

Over the last two decades, most of the water bodies in Ethiopia have become increasingly threatened due to pollution from different sources. Recently, many dead and floating fish on the surface of Chamo Lake at Arba Minch city indicated that lake water quality and ecosystem health had been deteriorated. The deteriorating quality of the lake or river systems is directly linked to the improper existing sewage and city waste disposal systems and untreated wastewater discharged from domestic, agricultural and industrial sources in Arba Minch, Ethiopia. This paper examined 23 water quality parameters to ascertain the water quality of Kulfo river stream as well as Chamo Lake and the impact of Kulfo river stream on Chamo Lake. Analysis of the data revealed that the concentration of Turbidity (21NTU), TDS (1070 mg/l), PO4-3 (1.1 mg/l), Iron (0.64 mg/l), Total Coliform bacteria (646), Ammonia (23.8 mg/l), pH (9.3) and Electrical Conductivity (1715µS/cm) are above the permissible limits in Kulfo river stream which is entering into the Chamo Lake. Besides, the dissolved oxygen levels were also very low as 5.2 mg/l. As per the field observations and laboratory analyses, the dissolved oxygen content in the lake was very low, whereas, the temperature was very high. The Ammonia concentration was very high which could be toxic for aquatic life, especially fish in the lake.