3. Trace Metal Concentrations in Commercially Important Fishes from some Coastal and Inland Waters in Ghana

Abstract

An assessment was conducted on the concentrations of zinc, copper, manganese, iron, lead and cadmium in 10 different fish species caught from some coastal and inland waters in Ghana, as part of a project on monitoring of pollution in water bodies in Ghana. Shellfish species (Egeria paradoxa galanata and Atya gabonensis) caught from inland waters had higher elemental concentrations than those caught from coastal waters. Mean concentrations of Fe and Mn were higher in E. paradoxa galanata, A. gabonensis and Trachiurus trachiurus, while Panulirus regius and Sardinella eba had higher mean concentrations of Cu. T. trachiurus, Dentex congoensis and T. ovatus had higher mean concentrations of Pb, while T. trachiurus and S. eba had higher mean concentrations of Zn. Mean Cd concentrations in the fish species were relatively low, with mean concentrations of Cynoglossus cadenati, D. congoensis and T. ovatus below detection limits. The mean concentrations of Zn, Cu, Pb and Cd for shell fishes were comparable to those obtained from previous studies in Ghana. However, they were lower than those reported in other areas of the sub-region. The mean concentrations of Zn, Cu, Pb and Cd in fin fishes were higher than those obtained from previous studies in Ghana. However, these values were comparable to those obtained from other areas in the sub-region. Compared to WHO limits, the levels of Zn, Pb, Cu and Cd in the fish species were lower, and, therefore, safe for human consumption. The study also showed that all the fish species except S. eba, Solar crumophthalmus and P. regius are safe for human consumption with respect to Zn, Cu and Fe.