Mining activity effects on the community of macroinvertebrates in lotic wa- ter bodies, in the San Juan Subregion, Chocó, Colombia

Abstract

The effects of active mining on the numerical structure of the macroinvertebrate community was evaluated from the analysis in four bodies of water intervened by alluvial mining, with intervention times between 0 and more than 30 years. The community of aquatic macroinvertebrates was represented by 2019 individuals, of which the Epheferoptera order stands out as the most abundant with 454 individuals for the Pichirí stream, followed by the Odonata and Tricoptera order, both with 96 individuals; In the Sabaleta stream, the order of Diptera stands out as the most representative with 109 individuals; in the Marcos Díaz stream, the Diptera order was the most abundant with 767 individuals, followed by the Odonata order with 187 individuals. In the case of the Jorobidó stream, there were no records, possibly due to the continuous presence of mining discharges, which alter the physicoche- mical characteristics of the water and therefore the optimal conditions for the development of hydrobiological processes. In this sense, it was possible to determine that one of the effects generated by the mining activity on the community of aquatic macroinvertebrates, is related to the behavior of these organisms in terms of their numerical distribution, as the physical-chemical conditions of the water, the supply of food and the possibility of refuges are modified during the time in which the mining is carried out, as well as with the variation of these conditions as the time of cessation of activity or presence of the disturbance passes.