Total mercury levels in nine species of freshwater fish from two hydroelectric reservoirs and a crater lake in Ghana

• Published in: Environmental monitoring and assessment 2009-06, Vol.153 (1-4), p.383-389
• Main Authors: Agorku, E. S, Voegborlo, R. B, Adimado, A. A
• Format: Article
• Language: English
• Subjects: Agnatha. Pisces; Akosombo; Animal tissues; Animal, plant and microbial ecology; Animals; Applied ecology; Aquatic environment; Atmospheric Protection/Air Quality Control/Air Pollution; Atomic absorption spectroscopy; Bioaccumulation; Biological and medical sciences; Contamination; Crater lake; Earth and Environmental Science; Ecology; Ecotoxicology; Ecotoxicology, biological effects of pollution; Effects of pollution and side effects of pesticides on vertebrates; Environment; Environmental Management; Environmental monitoring; Environmental Monitoring - methods; fish; Fishes - metabolism; Fresh Water; Freshwater ecology; Freshwater fish; Fundamental and applied biological sciences. Psychology; Ghana; Gold mines & mining; Hydroelectric plants; Kpong; Laboratories; Lake Bosomtwi; Lakes; Mercury; Monitoring/Environmental Analysis; Reservoirs; Spectral analysis; Spectrometry; Studies; Sulfuric acid; Water analysis; Water Pollutants, Chemical - analysis; Water Pollutants, Chemical - metabolism
• ISSN: 0167-6369; 1573-2959
• DOI: 10.1007/s10661-008-0365-8

Total mercury (Hg) concentrations were determined in the muscle tissue of fish from three reservoirs in Ghana, namely, Lake Bosomtwi, Kpong and Akosombo Hydroelectric Reservoirs. A total of 165 fish samples covering nine species were collected and analysed for total mercury. A mixture of HNO₃, H₂SO₄ and HClO₄ were used for complete oxidation of organic tissues. Hg was detected by the Cold Vapour Atomic Absorption Spectrometry technique using an automatic mercury analyzer. Total mercury concentrations in μg g ⁻ ¹ (wet weight) ranged from below 0.001 to 0.070 for fish from Lake Bosomtwi, 0.010 to 0.275 for fish from Kpong Reservoir and from below 0.001 to 0.042 for fish from Akosombo Reservoir. All the results obtained are below the World Health Organization limit of 0.5 μg g ⁻ ¹. The low levels of total mercury obtained in this study suggest that the three aquatic environments have not been significantly impacted by mercury contamination.