ASSESSMENT OF HEAVY METALS IN WATER, SEDIMENTS AND Sarotherodon galilaeus OF AWARA RESERVOIR IN IKARE AKOKO ONDO STATE

Abstract

This study assessed heavy metals levels in water, sediments and Sarotherodon galilaeus of Awara Reservoir, Ikare-Akoko Ondo state. Samples were collected from January to June 2019 and were analysed using standards methods. Pb, Cu, Fe, Cd, Cr, Zn and Mn were determined using Atomic Absorption Spectrophotometer (AAS). Pb was absent in S. galilaeus throughout the months of study. Cadmium was not found across the period of study except in March (0.06 mg/l). The concentration of manganese was highest in March (0.30mg/l) and lowest in January (0.15 mg/l) while the concentration of zinc was highest in May (0.85 mg/l) and lowest in April (0.18 mg/l). Heavy metals in sediment revealed high concentration when compared with the standard limit described by WHO. Lead ranged from 0.14±0.47 mg/l. Copper ranged from 0.30±1.23 mg/l Heavy metal concentration in the gills and muscle of S. galilaeus revealed the concentration of all the heavy metals except cadmium in January, February, April and June to be within the FAO standard limit of safety. The order of accumulation was ediment>gill>muscle>water. The mean condition factor of S. galilaeus is 2.11±0.19 while the b value (Length-Weight Relationship) was ranged between 2.47(a= −2.56) and 2.59(a= −2.00) indicating an allometric growth pattern. Heavy metals in the water and fish were below the FAO and FEPA permissible limit, except for sediment when compared with the standard limit described by WHO. Hence, these metals have no immediate health threat on the consumers of fish and water from Awara reservoir. However periodic monitoring of heavy metals is recommended since the reservoir serves as source of fish, portable water and irrigation farming for the people living around the study area.