Investigation of trace metals in the tissues of a freshwater fish (Crysichthys nigrodigitatus) from the Ikpoba River Dam, Benin City Nigeria

The concentrations of zinc (Zn), cadmium (Cd), copper (Cu), lead (Pb) and chromium (Cr) were evaluated in whole fish, muscle, liver and gills of the benthic fresh water fish, Crysichthys nigrodigitatus, from Ikpoba River Dam in Benin City, Nigeria, by atomic absorption spectrometric technique. The concentrations of the aforementioned trace metals were also determined in water and sediment. The concentration profile of Zn in fish tissue in descending order was liver > muscle > whole fish > gills while for Cd the profile in descending order was liver > whole fish > gills > muscle. The concentration profile in descending order for Cr, Pb and Cu was liver > whole fish > muscle > gills, liver > gills >whole fish > muscle and muscle > whole fish > liver > gills respectively. The concentration profile of the metals in descending order in water was Zn > Pb > Cd > Cr > Cu while in sediment the concentration profile was Zn > Cu > Pb > Cd > Cr. The mean concentration of Cr in the examined fish tissues exceeded the WHO maximum allowable limit for food and fish while the mean concentration of Pb in water exceeded the WHO maximum allowable limit for drinking water. It was advocated that regulatory agencies should further monitor the Dam in other to produce sufficient data to implement better management strategies which would alleviate negative impacts.Keywords: Trace Metals, Zinc, Cadmium, Copper, Lead, Chromium, Crysichthys nigrodigitatus, Ikpoba Dam, Benin City, NigeriaAnimal Research International (2012) 9(1): 1506 – 151