Tropical Creek Affected By Mining Using an Ecological Quality Index Based on Periphytic Algae

3. Research Group GAIA, Faculty of Engineering, University of Antioquia, Medellín 050001, Colombia

Abstract: In order to analyze lotic water bodies with different temporality of mining abandonment (without mining S0, 5 to 10 years S1, 30 years S2 and current mining S3), the physicochemical variables of the water and the assembly of periphytic algae were correlated to evaluate the impact of the mining disturbance in Jigualito (Choco-Colombia) through the ecological quality index (EQI). One sampling point was established upstream and one downstream in each station. It was found that the frequency and abundance of the species is conditioned by the physicochemical state of the environment and that the EQI values increased in the sites without mining exploitation such as S0 (EQI: 6.9), while the most disturbed point in terms of ecological was located downstream of S2 and S3 (EQI: 5.2), where the current mining is located and in intermediate conditions were stations S1, S2 (upstream) and S3 (upstream). The relationships between the EQI and physicochemical variables suggest that the ecological quality of the habitat for algae decreases when there is over saturation of nutrients and suspended material in the water. The taxa that presented high optimal and low tolerance could be used as bioindicators of the environmental gradient in systems disturbed by mining.