Heavy Metal Contamination In Surface Water And Macrobrachium Tissues Along Eagle Island, Niger Delta, Nigeria

Abstract

This study evaluated the level of selected heavy metals in the surface water and macrobrachium along Eagle Island, Bonny Estuary. Triplicate samples were collected from four locations for six months (May-October 2021). Samples were processed and analysed for heavy metals according to standards. The result showed that the concentration of heavy metals (chromium: Cr, lead: Pb, nickel: Ni and zinc: Zn) in water from the four studied locations had similar mean values of 0.001±0.00.  Meanwhile, there was a significant variation in the level of heavy metals in macrobrachium in all the locations. The mean Cr value of 0.15±0.46 mg/kg, 0.001±0.00 mg/kg, 0.01±0.00 mg/kg and 0.03±0.05 mg/kg was observed. For Pb, 0.09±0.00 mg/kg, 2.15±0.03 mg/kg, 0.05±0.00 mg/kg and 0.003±0.00 mg/kg were recorded. For Ni, 0.23±0.01 mg/kg, 0.01±0.00 mg/kg, 0.08±0.00 mg/kg and 0.00±0.00 mg/kg were obtained. For Zn, 2.11±0.01 mg/kg, 2.06±0.00 mg/kg, 0.46±0.30 mg/kg and 0.00±0.00 mg/kg were recorded, respectively, from Eagle Island - UST Bar gate, Mgboshimili, Ogbogolo and Rumueme. The concentration of heavy metals in water fell below WHO and FEPA limits for drinking water. In contrast, some heavy metal levels in macrobrachium from Eagle Island exceeded the regulatory limits set by WHO. The observed increase in these heavy metals may be due to oil bunkering activities within the creeks. Thus, the level of some heavy metals in macrobrachium from water bodies (Station I and II) pose a concern as it may cause some health risks and implications for man, who is the final consumer.