A comparative study of the pollution status of Sakumo II and Muni Lagoons in Ghana

Abstract

The pollution status of Sakumo II and Muni Lagoons and Mamahuma and Gbagbla Ankonu feeder streams, which feed Sakumo II along the coast of Ghana, were assessed and compared. As expected of saline waters, pH values of both lagoons fell within a slightly neutral to saline range whilst, the feeder streams were moderately saline. Conductivity distribution also showed saline (>5.0 mS cm−1) characteristics of the lagoons, while, the feeder streams are brackish (1.5–5.0 mS cm−1). DO concentrations in both lagoons indicated a wide variation. Relatively high BOD and nutrients content of Sakumo II and the feeder streams suggested that, Sakumo II and its feeder streams are moderately to grossly polluted. However, Muni Lagoon was characterized by relatively low BOD and nutrients content suggesting relatively low anthropogenic impact. The ionic dominance patterns for Sakumo II and Muni Lagoons were: Na+ > Mg2 +  > Ca2 +  and Cl− > HCO3− > SO42−, Na+ > Ca2 +  > Mg2 +  and Cl− > HCO3− > SO42−, respectively. Using water quality index (WQI), Sakumo II was found to be grossly polluted and requires mitigation measures, while, Muni Lagoon was of fairly good quality and requires monitoring.