Influence of Species Differences, Relative Metals Concentrations and pH on Uptake of Metals in Water by Fish

This study was designed to assess the effect of relative metals concentrations, pH and species variations on the uptake of copper (Cu), iron (Fe), calcium (Ca) and magnesium (Mg) in water, fish and fish parts to monitor the toxicity potentials of consuming these fish. The water and fish samples were obtained from four locations (Farin gada stream, Lamingo Dam, Nasco pond and mining pond) in Jos Metropolis, Plateau State, Nigeria, Water and six fish species samples were collected from the four locations, digested and analysed using Buck Scientific Atomic Absorption Spectrophotometer, model 210VGP. Results show that pH of the water sources from Farin gada stream, Lamingo Dam, Nasco pond and mining pond were 7.1, 6.5, 7.0 and 7.2 respectively. The concentrations of Cu in the water sources were 0.030±0.001, 0.010±0.003, 0.020±0.000, 0.027±0.000 in Farin Gada stream, Nasco pond, Lamingo Dam and mining pond respectively; Fe were 2.2±0.1, 0.0±0,000, 0.2±0.003 and 0.3±0.001; Ca were 305±3.0, 37±1.5, 110±3.5 and 163±4.5; Mg were 160±3.6, 126±4.8, 79±1.9 and 95±2.8 in that order above. Different fish species from the same water source bioaccumulated Cu, Fe, Ca and Mg at varying concentrations depending on source, fish species or the physicochemical properties. Different fish species have different preferences as to which part (body, gills and head) of the fish these metals are concentrated more. Lamingo Dam had five fish species, mining pond had three, while Nasco pond and Farin Gada stream had one each. The results established that uptake and bioavailability of Cu, Fe, Ca and Mg by fish in water depend on species variation, relative concentration of the metals in the source of water and the pH of the water.