Abstract

The distribution and concentration of Cadmium, Copper, Iron, Lead, Manganese and Zinc in the cephalothorax and abdomen of two species of shrimps (Nematopalaemon hastatus and Farfantepenaeus notialis) in coastal waters of Ondo State, Nigeria were investigated from April, 2014 to March, 2016 using Atomic Absorption Spectrophotometer. The metal bioaccumulation level in the shrimps was in the order; Zn > Fe > Mn > Cu > Pb > Cd. The highest concentration of Zn (7.519±0.259mg/kg) was recorded in abdomen of N. hastatus in the wet season, while the lowest value 5.485±0.494mg/kg was recorded in the abdomen of F. notialis in the wet season. The highest level of Fe (6.539±0.372mg/kg) was recorded in cephalothorax of F. notialis in dry season. Mn ranged between 4.305±0.616mg/kg in abdomen of F. notialis in the wet season and 2.388±0.356mg/kg in cephalothorax of F. notialis in dry season. The result showed that Zn and Mn exhibited seasonal variation (P<0.05) in N. hastatus while Fe and Mn showed seasonal variation (P<0.05) in F. notialis. The study also revealed that the value of Fe and Mn in the shrimps exceeded the 0.5mg/kg limit recommended by FEPA. Therefore, evaluation of metal pollution of the study area is suggested to minimize the health risk of the population that depends on it for water and fish supply.

Key Words: Coastal Water, Cephalothorax, Abdomen, Heavy metal pollution, Shrimps