Analysis of mercury concentrations in fish present in a water source subjected to mining disturbances, municipality of Río Quito, Chocó, Colombia

Abstract

Although there is a state mandate that recognizes the Atrato River as a subject of rights, with a view to guaranteeing its conservation and protection (T-622). Bad practices continue to be developed in gold and platinum mining, which are drastically transforming and contaminating the ecosystems of the Atrato River basin, releasing toxic elements such as mercury (Hg). The objective of this study was to evaluate the concentrations of total mercury (Hg-T) in fish from the Quito River. Traditional fishing techniques were used where species of continental fish most consumed in the community were collected. It was found that the 29 samples analyzed contain mercury, showing that the carnivorous species presented a significant difference in the levels of Hg-T, compared to the non-carnivorous ones (p<0.05), therefore, the highest average concentrations were found in Pseudopimelodus schultzi (1.63 mg/kg) and Ageneiosus pardalis (1.33 mg/kg). Of the total samples analyzed, 48.3% exhibited a Hg-T concentration higher than the 0.5 mg/ kg permissible for human consumption. At the end of this research, it was concluded that the concentration of mercury in fish is determined by various factors, and not only by the way they are fed, which suggests that these factors should not be evaluated separately, due to the strong relationship that exists. between variables such as length, weight, and sex of the species.