Heavy Metal Analysis of Selected Estuarine Fish Species from Oron River, Oron Local Government Area, Akwa Ibom State, Nigeria

Abstract

Environmental pollution is a worldwide problem, heavy metals belonging to the most important pollutants. The progress of industries has led to increased emission of pollutants into ecosystems. Oron River is one of the most important aquatic environment, which receives effluents discharges from heavily industrialized and highly populated settlements. Metals tend to accumulate in water and move up through the food chain. So, studies to ascertain the level of heavy metals in environment and determine potentially hazardous levels for human are necessary. In this study heavy the heavy metals profile [Lead (Pd), Zinc (Zn), Chromium (Cr), Cadmium (Cd), Iron (Fe)], in sea food with special reference to selected fishes Hydrocynus lineatus (African tiger fish), Chrysichthys aluuensis (Catfish), Distichodus rostratus (Grass eater), Tilapia guieensis (Tilapia), Arius gigas (Giant sea catfish) using Atomic Absorption spectrophotometer. The heavy metal profile was observed in the order of intestine, gills, skin and Lead, Cadmium, Chromium, Iron and Zinc respectively. Most of the metals were below the maximum allowable levels set by WHO, FEPA and USEPA except Chromium with 1.02 on the gills. This indicates that an urban and industrial waste discharged into Oron River has a significant effect on the ecological balance of the river, which shows that the fish species and seafood from the river are safe for consumption. In conclusion, the levels of heavy metals observed in the fish and water samples can be considered as a serious matter. More safe and economic methods for the elimination of heavy metals from contaminated waters are needed and continuous assessment of the level of pollution of the lake waters and fish with heavy metals is also necessary. Safe disposals of domestic sewage and industrial effluents as well as enforcement of laws enacted to protect our environment are therefore advocated.