CONCENTRATIONS OF HEAVY METALS IN THREE TILAPINE SPECIES OF AN ABANDONED GOLD MINE RESERVOIR IN IGUN, NIGERIA

Abstract

The concentrations of Arsenic, Chromium, Lead and Zinc in the fillet and gills of three economically important
tilapine species: Tilapia zillii, Hemichromis fasciatus and Sarotherodon galilaeus from an abandoned gold mining
reservoir in Igun village, Osun state, Nigeria were investigated between May 2008 and May 2009. Varying high
concentrations of Arsenic, Chromium and Zinc were recorded in all fish organs collected from the reservoir in wet
and dry seasons. Irrespective of the time of collection, Chromium was the most bioaccumulated heavy metal in the
gills and fillet of all fish species. Analysis, showed that H. fasciatus bioacccumulated Arsenic, Zinc and Chromium
at higher concentrations when compared to other fishes. It was noted that the concentration of Arsenic, Chromium
and Zinc in T. zillii, H. fasciatus and S. galilaeus were generally high when compared to the World Health
Organisation and Federal Environmental Protection Agency maximum allowable standards in fish food. Lead
concentrations in all fish samples were non-detectable.