Heavy metal pollution in benthic fishes from Kiri Dam in Guyuk local government area of Adamawa State, Nigeria

Abstract

Heavy metal concentrations in lungfish (Polypterus annectens), African carp (Heterotis niloticus) and catfish (Clarotes laticeps) in Kiri Dam in the Guyuk local government area, Adamawa State, Nigeria were studied. The concentrations of lead (Pb), cadmium (Cd), copper (Cu), zinc (Zn), nickel (Ni) and iron (Fe) were determined. These metals concentrations were measured by inductively coupled plasma-optical emission spectrometry (ICP-OES) in order to assess the fish contamination with these metals. The gills, muscles, bones and  intestines were analysed for each heavy metal. This research shows that catfish had the highest heavy metals  concentrations. Catfish Pb concentrations were 0.832, 0.480, 0.661 and 0.810 mg/L in the gills, muscles,  bones and intestine, respectively. The gills accumulated the highest level of these metals in C. laticeps  compared to the other species. Lungfish and African carp had higher concentrations of Cd in the examined parts of their bodies. Based on the results, it is apparent that the metal levels in all the fish species were below the recommended concentrations for human consumption, indicating that the study area is relatively less polluted with heavy metals.

Key words: Heavy metals, pollution, fishes, Kiri Dam, Nigeria.