Assessment of Selected Heavy Metals in Water, Sediment and Muscles of Some Edible Finfishes - Schilbe mystus, Sarotherodon galileus, Mormyrus rume and Clarias anguillaris from Ajiwa Irrigation Dam, Katsina State, Nigeria

Assessment of Selected Pollutants in Water, Sediment and Muscles of Some Edible Finfishes from Ajiwa Irrigation Dam, Katsina State, Nigeria

Abstract

The freshwater fishes (Schilbe mystus, Sarotherodon galileus, Mormyrus rume and Clarias anguillaris) are the most commercially important finfishes in Nigeria. Investigations were made on the accumulation of five (5) heavy metals: Lead (Pb), Chromium (Cr), Iron (Fe), Cadmium (Cd), and Zinc (Zn) collected from water, sediment and fish organs (gills, intestines and flesh) inhabiting the Ajiwa dam. Standard methods analyses revealed low accumulation of metals in the water and flesh of the finfishes for both seasons compared to the sediment. The mean concentration of heavy metals decreased in this sequence: Fe>Zn>Pb>Cr>Cd (wet season) and Fe>Zn>Cr>Cd>Pb (dry season) for all sampled fish organs. Fe had the highest mean concentration (106±2.30mg/l) in all the samples while Cd (0.43±0.02mg/l) and Pb (0.22±0.01) had the least mean concentration for the wet and dry seasons respectively. The bio-water accumulation factors showed that the flesh accumulated all the five metals with Fe (>0.5mg/l) as the highest and Zn (≤0.221mg/l) as the least. The bio-sediment accumulation factors in the flesh were ≤2 mg/kg. The results of heavy metals concentrations obtained from the sampled fish organs and water from the dam were within the limit of FAO/WHO recommendation for human consumption and striving of the finfishes.