ABSTRACT
This chapter focuses on one response-specific biomarker and provides an example where this biomarker was used to achieve regulatory relief in a context of prudent environmental management in Canada. It provides the narrow definition of biomarker: that is, a physiological, biochemical, or histological manifestation indicative of stress, toxic or otherwise. The concept of biomarker has been extended by some to refer to functional aspects of ecosystems such as measures of diversity, connectivity, or efficiency. The usefulness of such ecological measurements in assessing ecosystem health is intuitively obvious. Biomarkers can be ranked for their specificity and level of injury indicated. Measuring the inhibition of cholinesterase activity is a biomarker of very high specificity. The challenge will be for our society to come to an agreement as to what constitutes an appropriate objective for any given ecosystem and whether, in the absence of detailed ecological information, biomarkers of individual health will be acceptable and, actionable as surrogates for measures of ecosystem health.
