|
(80-36) Chemical and biological assessment of sediment quality in S. Domingos Mine (Portugal). Janssens de Bisthoven, L.*,1,2, Gerhardt, A.1,2, Guhr, K.1,2, Soares, A.2, 1 LimCo International, Ibbenbueren, Germany2 University of Aveiro, Aveiro, Portugal ABSTRACT- S. Domingos Mine, situated in the South Iberian mining belt, still provokes acid metal pollution in the drainage system, even at the confluence with the circumneutral Mosteirao stream, which flos in the Rio Chanca. Sediments in the pH and metal gradient were collected, grain size classes and LOI determined. Concentration of metals (Cd, Cu, Fe, Mn, Zn, As, Co and Pb) and other elements (Ca, K, Mg, Na, Cl and S) in suspended soils were determined. Bioassessment concentrated on chironomid species composition and abundance. Toxicity assessment was performed by screening of the mouth part deformities of locally occurring chironomid species. Species diversity was highest in the reference sites, being a small reservoir for collecting surface runoff and the Rio Vascao. At pH 3.3 only 4 taxa compared to 17 taxa at pH 6.4 were found. Deformity screening of the local species revealed very low percentages of deformed larvae. Key words: chironomids, biomonitoring, deformities, metal pollution |
