Assessment of Heavy Metal Contamination in Mullet Fish (Mugil Cephalus) from the New Calabar River, Rivers State, Nigeria.

Abstract:

This study investigates the influence of human activities on mullet fish (Mugil cephalus) by analyzing the levels of heavy metals in fish samples obtained from the New Calabar River in Rivers State. Fish were collected from three different sites over a three-month period (June to August), and tested for the presence of Lead (Pb), Zinc (Zn), and Cadmium (Cd). The concentration of these metals in the fish tissues was measured to evaluate their potential toxicity, the environmental impact on the river, and the suitability of the fish for human consumption. All three heavy metals were detected in the samples, with concentrations showing both spatial and temporal variations. Spatially, Lead ranged from 0.009 ± 0.001 mg/kg at station 1 to 0.021 ± 0.002 mg/kg at station 3; Zinc ranged from 2.24 ± 0.02 mg/kg at station 1 to 2.41 ± 0.05 mg/kg at station 3; and Cadmium ranged from 0.28 ± 0.04 mg/kg at station 1 to 0.37 ± 0.04 mg/kg at station 3. Temporally, Lead levels ranged from 0.01 ± 0.06 mg/kg in June to 0.02 ± 0.01 mg/kg in August; Zinc from 2.08 ± 0.34 mg/kg in June to 2.13 ± 0.34 mg/kg in August; and Cadmium from 0.34 ± 0.07 mg/kg in June to 0.36 ± 0.07 mg/kg in August. The measured concentrations were all below the safety thresholds established by the World Health Organization (WHO) and the Federal Environmental Protection Agency (FEPA), indicating that the fish are safe for human consumption.