Determination of Heavy Metals Concentration in Water, Oreochromis Niloticus and Labeobarbus Intermedius Samples from Abaya and Chamo Lakes

Abstract

The study was focused on the tissue organs of two varieties and water sample from both lakes. The sample were collected from three sampling sites each lakes. The P^H and EC of the water sample were analyzed by using PH-meter and electrical conductivity meter. The digestion procedure was used the mixture of HNO₃-H₂O₂ (12 mL) for gill, kidney, liver and 1:2.5 mL mixture of HNO₃-HCl for water samples used. Concentrations of six metals in water and their accumulation in the edible tissue of Tilapia (Oreochromis niloticus) and Barbus (Labeobarbus intermedius) fish species were determined using Flame Atomic Absorption Spectroscopy. The results revealed that the average heavy metal concentrations in water samples were; Zn 0.017, Cu 0.077, Fe 7.50, Cr 0.033, Cd 0.264 and Pb 1.731 mg/L respectivelty. The highest concentrations of iron (Fe) and lead (Pb) were observed at Chamo Park and Sile sites, respectively. The average contents of heavy metals in fish samples were; Zn 0.062, Cu 0.047, Fe 2.270, Cr 0.041, Cd 0.045 and Pb1.78 mg/Kg in both fish species. The highest accumulations of iron (Fe) and lead (Pb) concentration were observed in liver and gill of Tilapia fish from Chamo Lake. There was no significant difference between the two lakes in accumulating trace metals.

Keywords: ANOVA, Fish variety, Heavy metals, Lakes, Oreochromis niloticus, Labeobarbus intermedius