Incorporation of the biomarker concept in ecotoxicology calls for a redefinition of terms

Biomarkers have received a lot of attention but the biomarker concept has not yet been defined properly. As a consequence, various interpretations of the term 'biomarker' exist, some of which overlap with well-established ecotoxicological concepts. To allow incorporation of the biomarker concept within the framework of modern ecotoxicology, a clarification of terms is needed. In this paper, definitions are presented for the terms 'biomarker', 'bioindicator' and 'ecological indicator', which do not overlap and are linked to different levels of biological organization. The use of these concepts for ecological effects assessment is discussed.