Integrated biomarker response: a useful tool for ecological risk assessment.

A battery of biomarkers is often used to evaluate the effects of exposure to chemical contaminants and detect responses to environmental stress. Unfortunately, field application of biomarkers is subject to various constraints (e.g., the availability of living material) that can limit data acquisition and prevent the use of multivariate methods during statistical analysis. In these circumstances, a simple method is needed to summarize biomarker responses and simplify their interpretation in biomonitoring programs. The present study used star plots to display results for the panel of biomarkers used for each station and survey. Integrated biomarker response (IBR) was then computed as the star plot area. Star plots using IBR values instead of biomarker data make it possible to visualize between-site and/or between-survey differences for comparison with exposure conditions. This approach was applied to sites in the Baltic Sea and the Seine Estuary, English Channel. In both cases, IBR values were visually compared to polycyclic aromatic hydrocarbons (PAH) or polychlorobiphenyls (PCB) levels measured in mussel or fish tissues. The IBR, as an indicator of environmental stress, appears to be a useful tool for scientists and managers in assessing ecological risk.