Comportamiento de evasión y reproducción de la lombriz eisenia foetida en suelos agrícolas impactados por actividades mineras

The aim of this study was to determine the toxicity of agricultural soils in areas with mining activities on worm Eisenia foetida. Total concentrations of As, Cu, Zn, Pb, and soluble As and Cu, pCu⁺², granulometry, organic matter, pH and conductivity in the collected soil were determined. Toxicity was determined using bioassays of avoidance behavior and reproduction. The results show that the total concentrations of metals in soil have the following decreasing order: Cu > Zn > Pb > AS. Of the 14 soils studied, the two with highest concentrations of total copper had effect on the avoidance behavior of E. foetida. Soils with the highest percentage of organic matter and clay caused the lowest percentages of avoidance behavior. The production of cocoons was similar in most soils, except three in which it was significantly lower (p < 0.05); regarding juvenile production no significant variation (p > 0.05) was observed, except for one soil. These variables were inversely correlated to the concentration of total and soluble copper. In conclusion, most soils do not contain bioavailable chemical agents that provoke toxicity or affect the capacity of E. foetida both for habitat selection or reproduction. Avoidance behavior and reproduction were inversely related. Reproduction decreased in soils where evasion was higher. So the alternative use of bioassays of avoidance behavior, as an early warning tool, is suggested for monitoring soils that may contain potential toxic agents.