ABSTRACT
Aquatic ecosystems face contamination from various sources, including industrialization and urbanization, leading to the accumulation of heavy metals. Fish, as key indicators of aquatic pollution, accumulate these metals, posing risks to both aquatic life and human health. Traditional invasive methods for assessing heavy metal levels in fish are harmful, necessitating the development of non-invasive techniques. This study aims to evaluate non-invasive techniques for assessing heavy metal accumulation in Oreochromis aureus and Chromidotilapia guentheri from Ikpoba River, Edo State, Nigeria. Specifically, it assesses the efficacy of fish scales and caudal fin clips as non-invasive methods for determining heavy metal concentrations and evaluates their effectiveness as surrogates for muscle samples. Fish samples were collected and identified, and tissues (muscle, scales, and caudal fin clips) were analyzed for heavy metal concentrations using Atomic Absorption Spectrophotometers. In Oreochromis aureus, muscle concentrations were: 1.556mg/kg(Fe), 0.276mg/kg(Zn), 0.082mg/kg(Cu). In Chromidotilapia guentheri, muscle concentrations were: 3.523mg/kg(Fe), 0.101mg/kg(Zn), 0.05mg/kg(Cu). Scales in Oreochromis aureus showed 3.146mg/kg(Fe), 0.061mg/kg(Zn), 0.058mg/kg(Cu), while in Chromidotilapia guentheri, they showed 2.503mg/kg(Fe), 0.11mg/kg(Zn), 0.052mg/kg(Cu). Caudal fin clips in Oreochromis aureus exhibited 0.449mg/kg(Fe), 0.103mg/k(Zn), 0.055mg/kg(Cu), and in Chromidotilapia guentheri, 1.901mg/kg(Fe), 0.091mg/kg(Zn), 0.078mg/kg(Cu). For both species assessed heavy metals concentrates in the muscles as showed,showing positive correlation with the other tissues assessed(fin clips,scales)indicates the potential for using scales and fin clips as surrogates for muscle tissues in assessing heavy metals in fish.
