|
(42-06) The "middle-up and middle-down" approach: a tool to extrapolate from lab to field studies. Triebskorn, Rita*,1, Gernhöfer, Maike2, Luckenbach, Till2, Kilian, Maja2, Ferling, Hermann3, Schwaiger, Julia3, Schüürmann, Gerrit4, Köhler, Heinz-R.2, 1 Steinbeis-Transfer Center for Ecotoxicology and Ecophysiology, Rottenburg, Germany2 Animal Physiological Ecology, Tübingen, Germany3 Bavarian State Agency for Water Mangement, Wielenbach, Germany4 UFZ Center for Environmental Research, Leipzig, Germany ABSTRACT- Within the frame of the multidisciplinary project VALIMAR, biomarkers in two indigenous fish species were validated with respect to their toxicological and ecological relevance by a combination of chemical, biological, and statistical methods. On one hand, the basic experimental design of this project can be characterized as a "middle-up" approach in relating studies conducted under semi-field-conditions (mesocosm-like scenarios) at two differently polluted streams with the respective field situations. On the other hand, it also represents a "middle-down" approach when results obtained under semi-field conditions were related to data obtained in laboratory studies which were conducted to simulate field exposure conditions. The simulation of field exposure conditions in the lab were shown only to be practicable when exposing fish to xenobiotic concentrations recalculated from measured accumulation data in feral fish and not to real water concentrations measured in the field. For some biomarkers, e.g. stress protein hsp70, or ultrastructure of the kidney, similar responses were obtained for fish exposed under semi-field conditions and those caught in the field. For the same biomarkers, laboratory experiments were useful to interprete cause-effect relationships and kinetics of biomarker induction. In fish embryos, the step by step approach from the laboratory to the field via mesocosms allowed the evaluation of different stressors responsible for embryotoxicity at the two test streams and to reveal the sensitivity patterns of the endpoints investigated. Key words: biomarkers, validation, field relevance, stream pollution |
