The project VALIMAR (VALIdation of bioMARkers for the assessment of small stream pollution): objectives, experimental design, summary of results, and recommendations for the application of biomarkers in risk assessment

Abstract

Between 1995 and 1999, active and passivebiomonitoring experiments in two small streams,and tests with pollutant mixtures in thelaboratory were performed with brown trout(Salmo trutta f. fario) and stone loach(Barbatula barbatula) in order toevaluate the suitability of biomarkersrepresenting different levels of biologicalorganization for the assessment of pollution insmall streams. The following groups ofbiomarker responses were measured in bothspecies: (1) induction of stress proteins(hsp70) in fish liver, (2) alterations in theactivities of 13 metabolic enzymes and ofacetylcholine esterase in liver or brain in vivo as well as in cultured fish cells, (3)changes in phase I and II biotransformationenzyme activities in liver, (4) responses ofblood parameters, (5) histopathologicalalterations in liver, kidney, gills, andspleen, and (6) ultrastructural effects in theliver, gills, and kidney of individuals, aswell as in fish cell cultures. To supplementthese biomarker studies, (7) behavioral changesof fish and (8) impacts on embryo developmentwere also investigated. In parallel, the teststreams were characterized morphometrically,limnologically and analytically for five years.Furthermore, during the second-half of thisproject, ecological studies characterizingbrown trout and stone loach populationdemography and the fish, macro- andmeiozoobenthos communities in the two teststreams were also included. The present papersummarizes the aims and scopes and the generalresults of this project and provides a detaileddescription of the experimental designs whichare the basis of all related studies reportedin this issue. Recommendations are alsoprovided for the application of biomarkers inrisk assessment of small stream pollution.