Comparative Studies of Metals in Sediment, Water and Fish in Their Natural habitat at Lagos Lagoon

Abstract

The concentrations of Si, Na, Mg, Ca, Fe, Al, Cu, Sn, Ba, and Zn were determined in the fish Tilapia guineensis,
associated water and sediment from three selected areas of Lagos lagoon. The selected areas were Unilag, Ilaje
and Iwaya. The concentration ranges were high for five metals (Na, Si, Mg, Ca and Fe) while the remaining five
elements (Zn , Ba , Sn , Cu and Al) were reasonably lower. The level of metals was found generally to be higher in
sediment than in the surrounding waters. The levels in the fish were found to be higher than both the surrounding
water and sediment, with the exception of only Si, which was highest in the sediment. Higher values of metals in
fish were recorded for highly polluted sites (Iwaya and Ilaje) than Unilag where there was less pollution. The fish
appeared to concentrate many of the metals from the surrounding water and sediment, which serve as reservoir
into fish body. This study also reveals accumulation of metals in the body tissue of the fish rather than in the gills.