Concentration of heavy metal in sediment, water, and fish from Ankobra and Tano River Estuaries, Ghana

Abstract

Abstract. Awuah GK, Mensah JA, Fobil JN. 2020. Concentration of heavy metal in sediment, water, and fish from Ankobra and Tano River Estuaries, Ghana. Ocean Life 3: 94-101. The heavy metals arsenic (As), mercury (Hg), and lead (Pb) are all poisonous and found in nature. The increase in their concentrations, however, is a result of human activities that pose a danger to both aquatic life and humans. The researchers set out to measure the levels of arsenic (As), hexavalent chromium (Hg), and lead (Pb) in sediment, water, and fish from the Ankobra and Tano Rivers in Ghana's Western Region. That was thought to be heavily polluted due to human activity, particularly artisanal gold mining. To assess the prevalence of As, Hg, and Pb in fish and the aquatic media (water and sediment) in the Tano of Jaway Wharf - Ellenda and Ankobra River of Sanwoma basins, an analytical cross-sectional study was carried out. The Atomic Absorption Spectrophotometer (AAS) Pinnacle 900T was used to determine the levels of As, Hg, and Pb in the tissues (muscles) of "Ekpoke" Ctenopoma kingsleyae, "Adwene" Clarias gariepinus, "Nzerma" Pomadasys jubelini, "Bile" Parachanna obscura, "Ekpoke" Sarotherodon galilaues, "Ekpoke" Sarotherodon melanotheron, and "Senzeke" Parapenaeus longirostris (n=53), water samples (n=30), and sediment samples (n=25) (Perkin Elmer, USA). STATA version 13 and the Excel spreadsheet from Microsoft version 10 were used for the statistical Analysis (StataCorps LP, Chicago, USA). Hg, As, and Pb levels were the highest in all the analyzed locations. In general, Hg (2.09 ± 1.29 mg/kg) and As (2.80 ± 1.52 mg/kg) were found in the highest amounts in fish, next by sediment (1.40 ± 1.78 mg/kg) and (0.61 ± 0.40 mg/kg), and water (0.09 ± 0.36 mg/L) and (0.06 ± 0.05 mg/L), respectively. Sediment (1.46 ± 4.26 mg/kg), water (0.14 ± 0.10 mg/L), and fish (0.11 ± 0.11 mg/kg) all had higher Pb concentrations than the other two. The total heavy metal variability in soil, water, and fish was not different (p=0.828, 0.570, and 0.978, respectively). Concentrations of As, Hg, and Pb in river water, sediment, and fish did not differ significantly between the Ankobra and Tano Rivers. Tano and Ankobra have As and Hg concentrations higher than those considered safe by the World Health Organization (WHO) for use in freshwater habitats.