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2Q - Online Biomonitoring (WEP/158) Effects of Acid Mine Drainage on Atyaephyra desmaresti Millet (Decapoda) measured with the Multispecies Freshwater Biomonitor. Janssens de Bisthoven, L.1, 2, Gerhardt, A.1, 2, Soares, A.M.V.M.1, 1 University of Aveiro, Aveiro, Portugal2 LimCo International, Ibbenbueren, Germany ABSTRACT- The abandoned Sao Domingos mine in S. Portugal offers a natural pH and metal gradient in the Acid Mine Drainage water (AMD), an ideal model for toxicity studies. Short-term 48 h. toxicity bioassays were performed with the invasive freshwater shrimp Atyaephyra desmaresti in artificial flow-through systems with water from the AMD (pH 6.4, 5.5, 5.0, 4.4, 3.3), one local control water and the water from which the shrimps originated. Exposures were carried out in the laboratory and in situ. To estimate acid stress without metal toxicity, an additional lab.-exposure was carried out in reference water, acidified to the respective pH's. Behaviour and survival were continuously recorded with the Multispecies Freshwater Biomonitor (MFB), while water and organisms were analysed for 9 metals and 6 salts and nutrients. Time of survival, percentage of survival, and time spent on locomotion decreased with decreasing pH and increasing metals in the water. Increased ventilation behaviour followed as a second reaction, fitting to the Stepwise Stress Model. The shrimps tended to be more active in the field exposure (MFB with autonomous power supply) than in the laboratory. Atyaephyra desmaresti is a good invertebrate candidate to be used in a battery of biotests including online behaviour monitoring with the MFB for a rapid and cost-effective bioassessment of acid mine drainage. Key words: Multispecies Freshwater Biomonitor, acid mine drainage, behaviour, Atyaephyra desmaresti |
